Infectious diarrhoea & C diff Infections Flashcards
What duration is considered as acute diarrhoea?
Lasts < 14 days
What are some methods to help with diagnosis of acute infectious diarrhoea?
Fecal occult blood, Ova and parasite, stool cultures, PCR test
Diagnostic tests are usually not indicated as most cases are self limiting. These tests are reserved for which select patients?
- severe illness
- persistent fever
- bloody stools
- immunosuppression
- unresponsive to treatment
How to prevent acute infectious diarrhoea?
- good hand and food hygiene
- vaccinations: cholera and typhoid vaccines for travellers to endemic areas; rotavirus vaccine for infants or children
When do we treat acute infectious diarrhoea?
- most cases are self limiting and don’t need antibiotics.
- indications for antibiotics (any one of the following):
Severe disease: fever with bloody diarrhoea, or mucoid stools, or severe abdominal pain/cramps/tenderness)
Sepsis
Immunocompromised (cancer, transplant patients)
Treatment for acute infectious diarrhoea?
Empiric antibiotic therapy:
- ceftriaxone 2g IV Q24H
- ciprofloxacin 500mg PO BD (if penicillin allergy)
X 3-5 days
What is clostridiodes difficile?
- spore forming
- produces toxin A and B
- most common cause of nosocomial diarrhoea
- transmitted by fecal-oral route, contaminated environmental surfaces and hand carriage by healthcare workers.
What are the risk factors of C. Difficile?
Healthcare exposure:
- prior hospitalisation
- duration of hospitalisation
- residence in nursing home or long term care facility
Pharmacotherapy:
- systemic antibiotics - the number of agents, and duration of therapy
- high risk abx: Clindamycin, fluroquinolones, 2nd or higher gen cephalosporins
- use of gastric acid suppressive therapy
Patient factors:
- comorbidities
- immunosuppression
- advanced age > 65 years old
- history of CDI
What are the severities of C diff infection?
Mild:
- loose stools, abdominal cramps
Moderate:
- fever, nausea, malaise
- abdominal cramps and dissension
- leukocytosis
- hypovolemia
Severe or fulminant CDI:
- rather rare
- ileus, toxic mega colon, pseudomembranous colitis, perforation and death.
How to diagnose C diff?
Clinical suspicion:
- unexplained and new onset diarrhoea OR
- radiologic evidence of ileus or toxic mega colon
AND
Confirmatory test or findings:
- positive stool test result for c diff or it’s toxins OR
- histopathologic findings of pseudomembranous colitis
Are cultures routinely performed for c diff?
No, due to long turnaround time.
Can do diagnostic tests like Nucleic acid amplification test (NAAT) and Polymerase Chain reaction (PCR)
When should we not do testing?
Don’t test asymptotic patients
Don’t repeat testing in <7days
Don’t perform test of cure
Infection control for c diff?
Healthcare setting:
- hand hygiene
- contact precaution for 48 hours after diarrhoea resolves: wear gloves and gown, wash hands with soap and water before and after patient care
At home:
- wash hands w soap and water after using bathroom
- use separate bathroom if possible
- clean toilet, linen, towels, clothing with bleach.
Is empiric CDI treatment recommended?
No, empiric treatment recommended only if
- substantial delay > 48 hours in diagnostics OR
- fulminant CDI
Otherwise, wait for results and start if positive.
If possible, discontinue concurrent systemic antibiotics.
Treatment of initial episode of c diff?
Non severe -> WBC < 15 AND SCr < 133: First line: Vancomycin 125mg PO QDS Fidaxomicin 200mg PO BD Alternative: Metronidazole 400mg PO TDS
Severe -> WBC greater than equal to 15 OR SCr greater than or equal to 133:
First line:
Vancomycin 125mg PO QDS
Fidaxomicin 200mg PO BD
Fulminant -> Hypotension or ileus or megacolon: First line: Metronidazole 500mg IV Q8H + Vancomycin 500mg PO QDS \+/- Vancomycin 500mg PR QDS
X 10 days (can extend to 14 days if symptoms are not completely resolved)
