Comparison of Serological Methods (ELISA, DAT and IFA) for Diagnosis of Visceral Leishmaniasis Utilizing an Endemic Strain

Background: The causative agent of visceral leishmaniasis (VL) in Iran is Leishmania infantum (L. infantum) (Mediterranean type) and its major reservoir host is the dog. Ob-jective: To compare the serological methods including direct agglutination test (DAT), indirect immunofluorescent-antibody test (IFA) and enzyme-linked immunosorbent as-say (ELISA) for serodiagnosis of endemic strain of L. infantum. Methods: 61 blood samples from VL patients referred to Shiraz hospitals and 49 blood samples from con-trol group were collected. Native strain of the parasite isolated from a VL patient from the region was cultured and characterized. Antigens from this L. infantum parasite were used in ELISA and IFA system. Results: Anti-Leishmania antibody was detected in 43 (70.5%), 49 (80.3%) and 51(83.6%) cases using DAT, IFA and ELISA, respectively. Based on these results, sensitivity and specificity of DAT was found to be 70.5% and 100%, respectively. Sensitivities of IFA and ELISA in diagnosis of VL were 80.3% and 83.6% and their specificity was 90.5%. Conclusion: Results of this study showed that DAT and ELISA have the highest specificity and sensitivity in diagnosis of VL. DAT is a simple, cost-effective and field applicable test. Thus, it can be recommended for early and accurate diagnosis of VL, especially in regions where malaria, brucellosis and tu-berculosis are prevalent.