22 research outputs found
Assessment of control and epidemiologic details of the schistosomiasis mansoni in Bananal, SĂŁo Paulo, Brazil
Schistosomiasis mansoni in Bananal (State of SĂŁo Paulo, Brazil): I. Efficiency of diagnostic and treatment procedures
A taxonomic bibliography of the South American snakes of the Crotalus durissus complex (Serpentes, Viperidae)
Schistosomiasis mansoni in Bananal (State of SĂŁo Paulo, Brazil): II. Intermediate hosts
We conducted monthly snail captures in Bananal, State of SĂŁo Paulo, Brazil, between March 1998 and February 2001, to identify Schistosoma mansoni vectors, estimate seasonal population changes, and delimit foci. We also evaluated the impact of improvements in city water supply and basic sanitation facilities. We identified 28,651 vector specimens, 28,438 as Biomphalaria tenagophila, 49 of them (0.2%) infected with S. mansoni, and 213 as B. straminea, none of the latter infected. Vectors predominated in water bodies having some vegetation along their banks. Neither population density nor local vegetation could be linked to vector infection. We found the first infected snails in 1998 (from March to May). Further captures of infected snails ocurred, without exception, from July to December, when rainfall was least. Irrespective of season, overall temperature ranged from 16.5ÂșC to 21ÂșC; pH values, from 6.0 to 6.8. Neither factor was associated with snail population density. Frequent contact of people with the river result from wading across it, extracting sand from its bottom, fishing, washing animals, etc. Despite a marked reduction in contamination, cercaria shedding persists. Whatever the location along its urban course, contact with river Bananal, particularly of the unprotected skin, entails risks of infection