Animal reservoirs of visceral leishmaniasis in India

Visceral leishmaniasis (VL) is a disease that has both zoonotic and anthroponotic etiologies. In India, VL is endemic, considered to be anthroponotic, and caused by Leishmania donovani . Anthroponotic diseases are maintained by transmission from human to human and to a lesser extent from human to animals. Serum samples from 1,220 animals from 7 human VL endemic districts of Bihar, India, were tested for antibodies to a recombinant kinetoplast antigen (rK39 antigen) present in amastigotes of visceralizing Leishmania species, i.e., L. donovani complex. Additionally, PCR was used to examine samples positive by rK39 antigen serology. Antibodies to rK39 indicative of VL were detected in 33 of 1,220 animals. Thirty-one of 867 goats (Capra hircus), 1 of 161 cattle (Bos indicus), and 1 of 54 wild rats (Rattus sp.) were positive by rK39 serology. None of 106 chickens (Gallus domesticus), 26 sheep (Ovis aries), 3 water buffaloes (Bubalus bubalus), or 3 dogs (Canis familiaris) was positive by rK39 serology. Leishmania donovani DNA was detected by PCR in 20 rK39 positive blood samples from goats and 1 sample from a cow. The present study indicates that goats are potential animal reservoirs of human VL in India.