Diarrhea--viruses and protozoa Flashcards
1
Q
Rotavirus
A
- most common cause of acute diarrhea in infants!!
- watery diarrhea
- viral culture of PCR
- “wagon-wheel” appearance on electron microscopy!!
- tx- supportive care
- vaccine available
2
Q
Norwalk virus
A
(Norovirus)
- watery diarrhea
- cruise ships!!
- tx- supportive care
3
Q
Adenovirus (serotypes 40 and 41)
A
- children- 2nd to rotavirus
- fever, chills, myalgias, sore throat
- watery diarrhea
- conjunctivitis!!- most common cause of viral conjunctivitis in children
- 10 day course
- viral culture
- tx- supportive care
4
Q
CMV
A
- rare cause!!- in immunosuppressed pts!- CD4 <200
- fever, abd pain, bloody diarrhea
- persists for several wks
- endoscopy with biopsy of ulcerated lesions
5
Q
Entamoeba histolytica- sx, dx, tx
A
- most common cause of dysentery in the world!!!
- “flask-shaped ulcer”
- can penetrate bowel and into portal circulation- liver abscess!!! (or brain abscess)
- toxic megacolon or pneumatosis coli!!!
- stool ag!!!
- crowded living conditions
- tx- metronidazole!!!
6
Q
Giardia lamblia- sx, dx, tx
A
-pear-shaped, 2 nuclei, 4 flagella
-watery diarrhea
-steatorrhea, flatulence, abd pain, weight dec
-lasts 14-28 days
-fecal leukocytes -!
-stool ag detection!!
-acquired- water- hiking/camping!!!
tx- metronidazole
7
Q
Cryptosporidium
A
2 main clinical syndromes
- self-limited diarrhea in immunocompetent pts!
- life-threatening in immunosuppressed pts!- CD4 < 200; biliary dz
- watery diarrhea- large volume!
- swimming pools!!!!
- stool ag detection
- tx- supportive care
8
Q
Strongyloides stercoralis
A
- roundworm!!
- bare feet on contaminated soil!!
- risk factors- rural areas; HTLV-1 infected
- rhabditiform larvae in stool, eosinophils in stools!!
- Tx- Ivermectin
9
Q
Cyclospora cayetanesis
A
- from produce!! (lettuce, basil, raspberries)
- travel to endemic areas!!!
- watery diarrhea
- indefinitely in immunosuppressed
- oocysts in stool sample
- Tx- TMP/SMX
10
Q
Cystoisospora belli
A
- tropical and subtropical areas
- non-blood diarrhea- in immunosuppressed- severe diarrhea
- can last for wks- can result in malabs and weight loss
- repeated stool examinations
- duodenal specimens by biopsy!! (if stool -)
- oocysts- modified acid-fast stain
- tx- bactrim DS (TMP/SMX)
11
Q
Ascaris lumbricoides
A
- hook worm
- fecal-oral
- can cause bowel obstruction!!
12
Q
Diphyllobothrium latum
A
- fish tapeworm
- raw/undercooked fish
13
Q
Schistosoma mansoni
A
(schistosomiasis)
- Africa!
- 2nd most common cause of esophageal varices in africa!
- freshwater snails- contaminate water- skin
- bloody stools, bladder cancer, liver cysts!
14
Q
Taenia solum
A
(causes cysticercosis)
- pork tapeworm
- seizures!
15
Q
Echinococcus granulosus
A
- tapeworm
- sheeps, dogs- main carriers
- form cysts in liver or lungs!!
- free-flowing “hydatid sand” on cT!!
