Virgin soil: the spread of visceral leishmaniasis into Uttar Pradesh, India.

We conducted a cross-sectional study to determine the incidence of visceral leishmaniasis (VL) and risk factors in two villages in Uttar Pradesh, India reported to have had a recent outbreak. In 245 households with 2,203 people, we detected 3 current VL cases, 32 past cases, and 8 VL deaths since 2001 (annual incidence = 6 per 1,000). Risk factors included living in the same household as a VL case (odds ratio [OR] = 76, P < 0.0005 in one village and OR = 22, P < 0.0005 in the other village), sleeping downstairs and outside in the summer (OR = 4.7, P = 0.004), and an age > or = 15 years old (OR = 2.9, P = 0.024). Increasing cattle density was a risk factor in one village but not the other. We were not able to determine the route by which VL entered the villages. Our data demonstrate a new spread of VL in previously unaffected areas. We recommend carefully supervised spraying with DDT, surveillance to pinpoint other affected villages, and efforts to increase availability of diagnostic and treatment facilities.