Comparison of parasitological and immunological methods in the diagnosis of leishmaniasis in Ethiopia.

The sensitivity and specificity of parasite demonstration methods (smear, culture and histology) and serological assays (enzyme-linked immunosorbent assay [ELISA], direct agglutination test and immunoblot) were compared in the diagnosis of leishmaniasis in Ethiopia. Culture was found to be the most sensitive diagnostic method, followed by ELISA, for the diagnosis of cutaneous leishmaniasis (CL). When the clinical type of CL was taken into consideration, serological and parasitological methods were equally good for the diagnosis of diffuse cutaneous leishmaniasis. Overall, the serological assays were not sensitive enough to diagnose all the parasitologically confirmed cases of localized cutaneous leishmaniasis. Both groups of diagnostic methods performed equally well in the diagnosis of visceral leishmaniasis patients. In cases of CL where clinical diagnosis was a problem and histology could not give a definitive diagnosis due to the absence of demonstrable parasites, one of the serological assays, preferably ELISA, was very useful in establishing the final diagnosis.