Diarrhea--viruses and protozoa Flashcards Preview

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Flashcards in Diarrhea--viruses and protozoa Deck (24):
1

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

2

Norwalk virus

(Norovirus)
-watery diarrhea
-cruise ships!!
-tx- supportive care

3

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

4

CMV

-rare cause!!- in immunosuppressed pts!- CD4 <200
-fever, abd pain, bloody diarrhea
-persists for several wks
-endoscopy with biopsy of ulcerated lesions

5

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!!!

6

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

7

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

8

Strongyloides stercoralis

-roundworm!!
-bare feet on contaminated soil!!
-risk factors- rural areas; HTLV-1 infected
-rhabditiform larvae in stool, eosinophils in stools!!
-Tx- Ivermectin

9

Cyclospora cayetanesis

-from produce!! (lettuce, basil, raspberries)
-travel to endemic areas!!!
-watery diarrhea
-indefinitely in immunosuppressed
-oocysts in stool sample
-Tx- TMP/SMX

10

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)

11

Ascaris lumbricoides

-hook worm
-fecal-oral
-can cause bowel obstruction!!

12

Diphyllobothrium latum

-fish tapeworm
-raw/undercooked fish

13

Schistosoma mansoni

(schistosomiasis)
-Africa!
-2nd most common cause of esophageal varices in africa!
-freshwater snails- contaminate water- skin
-bloody stools, bladder cancer, liver cysts!

14

Taenia solum

(causes cysticercosis)
-pork tapeworm
-seizures!

15

Echinococcus granulosus

-tapeworm
-sheeps, dogs- main carriers
-form cysts in liver or lungs!!
-free-flowing "hydatid sand" on cT!!

16

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

17

prevention- alcohol gels are ineffective against?

Norovirus and C diff

18

prevention- vaccines?

-rotavirus, S typhi, V cholerae, Hep A

19

reactive arthritis- caused by

-salmonella, campylobacter, shigella, yersinia

20

yersiniosis- may lead to

-thyroiditis, pericarditis, glomerulonephritis

21

Guillian-Barre syndrome- caused by

Campylobacter jejuni

22

HUS- caused by

-EHEC (O157:H7)!!
-Shigella

23

small bowel affected- sx

-large volume
-watery stools
-abd cramps
-weight loss
-WBC's not in stool
-dehydration/malabs
-mid abd or diffuse

24

Large bowel affected- x

-frequent, small volume stools
-fever
-WBCs or blood in stool
-fecal leukocytes
-lower abd or rectum