diarrhea presenting with fever Flashcards Preview

Micro > diarrhea presenting with fever > Flashcards

Flashcards in diarrhea presenting with fever Deck (29)
Loading flashcards...
1
Q

Clostritium difficile
NF?
high carriage in??

A

G+, anaerobic spore-former
NF in 3% gen pop
20-40% carriage in nursing home/hosp. pts

2
Q

C. diff ribotype 078/ST 11 (clade 5)

A

animal and food assoc–>sev. CDI

3
Q

C. diff toxinotype III strain NAP1/BI/027
virulence??

via what genetic alteration??
associated with ???

A

hypervirulent strain, CA-CDI
produces 16x more toxin A and 20x more toxin B in vitro than other strains via…
deletion of tcdC gene (depressor of toxin prod.)
use of FQs (FQ resistant)

4
Q

C. diff produces 2 toxins

mechanism??

A

Toxin A and Toxin B (homology btw them)

both cause cytopathic effect by modifying proteins that regulate actin formation via glycosylation of Rho proteins

5
Q

in response to C. diff toxins: neurons release ?? and LP immune cells releases ??

A

neurons release substance P
immune cells of LP (i.e. MALT) release inflamm. mediators:
histamine, TNF-a, IL-1

6
Q

C. diff incidence: increasing?

A

yes by 26%/yr

7
Q

nosocomial C. diff usually trigger by ??

who is at risk more ??

A
abx therapy (new strains related to inc. FQ use)
oldies >60
8
Q

C. diff reservoir

A

calves, pigs, 3% of humans (more in hosp pts/nursing home)

9
Q

C. diff age/gender/season assoc.

A
old age (HCA-CDI)
young adults (CA-CDI)
No gender or season assoc.
10
Q

3 major C. diff risk factors

A

abx: weeks after tx (takes 3 mos to return to baseline risk)
* hospitalization*: inc. asymptomatic carriage in hosp/nursing home pts

Community-acquired: use of PPIs and H2 blocker use

11
Q

other C. diff risk factors

A

antineoplastic agents, cathartics, stool softeners, enemas, IBD, antacids, HIV

12
Q

C. diff pathogenesis: abx suppress NF, allowing (previously eaten, colonized) C. diff OG and toxin production
the cytotoxin produces a ??

A

pseudomembrane: fibrin mesh made of necrotic cells, PMNs, monocytes and RBCs
“white plaque” appearance

13
Q

C. diff cardinal symptom

others

A

febrile watery diarrhea, 10-15 stools/day!

lower abd. cramps, no cyst. symptoms

14
Q

C. diff causes loss of ?? in stool

A

serum proteins–>hypoalbuminemia, edema, ascites

15
Q

indicators of severed CDI
do what w. these pts ??
even more worrisome, req. prompt sx consult

A

fever >38, abd. distension, leukocytosis (>15-20,000)
admit to ICU, sx consult
leuks as high as 50,000 and lactic acidosis

16
Q

?? may proceed C. diff diarrhea

A

leukocytosis

17
Q

sev. CDI abd. pain caused by

A

ileus, colonic dilation, toxi megacolon **(get a consult)

18
Q

classic pseudomembronous colitis described as ?? over ??

symptoms??

what is pathognomonic for CDI??

A

elev. yellow plaques over inflamed mucosa

even more pronounced than sev. colitis

endoscopic appearance

19
Q

C. diff complications

A

bradycardia, hypotnsn, shock, megacolon, colonic perf

20
Q

C. diff dx: suspect when ??

A

abx in prev. 2 mos or diarrhea began 72 hr + after hospitalization

21
Q

C. diff dx

A
stool Cx (sn) (G+ rods with subterminal spores and leukos)
cytotoxin assay (sp) - do both!
EIA and latex agglutination: test for toxin A and B
22
Q

C. diff dx for special occasions, rapid dx

A

endoscopy

23
Q

in CA-CDI ppl who require hospitalization..

A

screen for C. diff toxins w. PCR:
tcdA and tcdB (and tcdC: regulatory) -sn and sp!
better than EIA

24
Q

C. diff ddx

A

UC, chronic IBD, Crohn’s

25
Q

C. diff tx

A

stop abx that cause it
fluid/e-lyte replacement
abx
probiotic/fecal transplant

26
Q

C. diff tx: abx?

A

metronidazole (FLD)
vancomycin (cell wall inhib, for sev. disease/metro resistance)
fidaxomicin (macrolide, prot. syn inhib, less effect on NF than vanco)

27
Q

avoid ?? while tx C. diff

why??

A
antiperistaltic agents (loperamide) 
may hide symptoms and induce toxic megacolon
28
Q

C. diff pts: how many will relapse?

A

20%

29
Q

C. diff prev.

A

barrier precautions
isolation
clean with sporicidal agents
wash hands w. soap and water
restrict abx use, esp: 2nd, 3rd gen cephs, clindamycin, FQs (or combo of the 3)
probiotics: Lactobacillus and Saccharomyces boulardii
wash bathroom with bleach

Decks in Micro Class (61):