infectious diarrhea

diarrhea

≥3 episodes in 24 hours

viral diarrhea causes

norovirus, rotavirus, adenoviruses, astrovirus

bacterial diarrhea causes

salmonella, campylobacter, shigella, enterotoxigenic e. coli, c. diff

protozoa diarrhea causes

cryptosporidium, giardia, cyclospora, entamoe ba

stool study indications

hypovolemia

>6 unformed stools in 24 hours

severe abdominal pain

bloody diarrhea

many small volume stools with blood/mucus

temp ≥101.3

high risk patient

symptoms > 1 week

public health concerns

bacterial stool culture

salmonella, shingella, campylobacter

escherichia O157:H7 culture

for e. coli

bloody diarrhea after ingestion of ground beef

stool leukocyte

presence of leukocytes can differentiate invasive vs non-invasive diarrhea

parasite testing

for ova and parasites

stool guaiac (hemoccult)

blood within stool

non-invasive diarrhea

large volumes of non-bloody diarrhea

no fecal WBCs

vomiting

small bowel affected

invasive diarrhea

small volumes of bloody diarrhea

fecal WBCs

vomiting and fever

large bowel affected

no anti-motility drugs

non-invasive diarrhea causes

cholera, norovirus, rotavirus, enterotoxigenic e. coli (ETEC), staph aureus, bacillus cereus,

cholera

from vibrio cholerae with incubation 1-2 days

why not to give anti-diarrhea medications

invasive diarrhea, must get bad bacteria out

invasive diarrhea causes

salmonella (typhoidal and nontyphoidal), shigella, campylobacter jejuni, enterohemorrhagic e. coli (O157:H7), c. diff

cholera etiology

contaminated food/water

cholera sx

rice water stools

cholera treatment

fluids

doxycycline

norovirus etiology

foodborne

“cruise ship vacation”

norovirus sx

2-3 days non-bloody diarrhea

norovirus treatment

symptoms - anti-motility meds

rotavirus risk factor

daycare

rotavirus sx

non-bloody diarrhea

rotavirus treatment

anti-motility meds

enterotoxigenic e.coli risk/etiology

traveler’s diarrhea

contaminated food/water

e. e. coli sx

non-bloody diarrhea

e. e. coli treatment

self limited, anti-motility

abx common

staph a pathophysiology

heat stable enterotoxin B

staph a risk factors

food borne illness

MCC dairy/mayo at room temp

staph a sx

non-bloody diarrhea

staph a treatment

self limiting, 24h

bacillus cereus risks

contaminated fried rice

bacillus cereus sx

non-bloody diarrhea

bacillus cereus treatment

self limited, 12h

typhoidal salmonellosis pathophysiology

salmonella typhi and paratyphi

typhoidal salmonellosis etiology

travel in south-central asia

typhoidal salmonellosis transmission

fecal oral

typhoidal salmonellosis clinical presentation

flu like prodrome

rose spots

pea soup diarrhea

typhoidal salmonellosis diagnostic

blood culture

typhoidal salmonellosis treatment

fluoroquinolones

non-typhoidal salmonellosis etiology

pork, poultry, or raw egg, reptiles

bloody diarrhea causes

non-typhoidal salmonellosis, shigella, campylobacter jejuni, e.e. coli, amebiasis,

non-typhoidal salmonellosis risks

elderly - not enough stomach acid

non-typhoidal salmonellosis sx

fever, cramping, chills, diarrhea (may be bloody)

non-typhoidal salmonellosis treatment

fluoroquinolones

shigella pathophysiology

gram negative rods, 1-3 day incubation

shigella transmission

contaminated foods (raw vegetables)

sexual transmission in MSM

shigella sx

bloody and mucousy diarrhea

shigella treatment

fluoroquinolone

NO ANTI-MOTILITY

campylobacter jejuni pathophysiology

motile gram negative rods

campylobacter jejuni etiology

ingestion/handling raw poultry

campylobacter jejuni sx

abdominal pain, bloody diarrhea

campylobacter jejuni diagnostics

stool culture - gram negative spiral/seagull shaped

campylobacter jejuni treatment

self limiting

fluoroquinolone or azithromycin in immunocompromised

campylobacter jejuni complications

guillain barre (ascending weakness)

enterohemorrhagic e. coli pathophysiology

shiga-like toxin leads to vascular damage in gut

enterohemorrhagic e. coli risks

undercooked ground beef

enterohemorrhagic e. coli sx

bloody diarrhea

enterohemorrhagic e. coli treatment

hydration

no abx in children - leads to hemolytic urea syndrome/kidney failure

NO ANTI-MOTILITY

c. diff pathophysiology

recent abx use kills good gut bacteria and overgrowth of bad bacteria occurs and release enterotoxin

c. diff risks

recent clindamycin or fluoroquinolone use or chemo

c. diff sx

≥3 episodes of diarrhea in 24 hours

when to test for c. diff

≥3 episodes of diarrhea in 24 hours

recent abx

when not to test for c. diff

within 7 days of initial

to assess treatment

c. diff diagnostics

stool culture, positive nucleic acid amplification test, GDH EIA

c. diff treatment

dc causative abx

first: oral vanc or fidaxomicin

recurrence: dificid (fidaxomicin)

severe: fecal transplant

giardia pathophysiology

flagellate protozoan parasite

giardia etiology

fecal oral

“fresh mountain water”

giardia risks

traveling to developing countries

giardia sx

foul smelling greasy/frothy/floating stool

giardia diagnostic

stool microscopy for trophozoites and cysts

giardia treatment

flagyl (metronidazole)

amebiasis pathophysiology

protozoan

amebiasis risks

fecal oral route with contaminated food

amebiasis sx

bloody stools

liver abscess may form

amebiasis diagnostics

stool microscopy for oval and parasite

amebiasis treatment

flagyl (metronidazole)

cause of traveler’s diarrhea

e. coli

cause of diarrhea after picnic/egg salad

staph a

cause of diarrhea from shellfish

virbrio cholerae

cause of diarrhea from poultry/pork

salmonella

cause of diarrhea after raw egg ingestion

salmonella

cause of diarrhea post abx

c. diff

cause of diarrhea from poorly canned home foods

c. perfringens

cause of diarrhea outbreak in daycare

rotavirus

cause of diarrhea after cruise ship

norovirus

cause of diarrhea after drinking “fresh” mountain water

giardia