[Hansen's disease, social conditions, and deforestation in the Brazilian Amazon].

OBJECTIVE: To analyze the association between social and environmental indicators and the Hansen's disease new case detection rate (HNCDR) in the Brazilian Amazon.

METHODS: This ecological study was based on the new cases of Hansen's disease reported to the Brazilian Disease Surveillance System SINAN in 2006. Analyses were performed considering 105 micro-regions formed by adjacent municipalities with economic and social similarities. HNCDRs per 10 000 people were calculated. Independent variables were total area deforested (km(2)) in each micro-region until 2006; proportion of people living in households with rudimentary septic tanks; proportion of people living in households with water supply from wells; and human development index (HDI) in 2000. Local empirical Bayes smoothing was applied to HNCDR. Analyses were carried out to determined correlations and differences between means (analysis of variance) for a significance level of 5%. The Kernel technique was used to investigate the geographic distribution of events of interest for all the study indicators.

RESULTS: A positive correlation was observed between HNCDR and total deforested area (r = 0.50; P < 0.000) and percent of households with rudimentary septic tanks (r = 0.49; P < 0.000). HDI was inversely correlated with HNCDR: the higher the HDI, the lower the HNCDR (r = -0.36; P < 0.000). Considering the entire region, proportion of households with water from wells was not associated with NCDR.

CONCLUSIONS: The Hansen's disease new case detection rate, which reflects the magnitude of disease, is associated with social conditions and land settlement practices in the Brazilian Amazon.