A Community Based Cohort Study on Usefulness of Leishmanin Skin Test in Detection of Immunoreactivity Against Leishmania donovani Infection in an Endemic Area of Kala-Azar, Bihar, India

Control efforts of visceral leishmaniasis (VL) are hindered due to inappropriate early case detection of Leishmania infection with varying degree of susceptibility to develop the disease.

We assessed the current infection status using Leishmanin skin test (LST) and direct agglutination test (DAT) in a cohort population (206 randomly selected individuals) in a VL endemic area of Bihar, India.

Cellular immunity was revealed in 18.4% and antibody response in 18.9% of the population. The age-group of 20-29 years were most vulnerable. DAT titer was inversely proportional to duration of past history of VL. The houses having present or past history of kala-azar in family were observed with high Leishmanin and DAT positivity, indicating relevance of household contacts in the disease transmission.

The reactivity of both LST and DAT tests may help in identifying the possible groups with varying degree of susceptibility and risk of infection or having prior exposure to the leishmania infection with or without development of the disease.