Risk factors for reinvasion of human dwellings by sylvatic triatomines in northern Bahia State, Brazil Fatores de risco para re-infestação de domicílios por triatomíneos silváticos no norte do Estado da Bahia

The aim of this study in Curaça, Bahia, Northeast Brazil was to explore possible factors associated with the infestation of human dwellings by Triatoma brasiliensis or Triatoma pseudomaculata, two sylvatic triatomine species. We use multiple logistic regression analysis to show how structural features of the peridomiciliary area combine with the number of animals and sociological factors to allow infestation of some dwellings. It is suggested that T. brasiliensis is associated with human activities, while T. pseudomaculata is associated with vegetation and animals. Peridomiciliary farm animals are a strong risk factor for triatomine infestation. Triatominae; Risk Factors; Vector Control Introduction In Northeast Brazil, the main vectors for American trypanosomiasis are currently Triatoma brasiliensis and Triatoma pseudomaculata, two widely distributed native species. They are captured in domiciliary and peridomiciliary areas which they reinvade from natural ecotopes 1. The potential for re-infestation of peridomiciliary annexes is high 2. Both of these vectors lodge in corral fences, chicken coops, and piles of various materials found in and around numerous buildings in this farming and livestock area 3,4,5. However, the joint effects of peridomiciliary structural features, the number of synanthropic animals, and sociological factors on domiciliary infestation are still not well known. In order to broaden the knowledge on risk factors for peridomiciliary re-infestation by sylvatic triatomines, the objective of this study was to assess the main characteristics of dwellings (environmental, demographic, and socioeconomic factors are the independent variables) associated with T. brasiliensis or T. pseudomaculata infestation. We use multiple logistic regression analysis to investigate variations among domiciliary units in terms of the likelihood of being infested by triatomines. REINVASION OF HUMAN DWELLINGS BY TRIATOMINES 975 Cad. Saúde Pública, Rio de Janeiro, 21(3):974-978, mai-jun, 2005 Material and methods