Internal Medicine

0521779407-08 CUNY1086/Karliner 0 521 77940 7 June 13, 2007 7:47

624 Giardiasis

■Basic tests: urine: normal

■Specific tests: Stool exam for O&P. A little more sensitive is ELISA-

based exam of stool for Giardia antigen.

■Other tests: Serology is available, but many false negatives, and pos-

itive could mean old disease. UGI may show dilation of upper small

bowel and thickened folds. Duodenal aspirate or biopsy useful when

less invasive tests indeterminate.

differential diagnosis

■Infectious diarrheas, other causes of malabsorption, amebiasis,

strongyloidiasis, isosporiasis

management

What to Do First

■Assess severity, evidence of malabsorption.

General Measures

■Determine source of infection, check others exposed.

specific therapy

Indications

■All symptomatic patients; asymptomatic patients who may transmit

infection

Treatment Options

■Metronidazole for 7 days

■Tinadazole single dose

■Paromomycin for 7 days

■Furazolidine for 10 days

Side Effects & Complications

■Metronidazole: metallic taste in mouth, mild GI complaints, dizzi-

ness. Antabuse-like reaction with alcohol.

■Paromomycin: nausea, vomiting, diarrhea

■Furazolidine: nausea, occasional allergic reactions, urticaria

■Contraindications to treatment: absolute: none

■Contraindications to treatment: relative: asymptomatic children in

day care centers. Treatment of asymptomatic persons in hygienic

settings is optional.

follow-up

During Treatment

■See that symptoms subside.