Clinical features, tissue smear and competitive enzyme linked immunosorbent assay as dignostic and prognostic procedures for visceral leishmaniasis in Yemen.

Twenty six Yemeni patients with clinically visceral leishmaniasis (VL) and laboratory abnormalities were subjected to L. donovani species-specific monoclonal antibody (D2) and a competitive enzyme-linked immunosorbent assay (C-ELISA). The results were compared with those obtained by microscopy Giemsa stained tissue smears of bone marrow or splenic aspiration. Of the patients, 51 (82.3%) were positive and 3 (4.8%) were negative by both microscopy and C-ELISA. An additional 8 (12.9%) who were negative by microscopy were positive by C-ELISA. 59 patients were treated with sodium antimony gluconate, 45 (76.3%) were drug responsive and 14 (23.7%) were drug resistant. The C-ELISA of 17 patients before and after chemotherapy showed a significant decrease in percent inhibition of monoclonal antibodies D2 in drug responsive patients. In drug-unresponsive patients the percent inhibition of D2 was unchanged or slightly increased. The results indicate that C- ELISA is more sensitive and specific than microscopy, especially for early diagnosis of VL and to evaluate the success of drug treatment.