CDI

Question 1

Acute infectious diarrhea:

Answer 1

Passage of loose/watery stools 3 times in 24 hr period
lasts <14 days
can be inflammatory/non-inflammatory

Question 2

Inflammatory acute infectious diarrhea

Answer 2

Caused by generally invasive/toxin producing bacteria
More likely to disrupt mucosal integrity which may lead to tissue invasion and destruction
Generally more severe than non-inflammatory cases

Question 3

Diagnostic testing for acute infectious diarrhea

Answer 3

lab tests usually not warranted for most patients
Recommended in patients with diarrhea accompanied by fever, bloody/mucoid stools, severe abdominal cramping/tenderness or signs of sepsis
Stool culture and PCr usually done
Test for: salmonella, shigella, campylobacter, yersina, clostridium difficile and shiga toxin producing E.coli

Question 4

Empiric therapy for Acute infectious diarrhea:

Answer 4

Ceftriaxone 2g IV q24 hr
Ciprofloxacin 500mg PO BD
Duration 3-5 days and may be extended in patients with bacteremia, extra intestinal infections and in ICU

Question 5

Clinical manifestations of CDI:

Answer 5

diarrhea without colitis: ≥3 episodes of unformed stools in 24 hrs
Colitis: fever, abdominal ain/cramps, nausea and anorexia
Severe colitis: sepsis, significant leukocytosis, renal impairment, increased total white
Fulminant colitis: complications (toxic megacolon, colonic perforation, intestinal paralysis, pseudomembranous colitis

Question 6

Risk factors for CDI:

Answer 6

Pharmacotherapy 
Past healthcare exposure
Host immunity
Age
CDI experience 
Antibiotics

Question 7

Pharmacotherapy risk factors for CDI:

Answer 7

• No. and days of systemic concomitant abx use
• high risk abx (clindamycin, FQ, 2nd gen cephalosporins
• PPI and histamine type 2 blockers

Question 8

Past healthcare exposure risk factors for CDI:

Answer 8

• Prior hospitalisation
• duration of hospitalisation
• log term care residency

Question 9

Host immunity risk factors for CDI

Answer 9

• lack of antibody response to D. difficile toxin
• Severity of underlying illness
• comorbidities

Question 10

Age risk factors for CDI

Answer 10

> 65 yo

per year increment over 18 years

Question 11

Antibiotics risk factors for CDI:

Answer 11

highest risk during antibiotic therapy and up to 1 mth post exposure
High risk antibiotics (clindamycin, 3-4 gen cephalosporins, FQ)
exposure dependent: number, dose and duration of antibiotics

Question 12

Treatment for initial non-severe CDI

Answer 12

Vancomycin 125mg PO q6h 10D

Metronidazole 400mg PO q8h 10D

Question 13

Treatment for initial severe CDI

Answer 13

vancomycin 125mg PO q6h 10D

Question 14

Treatment for initial fulminant CDI

Answer 14

Vancomycin 500mg PO q6h by mouth/NG tube +/- metronidazole 500mg IV q8h
if ileus, combination therapy suggested, consider adding PR vancomycin 500mg in 100mL NS PR q6h

Question 15

Treatment for 1st recurrent episode of CDI:

Answer 15

If 1st episode use metronidazole: 
Vancomycin 125mg PO q6h 10D 
If 1st ep use vancomycin: 
- van 125mg PO q6h 10-14D --> van 125mg PO q12h 7D --> van 125mg PO q24h 7D --> van 125mg PO q2-3d 2-8wk
- fdx 200mg PO q12h 10D

Question 16

treatment for 2nd recurrent episode onwards:

Answer 16

van 125mg po q6h 10d – rifaximin 400mg po q8h 20d

fecal microbiota transplantation