Patterns of migration and risks associated with leprosy among migrants in Maranhão, Brazil

PLoS Negl Trop Dis. 2013 Sep 5;7(9):e2422. doi: 10.1371/journal.pntd.0002422. eCollection 2013.

Abstract

Leprosy remains a public health problem in Brazil with new case incidence exceeding World Health Organization (WHO) goals in endemic clusters throughout the country. Migration can facilitate movement of disease between endemic and non-endemic areas, and has been considered a possible factor in continued leprosy incidence in Brazil. A study was conducted to investigate migration as a risk factor for leprosy. The study had three aims: (1) examine past five year migration as a risk factor for leprosy, (2) describe and compare geographic and temporal patterns of migration among past 5-year migrants with leprosy and a control group, and (3) examine social determinants of health associated with leprosy among past 5-year migrants. The study implemented a matched case-control design and analysis comparing individuals newly diagnosed with leprosy (n = 340) and a clinically unapparent control group (n = 340) without clinical signs of leprosy, matched for age, sex and location in four endemic municipalities in the state of Maranhão, northeastern Brazil. Fishers exact test was used to conduct bivariate analyses. A multivariate logistic regression analysis was employed to control for possible confounding variables. Eighty cases (23.5%) migrated 5-years prior to diagnosis, and 55 controls (16.2%) migrated 5-years prior to the corresponding case diagnosis. Past 5 year migration was found to be associated with leprosy (OR: 1.59; 95% CI 1.07-2.38; p = 0.02), and remained significantly associated with leprosy after controlling for leprosy contact in the family, household, and family/household contact. Poverty, as well as leprosy contact in the family, household and other leprosy contact, was associated with leprosy among past 5-year migrants in the bivariate analysis. Alcohol consumption was also associated with leprosy, a relevant risk factor in susceptibility to infection that should be explored in future research. Our findings provide insight into patterns of migration to localize focused control efforts in endemic areas with high population mobility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Brazil / epidemiology
  • Case-Control Studies
  • Female
  • Humans
  • Leprosy / epidemiology*
  • Male
  • Middle Aged
  • Risk Factors
  • Transients and Migrants*
  • Young Adult

Grants and funding

This research was co-financed by the Brazilian Research Council (CNPq, http://www.cnpq.br/) and the Department of Science and Technology of the Brazilian Ministry of Health (DECIT, http://portal.saude.gov.br/portal/saude/profissional/visualizar_texto.cfm?idtxt=29045&janela=1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.