Exam 2 - Diarrhea Flashcards
host defenses - physical barriers to GI tract
gastric acidity, bile, mucosal layer, intestinal motility, normal enteric flora
host defenses - innate immune system GI tract
antimicrobial peptides, acids
host defenses - adaptive immune system GI tract
mucosal IgA antibodies, T cells, Peyer’s patches
where is an exotoxin secreted
into the environment
what is an enterotoxin
a toxin that acts on intestine, often secretory
what is a cytotoxin
a toxin that acts on cells, causing cell damage - often inflammatory
characteristics of inflammatory diarrhea
invasive, bloody stools, systemic symptoms, fever
characteristics of secretory diarrhea
non-invasive, non-bloody, larger volumes, may have N/V, no systemic symptoms or fever
diarrhea definition
3 loose stools in 24 hours or greater than 200 grams/day
acute diarrhea timeline
less than 2 weeks
persistent diarrhea timeline
2-4 weeks
chronic diarrhea timeline
greater than 4 weeks
secretory diarrhea mechanism
enterotoxin/adherence
inflammatory diarrhea mechanism
cytotoxin/invasion
stool findings in secretory diarrhea
no fecal leukocytes
stool findings in inflammatory diarrhea
fecal leukocytes
secretory diarrhea pathogens
viruses, travelers diarrhea pathogens, b. cereus, giardia, vibrio cholerae, some e. coli, most parasites
inflammatory diarrhea pathogens
c diff, shigella, salmonella, campylobacter, yersinia, some e. coli, entamoeba histolytica
when to test for stool pathogens
persistent symptoms after 7 days
what GI infections can be detected with PCR
viral infections (norovirus, enterovirus, adenovirus), salmonella, shigella, campylobacter, EC0157
what GI infections can be detected with EIA
giardia, cryptosporidium, rotavirus, e. histolytica
when to perform O&P
only if immunocompromised or foreign travel is documented
what GI infections can be detected using toxin assay
c diff, shiga-toxin producing e coli (0157)
what GI infections are detected using histology
Hepatitis A IgM, entamoeba histolytica
antibiotic associated diarrhea pathogen
c diff
daycare-associated diarrhea pathogens
giardia, rotavirus, norovirus
waterborne secretory diarrheas
cryptosporidium, vibrio cholera
waterborne inflammatory diarrheas
plesiomonas, vibrio vulnificus
foodborne secretory diarrheas
hep A, B. cereus (rice)
foodborne inflammatory diarrheas
E. coli 0157, campylobacter, yersinia, listeria
E coli 0157 food
ground beef
campylobacter food
poultry, milk
yersinia food
pork
listeria food
deli meats
travel associated diarrhea
norowalk virus, giardia, ETEC
immunocompromise-associated diarhea
cyclospora, cryptosporidium
animal associated diarrhea
giardia, salmonella
immunocompromised associated diarrhea
cyclospora, cryptosporidium
diarrhea pathogen associated with fried rice
bacillus cereus
diarrhea pathogen associated with salad dressing/custards
staph aureus
diarrhea pathogen associated with poultry, beef, gravy
clostridium perfringes
diarrhea pathogen associated with poultry, eggs, milk, beef, turtles
salmonella
diarrhea pathogen associated with salads, raw vegetables, contaminated water, undercooked meats
shigella
diarrhea pathogen associated with poultry, unpasteurized milk
campylobacter
diarrhea pathogen associated with undercooked beef
E. coli 0157:H7
diarrhea pathogens with incubation period < 12 hours
bacillus cereus, staph aureus, clostridium perfringens
diarrhea pathogens with medium incubation period (hours-days)
salmonella, shigella, E coli 0157
diarrhea pathogen with long incubation period (days)
campylobacter
b cereus clinical characteristics
preformed toxin causes emesis, and later heat tolerant spores cause diarrhea
staph aureus clinical characteristics
ingestion of preformed enterotoxin causes emesis>diarrhea of 1-2 days duration
clostridium perfringens clinical characteristics
spores germinate and then release toxin leading to water diarrhea of 1 day duration
salmonella clinical characteristics
invasive inflammatory diarrhea
shigella clinical characteristics
invasive inflammatory diarrhea with very low inoculum required