Socioeconomic, environmental, and behavioural risk factors for leprosy in North-east Brazil: results of a case-control study.
BACKGROUND
Brazil reports almost 80% of all leprosy cases in the Americas. This study aimed to identify socioeconomic, environmental, and behavioural factors associated with risk of leprosy occurrence in the endemic North-eastern region.


METHODS
A case-control study in four municipalities.


METHODS
cases of leprosy diagnosed in the previous 2 years, with no other known, current, or past case of leprosy in the household or in the neighbourhood.


METHODS
individuals presenting for reasons other than skin problems to the health unit where the case was diagnosed and who lived in the same municipality as the case with whom it was matched. For each case four controls were selected. A semi-structured questionnaire was used to collect demographic, socioeconomic, environmental, and behavioural data. A multivariate hierarchical analysis was performed according to a previously defined framework.


RESULTS
226 cases and 857 controls were examined. Low education level, ever having experienced food shortage, bathing weekly in open water bodies (creek, river and/or lake) 10 years previously, and a low frequency of changing bed linen or hammock (>or=biweekly) currently were all significantly associated with leprosy. Having a BCG vaccination scar was found to be a highly significant protective factor.


CONCLUSIONS
Except for BCG vaccination, variables that remained significant in the hierarchical analysis are cultural or linked to poverty. They may act on different levels of the transmission of Mycobacterium leprae and/or the progress from infection to disease. These findings give credit to the hypothesis that person-to-person is not the only form of M. leprae transmission, and that indirect transmission might occur, and other reservoirs should exist outside the human body.
Kerr-Pontes
Ligia R S
LR
Departamento de Saúde Comunitária, Faculdade de Medicina, Universidade Federal do Ceará, R: Prof. Costa Mendes, 1608-5o Andar, CEP 60431-140 Fortaleza, CE, Brazil. ligia@ufc.br
Barreto
Maurício L
ML
Evangelista
Clara M N
CM
Rodrigues
Laura C
LC
Heukelbach
Jorg
J
Feldmeier
Hermann
H
D000328:Adult; D000368:Aged; D001512:Bedding and Linens; D001938:Brazil; D016022:Case-Control Studies; D004197:Disease Reservoirs; D004522:Educational Status; D005260:Female; D005508:Food Deprivation; D006801:Humans; D006920:Hygiene; D007918:Leprosy / Q000209:etiology* / Q000635:transmission; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009163:Mycobacterium bovis; D009166:Mycobacterium leprae; D016017:Odds Ratio; D012111:Residence Characteristics; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors