Diarrhea--viruses and protozoa Flashcards
Rotavirus
- 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
Norwalk virus
(Norovirus)
- watery diarrhea
- cruise ships!!
- tx- supportive care
Adenovirus (serotypes 40 and 41)
- 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
CMV
- rare cause!!- in immunosuppressed pts!- CD4 <200
- fever, abd pain, bloody diarrhea
- persists for several wks
- endoscopy with biopsy of ulcerated lesions
Entamoeba histolytica- sx, dx, tx
- 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!!!
Giardia lamblia- sx, dx, tx
-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
Cryptosporidium
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
Strongyloides stercoralis
- roundworm!!
- bare feet on contaminated soil!!
- risk factors- rural areas; HTLV-1 infected
- rhabditiform larvae in stool, eosinophils in stools!!
- Tx- Ivermectin
Cyclospora cayetanesis
- from produce!! (lettuce, basil, raspberries)
- travel to endemic areas!!!
- watery diarrhea
- indefinitely in immunosuppressed
- oocysts in stool sample
- Tx- TMP/SMX
Cystoisospora belli
- 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)
Ascaris lumbricoides
- hook worm
- fecal-oral
- can cause bowel obstruction!!
Diphyllobothrium latum
- fish tapeworm
- raw/undercooked fish
Schistosoma mansoni
(schistosomiasis)
- Africa!
- 2nd most common cause of esophageal varices in africa!
- freshwater snails- contaminate water- skin
- bloody stools, bladder cancer, liver cysts!
Taenia solum
(causes cysticercosis)
- pork tapeworm
- seizures!
Echinococcus granulosus
- tapeworm
- sheeps, dogs- main carriers
- form cysts in liver or lungs!!
- free-flowing “hydatid sand” on cT!!
Treatment
- Hydration and maintaining electrolyte balance (PO or IV)
- abx not required in most cases
- anti-motility agents- not to be used in C diff or EHEC
- BRAT diet- bananas, rice, applesauce, toast
- easily digestible foods
prevention- alcohol gels are ineffective against?
Norovirus and C diff
prevention- vaccines?
-rotavirus, S typhi, V cholerae, Hep A
reactive arthritis- caused by
-salmonella, campylobacter, shigella, yersinia
yersiniosis- may lead to
-thyroiditis, pericarditis, glomerulonephritis
Guillian-Barre syndrome- caused by
Campylobacter jejuni
HUS- caused by
- EHEC (O157:H7)!!
- Shigella
small bowel affected- sx
- large volume
- watery stools
- abd cramps
- weight loss
- WBC’s not in stool
- dehydration/malabs
- mid abd or diffuse
Large bowel affected- x
- frequent, small volume stools
- fever
- WBCs or blood in stool
- fecal leukocytes
- lower abd or rectum
