Evaluation of direct agglutination test (DAT) and ELISA for serodiagnosis of visceral leishmaniasis in India.

The direct agglutination test (DAT) and the enzyme-linked immunosorbent assay (ELISA) were used for serodiagnosis of parasitologically confirmed Indian visceral leishmaniasis (VL) cases. All the sera of VL cases were positive by both the methods. DAT titres of VL cases were greater than or equal to 1:3,200, and ELISA values were greater than or equal to 0.55 1:400 dilution. In the control group, sera of widely prevalent diseases of India, such as leprosy, tuberculosis, malaria, and liver cirrhosis, were included. Both tests could discriminate between VL and other patients of the control group. The sera of post-kala-azar dermal leishmaniasis (PKDL) patients gave OD values of greater than 0:55 and had DAT titres of 1:1,600. Both tests are sensitive and specific for the diagnosis of VL cases. DAT, being simpler and more economical, will be suitable for diagnosis and epidemiological studies for VL under rural conditions of India.