Geographical distribution of snakes of medical importance and snakebites in São Paulo and Paraná States

FAN, H.W.(1), SANT’ANNA, S.S.(1), MÁLAQUE, C.M.S.(1), RÚBIO, G.B.G.(2), DA SILVA, E.M.(3), LEITE, J.C.M.(4), ALBUQUERQUE, M.J.(5), FRANCO, F.L.(1), FURTADO, M.F.(1), FERNANDES, W.(1), FRANÇA, F.O.S.(1), CARDOSO, J.L.C.(1)

(1)Instituto Butantan, SES/SP, (2)Centro de Saúde Ambiental, SES/PR, (3)Centro de Produção e Pesquisa em Imunológicos, SES/PR, (4)Museu de História Natural “Capão da Imbúia”, Secretaria Municipal do Meio Ambiente, Curitiba, (5)SES/SP.

Distribution of snakebites and poisonous snakes are influenced by vegetation cover, modified in consequence of agricultural occupation that changed the natural landscape. The objective of this study was to analyze altogether the geographical distribution of snakebites, poisonous snakes and environmental changes. Data collection included snakebites registered in São Paulo (SP) and Paraná (PR) States between 1988 and 1997, snakes captured and maintained at Instituto Butantan (SP), Museu de História Natural (PR) and Centro de Produção e Pesquisa em Imunobiológicos (PR) herpetological collections, and secondary data from vegetation cover and percentage of agricultural occupation. Maps were obtained using a geographical information system. Bothrops jararaca showed a wide distribution in open fields, primitive and modified forest, and even in regions under anthropic influence. B. moojeni and B. neuwiedi were found predominantly in open fields. Crotalus occupied areas originally constituted by semi decidual seasoned forest and “cerrado”. Incidence of snakebites varied from 4.31 to 10.57 cases/100.000 population, decreasing through the period, both for Bothrops(88%) and Crotalus (11%). Micrurus accidents were rare. There was no correlation between municipalities where snakes occurred and nowadays vegetation cover, except for B. jararacussu in the remaining forest at Vale do Ribeira. No correlation was observed between the percentage of agricultural occupation and Bothrops snakebites, for Crotalus snakebites, a small negative correlation was observed in areas occupied by sugar cane. A decreasing tendency was observed in the number of snakebites and snakes of medical importance captured, with predominance of Bothrops. Maps of distribution of poisonous snakes and snakebites permitted a better definition of risk areas. The anthropic pressure probably had influenced the result of no correlation between areas of distribution of snakes with the vegetation cover, while some agricultural practices may had determined changes in the risk areas for snakebites.

CORRESPONDENCE TO:

WEN, F.H., Hospital Vital Brazil, Instituto Butantan, Avenida Vital Brasil, 1500, São Paulo, 05503-900, SP, Brasil, Email: fanhui@butantan.gov.br