IC17 C Diff infection Flashcards
What feature of C Diff bacteria allows it to stay in our environment for very long even despite disinfection?
C diff forms spores
What does C Diff bacteria produce?
toxins A & B
What is the route of transmission of C Diff?
fecal oral
What are the risk factors for CDI?
- use of abx
- acid suppression therapy
- history of CDI
- GI surgery
- tube feeding
- residence in nursing homes & long term care facilities
- old age >65
- immunosuppression
- multiple/severe comorbidities
- prior hospitalization in the past 1 year
- prolonged hospitalization
What antibiotics are associated with higher CDI risk?
- clindamycin
- cephalosporins (3rd & 4th gen)
- fluoroquinolones
- amox-clav (BLI component)
What antibiotics have protective effects against CDI?
Doxycycline/tigecycline
Why do they have protective effects against CDI?
- active against C Diff
- inhibit toxin production
- minimal effects on gut microbiome
What are the steps for infection control for CDI?
- isolation
- practice hand and personal hygiene (wear PPE [gloves & gown], handwash with soap & water > alcohol handrub)
- environmental sanitation w sporicidal agents
- antimicrobial stewardship
What is the ONE symptom that CDI always present with?
watery diarrhoea (≥3 loose stools in 24h)
What are the risk classifications of CDI?
- mild
- moderate
- severe
- fulminant
What are the symptoms of mild CDI?
- Diarrhoea
- Abdominal cramps
(No systemic signs of infection)
What are the symptoms of moderate CDI?
- Diarrhoea
- Abdominal cramps & distension
- Fever
- Nausea
- Malaise
- Leukocytosis (elevated WBC)
- Hypovolemia
What are the symptoms of severe CDI?
- Diarrhoea
- Diffused abdominal cramps & distention
- Fever
- WBC ≥15 or SCr ≥133
What are the symptoms of fulminant CDI?
- Hypovolemia/shock
- Ileus (no more peristalsis)
- Megacolon (become v large)
What are the diagnostic criteria for CDI?
A + B
A
- diarrhoea (≥3 loose stools in 24h)
- radiographic evidence of toxic megacolon/ileus
B
- positive stool test for C Diff/toxins
- colonoscopic/histopathologic evidence of pseudomembranous colitis
When do we perform stool test?
ONLY for symptomatic patients (ie. have diarrhoea)
What do we need to look out for when performing stool test?
prior laxative use 48h before test
What is the minimum duration before we can repeat stool test?
7 days
Do we repeat stool test to determine if the patient is cured of CDI?
NO
What are the antibiotics available for use for the first episode of CDI?
- Vanco
- Fidaxomicin
- Metronidazole
What is the definition of non-severe (ie. mild to moderate) CDI?
- diarrhoea
- positive stool test
- WBC <15 AND SCr <133 umol/L
What antibiotics (& what formulation) can we use for non-severe CDI?
first line:
PO vanco
PO fidaxomicin
alternative:
PO metronidazole
What is the definition of severe CDI?
- diarrhoea
- positive stool test
- WBC ≥15 OR SCr ≥133 umol/L
What antibiotics (& what formulation) can we use for severe CDI?
PO vanco
PO fidaxomicin