title: Human migration, railways and the geographic distribution of leprosy in Rio Grande do Norte State--Brazil.
abstract: BACKGROUND
  Leprosy is a public health problem in Brazil where 31,044 new cases were detected in 2013. Rio Grande do Norte is a small Brazilian state with a rate of leprosy lower than other areas in the same region, for unknown reasons.
  
  
  OBJECTIVE
  We present here a review based on the analysis of a database of registered leprosy cases in Rio Grande do Norte state, comparing leprosy's geographic distribution among municipalities with local socio-economic and public health indicators and with historical documents about human migration in this Brazilian region.
  
  
  RESULTS
  The current distribution of leprosy in Rio Grande do Norte did not show correlation with socio-economic or public health indicators at the municipal level, but it appears related to economically emerging municipalities 100 years ago, with spread facilitated by railroads and train stations. Drought-related migratory movements which occurred from this state to leprosy endemic areas within the same period may be involved in the introduction of leprosy and with its present distribution within Rio Grande do Norte.
  
  
  CONCLUSIONS
  Leprosy may disseminate slowly, over many decades in certain circumstances, such as in small cities with few cases. This is a very unusual situation currently and a unique opportunity for epidemiologic studies of leprosy as an emerging disease.
authors.forename: Mauricio Lisboa
authors.initials: ML
authors.lastname: Nobre
authors.forename: Kathryn Margaret
authors.initials: KM
authors.lastname: Dupnik
authors.forename: Paulo José Lisboa
authors.initials: PJ
authors.lastname: Nobre
authors.forename: Márcia Célia
authors.initials: MC
authors.lastname: Freitas De Souza
authors.forename: Nádia Cristina
authors.initials: NC
authors.lastname: Dűppre
authors.forename: Euzenir Nunes
authors.initials: EN
authors.lastname: Sarno
authors.forename: Selma Maria Bezerra
authors.initials: SM
authors.lastname: Jerŏnimo
mesh_terms: D001938:Brazil / Q000453:epidemiology; D063426:Human Migration; D006801:Humans; D007918:Leprosy / Q000453:epidemiology* / Q000635:transmission; D011634:Public Health; D014195:Travel