Internal Medicine

0521779407-10 CUNY1086/Karliner 0 521 77940 7 June 6, 2007 17:44

Isosporiasis 877

Isosporiasis........................................

J. GORDON FRIERSON, MD

history & physical

History

■Life cycle: ingested sporozoites of Isospora belli release sporozoites

in small bowel, which invade epithelial cells, mature, are re-released

to invade new cells. Some produce sporozoites, which mature to

sporocysts and pass in stool.

■Exposure: ingestion of sporocysts through contaminated food and

water

Signs & Symptoms

■Some pts are asymptomatic. Others may develop diarrhea, abdom-

inal cramps, flatulence, anorexia, sometimes low-grade fever.

Abdominal exam may show mild tenderness, distention. Usually

self-limited infection, lasting a few weeks, occasionally chronic.

Immunocompromised patients can have very prolonged symptoms.

tests

■Basic tests: blood: may show eosinophilia

■Basic tests: urine: normal

■Specific tests: Stool exam for O&P, which should include acid-fast

stain or immunofluorescence assays. May need multiple stools.

■Other tests: Entero-test (string test) or small bowel drainage and/or

biopsy will show organisms.

differential diagnosis

■Other causes of diarrhea, especially giardiasis, cyclosporiasis, cryp-

tosporidiosis, travelers’ diarrhea

management

What to Do First

■Assess need for fluids, electrolyte therapy.

General Measures

■Assess for source of infection.

specific therapy

Indications

■All symptomatic patients