for strongyloidiasis are indicated when the infection is suspected and the organism cannot
be demonstrated by duodenal aspiration, string tests, or by repeated examinations of
stool. Antibody detection tests should use antigens derived from Strongyloides
stercoralis filariform larvae for the highest sensitivity and specificity.
Although indirect fluorescent antibody (IFA) and indirect hemagglutination (IHA) tests
have been used, enzyme immunoassay (EIA) is currently recommended because of its greater
sensitivity (90%). Immunocompromised persons with disseminated
strongyloidiasis usually have detectable IgG antibodies despite their
immunodepression. Cross-reactions in patients with filariasis and some other nematode infections may
occur. Antibody test results cannot be used to differentiate
between past and current infection. A positive test warrants continuing efforts to
establish a parasitological diagnosis followed by antihelminthic treatment.
Serologic monitoring may be useful in the follow-up of immunocompetent treated patients:
antibody levels decrease markedly within 6 months after successful chemotherapy.
Genta RM. Predictive value of an enzyme-linked immunosorbent assay (ELISA) for the
serodiagnosis of strongyloidiasis. Am J Clin Pathol 1988;89:391-394.