Risk factors for visceral leishmaniasis and asymptomatic Leishmania donovani infection in India and Nepal

PLoS One. 2014 Jan 31;9(1):e87641. doi: 10.1371/journal.pone.0087641. eCollection 2014.

Abstract

There is increasing interest in the role of asymptomatic infection in transmission of Visceral Leishmaniasis (VL). We studied the individual, household and environmental factors associated with asymptomatic Leishmania donovani infected individuals and VL. 7,538 individuals living in VL endemic villages in India and Nepal were divided into three mutually exclusive groups based on their VL history and Direct Agglutination Test (DAT) results in yearly serosurveys over a two-year period. The groups were (1) VL cases, (2) asymptomatically infected individuals (seroconverters) and (3) seronegative individuals. VL cases and seroconverters were compared to seronegative individuals in mixed logistic regression models. The risk of seroconversion and disease was significantly increased in individuals aged 14 to 24 years old and by the presence of other DAT-positive, asymptomatically infected individuals and VL cases in the house. The risk of seroconversion was higher in Indian than in Nepalese villages and it increased significantly with age, but not so for VL. This study demonstrates that, when risk factors for leishmanial infection and VL disease are evaluated in the same population, epidemiological determinants for asymptomatic infection and VL are largely similar.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Humans
  • India / epidemiology
  • Infant
  • Infant, Newborn
  • Leishmania donovani*
  • Leishmaniasis, Visceral* / blood
  • Leishmaniasis, Visceral* / epidemiology
  • Leishmaniasis, Visceral* / immunology
  • Male
  • Models, Biological*
  • Nepal / epidemiology
  • Risk Factors

Grants and funding

This study was funded by the European Union under its 6th Framework Program (INCODEV/Project 015374). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.