May7 A2-Diarrhea

Question 1

(EXAM) 5 organisms that cause dysentery (bloody diarrhea)

Answer 1

SSCYE
-salmonella spp
-shigella spp
-campylobacter spp
-yersinia spp
-escherichia coli O157
(+ entamoeba histolytica)

Question 2

(imp?) only parasite known to cause bloody diarrhea

Answer 2

entamoeba histolytica

Question 3

cause of typhoid fever

Answer 3

salmonella enterica serogroup typhi (salmonella has 2 types but many serogroups)

Question 4

what’s typhoid fever

Answer 4

• high fever
• stupor (lethargy, unconsciousness)
• cramps
• sepsis
• rose spots on the skin
• leukopenia with left shift
• bradycardia

Question 5

(EXAM) most important thing to remember about typhoid fever

Answer 5

Very often, there is NO DIARRHEA at all

Question 6

(imp) virus that causes diarrhea in children typically

Answer 6

rotavirus (gastroenteritis in children)

Question 7

(EXAM) 2 main viral causes of WATERY diarrhea

Answer 7

• ROTAVIRUS (big problem in infants, bit of vomiting, lot of morbidity and mortality in infants bc of dehydration)
• NOROVIRUS (24 hour stomach flu, explosive vomiting and diarrhea, very contagious, cruise ships. wash with quaternary ammonium compounds, not alcohol bc resistant)

Question 8

(EXAM) organisms that cause WATERY diarrhea in general and diagnosis (2)

Answer 8

1. parasites called the spora (intestinal protozoa)
   - microsporidium spp
   - cryptosporidium spp
   - cyclospora cayetanensis
   - isospora belli
   * need special staining or PCR to detect them*
2. giardia lamblia (common in dev countries: beaver fever, in beaver stool. abd cramps and bloating. protracted=long diarrhea)

Question 9

(EXAM) diagnostic testing principles to remember in patients with diarrhea (3)

Answer 9

• stool cultures are rarely positive and often negative
• in most cases, no need to document a pathogen, except if highly contagious, for public health (salmonella enterica typhi and shigella spp)
• most infectious causes and symptoms of acute diarrhea are self-limited

Question 10

(important) common presentation of viral diarrhea

Answer 10

acute and watery

Question 11

(important) what pathogens to consider with persistent diarrhea

Answer 11

parasites

Question 12

(important) when would you suspect a C.diff infection as the cause of diarrhea

Answer 12

• post antibiotics

- in hospitalized patients (or post hospital stay)

Question 13

(important) what are the complications of bloody diarrhea and diarrheal illnesses in general

Answer 13

• HUS (hemolytic uremic syndrome) with EHEC (E. coli O157): shigatoxin (verotoxin), renal failure, thrombocytopenia, vascular hemolysis, stupor, confusion, seizures)
• typhoid fever
• Guillain-Barré syndrome (immune demyelinating disease of the PNS, can kill if phrenic nerve, diaphragm prob)

Question 14

(important) investigations in diarrhea

Answer 14

send stool culture (especially for bloody diarrhea), even if often negative

Question 15

(important) who do you reserve C.diff testing for

Answer 15

-age >6 months
-symptomatic patient
(and obviously post Abx or hospitalized)

Question 16

(important) what diarrheas do you treat (TTSSCCBP)

Answer 16

• traveler’s diarrhea (empiric like cipro)
• typhoid (cipro or ceft)
• salmonella enterica typhi (cipro or ceft)
• shigella (cipro or ceft)
• campylobacter (azythromycin)
• C.diff (symptomatic) (flagyl or vanco)
• bacteremia
• parasitic (giardia or entamoeba = metro)

Question 17

(important) Abx or supportive treatment only in EHEC (E.coli O157) diarrhea

Answer 17

NO ABX bc makes it worse

-supportive tx only

Question 18

(important) antimotility agents in bloody diarrhea: yes or no

Answer 18

NO. want to get the pathogen out

Question 19

(important) key interventions to reduce diarrheal illnesses worldwide

Answer 19

prevention

• hygiene
• dietary measures
• vaccination

Question 20

(important) disease to consider when seeing diarrhea (that is not of infectious etiology)

Answer 20

IBD (inflammatory bowel disease)