Clostridium Difficile Diarrhoea Flashcards
What is defined as Acute Infectious diarrhoea?
- Defined as passage of loose or watery stools ≥3 times in a 24‐hour period that lasts for <14 days
- Noninflammatory (milder, usually viral) vs inflammatory (more severe, usually bacterial)
How is acute infectious diarrhoea transmitted?
Fecal-oral route (likely) – International travel – Food or water borne – Exposure infected animals or feces – Recent antimicrobial use
How is acute infectious diarrhoea usually managed?
Usually self-limiting disease (no abx) Supportive care (ORT, anti-diarrhoeals, avoid spicy food etc...)
How is diagnostic testing for acute infectious diarrhoea like?
– Recommended only in patients with diarrhea accompanied by fever, bloody or mucoid stools, severe abdominal cramping or tenderness, or signs of sepsis
– Test for Salmonella, Shigella, Campylobacter, Yersinia, Clostridium difficile, and Shiga toxin producing E. coli (STEC)
When are stool cultures and PCR testing done for acute infectious diarrhoea?
Pts who have more invasive disease, unable to mount response, chemo, pts on immunosuppressive meds, persistent and non-responding diarrhoea
When will abx therapy be recommended for acute infectious diarrhoea?
- Patient has severe disease (fever with bloody diarrhea or mucoid stools ± severe abdominal cramping or tenderness)
or - Patient appears septic
or - Patient is an immunocompromised host (ICH)
What is the empiric abx tx for acute infectious diarrhoea?
– Ceftriaxone 2g IV q24h or
– Ciprofloxacin 500mg PO BD (alternative)
– Duration: 3‐5 days
• Maybe extended in patients with bacteremia, extra intestinal infections and in ICH
What are things to monitor for in acute infectious diarrhoea?
Assess for symptom resolution, clinical improvement
- If persistent, further workup might be required
What are characteristics of Clostridioides difficile?
A gram‐positive, anaerobic, spore‐forming, toxin‐producing bacillus
What is the pathogenesis of C. diff infections (CDI)?
Broad spectrum abx wipe out C. diff competition but not C. diff
More endospores survive GIT due to PPIs
- C. diff produces toxins and damages mucosal membrane
Describe the range of clinical manifestations for CDI
– Diarrhea without colitis (≥3 episodes of unformed stools in 24h)
– Colitis (Fever, abdominal pain/cramps, nausea and anorexia)
– Severe colitis (Sepsis, significant leukocytosis, renal impairment)
– Fulminant colitis (severe + complicated colitis)
• Complications: toxic megacolon, colonic perforation, intestinal paralysis (ileus), pseudomembranous colitis
What are the risk factors for CDI?
Abx exposure PPI/H2-antagonist use Healthcare exposure Poor host immunity (co-morbidities, elderly, immunocompromised etc..) Previous CDI
Which abx are the highest risk for CDI?
Clindamycin, 3rd/4th cephs, FQs (broad spectrum abx)
When is the highest risk for CDI with regards to abx?
Highest risk during abx tx and up to 1 month post abx exposure
- Risk is exposure dependent
How can CDI be diagnosed?
Both 1 and 2:
1. Unexplained and new ONSET diarrhoea* (≥3
unformed stools in 24h) OR Radiologic evidence of
ileus or toxic megacolon
2. Positive stool test result for toxigenic C. difficile AND its toxins OR Histopathologic findings of pseudomembranous colitis
*not due to drugs, must have liquid consistency, compare against pt baseline
If a patient with an infection does not have diarrhoea, can we rule out CDI?
Ileus (complication of CDI) can prevent diarrhoea despite pt being infected with CDI
What is something to note regarding CDI lab tests?
Repeat testing not recommended within 2 weeks of previous positive test (likely to remain positive)
Can laboratory testing alone confirm presence of CDI?
No, as Laboratory testing alone cannot distinguish between asymptomatic colonization and clinical symptoms of infection
*Recall: C. diff is a normal gut commensal
What are the stool tests available for CDI?
- Glutamate dehydrogenase (GDH) EIA
- Toxin A and B EIA
- Nucleic acid amplification tests (NAAT) –> too sensitive = may have false positive i.e. asymptomatic or colonizer Cdiff/ (low bacterial load)
*at least 2 out these 3 tests must be positive for CDI diagnosis