Pre- and post-treatment antibody levels in visceral leishmaniasis

Abstract
Enzyme-linked immunosorbent assay (ELISA) and the direct agglutination test (DAT) were employed to test sera obtained from a visceral leishmaniasis (VL) endemic area, the Aba-Roba focus in south-west Ethiopia. Thirty sera of untreated VL patients, 37 sera 6–90 months after treatment, 18 sera from endemic controls, 8 sera from non-endemic controls and 23 sera from patients with other diseases (schistosomiasis, tuberculosis, cutaneous leishmaniasis) were tested. Based on ELISA, the percentages negative were found to be 50% up to one year and 89% from 2 to 8 years after treatment. In contrast, these rates based on DAT were 0% in one year and 33% from 1–8 years after treatment. The relevance of persisting antibodies in the kinetics and profile of antibody production during treatment is discussed. The use of ELISA in the evaluation of clinical prognosis and patient follow-up is recommended. Serum from a diffuse cutaneous leishmaniasis patient cross-reacted with the DAT and ELISA for VL.