B5.020 Diarrheal Pathogens

Question 1

types of manifestations of GI infections

Answer 1

typhoid fever
hepatitis
dysentery
chronic gastritis
food poisoning
secretory diarrhea

Question 2

differential for chronic gastritis (peptic and duodenal ulcer)

Answer 2

features: stomach, ab pain, no diarrhea
agents: H. pylori

Question 3

differential for food poisoning (pre formed toxin)

Answer 3

features: upper GI, nausea and vomiting, rapid onset
agents: staph aureus, bacillus cereus, C. perfringens, C. botulinum (peripheral nerves)

Question 4

differential for acute infectious secretory diarrhea

Answer 4

features: proximal small bowel, watery diarrhea (no fecal leukocytes)
agents: ETEC, EPEC, EHEC, EAEC, vibrio cholera, rotavirus, norovirus, giardia lamblia, cryptosporidium parvum

Question 5

differential for acute infectious dysentery

Answer 5

features: colon, fever, pain, blood, mucopurulent diarrhea
agents: campylobacter, salmonella, shigella, yersinia, EIEC, entamoeba histolytica, strongyloides, C.diff

Question 6

differential for acute infectious diarrhea hemorrhagic colitis

Answer 6

features: colon, pain, diarrhea, grossly bloody stools, HUS
agents: EHEC

Question 7

differential for typhoid fever

Answer 7

features: entry via small bowel, but systemic febrile illness, monocytic leuocytosis
agents: salmonella typhi, yersinia

Question 8

differential for chronic diarrhea in immunocompromised pts

Answer 8

features: small bowel, protracted watery diarrhea
agents: crypto, microsporidia, cyclo, CMV, mycobacterium avium

Question 9

location of secretory gastroenteritis

Answer 9

proximal small intestine

Question 10

type of illness associated with secretory gastroenteritis

Answer 10

watery diarrhea

Question 11

stool exam of secretory gastroenteritis

Answer 11

no fecal leukocytes

Question 12

mechanism of secretory gastroenteritis

Answer 12

enterotoxin or bacterial adherence/ invasion causes a shift in water and electrolyte excretion/absorption

Question 13

classic secretory gastroenteritis pathogens

Answer 13

vibrio cholera
ETEC
clostridium perfringens
Bacillus cereus
s. aureus

Question 14

location of inflammatory gastroenteritis

Answer 14

colon

Question 15

type of illness associated with inflammatory gastroenteritis

Answer 15

dysentery

Question 16

stool exam of inflammatory gastroenteritis

Answer 16

fecal polymorphonuclear leukocytes

Question 17

mechanism of inflammatory gastroenteritis

Answer 17

bacterial invasion or cytotoxins cause mucosal damage that leads to inflammation

Question 18

classic inflammatory gastroenteritis pathogens

Answer 18

shigella
EHEC
salmonella
vibrio parahaemolyticus
C. diff
campylobacter

Question 19

location of invasive gastroenteritis

Answer 19

distal small intestine

Question 20

type of illness associated with invasive gastroenteritis

Answer 20

enteric fever

Question 21

stool exam of invasive gastroenteritis

Answer 21

fecal mononuclear leukocytosis (if pt has diarrhea)

Question 22

mechanism of invasive gastroenteritis

Answer 22

bacteria penetrate the mucosa and invade the reticuloendothelial system

Question 23

classic invasive gastroenteritis pathogens

Answer 23

salmonella typhi/paratyphi

Yersinia