C.diff

Question 1

what type of bacteria is C diff

Answer 1

a. Anaerobic gram-positive spore-forming bacillus

Question 2

prevalence of C diff in non hospitalized

Answer 2

> 50% of healthy infants and part of normal colonic flora of 5-10% of healthy adults

Question 3

prevalence in hospitalized pts

Answer 3

c. 20-40% of pts hospitalized for >2 days (and >50% of those in LTCFs)

now leading cause of nosocomial diarrhea in US with 15% mortality in elderly.

Question 4

what two things are required for a c diff infection

Answer 4

i. Alteration of the normal microbiome (usually due to Abx)

ii. Exposure to organism (usually in a health care facility)

Question 5

which anbx are associated with c diff and how do you transfer it

Answer 5

all abnx assoc

fecal → oral, person to person

Question 6

how long can C diff spores persist in the environement

Answer 6

e. Spores can survive in environment for days/months and are resistant to common hospital disinfectants.

Question 7

% of pts that have colonization

what is the risk of an infection if you are colonized after admission?

Answer 7

a. Asymptomatic colonization (60-65%)

i. 6x higher risk of subsequent CDI in patients colonized at admission (21.8% vs. 3.4%)

Question 8

how common is a reoccurring infection

Answer 8

d. Recurrent infection (20-30%) í b/c of the spores

Question 9

standardized test for C diff

Answer 9

iii. PCR (mostly done now) = STANDARD TESTING

Question 10

other than PCR how can you test for C diff

Answer 10

Elisa
GDH
toxigenic
pet scan?

Question 11

prevention of C dfff

Answer 11

a. Greater antibiotic stewardship - use less abx
b. Isolation (when available), cohorting when not (? increased recurrence rates)
c. Hand Hygiene / Contact Precautions
i. HAND SANTIZERS DON’T WORK FOR C. DIFF
d. Neither recommends screening of asymptomatic patients or staff, or Rx of asymptomatic carriers.
e. Although “moderate evidence” that probiotics diminish antibiotic associated diarrhea, neither recommend their routine use to prevent CDI
i. If you overprescribe, then give them a probiotic for sure

Question 12

how do we tx C diff

Answer 12

a. Stop offending Abx if possible, avoid anti-peristaltics

b. Empiric Rx appropriate when high suspicion

Question 13

empiric anbx tx for cdiff

Answer 13

Metronidazole 500mg TID x10-14d (mild/moderate) = FIRST LINE tx

or

Vancomycin 125mg QID x10-14d (severe disease, metronidazole intolerant, pregnant/breastfeeding, or failure to respond 5-7 days)

Question 14

tx for c diff complicated

Answer 14

PO/PR vanco plus IV metro

Question 15

what is considered severe disease with c diff and what is the treatment

Answer 15

surgery :): loop ileostomy

severe disease is disease
shock, pressors, renal failure, MS changes, lactate >5mmol/l, intubation)

Question 16

Fidaxomicin

Answer 16

(guidelines non-definitive) - oral; not systemically absorbed

really expensive and looks like it is not beneficial

Question 17

chances of reoccurrence with C diff

Answer 17

a. 20% after initial Rx
b. 40% after 1st recurrence
i. People who recur keep recurring - largely d/t spores
c. 60% after 2 or more recurrences

Question 18

mechanisms of reoccurrence

Answer 18

i. ? Persistent spores
ii. ? Impaired host immune response (lower anti-toxin IgG antibody levels in patients with rCDI)
iii. Decreased biome diversity
iv. ? Reinfection from environment

Question 19

tx for reoccurrence of c diff

Answer 19

i. Same Rx as prior, unless severe (vanco)

2nd recurrence: taper/pulse regimen í withdraw therapy, allow spores to germinate and then start therapy again