ELISA FOR DETECTION OF ANTI-GIARDIA SPECIFIC IGM - RESPONSE IN SERUM

Infection with Giardia lamblia (G. duodenalis, G. intestinalis) is com mon all over the world, especially in children. Traditional diagnosis by faecal microscopy has only moderate sensitivity; serological tests, although not always positive, are acceptable to patients and useful i n epidemiological studies. We show here that serum IgM separated by co lumn chromatography and assayed by an indirect ELISA test can be a use ful tool for the diagnosis of giardiasis. One hundred and thirty-nine positive sera (based on a single faecal examination), and 97 negative serum samples from Riyadh, Saudi Arabia, were examined. Taking positiv e results as being 2 s.d. above the mean of the controls, there were 1 17 positive results among the microscopically negative controls (3% fa lse positives). The sensitivity of the test was 84% and the specificit y 97%; the predictive value of a positive result is 97.5% and of a neg ative one 81%.