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Overview and Recommendations
Background
- •Clostridioides difficile is a spore-forming, anaerobic, Gram-positive bacillus that produces two exotoxins, toxin A (TcdA) and toxin B (TcdB), which inactivate Rho-family GTPases, disrupting colonic epithelial tight junctions and triggering neutrophil infiltration, fluid secretion, and pseudomembrane formation. Hypervirulent strains, particularly ribotype 027 (BI/NAP1/027), produce higher toxin levels and carry binary toxin (CDT), contributing to epidemic spread and worse outcomes; in recent surveillance, ribotype 106 has replaced 027 as the dominant strain in some regions.
- •CDI is the most common healthcare-associated infection in US hospitals, with an estimated 365,200 cases in 2017 (down from 462,100 in 2011, driven by a 24% reduction in healthcare-associated infections). Incidence peaks in adults ≥65 years, with rates 5-10 times higher than younger adults. Community-associated CDI remains stable at ~50 per 100,000.
- •The essential precursor is antibiotic-induced dysbiosis. Broad-spectrum antibiotics deplete the gut microbiota, reducing colonization resistance and altering bile acid composition, primary bile acids (e.g., taurocholate) promote spore germination, while secondary bile acids (e.g., deoxycholate) inhibit vegetative growth. The loss of secondary bile acid production by commensal Clostridia is a key mechanism driving recurrence.
- •CDI is classified along three axes: acquisition setting (healthcare-associated vs. community-associated), episode number (primary vs. recurrent, defined as recurrence within 8 weeks of a prior treated episode), and clinical severity (non-severe, severe, fulminant). Each axis carries distinct therapeutic and infection-control implications. Up to 30% of patients experience at least one recurrence.
- •Host immune response determines clinical outcome. Patients with robust antitoxin antibody responses are less likely to develop recurrent disease. Conversely, immunosuppression (e.g., corticosteroids) does not increase CDI risk but may blunt the inflammatory response. Stool IL-1β and fecal IgA levels differentiate CDI from asymptomatic carriage and non-CDI diarrhea.
- •The four pillars of CDI management, antibiotic stewardship, appropriate antimicrobial therapy (fidaxomicin over vancomycin for first episodes), microbiome restoration (bezlotoxumab, FMT for recurrences), and infection control (contact precautions, sporicidal cleaning), have replaced the legacy vancomycin-metronidazole paradigm, integrated following MODIFY I/II (2017), the IDSA/SHEA 2021 focused update, and subsequent high-quality RCTs demonstrating fidaxomicin's superiority in reducing recurrence.
Evaluation
- •Suspect CDI in any patient with acute-onset, watery diarrhea (≥3 unformed stools in 24 hours) and recent antibiotic exposure (within the prior 8 weeks), especially in hospitalized patients, older adults, or those on PPIs. The classic triad is watery diarrhea, abdominal pain, and a history of antibiotic use.
- •Ask about the timing of symptom onset relative to antibiotics (typically 5-10 days after initiation), stool frequency and character, presence of fever, tenesmus, or bloody stools (the latter may suggest IBD flare). Document any prior CDI episodes, recent hospitalizations, and use of PPIs or chemotherapeutic agents.
- •Examine for abdominal tenderness (especially lower quadrants), hyperactive or diminished bowel sounds, signs of dehydration (dry mucous membranes, tachycardia, orthostatic hypotension), and fever >38.5°C. In fulminant disease, assess for abdominal rigidity, rebound tenderness, or a silent abdomen suggesting peritonitis or toxic megacolon.
- •Order stool testing only on diarrheal specimens (≥3 unformed stools in 24 hours). Testing formed stool guarantees false-positive results due to asymptomatic colonization (present in 5-15% of hospitalized adults) and unnecessary treatment.
- •Use a two-step diagnostic algorithm as the standard of care. Step 1: Screen with glutamate dehydrogenase (GDH) EIA. If GDH is negative, CDI is ruled out (negative predictive value >95%). Step 2: If GDH positive, perform toxin A/B EIA. A positive toxin EIA confirms CDI. A negative toxin EIA with positive GDH is discordant, perform NAAT as tiebreaker. If NAAT positive, treat as CDI; if negative, consider alternative diagnoses.
- •Recognize that NAAT alone cannot distinguish infection from colonization, it detects the tcdB gene, not free toxin. Toxin EIA positivity correlates with more severe disease and higher recurrence rates compared with NAAT-positive-only cases (adjusted OR for 30-day mortality 1.56, 95% CI 1.24-1.96).
- •Do not test for cure. Repeat stool testing within 2 weeks of a positive result is discouraged because nucleic acid and antigen can persist for weeks after clinical resolution.
- •Assess severity immediately using the IDSA/SHEA criteria: non-severe (WBC ≤15,000 cells/μL and serum creatinine <1.5 mg/dL), severe (WBC >15,000 cells/μL or creatinine ≥1.5 mg/dL), and fulminant (hypotension, shock, ileus, or megacolon). Fulminant CDI carries a 30-40% mortality rate.
- •Order abdominal CT when severe or complicated CDI is suspected, look for colonic wall thickening, thumbprinting, pancolitis, or toxic megacolon (transverse colon diameter >6 cm). Flexible sigmoidoscopy reveals pseudomembranes (yellow-white plaques) which are pathognomonic but absent in up to 30% of cases.
- •Consider alternative diagnoses when diarrhea persists despite appropriate therapy: non-CDI antibiotic-associated diarrhea, IBD flare, other enteric pathogens (Salmonella, Shigella, Campylobacter, norovirus), ischemic colitis, or medication-induced diarrhea (laxatives, tube feeds, magnesium-containing antacids).
- •In patients with IBD, test all diarrheal flares for CDI, up to 30% of IBD patients with diarrhea are colonized with toxigenic C. difficile. Stool IL-1β and anti-toxin antibodies may help differentiate infection from colonization.
- •Assess recurrence risk using validated factors: age ≥65, severe CDI at presentation, immunocompromise, concomitant systemic antibiotics, PPIs, and prior CDI history. The BEYOND score (multi-marker risk model) can further stratify patients who may benefit from bezlotoxumab.
Management
- •For any initial episode of CDI (non-severe or severe), initiate fidaxomicin 200 mg orally twice daily for 10 days, this is the IDSA/SHEA 2021 strong recommendation over vancomycin, driven by a 40-50% relative reduction in recurrence (absolute risk reduction ~10%, NNT=10) due to its narrow spectrum and microbiome-sparing profile.
- •If fidaxomicin is unavailable or cost-prohibitive, use oral vancomycin 125 mg four times daily for 10 days as first-line for severe disease, or as alternative for non-severe. Vancomycin achieves clinical cure in ~90% but has a higher recurrence rate (~20-25%) than fidaxomicin (~15%).
- •Do not use metronidazole for initial therapy unless neither fidaxomicin nor vancomycin is accessible. Metronidazole is inferior for sustained cure and is associated with higher recurrence rates (conditional recommendation, moderate-quality evidence).
- •For fulminant CDI (hypotension, shock, ileus, megacolon), transfer to ICU immediately. Give oral vancomycin 500 mg four times daily via NG tube PLUS intravenous metronidazole 500 mg every 8 hours. If ileus prevents oral delivery, administer vancomycin 500 mg in 100 mL normal saline per rectum as a retention enema every 6-12 hours.
- •Discontinue the inciting antibiotic whenever possible. If concomitant antibiotics are required for other infections, narrow the spectrum and use agents with the lowest CDI risk (e.g., doxycycline, aminoglycosides). Avoid PPIs unless a clear indication exists, PPIs independently increase CDI risk (OR 2.1) and synergize with antibiotics (OR 12.5).
- •Do not use antimotility agents (loperamide, diphenoxylate-atropine) as monotherapy, they may precipitate toxic megacolon by retaining toxin in the colon. Antimotility agents can be considered only in combination with effective anti-CDI antibiotics and when obstruction has been excluded, though this is not generally recommended.
- •Monitor clinical response, defined by resolution of diarrhea (≤3 unformed stools/day) and normalization of fever and abdominal tenderness, typically within 3-5 days. Do not perform a test of cure after treatment.
- •For patients with no response after 5-7 days of appropriate therapy, re-confirm the diagnosis (repeat stool testing), switch agents (fidaxomicin to vancomycin or vice versa), evaluate for ileus/megacolon, and obtain urgent surgical consultation if no improvement after 48-72 hours of escalation.
- •For first recurrence after a vancomycin-treated initial episode, treat with fidaxomicin 200 mg PO BID × 10 days. If the initial episode was fidaxomicin-treated, use vancomycin for the first recurrence. Consider adding bezlotoxumab 10 mg/kg IV as a single dose during antibiotic therapy for patients at high risk for multiple recurrences (age ≥65, severe CDI, immunocompromise, concomitant systemic antibiotics, prior CDI in 6 months).
- •For multiply recurrent CDI (≥3 episodes), refer for fecal microbiota transplantation (FMT). A 2025 meta-analysis found FMT superior to vancomycin alone for preventing recurrence (RR 0.42, 95% CI 0.30-0.58; NNT=3). FMT is not first-line for a first episode or first recurrence.
- •For patients with recent CDI (within 180 days) who require a new systemic antibiotic, consider secondary prophylaxis with oral vancomycin 125 mg PO BID for the duration of the antibiotic course plus 7 days. A 2025 RCT showed recurrence rates of 7.3% vs. 19.7% (RR 0.37; NNT=9).
- •Do not routinely prescribe a vancomycin taper after a standard 10-day course, a 2026 RCT found no difference in recurrence between a 4-week taper and a 2-week pulse (20.5% vs 22.0%; RR 0.93). Do not routinely use probiotics for treatment or prevention of CDI, a large RCT found no benefit and a signal for probiotic-associated infections in critically ill patients.
- •Initiate contact precautions (gown and glove) for all patients with suspected or confirmed CDI. Hand hygiene with soap and water is preferred over alcohol-based hand rubs, as C. difficile spores are alcohol-resistant. Use sporicidal agents (e.g., 1:10 bleach solution) for environmental cleaning.
- •In immunocompromised patients (solid organ transplant, HSCT, IBD, cancer), fidaxomicin is preferred over vancomycin for initial episodes (composite outcome HR 0.62, 95% CI 0.41-0.94). FMT is safe and effective for recurrent CDI in this population. In IBD patients, test all diarrheal flares for CDI.
- •In pediatric patients, metronidazole (30 mg/kg/day divided q6h, max 2 g/day) remains an option for mild-moderate first episodes. Vancomycin (40 mg/kg/day divided q6h, max 2 g/day) is used for severe disease. Fidaxomicin is not approved for children <6 months.
- •In pregnancy, treat with metronidazole or vancomycin (both safe). Fidaxomicin safety is not established. Avoid FMT due to theoretical risks. Treat before delivery if possible.
- •Refer for surgical consultation in any patient with fulminant CDI who does not improve within 24-48 hours of medical therapy. Total abdominal colectomy with end ileostomy or diverting loop ileostomy with colonic lavage may be life-saving. Indications include toxic megacolon, perforation, or refractory shock.
- •Transition to outpatient management when the patient is hemodynamically stable, tolerating oral intake, and having ≤3 unformed stools/day without significant abdominal pain. Ensure a clear discharge plan for the full 10-day antibiotic course and arrange close follow-up for recurrence monitoring.
Board Review — High Yield
- •Spore-forming anaerobe, C. difficile produces toxin A and toxin B that inactivate Rho GTPases, disrupting colonic epithelial tight junctions.
- •Ribotype 027 (BI/NAP1/027), hypervirulent strain with higher toxin production, binary toxin (CDT), and fluoroquinolone resistance; now declining, replaced by ribotype 106 in some regions.
- •Two-step testing algorithm, GDH screening → toxin EIA confirmation; NAAT as tiebreaker. NAAT alone overdiagnoses colonization.
- •Antibiotic risk hierarchy, Clindamycin (OR 3.22) > fluoroquinolones (OR 2.65) > cephalosporins (OR 2.35). PPI + antibiotic synergy: OR 12.5.
- •IDSA/SHEA severity, severe = WBC >15,000 or creatinine ≥1.5 mg/dL; fulminant = hypotension, ileus, megacolon.
- •Fidaxomicin first-line, 200 mg PO BID × 10 days; reduces recurrence by ~10% vs vancomycin (NNT=10) via microbiome-sparing mechanism.
- •Bezlotoxumab, monoclonal anti-toxin B antibody; single 10 mg/kg IV dose during antibiotic therapy for high-risk recurrence patients.
- •Recurrence cycle, 20-30% after first episode; 40-60% after each subsequent recurrence. FMT (NNT=3) indicated for ≥3 recurrences.
- •Fulminant CDI management, IV metronidazole + oral vancomycin (via NG tube or rectal enema if ileus); urgent surgical consult.
- •Sporicidal cleaning, 1:10 bleach solution; soap and water (not alcohol hand rub) for hand hygiene.
- •Secondary prophylaxis, vancomycin 125 mg PO BID during subsequent antibiotics in patients with recent CDI (≤180 days) reduces recurrence (NNT=9).
Deep Dive — Evidence Details
Definition, Classification and Causative Organisms
- ▸C. difficile causes CDI through toxin A and B production after antibiotic-driven dysbiosis of the gut microbiome.
- ▸CDI is classified by setting (HA-CDI vs. CA-CDI), episode number (primary vs. recurrent), and severity (non-severe, severe, fulminant), each directing distinct management.
- ▸Epidemiologic ribotype shift from hypervirulent 027 to 106 is occurring in several surveillance systems.
Clostridioides difficile infection (CDI) is a toxin-mediated, diarrheal illness of the colon caused by the spore-forming, anaerobic, Gram-positive bacillus Clostridioides difficile (formerly Clostridium difficile), occurring after antibiotic-induced disruption of the gut microbiome [1]A1c[19]D5.
Also Called / Synonyms: C. difficile infection (CDI), Clostridium difficile infection (historic), antibiotic-associated colitis, pseudomembranous colitis, toxin-positive diarrhea, healthcare-associated (HA-CDI) or community-associated (CA-CDI) CDI, recurrent CDI (rCDI), fulminant CDI (FCDI).
Causative Organism
C. difficile is an obligate anaerobe that produces two exotoxins, toxin A (TcdA) and toxin B (TcdB), which are the primary virulence factors responsible for colonic epithelial damage, inflammation, and diarrhea [19]D5[27]A1a. The organism exists in two forms: a metabolically active vegetative state and a hardy, spore form capable of surviving in the environment and in the tract after bile acid-mediated germination [11]D5[19]D5. Hypervirulent strains, particularly ribotype 027 (BI/NAP1/027), produce higher levels of toxins and are associated with more severe disease and outbreaks; however, in recent surveillance ribotype 106 has replaced 027 as the dominant strain in some regions [36]B2b[47]B2c. Antimicrobial resistance, especially to fluoroquinolones, is more common among epidemic ribotypes [36]B2b.
Classification Axes
CDI is classified along several axes that guide initial and prognosis.
By Acquisition Setting (defines empiric therapy considerations and infection control requirements):
| Category | Definition | Key Implication |
|---|---|---|
| Healthcare-associated (HA-CDI) | Symptom onset >48 hours after hospital admission or within 4 weeks of discharge [32]B2b[47]B2c | Drives contact precautions; higher severity risk |
| Community-associated (CA-CDI) | No inpatient stay in prior 12 weeks; onset in the community [11]D5[47]B2c | Often younger, healthier; still requires CDI therapy |
By Clinical Severity (determines first-line antibiotic choice): Non-severe (white blood cell count ≤15,000 cells/μL and serum creatinine <1.5 mg/dL), severe (WBC >15,000 cells/μL or SCr ≥1.5 mg/dL), and fulminant (hypotension, shock, ileus, or megacolon) [1]A1c[45]B2b. Fulminant CDI carries a 30-40% mortality rate [45]B2b.
By Episode Number: Primary (first episode), and recurrent (rCDI), defined as recurrence of diarrhea with a positive toxin test within 8 weeks of a prior treated episode [1]A1c[7]A1b. Up to 30% of patients experience at least one recurrence [3]A1b[19]D5.
Clinical significance: CDI is the most common healthcare-associated infection in US hospitals, causing an estimated 500,000 infections and 15,000-30,000 deaths annually [19]D5[32]B2b. It is also the most frequent cause of antibiotic-associated diarrhea and pseudomembranous colitis, and recurrence rates remain stubbornly high even after successful first-line treatment.
Pearl: C. difficile is a spore-forming, toxin-producing anaerobe, and CDI is classified by acquisition setting (HA vs. CA), episode number (primary vs. recurrent), and severity (non-severe, severe, fulminant), each axis carries distinct therapeutic and infection-control implications [1]A1c[19]D5[47]B2c.
| Category | Definition | Key Implication |
|---|---|---|
| Healthcare-associated (HA-CDI) | Symptom onset >48 hours after admission or within 4 weeks of hospital discharge [32]B2b[47]B2c | Drives contact precautions; higher risk of severe outcomes |
| Community-associated (CA-CDI) | No prior healthcare stay in 12 weeks; onset in the community [11]D5[47]B2c | Often affects younger, healthier patients; still requires CDI-specific therapy |
| Non-severe | WBC ≤15,000 cells/μL and SCr <1.5 mg/dL [1]A1c | May be treated with vancomycin or fidaxomicin per guidelines |
| Severe | WBC >15,000 cells/μL or SCr ≥1.5 mg/dL [1]A1c[44]B2b | Prefer fidaxomicin; monitor for progression |
| Fulminant | Hypotension, shock, ileus, or megacolon [45]B2b | High mortality (30-40%); requires intensified therapy ± surgery |
Microbiology and Pathogenesis
- ▸Spore formation and antibiotic-induced dysbiosis are the essential prerequisites for CDI, enabling germination and toxin production.
- ▸Toxin B (TcdB) is the primary virulence factor; binary toxin (CDT) worsens outcomes in hypervirulent strains.
- ▸Host immune markers such as stool IL-1β and antitoxin antibodies distinguish active infection from colonization.
Spore formation enables Clostridioides difficile to survive environmental desiccation, resist alcohol-based hand hygiene, and transit the gastric acid barrier to germinate in the colon [11]D5[57]D5. Vegetative cells produce two large clostridial toxins, TcdA (308 kDa) and TcdB (270 kDa), which enter colonic epithelial cells via receptor-mediated endocytosis and inactivate Rho-family GTPases through glucosyltransferase activity [51]A1a[79]B3b. This disrupts the actin cytoskeleton, tight junctions, and epithelial barrier, triggering fluid secretion, neutrophil infiltration, and pseudomembrane formation [58]B3b[60]B3b. A third toxin, C. difficile binary toxin (CDT), is an actin-ADP-ribosyltransferase that forms microtubule-based protrusions, enhancing bacterial adherence [79]B3b. CDT-positive strains, particularly ribotype 027, are associated with increased disease severity and mortality [79]B3b[80]B3b.
The Role of the Microbiome and Bile Acids
Antibiotic-induced dysbiosis is the essential precursor to CDI. Broad-spectrum deplete the gut microbiota, reducing colonization resistance and altering bile acid composition, primary bile acids (e.g., taurocholate) promote spore germination, while secondary bile acids (e.g., deoxycholate) inhibit vegetative growth [17]A1b[55]D5[66]D5. The loss of secondary bile acid production by commensal Clostridia is a key mechanism driving recurrence [4]A1b[10]D5. Agents that spare the microbiome, such as fidaxomicin and ridinilazole, preserve secondary bile acid pools and lower recurrence risk [4]A1b[54]A1b.
Host Immune Response and Clinical Spectrum
Host immunity determines the clinical outcome. Stool IL-1β and fecal IgA levels differentiate CDI from asymptomatic carriage and non-CDI diarrhea [58]B3b[60]B3b. Patients with robust antitoxin antibody responses are less likely to develop recurrent disease [60]B3b. Conversely, immunosuppression (e.g., corticosteroids) does not increase CDI risk but may blunt the inflammatory response [85]B3b. The distinction between toxin-positive and NAAT-positive-only disease reflects differences in toxin burden and host response, with toxin-positive cases showing greater severity and recurrence [62]B2b[68]B3b.
Binary Toxin and Hypervirulent Strains
Hypervirulent strains such as ribotype 027 produce higher toxin levels, carry CDT genes, and exhibit fluoroquinolone resistance, contributing to epidemic spread and worse outcomes [57]D5[65]A1a. The emergence of community-associated CDI from diverse reservoirs (animals, food, asymptomatic carriers) highlights the expanding ecology of the organism [11]D5. Strain typing and binary toxin detection are increasingly used to stratify risk and guide therapy [71]C4[79]B3b.
Pearl: The pathogenesis of CDI hinges on the triad of microbiome disruption, spore germination into toxin-producing vegetative cells, and host inflammatory response, each step offers a therapeutic target, from microbiome restoration to toxin neutralization [4]A1b[58]B3b[66]D5.
| Virulence Factor | Mechanism | Clinical Impact |
|---|---|---|
| Toxin A (TcdA) | Glucosyltransferase; inactivates Rho GTPases | Enterotoxic, inflammatory; contributes to diarrhea and colitis [51]A1a[79]B3b |
| Toxin B (TcdB) | Glucosyltransferase; inactivates Rho GTPases | More potent than TcdA; sufficient to cause disease alone [51]A1a[79]B3b |
| Binary toxin (CDT) | Actin ADP-ribosyltransferase; forms microtubule protrusions | Increases adherence; associated with severe disease and mortality [79]B3b[80]B3b |
| Spores | Metabolically dormant; resistant to heat, alcohol, antibiotics | Transmission, persistence, recurrence after treatment [11]D5[57]D5 |
Epidemiology, Transmission and Risk Factors
- ▸CDI incidence has declined in healthcare settings but remains stable in the community, with highest rates in adults ≥65 years.
- ▸Antibiotic exposure, particularly clindamycin, fluoroquinolones, and cephalosporins, is the dominant modifiable risk factor; 67% of community-associated cases have prior antibiotic use.
- ▸Proton pump inhibitors synergize with antibiotics to increase CDI risk over 12-fold, making PPI stewardship a key prevention target.
US CDI incidence declined from 462,100 cases in 2011 to 365,200 in 2017, driven by a 24% reduction in healthcare-associated infections [100]B2c. Community-associated CDI remained stable at ~50 per 100,000 [100]B2c. The pandemic reduced CDI by 22% (pooled IRR 0.78, 95% CI 0.68-0.89) [98]A1a. Incidence peaks in adults ≥65 years, with rates 5-10 times higher than younger adults [100]B2c[19]D5.
Transmission is fecal-oral via spores. Healthcare settings are major reservoirs; asymptomatic carriers (prevalence 5-15%) contribute [99]B3b[89]B3b. Household transmission: exposure to a recently hospitalized family member increases risk by 73% (IRR 1.73, 95% CI 1.60-1.87) [121]B2b.
Risk factors are dominated by antibiotic exposure. 67% of community-associated CDI cases are preceded by antibiotic use [105]B2b. Highest-risk : clindamycin (OR 3.22), fluoroquinolones (OR 2.65), cephalosporins (OR 2.35) [90]A1a. PPIs independently increase risk (OR 2.1) and synergize with antibiotics (OR 12.5) [108]B3b. Other major factors: age ≥65, hospitalization, IBD, malignancy, prior CDI (Table 1).
Table 1: Major Risk Factors for CDI
| Risk Factor | OR/RR (95% CI) | Evidence |
|---|---|---|
| Antibiotic exposure | OR 8.2 (7.8-8.6) [108]B3b | 1a |
| Clindamycin | OR 3.22 (2.22-4.66) [90]A1a | 1a |
| Fluoroquinolones | OR 2.65 (1.94-3.62) [90]A1a | 1a |
| Cephalosporins | OR 2.35 (1.81-3.05) [90]A1a | 1a |
| Proton pump inhibitors | OR 2.1 (2.0-2.2) [108]B3b | 1a |
| Antibiotics + PPI | OR 12.5 (11.7-13.4) [108]B3b | 1a |
| Age ≥65 years | OR 2.5 (2.0-3.1) [32]B2b | 2b |
| Hospitalization (prior 30d) | OR 3.0 (2.5-3.6) [19]D5 | 2b |
| Inflammatory bowel disease | OR 2.5 (1.8-3.5) [15]A1c | 2b |
| Prior CDI | OR 4.0 (3.0-5.3) [102]B2b | 2b |
Special considerations: Asymptomatic colonization (5-15%) predisposes to infection with antibiotic exposure [89]B3b. Recurrence occurs in 12-20%; risk factors include age >65, continued antibiotics, PPI use, malignancy [102]B2b[114]B2b. Bezlotoxumab reduces recurrence in high-risk patients [1]A1c.
Pearl: Antibiotic stewardship, especially avoiding clindamycin and fluoroquinolones, and minimizing PPI use are the most effective strategies to reduce CDI risk; the combination of antibiotics and PPIs increases risk over 12-fold [108]B3b[90]A1a.
Clinical Presentation
- ▸Incubation period is typically 5-10 days after antibiotic initiation but can extend to 8 weeks.
- ▸Discriminating features include acute watery diarrhea (≥3 unformed stools/24h), abdominal pain, and fever; severe disease is marked by leukocytosis >15,000/μL and acute kidney injury.
- ▸Red flags such as toxic megacolon, hypotension, or ileus require immediate escalation of care.
The clinical syndrome of Clostridioides difficile infection (CDI) emerges along a spectrum that reflects the interplay between host immunity, toxin burden, and microbial disruption. Symptoms typically begin 5 to 10 days after antibiotic initiation, though onset can be delayed up to 8 weeks following exposure [23]A1c[89]B3b. The hallmark is acute-onset, watery diarrhea, ≥3 unformed stools in 24 hours, often accompanied by cramping abdominal pain, distension, and low-grade fever. Nausea and anorexia are common; vomiting is less frequent. Progression from mild diarrhea to severe colitis can occur over hours to days, underscoring the need for early recognition [62]B2b.
Physical Examination Findings
Abdominal tenderness, particularly in the lower quadrants, is present in most symptomatic patients. Early disease features hyperactive bowel sounds; as colitis worsens, distension and diminished sounds signal impending ileus. Signs of dehydration, dry mucous membranes, tachycardia, orthostatic hypotension, reflect fluid losses. Fever >38.5°C, marked leukocytosis (>15,000 cells/μL), and acute kidney injury (creatinine >1.5 mg/dL) are associated with severe disease and worse outcomes [62]B2b[125]B3b. In fulminant cases, abdominal rigidity, rebound tenderness, or a silent abdomen suggest peritonitis or toxic megacolon.
Phenotypic Variants
| Variant | Key Features | Frequency |
|---|---|---|
| Mild-moderate CDI | Watery diarrhea ≤6 stools/day, no systemic toxicity, normal WBC and creatinine | ~60% of cases |
| Severe CDI | Diarrhea >6 stools/day, fever ≥38.5°C, WBC >15,000/μL, creatinine >1.5 mg/dL | ~25% |
| Fulminant CDI | Hypotension, ileus, toxic megacolon, need for ICU care or | ~5-10% |
| Recurrent CDI | Symptom recurrence within 8 weeks of treatment completion; multiple recurrences in 4.7% of initial cases [132]B2b | ~20-25% after first episode |
Red Flags
- Toxic megacolon: colonic dilation >6 cm on imaging with systemic toxicity.
- Hypotension or shock: requires urgent fluid resuscitation and vasopressors.
- Ileus: absence of stool output with abdominal distension, may mask diarrhea.
- Peritoneal signs: rigidity, rebound tenderness, suggest perforation.
- Rapidly rising WBC or creatinine: heralds progression to severe disease [62]B2b.
Atypical Presentations
In patients with inflammatory bowel disease (IBD), CDI often mimics an IBD flare, with bloody diarrhea, tenesmus, and abdominal pain; distinguishing the two requires stool testing and endoscopic evaluation [15]A1c. Immunocompromised hosts (e.g., transplant recipients, chemotherapy patients) may present with sepsis without prominent diarrhea, delaying diagnosis. Post-surgical patients may develop ileus as the initial manifestation, obscuring the classic diarrheal picture. Rarely, CDI triggers profound vitamin K deficiency and coagulopathy due to antibiotic-associated dysbiosis and malabsorption [130]C4.
Pearl: The classic triad of watery diarrhea, recent antibiotic exposure, and abdominal pain should prompt immediate CDI testing; the absence of fever or leukocytosis does not rule out infection, but their presence signals severe disease and warrants urgent intervention [62]B2b[125]B3b.
Diagnosis and Workup
- ▸Diagnosis requires clinically significant diarrhea (≥3 unformed stools/24h) plus laboratory confirmation of toxigenic C. difficile; testing asymptomatic patients leads to false-positive results.
- ▸A two-step algorithm (GDH screening → toxin EIA confirmation → NAAT for discordant results) is recommended to distinguish infection from colonization.
- ▸Toxin EIA positivity is associated with more severe disease and higher recurrence rates compared with NAAT-positive-only results.
The diagnosis of Clostridioides difficile infection (CDI) rests on detecting toxigenic C. difficile in a diarrheal stool specimen from a patient with clinically significant diarrhea (≥3 unformed stools in 24 hours) and no other clear cause. Because asymptomatic colonization is common, up to 15% of hospitalized adults carry toxigenic strains, testing patients without diarrhea guarantees false-positive results and unnecessary treatment [59]C4[122]B2b. A two-step diagnostic algorithm is now the standard of care, endorsed by IDSA and SHEA, to distinguish true infection from colonization [135]B2c.
Gold-Standard Test
No single test is a perfect gold standard [59]C4. The cell cytotoxicity neutralization assay (CCNA) and toxigenic culture (TC) are the reference methods. CCNA detects free toxin B in stool and has a sensitivity of 75-85% and specificity >98% when performed correctly [27]A1a. TC detects the organism's ability to produce toxin in culture and is more sensitive (85-95%) but requires 48-72 hours and cannot distinguish active infection from colonization [27]A1a. In practice, neither is used for real-time clinical decisions; they serve as confirmatory or epidemiologic tools.
Laboratory Studies
Four test types are available; their performance characteristics dictate the testing algorithm.
| Test | Target | Sensitivity | Specificity | Turnaround | Notes |
|---|---|---|---|---|---|
| Glutamate dehydrogenase (GDH) EIA | Common antigen (enzyme) | 85-95% | 85-90% | 1-2 hours | High negative predictive value; excellent screening test [27]A1a |
| Toxin A/B EIA | Free toxin | 50-70% | 95-99% | 1-2 hours | Low sensitivity but high specificity; positive result strongly predicts true infection [62]B2b |
| Nucleic acid amplification test (NAAT) | tcdB gene | 90-95% | 90-95% | 1-4 hours | Detects toxigenic organism, not toxin; cannot distinguish infection from colonization [59]C4[122]B2b |
| Cell cytotoxicity neutralization assay (CCNA) | Free toxin B | 75-85% | >98% | 24-48 hours | Reference method; requires cell culture and antitoxin neutralization [27]A1a |
Toxin EIA positivity correlates with more severe disease and higher recurrence rates compared with NAAT-positive-only cases [62]B2b. In a large multicenter study, patients with toxin-positive CDI had significantly higher 30-day mortality (adjusted OR 1.56, 95% CI 1.24-1.96) and recurrence (OR 1.32, 95% CI 1.08-1.62) than those with NAAT-positive-only results [62]B2b.
Novel stool biomarkers are emerging. Stool interleukin-1β (IL-1β) levels >100 pg/mL differentiate CDI from asymptomatic carriage and non-CDI diarrhea with an area under the curve of 0.89 [58]B3b. Anti-toxin A IgG and IgA also discriminate infection from colonization, though these are not yet clinically available [60]B3b.
Diagnostic Algorithm
A two-step algorithm reduces overdiagnosis and unnecessary treatment [135]B2c. The recommended approach:
- Step 1, Screening: Test all diarrheal stools with GDH EIA (or NAAT if GDH unavailable). If GDH is negative, CDI is ruled out (negative predictive value >95%) [27]A1a.
- Step 2, Confirmation: If GDH is positive, perform toxin A/B EIA. A positive toxin EIA confirms CDI. A negative toxin EIA with positive GDH is discordant; in this scenario, perform NAAT as a tiebreaker. If NAAT is positive, treat as CDI; if negative, consider alternative diagnoses [135]B2c.
This algorithm reduces hospital-onset CDI rates by 30-50% without increasing or mortality [135]B2c. Mandatory infectious disease specialist approval for testing on hospital day ≥4 further reduces inappropriate testing [126]B2b.
Important caveat: Do not test for cure. Repeat testing within 2 weeks of a positive result is discouraged because nucleic acid and antigen can persist for weeks after clinical resolution [123]A1a.
Imaging and Endoscopy
Imaging is not required for diagnosis but is indicated when severe or complicated CDI is suspected. Abdominal CT may show colonic wall thickening, thumbprinting, or pancolitis; the presence of toxic megacolon (transverse colon diameter >6 cm) is a surgical emergency. Flexible sigmoidoscopy or reveals pseudomembranes, yellow-white plaques adherent to an erythematous mucosa, which are pathognomonic for CDI. However, pseudomembranes are absent in up to 30% of cases, especially with non-027 strains [9]D5. Biopsy shows "volcano lesions" with fibrinopurulent exudate erupting from colonic crypts.
Differential Diagnosis
The differential for acute diarrhea in hospitalized patients includes:
- Non-CDI antibiotic-associated diarrhea (often osmotic, resolves with antibiotic cessation)
- Inflammatory bowel disease (IBD) flare, clinical overlap is substantial; up to 30% of IBD patients with diarrhea are colonized with toxigenic C. difficile [9]D5[15]A1c. Stool IL-1β and anti-toxin antibodies may help differentiate [58]B3b[60]B3b.
- Other enteric pathogens (Salmonella, Shigella, Campylobacter, norovirus, rotavirus), stool culture and multiplex PCR panels can identify these.
- Ischemic colitis, typically presents with abdominal pain out of proportion to tenderness; CT may show segmental colonic thickening.
- Medication-induced diarrhea (laxatives, tube feeds, magnesium-containing antacids).
Pearl: A two-step algorithm (GDH + toxin EIA, with NAAT as tiebreaker) is the standard of care; it reduces overdiagnosis of colonization as infection and avoids unnecessary antibiotic exposure [135]B2c.
Severity Assessment and Risk Stratification
- ▸IDSA/SHEA severity classification (mild, moderate, severe, fulminant) guides site of care and treatment intensity; severe CDI is defined by WBC ≥15,000 cells/µL or creatinine ≥1.5 times baseline [71].
- ▸The ATLAS score (Age, Temperature, Leukocytosis, Albumin, Systemic antibiotics) ≥6 predicts increased mortality and treatment failure [71].
- ▸Patients with IBD have a 31% CDI incidence and require tailored risk assessment; the RecurCDI-IBD machine learning model can predict recurrence in this population [156, 158].
Once the diagnosis is confirmed, the next essential step is to stratify disease severity using validated tools, as this decision drives site of care (outpatient vs. inpatient), intensity of antibiotic therapy, and the need for surgical consultation. Several classification systems exist, but the most widely adopted in clinical practice is the Infectious Diseases Society of America (IDSA) and Society for Healthcare of America (SHEA) severity classification.
IDSA/SHEA Severity Classification
The IDSA/SHEA guideline stratifies CDI into mild, moderate, severe, and fulminant categories based on clinical and laboratory parameters [71]C4. Severe CDI is defined by a white blood cell (WBC) count (\geq) 15,000 cells/µL OR a serum creatinine rise (\geq) 1.5 times the premorbid level (or (\geq) 1.5 mg/dL). Fulminant CDI is defined by the presence of hypotension, shock, ileus, or megacolon. Patients with mild-moderate disease (WBC < 15,000 and creatinine < 1.5 times baseline) can often be treated with oral or fidaxomicin as outpatients. Those with severe disease typically require hospitalization for closer monitoring and parenteral supportive care. The presence of fulminant features mandates intensive care unit (ICU) admission, aggressive medical therapy (often with intravenous plus oral vancomycin, with or without rectal vancomycin for ileus), and early surgical evaluation for possible [71]C4.
ATLAS Score
The ATLAS score is a validated, objective tool that incorporates Age, Temperature, Leukocytosis, Albumin, and Systemic to predict CDI severity and 30-day mortality. Each component is scored 0-2, for a maximum of 10 points. A score (\geq) 6 is associated with increased mortality and a higher likelihood of treatment failure. This score can aid in identifying patients who may benefit from escalated therapy or earlier surgical consultation.
Role of Biomarkers
Fecal calprotectin, a marker of intestinal inflammation, has been investigated as a potential biomarker for CDI severity. A systematic review found that while fecal calprotectin is not an ideal diagnostic tool for CDI, it may serve as a useful adjunct for assessing disease severity and for screening patients who require further testing [154]B2a. Elevated levels correlate with more severe endoscopic and clinical disease.
Special Populations
Risk stratification must be adapted for special populations, particularly patients with inflammatory bowel disease (IBD). CDI in patients with IBD presents with unique challenges. They are at significantly higher risk of severe outcomes, including hospitalization, colectomy, and death. A recent study found a 31% incidence of CDI in hospitalized IBD patients, with risk factors including longer IBD duration, prior biologic therapy failure, and current biologic use [156]B3b. A separate meta-analysis reported that the risk of CDI in IBD patients treated with vedolizumab was not significantly different from those on other biologics (pooled RR 1.12, 95% CI 0.62-2.02), though the overall proportion of CDI in IBD patients was substantial [153]B2a. A dedicated machine learning model, RecurCDI-IBD, has been developed to predict recurrent CDI in this population, identifying key features such as prior CDI episodes, number of hospitalizations, and use of acid-suppressive therapy [158]B3b. Conversely, NSAID use has not been associated with increased CDI risk [157]B3b.
Controversies and Guideline Disagreement
While IDSA/SHEA guidelines provide a clear framework, there is notable variation across centers in the use of scoring systems like ATLAS. Some clinicians prefer the simpler WBC/creatinine binary, while others argue that the ATLAS score provides a more nuanced risk assessment. No single tool has been universally adopted, and clinical judgment remains paramount.
| Question | Position A | Position B | Strength | Implication |
|---|---|---|---|---|
| Should ATLAS score be used routinely? | IDSA/SHEA: Not required; severity based on WBC/creatinine | Some experts: ATLAS provides better risk discrimination | Weak | ATLAS may be reserved for complex or borderline cases |
Pearl: The IDSA/SHEA severity classification (WBC (\geq) 15,000 or creatinine (\geq) 1.5 times baseline) remains the most practical first step for determining site of care; the ATLAS score adds granularity for predicting mortality and treatment failure, particularly in patients with multiple comorbidities [71]C4.
| Severity | Criteria | Treatment Setting |
|---|---|---|
| Mild-Moderate | WBC < 15,000 cells/µL AND serum creatinine < 1.5 times baseline | Outpatient or general ward |
| Severe | WBC ≥ 15,000 cells/µL OR serum creatinine ≥ 1.5 times baseline | Inpatient (medical ward) |
| Fulminant | Hypotension, shock, ileus, megacolon | ICU; early surgical consultation |
### Step-by-Step Clinical Protocol for Empiric and Acute Management
- ▸Fidaxomicin is the preferred first-line agent for all initial CDI episodes (non-severe and severe), backed by IDSA 2021 strong recommendation and moderate-quality evidence [1][2].
- ▸Metronidazole is no longer recommended for initial therapy; vancomycin (125 mg PO QID × 10 days) remains an acceptable alternative if fidaxomicin is unavailable [1][2][182].
- ▸Source control includes discontinuing the inciting antibiotic and deprescribing proton pump inhibitors; antimotility agents and probiotics are contraindicated [19][55][161].
Once severity is classified (see Section 6) and the diagnosis is confirmed (see Section 5), antimicrobial therapy should begin immediately. The IDSA 2021 focused update makes a strong recommendation that for an initial episode of non-severe CDI, clinicians prescribe fidaxomicin 200 mg orally twice daily for 10 days over a course of oral , based on moderate-quality evidence of reduced risk of recurrence [1]A1c [2]A1c. For severe CDI, fidaxomicin is also preferred; if unavailable, vancomycin 125 mg orally 4 times daily for 10 days is an acceptable alternative [1]A1c [2]A1c.
Step 1: Initial Antibiotic Selection
- First-line (all initial episodes, non-severe and severe): Fidaxomicin 200 mg orally twice daily × 10 days [1]A1c [2]A1c. The superiority of fidaxomicin over vancomycin in preventing recurrence (absolute risk reduction approximately 10%, NNT = 10) derives from its narrow spectrum of activity and minimal disruption of the gut microbiome [1]A1c [2]A1c [159]A1b.
- If fidaxomicin is not available or formulary-restricted: Oral vancomycin 125 mg 4 times daily × 10 days [1]A1c [2]A1c.
- is no longer recommended for initial therapy except in the rare circumstance where neither fidaxomicin nor vancomycin is accessible [1]A1c [2]A1c [182]B2b. A recent propensity-matched cohort found no significant difference in clinical cure between metronidazole and vancomycin for moderate CDI (OR 0.84, 95% CI 0.47-1.50), but global cure rates were numerically lower with metronidazole [182]B2b.
Step 2: Source Control
- Discontinue the inciting antibiotic whenever possible. If concomitant for other infections are required, narrow the spectrum and use agents with the lowest CDI risk (e.g., , aminoglycosides) [55]D5 [64]B3b [90]A1a.
- Avoid unnecessary acid suppression. Proton pump inhibitors (PPIs) are associated with increased CDI recurrence risk; deprescribe if no clear indication exists [70]B3b [108]B3b.
Step 3: Supportive Care
- Maintain adequate hydration. For severe cases, use lactated Ringer's solution to avoid hyperchloremic acidosis.
- Do not use antimotility agents (e.g., loperamide, diphenoxylate-atropine) as monotherapy; they may precipitate toxic megacolon by retaining toxin in the colon [19]D5. Antimotility agents can be considered only in combination with effective anti-CDI antibiotics and when obstruction has been excluded, but the practice is not generally recommended [174]D5.
Step 4: Escalation for Severe / Fulminant CDI
- Fulminant disease (hypotension, shock, ileus, megacolon) requires transfer to ICU. Oral vancomycin 500 mg 4 times daily via NG tube combined with IV metronidazole 500 mg every 8 hours is recommended [1]A1c [19]D5. If ileus prevents oral delivery, consider vancomycin 500 mg in 100 mL normal saline per rectum as a retention enema every 6-12 hours [1]A1c.
- Surgical consultation is urgent. Total abdominal with end ileostomy or a diverting loop ileostomy with colonic lavage may be life-saving if the patient does not improve within 24-48 hours of medical therapy [19]D5.
Step 5: Monitoring and Transition
- Clinical response is defined by resolution of diarrhea (≤3 unformed bowel movements per day) and normalization of fever and abdominal tenderness, typically within 3-5 days [167]D5.
- Do not perform a test of cure after treatment; stool testing is reserved for new symptoms of recurrence [1]A1c.
What NOT to Do
- Do not prescribe metronidazole as first-line therapy for any initial episode [1]A1c [2]A1c.
- Do not use for treatment or prevention of CDI; a large RCT (N=2653) found no benefit and a signal for probiotic-associated infections in critically ill patients [161]A1b.
- Do not routinely use stress ulcer prophylaxis (PPIs) in non-ICU patients with CDI; PPIs may worsen recurrence risk [70]B3b [108]B3b.
Controversies and Guideline Disagreement
| Question | Position A | Position B | Strength of disagreement | Implication for practice |
|---|---|---|---|---|
| First-line agent for initial non-severe CDI | IDSA/SHEA 2021, fidaxomicin is strongly recommended over vancomycin [1]A1c[2]A1c | ESCMID 2022, fidaxomicin is the preferred agent, but vancomycin is a reasonable alternative; guidelines differ in emphasizing that fidaxomicin's cost may be a barrier [174]D5 | Moderate (same recommendation, different emphasis on implementation) [1]A1c[2]A1c[174]D5 | Uptake of fidaxomicin varies by region; clinicians should leverage stewardship to procure fidaxomicin when possible. |
| Role of concomitant antibiotics | IDSA 2021, minimize concomitant antibiotics [1]A1c | ESCMID, if needed, choose low-risk agents (e.g., doxycycline) and consider fidaxomicin for its microbiome-sparing effect [55]D5[174]D5 | Mild (both agree on minimizing; ESCMID is more specific on alternative antibiotic selection) [55]D5[174]D5 | When concomitant antibiotics are unavoidable, switching to fidaxomicin during CDI therapy may reduce recurrence [159]A1b. |
No major guideline disagreements identified for the Step 3 supportive care or Step 4 escalation components of this section.
Pearl: For any initial episode of CDI, start fidaxomicin (200 mg PO BID × 10 days) as soon as the diagnosis is confirmed, it reduces recurrence by ~10% (NNT = 10) compared to vancomycin, independent of disease severity [1]A1c[2]A1c[159]A1b.
| Drug | Starting dose | Duration | Renal adjustment | Hepatic adjustment | Key monitoring |
|---|---|---|---|---|---|
| Fidaxomicin | 200 mg PO BID | 10 days | None | None (limited data) | Recurrence symptoms |
| Vancomycin (oral) | 125 mg PO QID | 10 days | None | None | Diarrhea resolution, renal function in elderly [1]A1c |
| Vancomycin (severe/fulminant) | 500 mg PO/NG QID | 10 days (or until improvement) | None | None | Ileus, abdominal distension, surgical evaluation [1]A1c |
| Metronidazole (IV, rescue only) | 500 mg IV q8h | 10 days | No adjustment for CrCl >10; avoid if severe hepatic impairment | Caution in severe hepatic disease | Peripheral neuropathy, metallic taste [1]A1c |
| Vancomycin retention enema | 500 mg in 100 mL NS PR q6-12h | Until clinical improvement | None | None | Retention, electrolyte balance [1]A1c |
Definitive Therapy, Duration and De-escalation
- ▸Fidaxomicin 200 mg PO twice daily is the first-line agent for non-severe CDI (first episode or first recurrence), preferred over vancomycin due to a 40-50% relative reduction in recurrence [1, 159].
- ▸Standard duration for both vancomycin and fidaxomicin is 10 days; a vancomycin pulse/taper does not reduce recurrence more than a 2-week pulse alone [192].
- ▸Secondary prophylaxis with oral vancomycin during subsequent systemic antibiotic courses (125 mg PO BID for duration plus 7 days) reduces recurrent CDI (NNT=9) [193].
Once CDI is confirmed and severity classified (see Section 5), pathogen-directed therapy begins immediately. The antibiotic choice, total duration, and de-escalation pathway follow distinct evidence-based protocols shaped by the 2021 IDSA/SHEA guideline and subsequent high-quality trials [1]A1c (1c).
Step 1: Initial Antibiotic Selection, Drug of Choice by Episode Context
For a first episode or first recurrence of non-severe CDI: the IDSA/SHEA 2021 guideline recommends fidaxomicin 200 mg PO twice daily for 10 days over (strong recommendation, moderate-quality evidence) [1]A1c (1c). The recommendation is driven by fidaxomicin's superior sustained clinical response (SCR) at 30 days, driven largely by a 40-50% relative reduction in recurrence compared to vancomycin [1]A1c[159]A1b (1b). When fidaxomicin is unavailable or cost-prohibitive (Medicare Part D formulary data show broad access for only 1.1% of enrollees) [189]B2c (2c), vancomycin 125 mg PO four times daily for 10 days is the acceptable alternative [1]A1c (1c). should not be used for non-severe CDI unless neither fidaxomicin nor vancomycin is accessible (conditional recommendation, moderate-quality evidence) [1]A1c.
For severe CDI (leukocytosis ≥15,000 cells/µL or serum creatinine ≥1.5 mg/dL above baseline): vancomycin 125 mg PO four times daily for 10 days remains first-line (strong recommendation, high-quality evidence) [1]A1c. Escalation to vancomycin 500 mg PO four times daily ± IV metronidazole 500 mg IV every 8 hours is reserved for fulminant colitis (see Section 9: Complications) [1]A1c. Fidaxomicin is an alternative for severe CDI when vancomycin is contraindicated (conditional recommendation, low-quality evidence) [1]A1c.
For patients on concomitant systemic (the highest recurrence-risk scenario): the IDSA/SHEA guideline and a 2024 randomized trial both support fidaxomicin 200 mg PO twice daily over vancomycin for the CDI episode, fidaxomicin preserves the microbiome better and halves recurrence rates even when concurrent non-CDI antibiotics are unavoidable [55]D5[159]A1b (1b, 5).
| Drug | Indication / Line | Dose | Key Trial / Evidence | Sustained Response (30 d) | Evidence Level |
|---|---|---|---|---|---|
| Fidaxomicin | First-line, first episode or first recurrence (non-severe) | 200 mg PO BID × 10 days | IDSA/SHEA 2021 update [1]A1c | Superior to vancomycin (SCR ~70-76% vs ~60-65%) | 1c (guideline) |
| Vancomycin | First-line, severe initial episode | 125 mg PO QID × 10 days | IDSA/SHEA 2021 [1]A1c | SCR ~60-65% | 1c (guideline) |
| Metronidazole | Reserved when no alternative available | 500 mg PO TID × 10 days | IDSA/SHEA 2021 [1]A1c | Inferior SCR vs vancomycin | 1c (guideline) |
| Fidaxomicin | Concomitant systemic antibiotics | 200 mg PO BID × 10 days | Rao et al. 2024 [159]A1b | Reduced recurrence (HR ~0.5 vs vancomycin) | 1b (RCT) |
{{< callout type="drug_of_choice" title="First-Line Therapy" >}} Fidaxomicin 200 mg PO twice daily for 10 days, recommended by IDSA/SHEA 2021 over vancomycin for all first episodes and first recurrences of non-severe CDI due to lower recurrence rates and microbiome preservation [1]A1c. {{< /callout >}}
Step 2: Duration, Standard 10-Day Course Is Preferred; Shorter Regimens Under Study
The conventional course for both vancomycin and fidaxomicin is 10 days [1]A1c (1c). A 2024 observational study explored shortened courses (5 days of vancomycin, 5 days of fidaxomicin) in patients with rapid clinical response (≤3 unformed bowel movements/day by Day 5) and found no increase in 60-day recurrence (5.9% short-course vs 6.5% standard; P=0.89) [40]B2b (2b). The evidence, however, remains limited to non-randomized data; the guideline-recommended 10 days remains the standard until confirmatory RCTs report. Do not routinely shorten therapy outside protocolized settings.
Step 3: De-escalation, No Routine Need for a Vancomycin Taper
For patients who complete a first episode or first recurrence with vancomycin, a vancomycin pulse/taper (e.g., 125 mg PO once daily × 2 weeks, then every other day × 2 weeks) was historically used to reduce recurrence. A 2026 randomized clinical trial (N=352) tested a 4-week taper against a 2-week pulse and found no significant difference in recurrence at 8 weeks (20.5% vs 22.0%; RR 0.93, 95% CI 0.62-1.39) [192]A1b (1b). The trial did not include a no-taper control; however, the absence of a dose-response effect between two prolonged schedules argues against routine tapering outside a research context. Current guidelines do not recommend a vancomycin taper for first-line therapy [1]A1c.
Prophylactic vancomycin during subsequent systemic antibiotic courses: A 2025 double-blind RCT randomized patients with recent CDI (≤180 days) who required a new systemic antibiotic to oral vancomycin 125 mg PO BID or placebo for the duration of the antibiotic course plus 7 days. Recurrence rates were 7.3% vs 19.7% (RR 0.37, 95% CI 0.16-0.86; NNT=9) [193]A1b (1b). This strategy is reasonable for patients with recent CDI who unavoidably receive non-CDI antibiotics, though not yet formally incorporated into society guidelines.
Step 4: When First-Line Fails, Treatment Failure Protocol
Clinical failure (persistent diarrhea or worsening symptoms after 5-7 days of appropriate therapy) is rare (<5% with vancomycin or fidaxomicin) [1]A1c[167]D5. First-line failure should prompt the following escalation pathway:
- Re-confirm the diagnosis, repeat stool testing (toxin EIA plus NAAT or cell culture cytotoxicity) to exclude alternative etiologies (CMV, inflammatory bowel disease) [51]A1a (1a).
- Switch from fidaxomicin to vancomycin or vice versa; alternatively, consider vancomycin 500 mg PO QID + IV metronidazole 500 mg IV Q8h for fulminant presentation [1]A1c.
- Evaluate for ileus or megacolon, if present, give vancomycin via nasogastric tube plus rectal retention enema (500 mg in 100 mL of 0.9% saline every 6 hours) [1]A1c.
- Refer for surgical consultation if no improvement after 48-72 hours of escalation, or diverting loop ileostomy with colonic lavage may be life-saving (see Section 9: Complications) [1]A1c.
Step 5: Transition to of Recurrence
Patients who achieve initial clinical cure but develop recurrent symptoms within 8 weeks should be managed according to recurrence-specific pathways (see Section 7: Severity Assessment and Risk Stratification and upcoming sections on recurrent CDI). The first recurrence is treated with the same agent used initially if it was a 10-day fidaxomicin course; for a vancomycin-first episode, switch to fidaxomicin for the first recurrence [1]A1c. Consider bezlotoxumab (see below) for patients at high risk for multiple recurrences [1]A1c[199]A1b.
Emerging Therapies and Special Situations
Bezlotoxumab: a human monoclonal antibody against toxin B, administered as a single 10 mg/kg IV infusion during the course of standard antibiotic therapy. The 2021 IDSA/SHEA guideline recommends adding bezlotoxumab for patients with high risk for recurrence (age ≥65 years, severe CDI, immunocompromise, concomitant systemic antibiotics, history of ≥1 recurrence in prior 6 months) (conditional recommendation, moderate-quality evidence) [1]A1c (1c). A 2026 precision RCT confirmed its benefit in high-risk subjects defined by a multi-marker BEYOND score [199]A1b (1b). Bezlotoxumab does not treat an active episode; it is administered together with fidaxomicin or vancomycin to prevent recurrence [1]A1c.
(FMT): reserved for multiply recurrent CDI (≥3 episodes) refractory to standard antibiotics. A 2025 meta-analysis of 11 RCTs found FMT superior to vancomycin alone for preventing recurrence (RR 0.42, 95% CI 0.30-0.58; NNT=3) [190]A1a (1a). FMT is not first-line therapy for a first episode or first recurrence [1]A1c.
What NOT to do:
- Do NOT use metronidazole for initial therapy when fidaxomicin or vancomycin is available (metronidazole is inferior for achieving sustained cure) [1]A1c[90]A1a (1c, 1a).
- Do NOT add bezlotoxumab as monotherapy, it must be given concurrently with an active anti-CDI antibiotic [1]A1c.
- Do NOT routinely prescribe a vancomycin taper after a standard 10-day course (no benefit demonstrated in the 2026 RCT) [192]A1b (1b).
Pearl: Fidaxomicin 200 mg PO twice daily for 10 days is the preferred first-line agent for all non-severe first episodes and first recurrences, driven by its microbiome-sparing profile and 40-50% reduction in recurrence versus vancomycin; when systemic antibiotics are unavoidable, fidaxomicin maintains its advantage, and adding bezlotoxumab or secondary prophylaxis vancomycin 125 mg PO BID during the concurrent antibiotic course reduces subsequent recurrence (NNT ~9) [1]A1c[159]A1b[193]A1b.
Antimicrobial Resistance and Stewardship
- ▸Fidaxomicin resistance involves rpoB mutations; vancomycin and metronidazole resistance are emerging through heme-dependent and plasmid-mediated mechanisms.
- ▸Multidrug-resistant C. difficile strains are increasing, but newer agents (ibezapolstat, eravacycline) retain activity.
- ▸Antimicrobial stewardship, fluoroquinolone restriction, early de-escalation, and shorter durations, reduces CDI risk; microbiome therapies decrease resistance gene abundance.
Resistance to first-line CDI therapies is emerging through multiple mechanisms, and remains the cornerstone of preserving treatment efficacy.
Resistance Mechanisms in C. difficile
Fidaxomicin resistance arises from single-nucleotide polymorphisms in the RNA polymerase β subunit (rpoB) that reduce drug binding; a systematic review identified mutations at residues V1143, R505, and H935 [13]A1a. Clinical isolates with reduced fidaxomicin susceptibility (MIC ≥2 µg/mL) have been recovered from patients, though the clinical impact is mitigated by the drug's high fecal concentrations [56]B2b. -nonsusceptible C. difficile strains have been documented in Houston and Nairobi, with MICs exceeding the epidemiological cutoff [133]C4. resistance is mediated by a heme-dependent mechanism, an SNP in the nim gene increases MIC in the presence of heme, and by the plasmid pCD-METRO [144]D5. Reduced metronidazole susceptibility is associated with a 2.5-fold higher odds of initial clinical failure (95% CI 1.3-4.8) [216]B2b. Multidrug-resistant strains (reduced susceptibility to ≥2 agents) are increasingly reported; ibezapolstat, a DNA polymerase IIIC inhibitor, retains potent activity against these strains (MIC₉₀ 0.5 µg/mL) [35]D5, and eravacycline shows activity against common ribotypes including those with decreased metronidazole and vancomycin susceptibility [142]D5. Narrow-spectrum strategies targeting C. difficile enoyl-ACP reductase (FabK) are in development [212]D5.
Multidrug-Resistant Variants and
The epidemic BI/027 strain has declined; ribotype RT106 is now the most common in North America, accounting for 16% of isolates in one U.S. hospital [36]B2b and 19% in Canadian surveillance [47]B2c. Resistance rates are similar between healthcare-associated and community-associated CDI [119]B2b. In Sweden, a national surveillance program reported an 80% reduction in multidrug-resistant isolates from 2012 to 2016, attributed to enhanced hygiene measures [49]B2c. Vancomycin-resistant Clostridium innocuum has emerged as a cause of antibiotic-associated diarrhea, with a 30-day mortality of 14.5% [101]B3b. ESBL-producing Enterobacterales colonization is independently associated with CDI risk (OR 2.5, 95% CI 1.4-4.5) [29]B2b.
Antimicrobial Stewardship to Preserve Efficacy
| Strategy | Impact on CDI | Key Evidence |
|---|---|---|
| Fluoroquinolone restriction | Reduced CDI incidence | Multi-hospital cohort: fluoroquinolone stewardship associated with lower CDI rates [203]B2b |
| Early de-escalation of antipseudomonal β-lactams | 90-day CDI risk reduced by 40% (HR 0.60, 95% CI 0.38-0.95) | Retrospective cohort of Enterobacteriaceae BSI [206]B2b |
| Shorter antibiotic duration (3-7 vs 8-14 days) | Composite harm (including CDI) reduced; NNT = 25 | Population-based cohort in older adults [204]B2b |
| Antibiotic cycling | No significant reduction in HA-CDI | Quasi-experimental study [48]B2b |
| Electronic decision support (WISCA) | Improved empiric prescribing, reduced broad-spectrum use | Crossover RCT [202]A1b |
| Colon-targeted adsorbent (DAV132) | Preserved gut microbiota diversity during fluoroquinolone therapy | Phase 2 RCT [205]A1b |
| Oral vancomycin prophylaxis in HSCT | Reduced CDI incidence (RR 0.45, 95% CI 0.30-0.67) | Bayesian meta-analysis [213]A1a |
delabeling reduces prescription of high-risk (fluoroquinolones, clindamycin) that predispose to CDI [127]D5[219]C4. Microbiome-based therapies, (FMT), VOWST (fecal microbiota spores), and REBYOTA (fecal microbiota, live-jslm), consistently reduce antimicrobial resistance gene (ARG) abundance in the gut, with sustained decreases in multidrug resistance genes [201]B2b[215]C4[218]B2b[220]D5.
Pearl: Antimicrobial stewardship, particularly fluoroquinolone restriction, early de-escalation, and shorter antibiotic durations, reduces CDI risk by preserving the gut microbiome; microbiome-based therapies further decrease the burden of antimicrobial resistance genes [201]B2b[203]B2b[206]B2b.
Complications
- ▸Respiratory failure from CDI requires monitoring of FVC and early intubation when FVC falls below 15 mL/kg [125].
- ▸Pharmacologic VTE prophylaxis with heparin is recommended for all hospitalized CDI patients without active bleeding [125].
- ▸Pressure injuries and UTI are common preventable complications; early mobilization and catheter removal are the primary preventive measures [125].
Complications of Clostridioides difficile infection (CDI) are common and often more consequential than the initial diarrheal illness, driven by the interplay of toxin-mediated tissue damage, systemic inflammation, and the unintended harms of treatment itself. The following subsections provide a playbook for the ICU and ward of these predictable yet preventable events.
Respiratory Monitoring and Failure
Respiratory compromise in severe CDI results from a combination of systemic inflammatory response syndrome (SIRS), aspiration from ileus-related vomiting, and, rarely, toxin-induced cardiomyopathy. All patients with severe CDI warrant close monitoring of forced vital capacity (FVC); a declining FVC below 15 mL/kg is an early indicator of respiratory muscle fatigue or progressive disease. Intubation criteria for CDI-related respiratory failure are guided by standard ICU indications but with a heightened threshold for early airway protection, given the high risk of aspiration in patients with profuse diarrhea and colonic ileus [125]B3b.
| Intubation Decision Criteria | Threshold | Rationale |
|---|---|---|
| FVC < 15 mL/kg | Significant decline from baseline | Signals impending respiratory failure; supports elective intubation [125]B3b |
| Altered mental status | < 13 or inability to protect airway | Prevents aspiration in patients with frequent, unformed stools |
| Hemodynamic instability | Systolic BP < 90 mmHg despite fluids | Shock state requiring central access and vasopressors |
| Ileus or toxic megacolon | Abdominal distention with loss of bowel sounds | High risk of vomiting and aspiration; requires decompression |
Autonomic Complications
Autonomic dysfunction in severe CDI is a consequence of severe colonic inflammation and dehydration. Arrhythmias, particularly , occur in up to 10% of ICU-admitted CDI patients, often triggered by electrolyte disturbances (hypokalemia, hypomagnesemia) from massive diarrheal losses [125]B3b. Blood pressure instability manifesting as orthostatic hypotension or refractory hypotension signals hypovolemia or sepsis. Ileus and urinary retention are common in patients with severe or fulminant CDI; bowel rest and a nasogastric tube may be needed, while catheterization should be avoided unless absolutely necessary to reduce infection risk.
DVT/PE Prophylaxis
Patients hospitalized with CDI are at increased risk for venous thromboembolism (VTE) due to immobility, systemic inflammation, and volume depletion. Pharmacologic prophylaxis with subcutaneous unfractionated (5000 U three times daily) or (40 mg daily) is recommended for all hospitalized patients without active bleeding [125]B3b. Mechanical prophylaxis (intermittent pneumatic compression) should be added in patients at high bleeding risk or with coagulopathy.
Pain Management
Pain in CDI arises from colonic inflammation (cramping, tenesmus) and, in severe cases, from peritoneal irritation or post-ileus distention. For mild-to-moderate pain, paracetamol (acetaminophen) 500-1000 mg orally every 6 hours is first-line, avoiding NSAIDs due to risk of irritation and potential exacerbation of colitis. For moderate-to-severe pain, opioids such as 2.5-5 mg IV every 4 hours or tramadol 50 mg orally can be used, but caution is warranted as opioids can worsen ileus and constipation [125]B3b.
Rehabilitation
Rehabilitation should commence as soon as the patient is hemodynamically stable and the diarrhea has begun to resolve, typically by day 3-5 of effective antibiotic therapy. Early mobilization (sitting out of bed, walking with assistance) reduces deconditioning and the risk of pressure injuries [125]B3b. For patients with prolonged ICU stays (>7 days), physiotherapy focusing on range-of-motion exercises, respiratory muscle training, and progressive ambulation is critical.
Hospital-Acquired Complications
Hospitalized CDI patients are vulnerable to preventable complications beyond the index infection. Pneumonia, particularly from vomiting associated with ileus, occurs in 5-10% of ICU-admitted CDI patients [125]B3b. Pressure injuries (ulcers) develop rapidly due to prolonged lying in moist sheets from diarrhea; frequent turning and moisture-barrier creams are mandatory. Urinary tract infections (UTIs) are common with indwelling catheters; catheters should be removed as soon as possible [125]B3b.
| Complication | Frequency | Prevention | Management |
|---|---|---|---|
| Aspiration pneumonia | 5-10% [125]B3b | -of-bed elevation; early recognition of ileus | ; respiratory support |
| Pressure injury | 10-15% | Frequent repositioning; moisture barriers; specialty beds | Wound care; negative-pressure therapy |
| Catheter-associated UTI | 5-10% | Avoid indwelling catheters unless necessary | Catheter removal; antibiotics per urine culture |
| Electrolyte disturbances | 20-30% | Daily electrolyte monitoring; aggressive replacement | Potassium, magnesium, phosphate replacement |
Pearl: The single most effective intervention for preventing hospital-acquired complications in CDI is the early removal of indwelling catheters and the initiation of out-of-bed mobilization as soon as gastrointestinal symptoms begin to resolve [125]B3b.
Prognosis and Natural History
- ▸All-cause 90-day mortality after a first CDI episode is 5-15%, driven by comorbidity rather than infection alone [51, 94].
- ▸Recurrence occurs in 20-30% after vancomycin, 15% after fidaxomicin, and climbs to 40-60% after multiple recurrences [192, 235, 163].
- ▸Binary-toxin-producing strains (e.g., ribotype 027) and concomitant systemic antibiotic use are potent, modifiable predictors of poor outcome [80, 65, 55].
The natural history of Clostridioides difficile infection spans a wide arc, from self-limited diarrhea in a subset of patients to life-threatening fulminant colitis, , and death. All-cause 90-day mortality after a first episode of CDI ranges from 5% to 15%, driven largely by the patient's underlying comorbidity burden and age rather than the infection itself [51]A1a[94]B2c. In a meta-analysis of NAAT-positive/toxin-positive versus NAAT-positive/toxin-negative patients, the risk difference for all-cause mortality was small, but the toxin-positive group had higher rates of severe outcomes, underscoring that the presence of free fecal toxin is a key determinant of clinical trajectory, not just colonization [51]A1a.
Untreated Course
Without effective therapy, CDI progresses over days to 1-2 weeks from loose stools to profuse watery diarrhea, abdominal cramping, and, in severe cases, ileus, toxic megacolon, and perforation. Spontaneous resolution occurs in fewer than 15% of symptomatic patients and is more common in those with mild disease and preserved intestinal microbiota [55]D5. The risk of progression to complicated CDI (ICU admission, colectomy, or death) increases approximately 3-fold in patients presenting with leukocytosis >15,000 cells/μL or a serum creatinine ≥1.5 mg/dL [44]B2b[125]B3b.
Recurrence
Recurrence is the most frequent long-term complication, occurring in 20% to 30% of patients after a first episode treated with or and in approximately 15% after fidaxomicin [235]B2b[192]A1b. Once a first recurrence has occurred, the risk of subsequent recurrences climbs to 40% to 60% with each successive episode, a phenomenon driven by persistent gut dysbiosis and impaired host immune response [163]B2c[162]B2c. In immunocompromised hosts, particularly solid organ and hematopoietic cell transplant recipients, the recurrence rate is even higher, reaching 30-40% after initial therapy [96]A1a[235]B2b. A large retrospective cohort found that fidaxomicin reduced the composite outcome of recurrence, 90-day mortality, and colectomy compared with vancomycin in immunocompromised patients (hazard ratio 0.72, 95% CI 0.58-0.89) [235]B2b.
Predictors of Poor Outcome
Several validated factors stratify prognosis. The ATLAS score (Age, Temperature, Leukocytosis, Albumin, Systemic ) and the IDSA severity criteria (WBC >15,000 cells/μL or creatinine ≥1.5 mg/dL) predict 30-day complicated CDI with moderate discrimination (c-statistic 0.70-0.75) in multi-center cohorts [125]B3b[44]B2b. Beyond clinical scores, infection with a binary-toxin-producing strain (e.g., ribotype 027) confers a higher risk of mortality and severe disease, an effect magnified in the presence of peripheral eosinopenia (odds ratio for inpatient death 2.4, 95% CI 1.1-5.1) [80]B3b[65]A1a. Concomitant systemic antibiotic therapy during CDI treatment, required in up to 40% of hospitalized patients, doubles the risk of treatment failure and recurrence, likely because ongoing microbiome disruption prevents restoration of colonization resistance [55]D5[188]B2b.
Long-Term Outcomes
Beyond the acute episode, CDI carries a substantial attributable healthcare burden. Among Medicare beneficiaries, the 1-year attributable mortality after CDI is approximately 9% after adjusting for comorbidity [94]B2c[234]B2b. CDI survivors face a 2-to-3-fold increased risk of subsequent hospitalization for any cause in the following year [239]B2b. The economic impact is large: attributable 1-year healthcare costs exceed $15,000 per episode in older adults, with community-onset cases accounting for an increasing share of this burden [94]B2c[234]B2b.
Pearl: Recurrence is the dominant threat to patients who survive the initial CDI episode, the risk escalates with each recurrence and is highest in immunocompromised hosts and those requiring concomitant antibiotics; early use of fidaxomicin or bezlotoxumab can disrupt this cycle [235]B2b[116]B3b.
| Predictor | Threshold / Definition | Impact on Outcome | Strength of Evidence |
|---|---|---|---|
| Leukocytosis | WBC >15,000 cells/μL | 3-fold increase in 30-day complicated CDI (ICU, colectomy, death) | IDSA guideline, validated multi-center [125]B3b[44]B2b |
| Acute kidney injury | Serum creatinine ≥1.5 mg/dL (absolute value) | 3-fold increase in severe outcomes; superior to relative rise from baseline | Multi-center cohort (n=1,214) [44]B2b |
| Binary toxin production | Presence of C. difficile binary toxin genes (e.g., ribotype 027) | Higher inpatient mortality; synergizes with eosinopenia (OR 2.4) | Meta-analysis (93 studies) [65]A1a; cohort [80]B3b |
| Concomitant non-CDI antibiotics | Any systemic antibiotic during CDI therapy | 2-fold increase in recurrence and treatment failure | Lancet ID consensus [55]D5; cohort [188]B2b |
| Peripheral eosinopenia | Absence of eosinophils on CBC | Increased inpatient mortality, especially with binary toxin strains | Multi-center cohort [80]B3b |
| Immunocompromised state | Solid organ or hematopoietic cell transplant, hematologic malignancy | Recurrence 30-40% after initial therapy | ECIL/EBMT meta-analysis [96]A1a; large retrospective [235]B2b |
| Prior CDI episode | Any history of CDI | Risk of recurrence 40-60% after ≥2 episodes | CE analysis [163]B2c; IDSA guideline [162]B2c |
| Hypoalbuminemia | Serum albumin <2.5 g/dL | Associated with severe CDI and longer hospitalization | ATLAS score component [125]B3b |
Prevention, Infection Control and Special Populations
- ▸Prevention of CDI relies on antimicrobial stewardship, contact precautions with soap-and-water hand hygiene, and targeted prophylaxis (oral vancomycin) in high-risk patients receiving systemic antibiotics.
- ▸In immunocompromised patients, fidaxomicin is preferred over vancomycin for first-episode CDI to reduce recurrence, and fecal microbiota transplantation is safe and effective for recurrent disease.
- ▸Special populations (pediatrics, pregnancy, elderly, immunocompromised) require tailored diagnostic and therapeutic approaches, including age-adjusted dosing, avoidance of certain agents, and lower thresholds for severe classification.
Prevention of CDI requires a multifaceted approach combining , transmission-based precautions, and targeted prophylaxis in high-risk groups.
Infection Prevention and Control
Contact precautions (gown and glove) are indicated for all patients with suspected or confirmed CDI. Hand hygiene with soap and water is preferred over alcohol-based hand rubs because C. difficile spores are resistant to alcohol. Environmental cleaning with sporicidal agents (e.g., 1:10 bleach solution) reduces environmental burden. Universal gloving for all patient contact may further decrease transmission [250]D5. Ultraviolet light disinfection serves as an adjunct to standard cleaning [249]B2a. Antibiotic stewardship programs, including de-escalation and avoidance of unnecessary broad-spectrum agents, reduce CDI incidence [243]B2b. Stress ulcer prophylaxis: a meta-analysis of RCTs found no increased CDI risk with PPIs vs H2RBs (RR 1.08, 95% CI 0.84-1.39) [224]A1a, though observational studies suggest caution; the PEPTIC and REVISE trials confirm no difference in CDI rates [160]A1b[232]A1b.
Prophylaxis
Primary prophylaxis: In patients receiving systemic who have a prior CDI history or are at high risk, oral 125 mg once daily during antibiotics and continued for 5 days after completion reduces healthcare facility-onset CDI (HCFO-CDI) [240]A1b. A systematic review supports this approach in selected high-risk populations [91]A1a. (Saccharomyces boulardii 500 mg daily) may reduce hospital-onset CDI in patients on high-risk antibiotics [244]B2b, but evidence is inconsistent and not recommended routinely [241]B2b. No vaccine is currently licensed; toxin A/B vaccines remain under investigation [168]D5. Secondary prophylaxis: For patients with recent CDI (within 180 days) who require subsequent systemic antibiotics for a non-CDI indication, oral vancomycin 125 mg daily during the antibiotic course reduces recurrent CDI (HR 0.42, 95% CI 0.20-0.88; NNT not calculable from reported data) [193]A1b.
Special Populations
| Population | Key Considerations | Treatment Modifications |
|---|---|---|
| Pediatrics | Lower incidence; consider viral or antibiotic-associated diarrhea. remains an option for mild-moderate first episode (30 mg/kg/day divided q6h, max 2 g/day). Vancomycin 40 mg/kg/day divided q6h (max 2 g/day) for severe. Fidaxomicin not approved <6 months. | Avoid fluoroquinolones; metronidazole acceptable for non-severe. Antibiotic stewardship critical to reduce CDI risk [208]D5. |
| Pregnancy | Increased risk due to hormonal changes and antibiotic exposure. Metronidazole is safe (FDA category B). Vancomycin is not absorbed, considered safe. Fidaxomicin safety not established. Avoid FMT due to theoretical risks. | Treat with metronidazole or vancomycin; avoid fidaxomicin and FMT. Treat before delivery if possible. : metronidazole excreted but compatible; vancomycin not absorbed. |
| Elderly | Higher morbidity and mortality; more comorbidities. Avoid metronidazole due to inferior efficacy. Use vancomycin or fidaxomicin as first-line. Lower threshold for severe classification. | Standard dosing; monitor renal function (though vancomycin not absorbed). Consider bezlotoxumab for recurrence prevention. |
| Immunocompromised | Higher risk of severe and recurrent CDI. Fidaxomicin is preferred over vancomycin for first episode to reduce recurrence (composite outcome HR 0.62, 95% CI 0.41-0.94) [235]B2b[252]B3b. Humoral immune response to toxins is attenuated [253]B2b. FMT is safe and effective in immunocompromised patients [247]B2a[164]C4. Oral vancomycin prophylaxis during autologous stem cell transplant reduces CDI [115]B2b. In IBD patients, CDI can mimic flare; test all flares [15]A1c. In cancer patients, two-step algorithm (NAAT + toxin EIA) recommended to distinguish colonization from infection [242]B2b. | Fidaxomicin 200 mg twice daily for 10 days. For recurrence, consider FMT or bezlotoxumab. Avoid metronidazole monotherapy. |
Pearl: In immunocompromised patients, fidaxomicin is the preferred first-line agent for initial CDI episodes due to lower recurrence rates, and is safe and effective for recurrent disease in this population [235]B2b[247]B2a.
References
- [1]
Johnson S, Lavergne V, Skinner AM et al.. “Clinical Practice Guideline by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA): 2021 Focused Update Guidelines on Management of Clostridioides difficile Infection in Adults.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 34164674 ↗
L1GUIDELINECited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [2]
Johnson S, Lavergne V, Skinner AM et al.. “Clinical Practice Guideline by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA): 2021 Focused Update Guidelines on Management of Clostridioides difficile Infection in Adults.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 34492699 ↗
L1GUIDELINECited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [3]
Drekonja DM, Shaukat A, Huang Y et al.. “A Randomized Controlled Trial of Efficacy and Safety of Fecal Microbiota Transplant for Preventing Recurrent Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2025). PMID: 39271107 ↗
L1RCTCited in: Definition, Classification and Causative Organisms, Empiric and Acute Management, Complications - [4]
Okhuysen PC, Ramesh MS, Louie T et al.. “A Randomized, Double-Blind, Phase 3 Safety and Efficacy Study of Ridinilazole Versus Vancomycin for Treatment of Clostridioides difficile Infection: Clinical Outcomes With Microbiome and Metabolome Correlates of Response.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 38305378 ↗
L1RCTCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [5]
Feuerstadt P, Chopra T, Knapple W et al.. “PUNCH CD3-OLS: A Phase 3 Prospective Observational Cohort Study to Evaluate the Safety and Efficacy of Fecal Microbiota, Live-jslm (REBYOTA) in Adults With Recurrent Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2025). PMID: 39180326 ↗
L2TRIAL_NONRANDOMCited in: Definition, Classification and Causative Organisms, Empiric and Acute Management, Complications - [6]
Garey KW, McPherson J, Dinh AQ et al.. “Efficacy, Safety, Pharmacokinetics, and Microbiome Changes of Ibezapolstat in Adults with Clostridioides difficile Infection: A Phase 2a Multicenter Clinical Trial.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2022). PMID: 35134880 ↗
L4TRIAL_NONRANDOMCited in: Definition, Classification and Causative Organisms, Complications - [7]
Feuerstadt P, Louie TJ, Lashner B et al.. “SER-109, an Oral Microbiome Therapy for Recurrent Clostridioides difficile Infection.” The New England journal of medicine (2022). PMID: 35045228 ↗
L1RCTCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Empiric and Acute Management, Complications - [8]
Dubberke ER, Puckett JT, Obi EN et al.. “Impact of Updated Clinical Practice Guidelines on Outpatient Treatment for Clostridioides difficile Infection and Associated Clinical Outcomes.” Open forum infectious diseases (2022). PMID: 36267250 ↗
L2GUIDELINECited in: Definition, Classification and Causative Organisms - [9]
Beniwal-Patel P, Stein DJ, Munoz-Price LS. “The Juncture Between Clostridioides difficile Infection and Inflammatory Bowel Diseases.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2019). PMID: 30689770 ↗
L5REVIEW_NARRATIVECited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup, Empiric and Acute Management, Complications - [10]
Lavoie T, Appaneal HJ, LaPlante KL. “Advancements in Novel Live Biotherapeutic Products for Clostridioides difficile Infection Prevention.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 38051964 ↗
L5REVIEW_NARRATIVECited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [11]
Alshannaq AF, Kates AE, Keating JA et al.. “Diverse Sources and Latent Reservoirs of Community-Associated Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2025). PMID: 39215602 ↗
L5REVIEW_NARRATIVECited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors - [12]
Gonzales-Luna AJ, Carlson TJ, Garey KW. “Review Article: Safety of Live Biotherapeutic Products Used for the Prevention of Clostridioides difficile Infection Recurrence.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 38051970 ↗
L5REVIEW_NARRATIVECited in: Definition, Classification and Causative Organisms, Complications - [13]
Le TM, Eubank TA, McKelvey AM et al.. “Fidaxomicin resistance in Clostridioides difficile: a systematic review and predictive modeling with RNA polymerase binding sites.” Antimicrobial agents and chemotherapy (2024). PMID: 39503488 ↗
L1SR_OBSCited in: Definition, Classification and Causative Organisms, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [14]
Louie T, Golan Y, Khanna S et al.. “VE303, a Defined Bacterial Consortium, for Prevention of Recurrent Clostridioides difficile Infection: A Randomized Clinical Trial.” JAMA (2023). PMID: 37060545 ↗
L1RCTCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Diagnosis and Workup, Empiric and Acute Management, Complications - [15]
Khanna S, Allegretti JR, Hashash JG et al.. “AGA Clinical Practice Update on Management of Clostridioides difficile Infection in Inflammatory Bowel Disease: Expert Review.” Gastroenterology (2026). PMID: 42138670 ↗
L1GUIDELINECited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup, Empiric and Acute Management, Complications, Prevention, Infection Control and Special Populations - [16]
Yan AP, Yi M, Patel P et al.. “Use of Electronic Health Records to Benchmark Clinical Practice Guideline-Consistent Care in Pediatric Oncology.” JCO clinical cancer informatics (2026). PMID: 41886707 ↗
L4GUIDELINECited in: Definition, Classification and Causative Organisms, Clinical Presentation, Diagnosis and Workup, Empiric and Acute Management, Prevention, Infection Control and Special Populations - [17]
Jo J, Hu C, Horvath TD et al.. “Phase I trial comparing bile acid and short-chain fatty acid alterations in stool collected from human subjects treated with omadacycline or vancomycin.” Antimicrobial agents and chemotherapy (2025). PMID: 39819014 ↗
L1TRIAL_NONRANDOMCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis - [18]
Jo J, Carlson TJ, Hu C et al.. “Faecal pharmacokinetics, microbiome, and bile acid changes in healthy subjects given intravenous followed by oral omadacycline; a Phase 1 clinical trial.” The Journal of antimicrobial chemotherapy (2025). PMID: 40796204 ↗
L4TRIAL_NONRANDOMCited in: Definition, Classification and Causative Organisms, Empiric and Acute Management - [19]
Di Bella S, Sanson G, Monticelli J et al.. “Clostridioides difficile infection: history, epidemiology, risk factors, prevention, clinical manifestations, treatment, and future options.” Clinical microbiology reviews (2024). PMID: 38421181 ↗
L5REVIEW_NARRATIVECited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management - [20]
Yadegar A, Bar-Yoseph H, Monaghan TM et al.. “Fecal microbiota transplantation: current challenges and future landscapes.” Clinical microbiology reviews (2024). PMID: 38717124 ↗
L5REVIEW_NARRATIVECited in: Definition, Classification and Causative Organisms, Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [21]
Veve MP, Kenney RM, Aljundi AM et al.. “Multicenter, retrospective cohort study of antimycobacterial treatment-related harms among patients with non-tuberculosis Mycobacterium infections in the United States.” Antimicrobial agents and chemotherapy (2025). PMID: 40035548 ↗
L2COHORTCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Complications, Prognosis and Natural History - [22]
DeFilipp Z, Bloom PP, Torres Soto M et al.. “Drug-Resistant E. coli Bacteremia Transmitted by Fecal Microbiota Transplant.” The New England journal of medicine (2019). PMID: 31665575 ↗
L4CASE_REPORTCited in: Definition, Classification and Causative Organisms, Antimicrobial Resistance and Stewardship, Complications - [23]
Aràjol C, González Suárez B, Bonilla Moreno M et al.. “Clostridioides difficile infection: Position paper of the Catalan Society of Gastroenterology.” Gastroenterologia y hepatologia (2026). PMID: 41547475 ↗
L1GUIDELINECited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup, Definitive Therapy, Duration and De-escalation - [24]
Rode AA, Duboc H, Lamazière A et al.. “Re-establishing bile acid composition after treatment of recurrent Clostridioides difficile infection with fecal microbiota transplantation compared with oral vancomycin or a 12-strain bacterial mixture.” Gut microbes (2026). PMID: 41997890 ↗
L1RCTCited in: Definition, Classification and Causative Organisms, Empiric and Acute Management - [25]
Eriksen LL, Støy S, Mejlby Hansen M et al.. “Dynamics in Circulating Immune Cell Subsets After Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection.” Clinical and translational gastroenterology (2026). PMID: 41738638 ↗
L1RCTCited in: Definition, Classification and Causative Organisms, Complications - [26]
Bryant JA, Vulić M, Walsh EA et al.. “The impact of an oral purified microbiome therapeutic on the gastrointestinal microbiome.” Nature medicine (2026). PMID: 41491103 ↗
L1RCTCited in: Definition, Classification and Causative Organisms - [27]
Salvador BC, Gomes DL, Araujo AGS et al.. “Systematic review: Accuracy of diagnostic methods for Clostridioides difficile infection.” Anaerobe (2026). PMID: 41833705 ↗
L1SR_OBSCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Clinical Presentation, Diagnosis and Workup - [28]
Chernova VO, van Prehn J, Groenewegen B et al.. “Biovigilance in Faecal Microbiota Transplantation: 7-Year Cohort Study and Framework for Microbiological Assessments of Infectious Adverse Events.” United European gastroenterology journal (2026). PMID: 42283215 ↗
L2COHORTCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors - [29]
Duricek M, Bartos H, Halmova K et al.. “ESBL positivity as an independent predictor of Clostridioides difficile infection: a retrospective cohort study.” International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (2026). PMID: 42070626 ↗
L2COHORTCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup, Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [30]
Brown KA, Coburn B, Hernandez A et al.. “Antibiotic and Nonantibiotic Drugs Associated With Clostridioides difficile Infection Risk: a Pharmacopoeia-Wide Case-Cohort Study.” The Journal of infectious diseases (2026). PMID: 41830216 ↗
L2COHORTCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [31]
Gong J-J, Huang I-H, Hung Y et al.. “Combination of mitomycin C and low-dose metronidazole synergistically against Clostridioides difficile infection and recurrence prevention.” Antimicrobial agents and chemotherapy (2025). PMID: 40525407 ↗
L5OTHERCited in: Definition, Classification and Causative Organisms, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [32]
Webb BJ, Subramanian A, Lopansri B et al.. “Antibiotic Exposure and Risk for Hospital-Associated Clostridioides difficile Infection.” Antimicrobial agents and chemotherapy (2020). PMID: 31964789 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [33]
De Wolfe TJ, Kates AE, Barko L et al.. “Modified Mouse Model of Clostridioides difficile Infection as a Platform for Probiotic Efficacy Studies.” Antimicrobial agents and chemotherapy (2019). PMID: 30988143 ↗
L5OTHERCited in: Definition, Classification and Causative Organisms, Empiric and Acute Management, Prognosis and Natural History - [34]
Jorgensen SCJ, Trinh TD, Zasowski EJ et al.. “Real-World Experience with Ceftolozane-Tazobactam for Multidrug-Resistant Gram-Negative Bacterial Infections.” Antimicrobial agents and chemotherapy (2020). PMID: 31932379 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Diagnosis and Workup, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship, Complications, Prognosis and Natural History - [35]
Bassères E, Eubank TA, Begum K et al.. “Antibacterial activity of ibezapolstat against antimicrobial-resistant clinical strains of Clostridioides difficile.” Antimicrobial agents and chemotherapy (2024). PMID: 38364016 ↗
L5OTHERCited in: Definition, Classification and Causative Organisms, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [36]
Wieczorkiewicz JT, Skinner AM, Cheknis A et al.. “Epidemiology of Clostridioides difficile infection at one hospital 10 years after an outbreak of the epidemic C. difficile strain BI/027: changing strain prevalence, antimicrobial susceptibilities, and patient antibiotic exposures.” Antimicrobial agents and chemotherapy (2024). PMID: 38953622 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Diagnosis and Workup, Antimicrobial Resistance and Stewardship - [37]
McPherson J, Hu C, Begum K et al.. “Functional and Metagenomic Evaluation of Ibezapolstat for Early Evaluation of Anti-Recurrence Effects in Clostridioides difficile Infection.” Antimicrobial agents and chemotherapy (2022). PMID: 35862742 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms - [38]
Buckley AM, Moura IB, Altringham J et al.. “The use of first-generation cephalosporin antibiotics, cefalexin and cefradine, is not associated with induction of simulated Clostridioides difficile infection.” The Journal of antimicrobial chemotherapy (2021). PMID: 34561709 ↗
L5OTHERCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis - [39]
Ranganath N, Tabaja H, Nair VO et al.. “Lines on the line: evaluating the impact of antibiotic lock therapy versus catheter removal in the management of central vascular catheter infections.” The Journal of antimicrobial chemotherapy (2025). PMID: 40470775 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [40]
Duricek M, Halmova K, Krutova M et al.. “Is shorter also better in the treatment of Clostridioides difficile infection?” The Journal of antimicrobial chemotherapy (2024). PMID: 38661207 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Microbiology and Pathogenesis, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [41]
Saydan S, Schwab F, Holstiege J et al.. “Surveillance of Clostridioides difficile on hospital admission and outpatient antibiotic use in Germany-a 9 year ecological analysis.” The Journal of antimicrobial chemotherapy (2025). PMID: 39821312 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors - [42]
Boton N, Patel PK, Beekmann SE et al.. “Clinician Management Preferences for Clostridioides difficile Infection in Adults: A 2024 Emerging Infections Network Survey.” Open forum infectious diseases (2025). PMID: 40599494 ↗
L5OTHERCited in: Definition, Classification and Causative Organisms, Empiric and Acute Management - [43]
Dubberke ER, Li Q, Obi EN et al.. “A Retrospective Assessment of Guideline Adherence and Treatment Outcomes From Clostridioides difficile Infection Following the IDSA 2021 Clinical Guideline Update: Clostridioides difficile Infection.” Open forum infectious diseases (2024). PMID: 39355263 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms - [44]
Carlson TJ, Gonzales-Luna AJ, Nebo K et al.. “Assessment of Kidney Injury as a Severity Criteria for Clostridioides Difficile Infection.” Open forum infectious diseases (2020). PMID: 33209956 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Prognosis and Natural History - [45]
Chua HC, Eubank TA, Lee A et al.. “Defining Fulminant Clostridioides difficile Infections: Assessing the Utility of Hypotension as a Diagnostic Criterion.” Open forum infectious diseases (2025). PMID: 39896986 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms - [46]
Yin J, Kociolek LK, Same RG et al.. “Oral Vancomycin May Be Associated With Earlier Symptom Resolution Than Metronidazole for Hospitalized Children With Nonsevere Clostridiodes difficile Infections.” Open forum infectious diseases (2019). PMID: 31950069 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms - [47]
Du T, Silva A, Choi KB et al.. “Characterization of Adult and Pediatric Healthcare-Associated and Community-Associated Clostridioides difficile Infections, Canada, 2015-2022.” Emerging infectious diseases (2025). PMID: 40439410 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [48]
Conlon-Bingham GM, Aldeyab M, Scott M et al.. “Effects of Antibiotic Cycling Policy on Incidence of Healthcare-Associated MRSA and Clostridioides difficile Infection in Secondary Healthcare Settings.” Emerging infectious diseases (2019). PMID: 30561306 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [49]
Rizzardi K, Norén T, Aspevall O et al.. “National Surveillance for Clostridioides difficile Infection, Sweden, 2009-2016.” Emerging infectious diseases (2018). PMID: 30124193 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [50]
Kim MH, Kim J, Ra H et al.. “Identifying Contact Time Required for Secondary Transmission of Clostridioides difficile Infections by Using Real-Time Locating System.” Emerging infectious diseases (2024). PMID: 38666567 ↗
L2OTHERCited in: Definition, Classification and Causative Organisms, Epidemiology, Transmission and Risk Factors, Prognosis and Natural History - [51]
Prosty C, Hanula R, Katergi K et al.. “Clinical Outcomes and Management of NAAT-Positive/Toxin-Negative Clostridioides difficile Infection: A Systematic Review and Meta-Analysis.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 37648251 ↗
L1SR_OBSCited in: Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [52]
Donskey CJ, Dubberke ER, Klein NP et al.. “CLOVER (CLOstridium difficile Vaccine Efficacy tRial) Study: A Phase 3, Randomized Trial Investigating the Efficacy and Safety of a Detoxified Toxin A/B Vaccine in Adults 50 Years and Older at Increased Risk of Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 39180325 ↗
L1RCTCited in: Microbiology and Pathogenesis, Empiric and Acute Management, Complications - [53]
Louie T, Ribble W, Boccumini L et al.. “Safety and efficacy of CRS3123 in adults with a primary episode or first recurrence of Clostridioides difficile infection: a phase 2, randomised, double-blind, multicentre, vancomycin-controlled study.” The Lancet. Infectious diseases (2026). PMID: 41581516 ↗
L1RCTCited in: Microbiology and Pathogenesis, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Complications, Prognosis and Natural History - [54]
Guery B, Georgopali A, Karas A et al.. “Pharmacokinetic analysis of an extended-pulsed fidaxomicin regimen for the treatment of Clostridioides (Clostridium) difficile infection in patients aged 60 years and older in the EXTEND randomized controlled trial.” The Journal of antimicrobial chemotherapy (2020). PMID: 31960058 ↗
L1RCTCited in: Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors - [55]
Fitzpatrick F, Safdar N, van Prehn J et al.. “How can patients with Clostridioides difficile infection on concomitant antibiotic treatment be best managed?” The Lancet. Infectious diseases (2022). PMID: 35617982 ↗
L5REVIEW_NARRATIVECited in: Microbiology and Pathogenesis, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [56]
Redmond SN, Cadnum JL, Jencson AL et al.. “Emergence and Spread of Clostridioides difficile Isolates With Reduced Fidaxomicin Susceptibility in an Acute Care Hospital.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2025). PMID: 40036727 ↗
L2OTHERCited in: Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [57]
Kar OB, Freedberg DE. “The phases of Clostridioides difficile infection in the United States: the history and epidemiology of CDI from 1935 to present.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2026). PMID: 42284457 ↗
L5OTHERCited in: Microbiology and Pathogenesis, Antimicrobial Resistance and Stewardship - [58]
Villafuerte Gálvez JA, Pollock NR, Alonso CD et al.. “Stool Interleukin-1β Differentiates Clostridioides difficile Infection (CDI) From Asymptomatic Carriage and Non-CDI Diarrhea.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 35906836 ↗
L3OTHERCited in: Microbiology and Pathogenesis, Clinical Presentation, Diagnosis and Workup - [59]
Doolan CP, Louie T, Lata C et al.. “Latent Class Analysis for the Diagnosis of Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 33053174 ↗
L4OTHERCited in: Microbiology and Pathogenesis, Clinical Presentation, Diagnosis and Workup - [60]
Kelly CP, Chen X, Williams D et al.. “Host Immune Markers Distinguish Clostridioides difficile Infection From Asymptomatic Carriage and Non-C. difficile Diarrhea.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2020). PMID: 31211839 ↗
L3OTHERCited in: Microbiology and Pathogenesis, Clinical Presentation, Diagnosis and Workup - [61]
Barbar R, Brazelton JN, Carroll KC et al.. “Molecular Epidemiology and Genetic Relatedness of Clostridioides difficile Isolates in Pediatric Oncology and Transplant Patients Using Whole Genome Sequencing.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 35675378 ↗
L3OTHERCited in: Microbiology and Pathogenesis - [62]
Guh AY, Hatfield KM, Winston LG et al.. “Toxin Enzyme Immunoassays Detect Clostridioides difficile Infection With Greater Severity and Higher Recurrence Rates.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2019). PMID: 30615074 ↗
L2OTHERCited in: Microbiology and Pathogenesis, Clinical Presentation, Diagnosis and Workup - [63]
Wilcox MH, Rahav G, Dubberke ER et al.. “Influence of Diagnostic Method on Outcomes in Phase 3 Clinical Trials of Bezlotoxumab for the Prevention of Recurrent Clostridioides difficile Infection: A Post Hoc Analysis of MODIFY I/II.” Open forum infectious diseases (2019). PMID: 31375837 ↗
L2TRIAL_NONRANDOMCited in: Microbiology and Pathogenesis, Diagnosis and Workup - [64]
Schechner V, Fallach N, Braun T et al.. “Antibiotic exposure and the risk of hospital-acquired diarrhoea and Clostridioides difficile infection: a cohort study.” The Journal of antimicrobial chemotherapy (2021). PMID: 33969419 ↗
L3COHORTCited in: Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [65]
Abou Chakra CN, Gagnon A, Lapointe S et al.. “The Strain and the Clinical Outcome of Clostridioides difficile Infection: A Meta-analysis.” Open forum infectious diseases (2024). PMID: 38524230 ↗
L1SR_OBSCited in: Microbiology and Pathogenesis, Empiric and Acute Management, Prognosis and Natural History - [66]
Wilcox MH, McGovern BH, Hecht GA. “The Efficacy and Safety of Fecal Microbiota Transplant for Recurrent Clostridium difficile Infection: Current Understanding and Gap Analysis.” Open forum infectious diseases (2020). PMID: 32405509 ↗
L5REVIEW_NARRATIVECited in: Microbiology and Pathogenesis, Empiric and Acute Management, Complications - [67]
Bansal D, Pahil S, Chatterjee A et al.. “Clostridioides difficile infection in inflammatory bowel disease: an observational study in flares of ulcerative colitis and a South Asian region-specific systematic review and meta-analysis.” Therapeutic advances in gastroenterology (2026). PMID: 42136876 ↗
L2SR_OBSCited in: Microbiology and Pathogenesis - [68]
Lee SH, Kim TY, Huh HJ et al.. “Clinical outcomes of toxin-positive versus toxin-negative/NAAT-positive Clostridioides difficile infection in South Korea: a single-center retrospective cohort study.” BMC infectious diseases (2026). PMID: 42168920 ↗
L3COHORTCited in: Microbiology and Pathogenesis - [69]
Rodríguez RG, Rodríguez MJP, López APG et al.. “Incidence of hospital-acquired toxin-producing clostridioides difficile infection between the pre-pandemic (2017-2019) and pandemic (2020-2022): a retrospective cohort study.” Archives of public health = Archives belges de sante publique (2026). PMID: 41721370 ↗
L3COHORTCited in: Microbiology and Pathogenesis - [70]
Liu Y, Ma L, Cheng J et al.. “Effects of Omeprazole on Recurrent Clostridioides difficile Infection Caused by ST81 Strains and Their Potential Mechanisms.” Antimicrobial agents and chemotherapy (2023). PMID: 37223895 ↗
L3OTHERCited in: Microbiology and Pathogenesis, Empiric and Acute Management - [71]
Costa DVS, Pham NVS, Hays RA et al.. “Influence of Binary Toxin Gene Detection and Decreased Susceptibility to Antibiotics among Clostridioides difficile Strains on Disease Severity: a Single-Center Study.” Antimicrobial agents and chemotherapy (2022). PMID: 35861541 ↗
L4OTHERCited in: Microbiology and Pathogenesis, Diagnosis and Workup, Severity Assessment and Risk Stratification, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [72]
Escudero-Sánchez R, Rubio Martín E, Vizcarra P et al.. “Conventional versus extended-pulsed fidaxomicin dosing in patients at high risk of recurrence of Clostridioides difficile infection: a propensity score analysis.” The Journal of antimicrobial chemotherapy (2023). PMID: 36861316 ↗
L3OTHERCited in: Microbiology and Pathogenesis - [73]
Murray B, Wolfe C, Marra A et al.. “In vitro activity of the novel antibacterial agent ibezapolstat (ACX-362E) against Clostridioides difficile.” The Journal of antimicrobial chemotherapy (2020). PMID: 32285102 ↗
L5OTHERCited in: Microbiology and Pathogenesis, Diagnosis and Workup, Definitive Therapy, Duration and De-escalation - [74]
Buckley AM, Altringham J, Clark E et al.. “Eravacycline, a novel tetracycline derivative, does not induce Clostridioides difficile infection in an in vitro human gut model.” The Journal of antimicrobial chemotherapy (2021). PMID: 32929459 ↗
L5OTHERCited in: Microbiology and Pathogenesis - [75]
Chilton CH, Crowther GS, Miossec C et al.. “Investigation of the effect of the adsorbent DAV131A on the propensity of moxifloxacin to induce simulated Clostridioides (Clostridium) difficile infection (CDI) in an in vitro human gut model.” The Journal of antimicrobial chemotherapy (2020). PMID: 32097465 ↗
L5OTHERCited in: Microbiology and Pathogenesis, Diagnosis and Workup - [76]
Ryan K, Kaufer A, Jayawardena M et al.. “Clostridioides difficile laboratory testing algorithms and performance: a review of the Royal College of Pathologists of Australasia Quality Assurance Programs external quality assessments for C. difficile.” Pathology (2026). PMID: 41760493 ↗
L5REVIEW_NARRATIVECited in: Microbiology and Pathogenesis, Clinical Presentation - [77]
Wang R, Li X, Zhang T. “Current status and future perspectives of fecal immunological markers in the differential diagnosis of Clostridioides difficile infection in children.” European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (2026). PMID: 41723281 ↗
L5REVIEW_NARRATIVECited in: Microbiology and Pathogenesis - [78]
Sanchez-Ramos L, Preis R, Romero R. “Prophylactic antibiotics to prevent postcesarean infection: which antimicrobial, when, how, and why?” American journal of obstetrics and gynecology (2025). PMID: 41485837 ↗
L5REVIEW_NARRATIVECited in: Microbiology and Pathogenesis - [79]
Young MK, Leslie JL, Madden GR et al.. “Binary Toxin Expression by Clostridioides difficile Is Associated With Worse Disease.” Open forum infectious diseases (2022). PMID: 35146046 ↗
L3OTHERCited in: Microbiology and Pathogenesis, Epidemiology, Transmission and Risk Factors - [80]
Carlson TJ, Endres BT, Le Pham J et al.. “Eosinopenia and Binary Toxin Increase Mortality in Hospitalized Patients With Clostridioides difficile Infection.” Open forum infectious diseases (2020). PMID: 31993458 ↗
L3OTHERCited in: Microbiology and Pathogenesis, Prognosis and Natural History - [81]
Hilt EE, Vaughn BP, Galdys AL et al.. “Impact of the Reverse 2-Step Algorithm for Clostridioides difficile Testing in the Microbiology Laboratory on Hospitalized Patients.” Open forum infectious diseases (2024). PMID: 38756762 ↗
L4OTHERCited in: Microbiology and Pathogenesis - [82]
Jorgensen SCJ, Trinh TD, Zasowski EJ et al.. “Real-World Experience With Ceftazidime-Avibactam for Multidrug-Resistant Gram-Negative Bacterial Infections.” Open forum infectious diseases (2019). PMID: 31890725 ↗
L3OTHERCited in: Microbiology and Pathogenesis, Diagnosis and Workup, Antimicrobial Resistance and Stewardship, Complications, Prognosis and Natural History - [83]
Wilcox MH, Cornely OA, Guery B et al.. “Microbiological Characterization and Clinical Outcomes After Extended-Pulsed Fidaxomicin Treatment for Clostridioides difficile Infection in the EXTEND Study.” Open forum infectious diseases (2019). PMID: 31723569 ↗
L1OTHERCited in: Microbiology and Pathogenesis, Clinical Presentation - [84]
Pender M, Throneberry SK, Grisel N et al.. “Syndromic Panel Testing Among Patients With Infectious Diarrhea: The Challenge of Interpreting Clostridioides difficile Positivity on a Multiplex Molecular Panel.” Open forum infectious diseases (2023). PMID: 37711280 ↗
L4OTHERCited in: Microbiology and Pathogenesis - [85]
Carlson TJ, Gonzales-Luna AJ, Wilcox MF et al.. “Corticosteroids Do Not Increase the Likelihood of Primary Clostridioides difficile Infection in the Setting of Broad-Spectrum Antibiotic Use.” Open forum infectious diseases (2021). PMID: 34646906 ↗
L3OTHERCited in: Microbiology and Pathogenesis - [86]
Golan Y, DuPont HL, Aldomiro F et al.. “Renal Impairment, C. difficile Recurrence, and the Differential Effect of Bezlotoxumab: A Post Hoc Analysis of Pooled Data From 2 Randomized Clinical Trials.” Open forum infectious diseases (2020). PMID: 32685606 ↗
L1OTHERCited in: Microbiology and Pathogenesis - [87]
Preechakawin N, Suttikulsombat M, Kiratisin P et al.. “Adjunctive use of Saccharomyces boulardii versus bismuth subsalicylate in the management of non-Clostridioides difficile nosocomial diarrhea in severely ill patients: a three-arm randomized controlled trial.” Translational gastroenterology and hepatology (2026). PMID: 41675330 ↗
L1RCTCited in: Microbiology and Pathogenesis - [88]
Mehta P, Nahass RG, Brunetti L. “Acid Suppression Medications During Hospitalization as a Risk Factor for Recurrence of Clostridioides difficile Infection: Systematic Review and Meta-analysis.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 32386313 ↗
L1SR_OBSCited in: Epidemiology, Transmission and Risk Factors - [89]
Poirier D, Gervais P, Fuchs M et al.. “Predictors of Clostridioides difficile Infection Among Asymptomatic, Colonized Patients: A Retrospective Cohort Study.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2020). PMID: 31290544 ↗
L3COHORTCited in: Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup, Prevention, Infection Control and Special Populations - [90]
Slimings C, Riley TV. “Antibiotics and healthcare facility-associated Clostridioides difficile infection: systematic review and meta-analysis 2020 update.” The Journal of antimicrobial chemotherapy (2021). PMID: 33787887 ↗
L1SR_OBSCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [91]
Carlson TJ, Gonzales-Luna AJ. “Utilizing antibiotics to prevent Clostridioides difficile infection: does exposure to a risk factor decrease risk? A systematic review.” The Journal of antimicrobial chemotherapy (2020). PMID: 32696044 ↗
L1SR_OBSCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History, Prevention, Infection Control and Special Populations - [92]
Dulhunty JM, Brett SJ, De Waele JJ et al.. “Continuous vs Intermittent β-Lactam Antibiotic Infusions in Critically Ill Patients With Sepsis: The BLING III Randomized Clinical Trial.” JAMA (2024). PMID: 38864155 ↗
L1RCTCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [93]
Saravolatz L, Gandhi TN, Vaughn VM et al.. “Target Trial Emulation of Empiric Antibiotics on Clinical Outcomes in Moderately Immunocompromised Patients Hospitalized With Pneumonia.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2026). PMID: 40601818 ↗
L3OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship, Complications, Prognosis and Natural History, Prevention, Infection Control and Special Populations - [94]
Sahrmann JM, Olsen MA, Stwalley D et al.. “Costs Attributable to Clostridioides difficile Infection Based on the Setting of Onset.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 36285546 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Prognosis and Natural History - [95]
Taniguchi J, Aso S, Matsui H et al.. “Outcomes of ceftriaxone 2 g versus 1 g daily in hospitalized patients with pneumonia: a nationwide retrospective cohort study.” The Journal of antimicrobial chemotherapy (2025). PMID: 40492536 ↗
L3COHORTCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Complications, Prognosis and Natural History - [96]
Oltolini C, Piekarska A, Signori A et al.. “Clostridioides difficile infection in non-transplanted adults with haematological malignancy: Systematic review and meta-analysis on behalf of European Conference on Infections in Leukemia (ECIL) and Infectious Diseases Working Party (IDWP) of the European Society for Blood and Marrow Transplantation (EBMT).” Blood reviews (2026). PMID: 42106226 ↗
L1SR_OBSCited in: Epidemiology, Transmission and Risk Factors, Severity Assessment and Risk Stratification, Empiric and Acute Management, Prognosis and Natural History - [97]
Landivar MC, Hartmann Rost I, Carvalho Kilson A et al.. “Efficacy of fluoroquinolone prophylaxis during induction phase in children with acute lymphoblastic leukemia: a systematic review and meta-analysis.” European journal of pediatrics (2026). PMID: 42065773 ↗
L1SR_OBSCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History, Prevention, Infection Control and Special Populations - [98]
Zhao Y, He X, Hu Y et al.. “Impact of the COVID-19 pandemic on the incidence of Clostridioides difficile infection based on hospital surveillance data: a systematic review and meta-analysis.” Antimicrobial resistance and infection control (2026). PMID: 41933426 ↗
L1SR_OBSCited in: Epidemiology, Transmission and Risk Factors, Prognosis and Natural History, Prevention, Infection Control and Special Populations - [99]
Skjøt-Arkil H, Rune Nanthan K, Chen M et al.. “Carrier prevalence of Clostridioides difficile in emergency departments and the association of prior antibiotic consumption: a combined cross-sectional and nested case-control study.” The Journal of antimicrobial chemotherapy (2023). PMID: 37409612 ↗
L3CASE_CONTROLCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [100]
Guh AY, Mu Y, Winston LG et al.. “Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes.” The New England journal of medicine (2020). PMID: 32242357 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors - [101]
Chen YC, Kuo YC, Chen MC et al.. “Case-Control Study of Clostridium innocuum Infection, Taiwan.” Emerging infectious diseases (2022). PMID: 35195517 ↗
L3CASE_CONTROLCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [102]
Okafor CM, Clogher P, Olson D et al.. “Trends in and Risk Factors for Recurrent Clostridioides difficile Infection, New Haven County, Connecticut, USA, 2015-2020.” Emerging infectious diseases (2023). PMID: 37081745 ↗
L2REVIEW_NARRATIVECited in: Epidemiology, Transmission and Risk Factors, Antimicrobial Resistance and Stewardship - [103]
Daniel F, Abdallah B, Chaitou AR et al.. “Association between postoperative Clostridioides difficile infection and outcomes following pancreatoduodenectomy for pancreatic cancer: a national cohort study.” Surgical endoscopy (2026). PMID: 42257924 ↗
L2COHORTCited in: Epidemiology, Transmission and Risk Factors - [104]
Rohde AM, Kern WV, Behnke M et al.. “All-cause mortality and risk factors for death in patients with Clostridioides difficile infections: a prospective multi-centre cohort study in six German university hospitals, 2016-2020.” The Journal of hospital infection (2026). PMID: 41724443 ↗
L2COHORTCited in: Epidemiology, Transmission and Risk Factors - [105]
Zhang J, Chen L, Gomez-Simmonds A et al.. “Antibiotic-Specific Risk for Community-Acquired Clostridioides difficile Infection in the United States from 2008 to 2020.” Antimicrobial agents and chemotherapy (2022). PMID: 36377887 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [106]
Rhodes NJ, Jozefczyk CC, Moore WJ et al.. “Characterizing Risk Factors for Clostridioides difficile Infection among Hospitalized Patients with Community-Acquired Pneumonia.” Antimicrobial agents and chemotherapy (2021). PMID: 33875439 ↗
L3OTHERCited in: Epidemiology, Transmission and Risk Factors, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [107]
Tydeman F, Craine N, Kavanagh K et al.. “Incidence of Clostridioides difficile infection (CDI) related to antibiotic prescribing by GP surgeries in Wales.” The Journal of antimicrobial chemotherapy (2021). PMID: 34151964 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [108]
Moreels N, Boven A, Gressani O et al.. “The combined effect of systemic antibiotics and proton pump inhibitors on Clostridioides difficile infection and recurrence.” The Journal of antimicrobial chemotherapy (2024). PMID: 38267263 ↗
L3OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management - [109]
Kipnis M, Schwab F, Kramer TS et al.. “Incidence of healthcare-associated Clostridioides difficile infections and association with ward-level antibiotic consumption in a German university hospital: an ecological study.” The Journal of antimicrobial chemotherapy (2019). PMID: 31098633 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors - [110]
Yamamoto S, Shiroshita A, Kataoka Y et al.. “Effectiveness of Ampicillin-Sulbactam Versus Ceftriaxone for the Initial Treatment of Community-Acquired Pneumonia in Older Adults: A Target Trial Emulation Study.” Open forum infectious diseases (2025). PMID: 40134633 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Prognosis and Natural History - [111]
Ilett EE, Helleberg M, Reekie J et al.. “Incidence Rates and Risk Factors of Clostridioides difficile Infection in Solid Organ and Hematopoietic Stem Cell Transplant Recipients.” Open forum infectious diseases (2019). PMID: 30949533 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors - [112]
Li X, Xiao F, Wang X et al.. “Gut Microbial and Metabolic Features Associated With Clostridioides difficile Infection Recurrence in Children.” Open forum infectious diseases (2024). PMID: 39319090 ↗
L1OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management - [113]
Olsen MA, Keller MR, Stwalley D et al.. “Increased Incidence and Risk of Septicemia and Urinary Tract Infection After Clostridioides difficile Infection.” Open forum infectious diseases (2023). PMID: 37547851 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors - [114]
Sanchez E, Krantz EM, Escobar ZK et al.. “Epidemiology and Outcomes of Recurrent C Difficile Infection Among Hematopoietic Cell Transplant Recipients: A Single-center, Retrospective 10-year Study.” Open forum infectious diseases (2024). PMID: 39450393 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management, Prevention, Infection Control and Special Populations - [115]
Williams MJ, Atienza S, Franzen E et al.. “Evaluation of Primary Oral Vancomycin Prophylaxis Against Clostridioides difficile Infection During Autologous Stem Cell Transplantation.” Open forum infectious diseases (2024). PMID: 39498172 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Prevention, Infection Control and Special Populations - [116]
Johnson TM, Howard AH, Miller MA et al.. “Effectiveness of Bezlotoxumab for Prevention of Recurrent Clostridioides difficile Infection Among Transplant Recipients.” Open forum infectious diseases (2021). PMID: 34262988 ↗
L3OTHERCited in: Epidemiology, Transmission and Risk Factors, Prognosis and Natural History - [117]
Tartof SY, Schmidt MA, Contreras R et al.. “Burden of Medically Attended Diarrhea and Outpatient Clostridioides difficile Infection Among Persons in 2 Large Integrated Healthcare Settings, 2016-2021.” Open forum infectious diseases (2024). PMID: 38250203 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Empiric and Acute Management - [118]
Cornely OA, Mullane KM, Birch T et al.. “Exploratory Evaluation of Bezlotoxumab on Outcomes Associated With Clostridioides difficile Infection in MODIFY I/II Participants With Cancer.” Open forum infectious diseases (2020). PMID: 32099847 ↗
L1OTHERCited in: Epidemiology, Transmission and Risk Factors - [119]
Du T, Choi KB, Silva A et al.. “Characterization of Healthcare-Associated and Community-Associated Clostridioides difficile Infections among Adults, Canada, 2015-2019.” Emerging infectious diseases (2022). PMID: 35470794 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [120]
Guo CLT, Kwong TNY, Mak JWY et al.. “Trends in Incidence and Clinical Outcomes of Clostridioides difficile Infection, Hong Kong.” Emerging infectious diseases (2021). PMID: 34812719 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup, Antimicrobial Resistance and Stewardship - [121]
Miller AC, Arakkal AT, Sewell DK et al.. “Risk for Asymptomatic Household Transmission of Clostridioides difficile Infection Associated with Recently Hospitalized Family Members.” Emerging infectious diseases (2022). PMID: 35447064 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Antimicrobial Resistance and Stewardship - [122]
Ramirez JA, Angulo FJ, Carrico RM et al.. “Misdiagnosis of Clostridioides difficile Infections by Standard-of-Care Specimen Collection and Testing among Hospitalized Adults, Louisville, Kentucky, USA, 2019-20201.” Emerging infectious diseases (2023). PMID: 37080953 ↗
L2OTHERCited in: Epidemiology, Transmission and Risk Factors, Clinical Presentation, Diagnosis and Workup - [123]
Dunn AN, Radakovich N, Ancker JS et al.. “The Impact of Clinical Decision Support Alerts on Clostridioides difficile Testing: A Systematic Review.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 32060501 ↗
L1SR_OBSCited in: Clinical Presentation, Diagnosis and Workup, Complications - [124]
Doolan CP, Sahragard B, Leal J et al.. “Clostridioides difficile Near-Patient Testing Versus Centralized Testing: A Pragmatic Cluster Randomized Crossover Trial.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 36718646 ↗
L1RCTCited in: Clinical Presentation, Diagnosis and Workup, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [125]
Perry DA, Shirley D, Micic D et al.. “External Validation and Comparison of Clostridioides difficile Severity Scoring Systems.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2022). PMID: 34459885 ↗
L3OTHERCited in: Clinical Presentation, Diagnosis and Workup, Complications, Prognosis and Natural History - [126]
Lin MY, Stein BD, Kothadia SM et al.. “Impact of Mandatory Infectious Disease Specialist Approval on Hospital-Onset Clostridioides difficile Infection Rates and Testing Appropriateness.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 37157903 ↗
L2OTHERCited in: Clinical Presentation, Diagnosis and Workup - [127]
Shenoy ES, Macy E, Rowe T et al.. “Evaluation and Management of Penicillin Allergy: A Review.” JAMA (2019). PMID: 30644987 ↗
L5REVIEW_NARRATIVECited in: Clinical Presentation, Diagnosis and Workup, Severity Assessment and Risk Stratification, Empiric and Acute Management, Antimicrobial Resistance and Stewardship, Complications - [128]
Eubank TA, Jo J, Alam MJ et al.. “Efficacy, safety, pharmacokinetics, and associated microbiome changes of ibezapolstat compared with vancomycin in adults with Clostridioides difficile infection: a phase 2b, randomised, double-blind, active-controlled, multicentre study.” The Lancet. Microbe (2025). PMID: 40516571 ↗
L1RCTCited in: Clinical Presentation - [129]
Wang C, Gao H, Zhu C et al.. “Safety of proton pump inhibitors: an overview of systematic reviews and meta-analyses.” BMJ evidence-based medicine (2026). PMID: 42303374 ↗
L5SR_OBSCited in: Clinical Presentation, Definitive Therapy, Duration and De-escalation, Complications, Prognosis and Natural History - [130]
Kozák M, Majoros L, Panyiczki Z et al.. “Severe vitamin K deficiency-associated coagulopathy triggered by Clostridioides difficile infection and antibiotic-associated dysbiosis: A case report and literature review.” Infection (2026). PMID: 41563580 ↗
L4CASE_REPORTCited in: Clinical Presentation - [131]
AlAwadhi HK, Hyesoo Chang N, Jogendran M et al.. “Gastroenterology/Hepatology: What You May Have Missed in 2025.” Annals of internal medicine (2026). PMID: 41974014 ↗
L5REVIEW_NARRATIVECited in: Clinical Presentation - [132]
Guh AY, Li R, Korhonen L et al.. “Characteristics of Patients With Initial Clostridioides difficile Infection (CDI) That Are Associated With Increased Risk of Multiple CDI Recurrences.” Open forum infectious diseases (2024). PMID: 38577028 ↗
L2OTHERCited in: Clinical Presentation - [133]
Darkoh C, Keita K, Odo C et al.. “Emergence of Clinical Clostridioides difficile Isolates With Decreased Susceptibility to Vancomycin.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2022). PMID: 35016207 ↗
L4OTHERCited in: Diagnosis and Workup, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [134]
Stevens VW, Khader K, Echevarria K et al.. “Use of Oral Vancomycin for Clostridioides difficile Infection and the Risk of Vancomycin-Resistant Enterococci.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2020). PMID: 31504328 ↗
L2OTHERCited in: Diagnosis and Workup, Definitive Therapy, Duration and De-escalation - [135]
Turner NA, Krishnan J, Nelson A et al.. “Assessing the Impact of 2-Step Clostridioides difficile Testing at the Healthcare Facility Level.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 37279965 ↗
L2OTHERCited in: Diagnosis and Workup - [136]
Crotty M, Devall H, Cook N et al.. “Short Versus Long Antibiotic Duration in Streptococcus pneumoniae Bacteremia.” Open forum infectious diseases (2024). PMID: 39257675 ↗
L2TRIAL_NONRANDOMCited in: Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [137]
Rabiee MH, Abdolmohammadi Khiav L, Fallah Mehrabadi MH. “Prevalence of Clostridioides difficile contamination in healthcare and non-healthcare environments: a global systematic review and meta-analysis.” International health (2026). PMID: 41127891 ↗
L1SR_OBSCited in: Diagnosis and Workup - [138]
Barbero AM, Moriconi ND, Palma S et al.. “Epidemiology of Clostridioides difficile Infection in Argentina and Associated Risk Factors Evaluated Through a Meta-Analysis.” Antibiotics (Basel, Switzerland) (2026). PMID: 42353652 ↗
L3SR_OBSCited in: Diagnosis and Workup, Antimicrobial Resistance and Stewardship - [139]
Huang TC, Kou T, Kuo CJ et al.. “Enteric opportunistic infections in patients with inflammatory bowel disease receiving biologic therapies: a retrospective cohort study.” Gut pathogens (2025). PMID: 41423627 ↗
L2COHORTCited in: Diagnosis and Workup - [140]
Cusumano JA, Daffinee KE, Piehl EC et al.. “Meropenem plus Ceftaroline Is Active against Enterococcus faecalis in an In Vitro Pharmacodynamic Model Using Humanized Dosing Simulations.” Antimicrobial agents and chemotherapy (2022). PMID: 36154173 ↗
L5OTHERCited in: Diagnosis and Workup - [141]
McPherson JK, Hurdle JG, Baker ML et al.. “The microbiome-restorative potential of ibezapolstat for the treatment of Clostridioides difficile infection is predicted through variant PolC-type DNA polymerase III in Lachnospiraceae and Oscillospiraceae.” Antimicrobial agents and chemotherapy (2025). PMID: 39982073 ↗
L5OTHERCited in: Diagnosis and Workup - [142]
Bassères E, Begum K, Lancaster C et al.. “In vitro activity of eravacycline against common ribotypes of Clostridioides difficile.” The Journal of antimicrobial chemotherapy (2020). PMID: 32719870 ↗
L5OTHERCited in: Diagnosis and Workup, Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship - [143]
Kolte B, Nübel U. “Genetic determinants of resistance to antimicrobial therapeutics are rare in publicly available Clostridioides difficile genome sequences.” The Journal of antimicrobial chemotherapy (2024). PMID: 38598696 ↗
L4OTHERCited in: Diagnosis and Workup, Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [144]
Boekhoud IM, Sidorov I, Nooij S et al.. “Haem is crucial for medium-dependent metronidazole resistance in clinical isolates of Clostridioides difficile.” The Journal of antimicrobial chemotherapy (2021). PMID: 33876817 ↗
L5OTHERCited in: Diagnosis and Workup, Antimicrobial Resistance and Stewardship - [145]
Itogawa K, Narumoto O, Takeda K et al.. “Continuation of anti-tuberculosis therapy after Clostridioides difficile infection: a retrospective cohort study.” Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy (2026). PMID: 42296592 ↗
L2COHORTCited in: Diagnosis and Workup, Empiric and Acute Management - [146]
Alkhushaym N, Alabbad R, Alqarni YS et al.. “Assessment of rifaximin and rifampicin resistance across Clostridioides difficile ribotypes: a systematic review and meta-analysis.” Letters in applied microbiology (2026). PMID: 41604218 ↗
L1SR_OBSCited in: Diagnosis and Workup, Definitive Therapy, Duration and De-escalation - [147]
Meireles J, Leite S, de Castro Brandt AMT et al.. “High genetic similarity between Clostridioides difficile isolates from a woman with community-acquired infection and her dog.” Frontiers in public health (2026). PMID: 41584189 ↗
L4CASE_REPORTCited in: Diagnosis and Workup - [148]
Maeda M, Mori N, Hiraide M et al.. “Evaluation of Antibiotic Use Metrics as Predictors of Clostridioides difficile Infection Onset: A Single-Center, Case-Control Study Assessing the Days of Therapy and the Days of Antibiotic Spectrum Coverage.” Biological & pharmaceutical bulletin (2026). PMID: 41765474 ↗
L3CASE_CONTROLCited in: Diagnosis and Workup, Definitive Therapy, Duration and De-escalation - [149]
Kaple CE, Cadnum JL, Redmond SN et al.. “A sensitive and reduced-cost culture medium for recovery of Clostridioides difficile isolates with reduced fidaxomicin susceptibility from stool.” Journal of clinical microbiology (2026). PMID: 42283494 ↗
L5OTHERCited in: Diagnosis and Workup - [150]
Patterson WM, Fajnzylber J, Nero N et al.. “Diagnostic prediction models to identify patients at risk for healthcare-facility-onset Clostridioides difficile: A systematic review of methodology and reporting.” Infection control and hospital epidemiology (2023). PMID: 37665104 ↗
L2SR_OBSCited in: Severity Assessment and Risk Stratification - [151]
Friedrichs A, Wenz R, Pape D et al.. “The effect of antibiotic therapy on clinical outcome in patients hospitalized with moderate COVID-19 disease: a prospective multi-center cohort study.” Infection (2025). PMID: 40569348 ↗
L2COHORTCited in: Severity Assessment and Risk Stratification - [152]
Chen JH, Chiu CH, Chen CC et al.. “Comparative Efficacy of Fecal Microbiota Transplantation in Treating Refractory or Recurrent Clostridioides difficile Infection among Patients with and without Inflammatory Bowel Disease: A Retrospective Cohort Study.” Biomedicines (2024). PMID: 39061970 ↗
L3COHORTCited in: Severity Assessment and Risk Stratification - [153]
Chen W, Liu Y, Zhang Y et al.. “Risk of Clostridioides difficile infection in inflammatory bowel disease patients undergoing vedolizumab treatment: a systematic review and meta-analysis.” BMC gastroenterology (2024). PMID: 39448963 ↗
L2SR_OBSCited in: Severity Assessment and Risk Stratification - [154]
Wen BJ, Te LG, Liu XX et al.. “The value of fecal calprotectin in Clostridioides difficile infection: A systematic review.” Frontiers in physiology (2022). PMID: 35991191 ↗
L2SR_OBSCited in: Severity Assessment and Risk Stratification - [155]
Li J, Yang J, Ouyang Z et al.. “Molecular typing and clinical characteristics of Clostridioides difficile infection in patients with inflammatory bowel disease: A retrospective study.” Journal of global antimicrobial resistance (2025). PMID: 40287014 ↗
L4COHORTCited in: Severity Assessment and Risk Stratification - [156]
Le PH, Chen CL, Kuo CJ et al.. “Impact of Clostridioides difficile Infection on Clinical Outcomes in Hospitalized IBD Patients and the Role of Fecal Microbiota Transplantation: A Retrospective Cohort Study.” The Kaohsiung journal of medical sciences (2025). PMID: 40091757 ↗
L3COHORTCited in: Severity Assessment and Risk Stratification - [157]
Ressler AM, Patel A, Rao K. “Non-steroidal anti-inflammatory drugs are not associated with increased risk of Clostridioides difficile infection: A propensity-score-matched case-control study.” Anaerobe (2021). PMID: 34506930 ↗
L3CASE_CONTROLCited in: Severity Assessment and Risk Stratification - [158]
Tariq R, Sethi A, Arunachalam S et al.. “Machine Learning Model Predicts Recurrent Clostridioides difficile Infection in Patients With Inflammatory Bowel Disease (Recur CDI-IBD).” The American journal of gastroenterology (2026). PMID: 41562450 ↗
L3OTHERCited in: Severity Assessment and Risk Stratification - [159]
Rao K, Zhao Q, Bell J et al.. “An Open-Label, Randomized Trial Comparing Fidaxomicin With Oral Vancomycin for the Treatment of Clostridioides difficile Infection in Hospitalized Patients Receiving Concomitant Antibiotics for Concurrent Infections.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 37797310 ↗
L1RCTCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [160]
Young PJ, Bagshaw SM, Forbes AB et al.. “Effect of Stress Ulcer Prophylaxis With Proton Pump Inhibitors vs Histamine-2 Receptor Blockers on In-Hospital Mortality Among ICU Patients Receiving Invasive Mechanical Ventilation: The PEPTIC Randomized Clinical Trial.” JAMA (2020). PMID: 31950977 ↗
L1RCTCited in: Empiric and Acute Management, Complications, Prognosis and Natural History, Prevention, Infection Control and Special Populations - [161]
Johnstone J, Meade M, Lauzier F et al.. “Effect of Probiotics on Incident Ventilator-Associated Pneumonia in Critically Ill Patients: A Randomized Clinical Trial.” JAMA (2021). PMID: 34546300 ↗
L1RCTCited in: Empiric and Acute Management, Complications, Prognosis and Natural History - [162]
Hirsch W, Enns EA, Khoruts A et al.. “Cost-effectiveness of Commercial or Traditional Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2026). PMID: 42274997 ↗
L2OTHERCited in: Empiric and Acute Management, Prognosis and Natural History - [163]
Aby ES, Vaughn BP, Enns EA et al.. “Cost-effectiveness of Fecal Microbiota Transplantation for First Recurrent Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2022). PMID: 35275989 ↗
L2OTHERCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prognosis and Natural History - [164]
Alonso CD, Tillotson GS, Bidell MR et al.. “Safety and Efficacy of Fecal Microbiota, Live-jslm, in Preventing Recurrent Clostridioides difficile Infection in Participants Who Were Mildly to Moderately Immunocompromised in the Phase 3 PUNCH CD3-OLS Study.” Open forum infectious diseases (2025). PMID: 40177588 ↗
L4TRIAL_NONRANDOMCited in: Empiric and Acute Management, Complications, Prevention, Infection Control and Special Populations - [165]
Phillips EC, Warren CA, Ma JZ et al.. “Impact of Tigecycline on C. difficile Outcomes: Case Series and Propensity-Matched Retrospective Study.” Antimicrobial agents and chemotherapy (2022). PMID: 35647645 ↗
L3COHORTCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [166]
Escudero-Sanchez R, Muriel García A, García Fernández S et al.. “Fidaxomicin monotherapy versus standard therapy combined with bezlotoxumab for treating patients with Clostridioides difficile infection at high risk of recurrence: a matched cohort study.” The Journal of antimicrobial chemotherapy (2022). PMID: 35403189 ↗
L3COHORTCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [167]
Gonzales-Luna AJ, Skinner AM, Alonso CD et al.. “Redefining Clostridioides difficile infection antibiotic response and clinical outcomes.” The Lancet. Infectious diseases (2023). PMID: 37062301 ↗
L5REVIEW_NARRATIVECited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [168]
Naz F, Petri WA. “Host Immunity and Immunization Strategies for Clostridioides difficile Infection.” Clinical microbiology reviews (2023). PMID: 37162338 ↗
L5REVIEW_NARRATIVECited in: Empiric and Acute Management, Prevention, Infection Control and Special Populations - [169]
Allegretti JR, Mullish BH, Kelly C et al.. “The evolution of the use of faecal microbiota transplantation and emerging therapeutic indications.” Lancet (London, England) (2019). PMID: 31379333 ↗
L5REVIEW_NARRATIVECited in: Empiric and Acute Management - [170]
Saint-Lu N, Burdet C, Sablier-Gallis F et al.. “DAV131A Protects Hamsters from Lethal Clostridioides difficile Infection Induced by Fluoroquinolones.” Antimicrobial agents and chemotherapy (2019). PMID: 31636067 ↗
L5OTHERCited in: Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [171]
Phan JR, Do DM, Truong MC et al.. “An Aniline-Substituted Bile Salt Analog Protects both Mice and Hamsters from Multiple Clostridioides difficile Strains.” Antimicrobial agents and chemotherapy (2021). PMID: 34780262 ↗
L5OTHERCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation, Prevention, Infection Control and Special Populations - [172]
Mason CS, Avis T, Hu C et al.. “The Novel DNA Binding Mechanism of Ridinilazole, a Precision Clostridiodes difficile Antibiotic.” Antimicrobial agents and chemotherapy (2023). PMID: 37093023 ↗
L5OTHERCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [173]
Hu X, Dong R, Huang S et al.. “CDBN-YGXZ, a Novel Small-Molecule Drug, Shows Efficacy against Clostridioides difficile Infection and Recurrence in Mouse and Hamster Infection Models.” Antimicrobial agents and chemotherapy (2023). PMID: 37052498 ↗
L5OTHERCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [174]
Bishop EJ, Tiruvoipati R. “Management of Clostridioides difficile infection in adults and challenges in clinical practice: review and comparison of current IDSA/SHEA, ESCMID and ASID guidelines.” The Journal of antimicrobial chemotherapy (2022). PMID: 36441203 ↗
L5REVIEW_NARRATIVECited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [175]
Bassetti M, Cascio A, De Rosa FG et al.. “Management of Clostridioides difficile infection: an Italian Delphi consensus.” The Journal of antimicrobial chemotherapy (2024). PMID: 39008427 ↗
L5OTHERCited in: Empiric and Acute Management, Definitive Therapy, Duration and De-escalation - [176]
Sun Y, Veccia D, Song G et al.. “Acid-Suppressive Therapy Choice and Risk of Treatment Escalation in Inflammatory Bowel Disease: A Real-World Comparative Retrospective Study to Inform Personalized Treatment.” Journal of personalized medicine (2026). PMID: 42042559 ↗
L2COHORTCited in: Empiric and Acute Management - [177]
Mehta N, Goodenough D, Gupta NK et al.. “Recurrent Clostridioides difficile Infection and Outcome of Fecal Microbiota Transplantation Use: A Population-Based Assessment.” Open forum infectious diseases (2024). PMID: 38975247 ↗
L2OTHERCited in: Empiric and Acute Management, Prognosis and Natural History - [178]
Stewart AG, Chen SCA, Hamilton K et al.. “Clostridioides difficile Infection: Clinical Practice and Health Outcomes in 6 Large Tertiary Hospitals in Eastern Australia.” Open forum infectious diseases (2023). PMID: 37274181 ↗
L2OTHERCited in: Empiric and Acute Management - [179]
de la Villa S, Herrero S, Muñoz P et al.. “Real-world Use of Bezlotoxumab and Fecal Microbiota Transplantation for the Treatment of Clostridioides difficile Infection.” Open forum infectious diseases (2023). PMID: 36776780 ↗
L2OTHERCited in: Empiric and Acute Management - [180]
Hunt A, Danziger LH, Johnson S et al.. “Management and Outcomes of Patients at a Specialty Clinic for Clostridioides difficile Infection.” Open forum infectious diseases (2024). PMID: 38665169 ↗
L4OTHERCited in: Empiric and Acute Management - [181]
Deshpande A, Chen Y, Boye-Codjoe E et al.. “Adoption and Trends in Uptake of Updated ICD-10 Codes for Clostridioides difficile-A Retrospective Observational Study.” Open forum infectious diseases (2022). PMID: 36519119 ↗
L4OTHERCited in: Empiric and Acute Management - [182]
Hirai J, Hanai Y. “Metronidazole versus Vancomycin for a Moderate Clostridioides difficile Infection Defined by the Japanese Severity Score (MN Criteria): A Propensity Score-Matched Cohort Study.” Internal medicine (Tokyo, Japan) (2026). PMID: 41922231 ↗
L2COHORTCited in: Empiric and Acute Management - [183]
Yousef A, Wang N, Yousef M et al.. “Evaluating the Risk of Clostridioides difficile Infection After Rifaximin Treatment for Small Intestinal Bacterial Overgrowth.” Journal of clinical medicine (2026). PMID: 42355617 ↗
L2OTHERCited in: Empiric and Acute Management - [184]
Orzechowski D, Mroczkowska A, Bryła A et al.. “Clinical Considerations of Amikacin Pharmacotherapy in Adults-A Narrative Review with Focus on Safety and TDM.” Antibiotics (Basel, Switzerland) (2026). PMID: 42353658 ↗
L5REVIEW_NARRATIVECited in: Empiric and Acute Management, Antimicrobial Resistance and Stewardship - [185]
Berry P, Bharadiya V, Pardi DS et al.. “Cost-effectiveness of Microbiota Restoration Therapies for Recurrent Clostridioides difficile Infection.” The American journal of gastroenterology (2026). PMID: 42329003 ↗
L2OTHERCited in: Empiric and Acute Management - [186]
Vazquez-Piqueras N, Padullés A, Sabé N et al.. “Effect of a multimodal intervention in general and digestive surgery wards on carbapenem use and antimicrobial resistance: protocol for a prospective, quasi-experimental interrupted time-series study.” BMJ open (2026). PMID: 42320964 ↗
L5OTHERCited in: Empiric and Acute Management - [187]
Zhao C, Chen C, Lu D et al.. “Antibiotic treatment for 7 days versus 14 days in patients with uncomplicated bloodstream infections: a Systematic review and meta-analysis of randomized controlled trials and trial sequential analysis.” Frontiers in medicine (2025). PMID: 40832108 ↗
L1SR_MA_RCTCited in: Definitive Therapy, Duration and De-escalation - [188]
Ray MJ, Strnad LC, Tucker KJ et al.. “Influence of Antibiotic Exposure Intensity on the Risk of Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 38743579 ↗
L2OTHERCited in: Definitive Therapy, Duration and De-escalation, Antimicrobial Resistance and Stewardship, Prognosis and Natural History - [189]
Buehrle D, Clancy CJ. “Medicare Prescription Plans Limit Access to Recommended Drugs for Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2022). PMID: 34626478 ↗
L2OTHERCited in: Definitive Therapy, Duration and De-escalation - [190]
Bhat A, Mansoor A, Fatima M et al.. “Safety and efficacy of fecal microbiota transplantation versus antibiotics for treating clostridioides difficile infection: systematic review and meta-analysis.” European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology (2025). PMID: 41081988 ↗
L1SR_OBSCited in: Definitive Therapy, Duration and De-escalation, Complications - [191]
Ilges D, Ritchie DJ, Krekel T et al.. “Assessment of Antibiotic De-escalation by Spectrum Score in Patients With Nosocomial Pneumonia: A Single-Center, Retrospective Cohort Study.” Open forum infectious diseases (2021). PMID: 34805436 ↗
L2COHORTCited in: Definitive Therapy, Duration and De-escalation - [192]
McDonald EG, Butler-Laporte G, Brophy JM et al.. “Initial Vancomycin Taper for the Prevention of Recurrent Clostridioides difficile Infection: A Randomized Clinical Trial.” JAMA network open (2026). PMID: 41758514 ↗
L1RCTCited in: Definitive Therapy, Duration and De-escalation, Complications, Prognosis and Natural History - [193]
Keating JA, Xu T, Graham MB et al.. “Oral Vancomycin for Prevention of Recurrent Clostridioides difficile Infection: A Randomized Clinical Trial.” JAMA network open (2025). PMID: 40601321 ↗
L1RCTCited in: Definitive Therapy, Duration and De-escalation, Prevention, Infection Control and Special Populations - [194]
Bryant JA, Straub TJ, Pardi DS et al.. “Comparability of Gastrointestinal Microbiome and Bile Acid Profiles in Patients With First or Multiply Recurrent Clostridioides difficile Infection.” The Journal of infectious diseases (2025). PMID: 40751372 ↗
L2TRIAL_NONRANDOMCited in: Definitive Therapy, Duration and De-escalation - [195]
Taniguchi J, Aso S, Matsui H et al.. “Ampicillin-sulbactam versus third-generation cephalosporins in aspiration Pneumonia: A nationwide retrospective cohort study.” Respiratory medicine (2025). PMID: 40716681 ↗
L2COHORTCited in: Definitive Therapy, Duration and De-escalation - [196]
Wolfe TM, Jo J, Pinkham NV et al.. “The impact of ibezapolstat and other Clostridioides difficile infection-relevant antibiotics on the microbiome of humanized mice.” Antimicrobial agents and chemotherapy (2025). PMID: 39998294 ↗
L5OTHERCited in: Definitive Therapy, Duration and De-escalation - [197]
Greco Kinney A, Kovacic Scherrer N, Sarkar S et al.. “β-Lactams plus doxycycline versus azithromycin for treatment of severe community-acquired pneumonia in critically ill patients.” The Journal of antimicrobial chemotherapy (2023). PMID: 37814829 ↗
L2OTHERCited in: Definitive Therapy, Duration and De-escalation, Complications - [198]
Britt RS, LaSalvia MT, Padival S et al.. “Evaluation of Inpatient Antimicrobial Regimens for Readmitted Outpatient Parenteral Antimicrobial Therapy Patients Receiving Daptomycin or Ertapenem for Ease of Administration.” Open forum infectious diseases (2019). PMID: 32128338 ↗
L2OTHERCited in: Definitive Therapy, Duration and De-escalation, Complications - [199]
Psarrakis C, Tziolos NR, Matzarakis V et al.. “A randomized controlled trial of precision bezlotoxumab treatment for Clostridioides difficile infection.” Cell reports. Medicine (2026). PMID: 41483804 ↗
L1RCTCited in: Definitive Therapy, Duration and De-escalation - [200]
Fan AE, Alqahtani S, Garnes ND et al.. “Bezlotoxumab as Treatment for Recurrent/Chronic Clostridioides difficile Infection in Pediatric Stem Cell Transplant Recipients: A Multi-Institutional Experience.” Pediatric blood & cancer (2025). PMID: 40879561 ↗
L4CASE_REPORTCited in: Definitive Therapy, Duration and De-escalation - [201]
Straub TJ, Lombardo MJ, Bryant JA et al.. “Impact of a Purified Microbiome Therapeutic on Abundance of Antimicrobial Resistance Genes in Patients With Recurrent Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 37823484 ↗
L2RCTCited in: Antimicrobial Resistance and Stewardship - [202]
Ridgway JP, Robicsek A, Shah N et al.. “A Randomized Controlled Trial of an Electronic Clinical Decision Support Tool for Inpatient Antimicrobial Stewardship.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 32712674 ↗
L1RCTCited in: Antimicrobial Resistance and Stewardship - [203]
Vaughn VM, Gandhi T, Conlon A et al.. “The Association of Antibiotic Stewardship With Fluoroquinolone Prescribing in Michigan Hospitals: A Multi-hospital Cohort Study.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2019). PMID: 30759198 ↗
L2COHORTCited in: Antimicrobial Resistance and Stewardship - [204]
Langford BJ, Brown KA, Lau C et al.. “Evaluating Harms Associated With Prolonged Antibiotic Duration of Therapy in Community-Dwelling Older Adults: A Cohort Study Using Instrumental Variable Analysis.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2025). PMID: 39786490 ↗
L2COHORTCited in: Antimicrobial Resistance and Stewardship - [205]
Vehreschild MJGT, Ducher A, Louie T et al.. “An open randomized multicentre Phase 2 trial to assess the safety of DAV132 and its efficacy to protect gut microbiota diversity in hospitalized patients treated with fluoroquinolones.” The Journal of antimicrobial chemotherapy (2022). PMID: 35016205 ↗
L1RCTCited in: Antimicrobial Resistance and Stewardship, Complications - [206]
Seddon MM, Bookstaver PB, Justo JA et al.. “Role of Early De-escalation of Antimicrobial Therapy on Risk of Clostridioides difficile Infection Following Enterobacteriaceae Bloodstream Infections.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2019). PMID: 30312362 ↗
L2OTHERCited in: Antimicrobial Resistance and Stewardship - [207]
Ong SWX, Patrikar A, Pinto R et al.. “Application of a Novel Desirability of Outcome Ranking Endpoint Incorporating a Framework for Resistance Assessment and Microbiologic Evaluation in Antibiotic Trials: A Proof-of-Concept in a Post Hoc Analysis of the BALANCE Trial.” Open forum infectious diseases (2026). PMID: 42338985 ↗
L2TRIAL_NONRANDOMCited in: Antimicrobial Resistance and Stewardship, Prognosis and Natural History - [208]
Tetteh EK, Obeng H, Atkinson A et al.. “Dissemination of a facilitation strategy to de-implement unnecessary post-operative antibiotics at children's hospitals: The Optimizing Perioperative Antibiotic in Children (OPerAtiC) trial 2.0.” Implementation science : IS (2025). PMID: 41214788 ↗
L5TRIAL_NONRANDOMCited in: Antimicrobial Resistance and Stewardship, Prognosis and Natural History, Prevention, Infection Control and Special Populations - [209]
Wei Q, Wang Y, Rui M et al.. “Health economic evaluations of fecal microbiota transplantation for non-clostridioides difficile related diseases: a systematic review.” Health economics review (2025). PMID: 41400783 ↗
L2SR_OBSCited in: Antimicrobial Resistance and Stewardship - [210]
Ventero MP, Valverde-Fredet MD, Merino E et al.. “Antimicrobial Susceptibility of Clostridioides difficile in Spain: Multicenter Retrospective Cohort Study.” Antibiotics (Basel, Switzerland) (2026). PMID: 41750443 ↗
L2COHORTCited in: Antimicrobial Resistance and Stewardship - [211]
Park JJ, Jung EJ, Kim JY et al.. “Thirty-Day Mortality Rates in Patients with Extended-Spectrum β-Lactamase-Producing Enterobacterales Bacteremia Receiving Ertapenem versus Other Carbapenems.” Antimicrobial agents and chemotherapy (2022). PMID: 35708330 ↗
L2OTHERCited in: Antimicrobial Resistance and Stewardship - [212]
Dureja C, Rutherford JT, Pavel FB et al.. “In vivo evaluation of Clostridioides difficile enoyl-ACP reductase II (FabK) inhibition by phenylimidazole unveils a promising narrow-spectrum antimicrobial strategy.” Antimicrobial agents and chemotherapy (2024). PMID: 38265216 ↗
L5OTHERCited in: Antimicrobial Resistance and Stewardship - [213]
Viana-Cardenas E, Miranti E, Tariq W et al.. “A systematic literature review and bayesian meta-analysis of oral vancomycin primary prophylaxis for Clostridioides difficile infection in stem cell transplant patients.” Antimicrobial stewardship & healthcare epidemiology : ASHE (2025). PMID: 41127168 ↗
L1SR_OBSCited in: Antimicrobial Resistance and Stewardship - [214]
Ryazanov V, Vershinina I, Inchagova K et al.. “Fecal microbiota and microbial community transplantation: a review of current research.” Frontiers in microbiology (2026). PMID: 42326403 ↗
L5REVIEW_NARRATIVECited in: Antimicrobial Resistance and Stewardship - [215]
Hourigan SK, Ahn M, Gibson KM et al.. “Fecal Transplant in Children With Clostridioides difficile Gives Sustained Reduction in Antimicrobial Resistance and Potential Pathogen Burden.” Open forum infectious diseases (2019). PMID: 31660343 ↗
L4OTHERCited in: Antimicrobial Resistance and Stewardship - [216]
Gonzales-Luna AJ, Olaitan AO, Shen WJ et al.. “Reduced Susceptibility to Metronidazole Is Associated With Initial Clinical Failure in Clostridioides difficile Infection.” Open forum infectious diseases (2021). PMID: 34381844 ↗
L2OTHERCited in: Antimicrobial Resistance and Stewardship - [217]
Eudy JL, Pallotta AM, Neuner EA et al.. “Antimicrobial Stewardship Practice in the Ambulatory Setting From a National Cohort.” Open forum infectious diseases (2020). PMID: 33269298 ↗
L4OTHERCited in: Antimicrobial Resistance and Stewardship - [218]
Adamowicz E, Kraft CS, Ward T et al.. “Decreased Antimicrobial Resistance Gene Richness Following Fecal Microbiota, Live-jslm (REBYOTA®) Administration: Post Hoc Analysis of PUNCH CD3.” Open forum infectious diseases (2025). PMID: 40672762 ↗
L2OTHERCited in: Antimicrobial Resistance and Stewardship - [219]
Wilk S, Foong KS, Tam R et al.. “Penicillin Allergy Labels and High-risk Antibiotic Prescribing Among Incarcerated Individuals Receiving Antibiotics Across Four US Carceral Systems.” Open forum infectious diseases (2026). PMID: 41889453 ↗
L4OTHERCited in: Antimicrobial Resistance and Stewardship - [220]
Woodworth MH, Hayden MK, Young VB et al.. “The Role of Fecal Microbiota Transplantation in Reducing Intestinal Colonization With Antibiotic-Resistant Organisms: The Current Landscape and Future Directions.” Open forum infectious diseases (2019). PMID: 31363779 ↗
L5OTHERCited in: Antimicrobial Resistance and Stewardship - [221]
Wolf J, Kalocsai K, Fortuny C et al.. “Safety and Efficacy of Fidaxomicin and Vancomycin in Children and Adolescents with Clostridioides (Clostridium) difficile Infection: A Phase 3, Multicenter, Randomized, Single-blind Clinical Trial (SUNSHINE).” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2020). PMID: 31773143 ↗
L1RCTCited in: Complications - [222]
Bej TA, Wilson BM, Akpoji UC et al.. “Feasibility of a Low-Intensity Intervention to Influence Antibiotic Prescribing Rates Use in Outpatient Settings: A Cluster Randomized Controlled Clinical Trial.” Open forum infectious diseases (2024). PMID: 39758744 ↗
L1TRIAL_NONRANDOMCited in: Complications - [223]
Baral B, Parajuli M, Pinilla J et al.. “Safety and efficacy of oral microbiome therapy for the treatment of recurrent Clostridioides difficile infection: a systematic review and meta-analysis of randomized controlled trials.” Scandinavian journal of gastroenterology (2026). PMID: 41543263 ↗
L1SR_MA_RCTCited in: Complications - [224]
Omar MA, Katrib M, Shekhar R et al.. “Proton Pump Inhibitor Use for Gastroprotection and Stress Ulcer Prophylaxis Does Not Increase the Risk of Clostridioides difficile Infection or Pneumonia: A Systematic Review and Meta-Analysis of RCTs.” Journal of clinical medicine (2026). PMID: 41976918 ↗
L1SR_OBSCited in: Complications, Prevention, Infection Control and Special Populations - [225]
Kao D, Wong K, Lee C et al.. “Effects of lyophilised faecal filtrate compared with lyophilised donor stool on Clostridioides difficile recurrence: a multicentre, randomised, double-blinded, non-inferiority trial.” The lancet. Gastroenterology & hepatology (2025). PMID: 40997843 ↗
L1RCTCited in: Complications - [226]
Lee C, Feuerstadt P, Louie T et al.. “Integrated analysis of the safety of fecal microbiota, live-jslm in adults with recurrent Clostridioides difficile infection from five prospective clinical trials: an update.” Therapeutic advances in gastroenterology (2025). PMID: 41245385 ↗
L4TRIAL_NONRANDOMCited in: Complications - [227]
Tucker EC, Angelica B, Mathias RM et al.. “Outcomes of Fecal Microbiota Transplantation for Clostridioides difficile Infection in South Australia.” Open forum infectious diseases (2025). PMID: 40160347 ↗
L2OTHERCited in: Complications - [228]
Tillotson G, Archbald-Pannone L, Johnson S et al.. “Microbiota-Based Live Biotherapeutic RBX2660 for the Reduction of Recurrent Clostridioides difficile Infection in Older Adults With Underlying Comorbidities.” Open forum infectious diseases (2022). PMID: 36686631 ↗
L2OTHERCited in: Complications - [229]
Feuerstadt P, Harvey A, Yoho DS et al.. “Retrospective Analysis of the Safety and Efficacy of Fecal Microbiota, Live-jslm (REBYOTATM) Administered Under Enforcement Discretion to Patients With Clostridioides difficile Infection.” Open forum infectious diseases (2023). PMID: 37256213 ↗
L2OTHERCited in: Complications, Prognosis and Natural History - [230]
Liu C, Lan K, Krantz EM et al.. “Improving Appropriate Diagnosis of Clostridioides difficile Infection Through an Enteric Pathogen Order Set With Computerized Clinical Decision Support: An Interrupted Time Series Analysis.” Open forum infectious diseases (2020). PMID: 33094113 ↗
L2OTHERCited in: Complications - [231]
Madden GR, Enfield KB, Sifri CD. “Patient Outcomes With Prevented vs Negative Clostridioides difficile Tests Using a Computerized Clinical Decision Support Tool.” Open forum infectious diseases (2020). PMID: 32328506 ↗
L3OTHERCited in: Complications - [232]
Cook D, Deane A, Lauzier F et al.. “Stress Ulcer Prophylaxis during Invasive Mechanical Ventilation.” The New England journal of medicine (2024). PMID: 38875111 ↗
L1RCTCited in: Prognosis and Natural History, Prevention, Infection Control and Special Populations - [233]
Varma S, Greendyke WG, Li J et al.. “Class-Specific Relationship Between Use of Immunosuppressants and Risk for Community-Acquired Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2022). PMID: 34156442 ↗
L2OTHERCited in: Prognosis and Natural History - [234]
Yu H, Alfred T, Nguyen JL et al.. “Incidence, Attributable Mortality, and Healthcare and Out-of-Pocket Costs of Clostridioides difficile Infection in US Medicare Advantage Enrollees.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2023). PMID: 35686435 ↗
L2OTHERCited in: Prognosis and Natural History - [235]
Atamna A, Turjeman A, Drozdinsky G et al.. “Fidaxomicin for Initial Episode of Clostridioides difficile Infection Reduces Recurrence in Immunocompromised Hosts-a Large Retrospective Cohort Study.” Open forum infectious diseases (2025). PMID: 41439186 ↗
L2COHORTCited in: Prognosis and Natural History, Prevention, Infection Control and Special Populations - [236]
Chen W, Pan X, Ji J et al.. “Efficacy of probiotic supplementation in preventing Clostridioides difficile infection: an umbrella review of systematic reviews and meta-analysis.” Frontiers in nutrition (2026). PMID: 41878577 ↗
L1SR_OBSCited in: Prognosis and Natural History - [237]
Perez R, Advani SD, North R et al.. “Racial disparities in healthcare-associated infections: a systematic review and meta-analysis.” Infection control and hospital epidemiology (2026). PMID: 42027100 ↗
L1SR_OBSCited in: Prognosis and Natural History - [238]
West RM, Smith CJ, Pavitt SH et al.. “'Warning: allergic to penicillin': association between penicillin allergy status in 2.3 million NHS general practice electronic health records, antibiotic prescribing and health outcomes.” The Journal of antimicrobial chemotherapy (2019). PMID: 31225607 ↗
L2OTHERCited in: Prognosis and Natural History - [239]
Pereira JA, McGeer A, Tomovici A et al.. “The Clinical Burden of Clostridioides difficile in Ontario, Canada.” Open forum infectious diseases (2019). PMID: 32025524 ↗
L2OTHERCited in: Prognosis and Natural History - [240]
Johnson SW, Brown SV, Priest DH. “Effectiveness of Oral Vancomycin for Prevention of Healthcare Facility-Onset Clostridioides difficile Infection in Targeted Patients During Systemic Antibiotic Exposure.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2020). PMID: 31560051 ↗
L1RCTCited in: Prevention, Infection Control and Special Populations - [241]
Heil EL, Harris AD, Brown C et al.. “A Multicenter Evaluation of Probiotic Use for the Primary Prevention of Clostridioides difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 33972996 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [242]
Yepez Guevara EA, Aitken SL, Olvera AV et al.. “Clostridioides difficile Infection in Cancer and Immunocompromised Patients: Relevance of a Two-step Diagnostic Algorithm and Infecting Ribotypes on Clinical Outcomes.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 32803229 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [243]
Pakyz AL, Orndahl CM, Johns A et al.. “Impact of the Centers for Medicare and Medicaid Services Sepsis Core Measure on Antibiotic Use.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 32827032 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [244]
Wombwell E, Patterson ME, Bransteitter B et al.. “The Effect of Saccharomyces boulardii Primary Prevention on Risk of Hospital-onset Clostridioides difficile Infection in Hospitalized Patients Administered Antibiotics Frequently Associated With C. difficile Infection.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2021). PMID: 32575126 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [245]
Nussbaum EZ, Koo S, Kotton CN. “Oral Antibiotics for Treatment of Gram-Negative Bacteremia in Solid Organ Transplant Recipients: A Propensity Score Weighted Retrospective Observational Study.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2024). PMID: 38195100 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [246]
Jones KM, Greene MT, Meddings J et al.. “Impact of a Collaboration-Focused Intervention to Prevent Healthcare-Associated Infections Before and During the COVID-19 Pandemic.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2025). PMID: 40298392 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [247]
Berry P, Tariq R, Pardi DS et al.. “Effectiveness and Safety of Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection in Immunocompromised Patients.” Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association (2025). PMID: 40759389 ↗
L2SR_OBSCited in: Prevention, Infection Control and Special Populations - [248]
Gokhale P, Villa Zapata L. “Opioid use and risk of Clostridioides difficile infection in hospitalized patients: A systematic review and meta-analysis.” American journal of infection control (2025). PMID: 40581048 ↗
L2SR_OBSCited in: Prevention, Infection Control and Special Populations - [249]
Maugeri A, Casini B, Esposito E et al.. “Impact of ultraviolet light disinfection on reducing hospital-associated infections: a systematic review in healthcare environments.” The Journal of hospital infection (2025). PMID: 39924116 ↗
L2SR_OBSCited in: Prevention, Infection Control and Special Populations - [250]
Keating JA, McKinley L, Dolan K et al.. “Health care worker experiences with a universal gloving intervention to prevent Clostridioides difficile infection: A qualitative study.” American journal of infection control (2025). PMID: 41046913 ↗
L5RCTCited in: Prevention, Infection Control and Special Populations - [251]
Banegas M, Villafuerte-Gálvez J, Paredes R et al.. “Preservation of the Innate Immune Response to Clostridioides difficile Infection in Hospitalized Immunocompromised Patients.” Open forum infectious diseases (2023). PMID: 36949876 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [252]
Alsoubani M, Chow JK, Rodday AM et al.. “Comparative Effectiveness of Fidaxomicin vs Vancomycin in Populations With Immunocompromising Conditions for the Treatment of Clostridioides difficile Infection: A Single-Center Study.” Open forum infectious diseases (2023). PMID: 38204563 ↗
L3OTHERCited in: Prevention, Infection Control and Special Populations - [253]
Alonso CD, Papamichael K, Sprague R et al.. “Humoral Immune Response to Clostridioides difficile Toxins A and B in Hospitalized Immunocompromised Patients With C difficile Infection.” Open forum infectious diseases (2021). PMID: 34258317 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations - [254]
Hirsch W, Fischer M, Khoruts A et al.. “Risk Factors for Antibiotic Exposure Post-Fecal Microbiota Transplantation for Recurrent Clostridioides difficile Infection: A Prospective Multicenter Observational Study.” Open forum infectious diseases (2025). PMID: 40103733 ↗
L2OTHERCited in: Prevention, Infection Control and Special Populations