Quiz diarrhea

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Entamoeba histolytica

• Trophozoite and cystic form• Invasive produce colonic ulceration• <1% spread outside the intestine :liver ,brain

infection, pleural or pericardial effusion• Complication: GI bleeding, toxic megacolon,

intussusception, stricture,perforation• Stools: blood-streaked mucus• Ab-based enzyme immunoessay sens and spec

95%

• Rx : paromomycin, iodoquinol, diloxanide furoate

• Severe symptoms:metronidazole750 mg tid x10 day

Enterobius vermicularis

• Pinworm or seatworm• Natural host: human• Noninvasive• Perianal tingling or itching at night• Cellophane tape test• Rx empirically all other familial member• Albendazole 400 mg once,2nd dose at 2 wk

later

Giardia

• Backpacker’s diarrhea• Pt with decreased gastric acid: susceptible to

Giardia infection• Proximal bowel,superficial invasion of the

mucosa• Symptoms:from malabsorption• Abdominal distension, colicky pain, flatulence,

frequency explosive diarrhea

Giardia

• Acute infection: stool exam sens>95%• Chronic infection: ELISA, DFA• Rx:metronidazole 250 mg tid x7 day

Ascaris lumbricoides• eggs are swallowed invade intestine

mucosalungsthe bronchial tree swallowing to the small intestine

• adult worms in the small intestine: no symptoms• nonproductive cough ,substernal

discomfort,dyspnea,fever,eosinophilia • Rx:Albendazole (400 mg once), mebendazole

(500 mg once), or ivermectin (150–200 g/kg once)

5 micron

20 micron

Coccidial infection

Cryptosporidium• most common cause of chronic diarrhea in

AIDSIsospora belli• OI in AIDS

Coccidial infection

• Non invasive• Mild to profuse watery diarrhea• Dx:oocysts in stool, acid fast stain ,EISA• Cryptosporidium 5 micron, Isospora 20 micron• Cryptosporidium Rx:Self-limited in

immunocompetent, AIDS:HAART• Isosporisis: TMP-SMX

Cyclospora

Cyclospora cayetamemsis

• Acute explosive watery diarrhea and abdominal cramps ,subside in 1-3 day

• Followed by intermittent mild diarrhea and marked anorexia and fatigue

• Dx: modified acid fast stain 8-10 micron,DDx cryptosporidium

• Rx:TMP-SMX

Strongyloides stercoralis• uncomplicated strongyloidiasis: asymptomatic• Immunocompromise host: Colitis, enteritis, or

malabsorption • In disseminated strongyloidiasis:GI,lungs,CNS , peritoneum,

liver, and kidneys• Gram-negative sepsis, pneumonia, or meningitis may

complicate• Dx: larvae in stool• Rx:Ivermectin 200 g/kg daily for 2 days, albendazole 400

mg daily for 3 days• For disseminated strongyloidiasis rx at least 5–7 days or

until the parasites are eradicated.

Tenia

• Intestinal infections with T. solium may be asymptomatic

• In cysticercosis: cysticerci can be found anywhere in the body but are most commonly detected in the brain

• Dx: proglottid in stool• Rx:A single dose of praziquantel (10 mg/kg) is

highly effective