Unsusceptibility of Biomphalaria occidentalis to infection with a strain of Schistosoma mansoni

Abstract

Susceptibility experiments with 1582 specimens of Biomphalaria occidentalis, 3-6 mm in shell diameter, from 10 localities of the states of Mato Groso, Mato Grosso do Sul, Paraná and São Paulo, exposed individually to 5 miracidia of Schistosoma mansoni (SJ2 strain), gave negative results. B. tenagophila from Joinville (Santa Catarina) and Taubaté (São Paulo), used as controls, showed infection rates of 17.9% and 14.8%, respectively. Experiments with other strains of S. mansoni are in progress. If the present results are confirmed, expansion of schistosomiasis toward far-western Brazil through the agency of B. occidentalis becomes less probable.<br>Experiências de suscetibilidade com 1582 espécimes de Biomphalaria occidentalis, medindo 3-6 mm de diâmetro, de 10 localidades dos Estados de Mato Grosso, Mato Grosso do Sul, Paraná e São Paulo, expostos individualmente a cinco miracídios de Schistosoma mansoni (cepa S12), deram resultados negativos. Como controles foram usados exemplares de B. tenagophila de Joinville (Santa Catarina) e Taubaté (São Paulo), apresentaram índices de infecção de 17.9% e 14.8%, respectivamente. Estão em andamento experiências com outras cepas de S. mansoni. Se os resultados atuais forem confirmados, torna-se menos provável uma contribuição da B. occidentalis para a expansão da xistosomose em direção ao extremo oeste do Brasil

Susceptibility of Biomphalaria amazonica and Biomphalaria occidentalis from Manso Dam, Mato Grosso, Brazil to infection with three strains of Schistosoma mansoni

“…However, these results pointed to the possibility of introduction of schistosomiasis mansoni into the Amazonian region, where this species is widespread. As for B. occidentalis, the results of experiments realized (Paraense & Corrêa 1982, Coimbra Jr & Engel 1982 revealed unsusceptibility of this species to strains of S. mansoni from the states of São Paulo and Pernambuco. These authors however pointed out the need of additional studies with other strains of the parasite.…”

“…Paraense and Corrêa (1982) demonstrated unsusceptibility of B. occidentalis to infection with SJ S. mansoni strain, using 1582 specimens from ten localities of the states of Mato Grosso, Mato Grosso do Sul, Paraná, and São Paulo. Similarly, Coimbra Jr. and Engel (1982) did not get infection in the two samples analyzed (Acre and Mato Grosso) after experimental exposition to the PE and SP S. mansoni strains; both strains were established in the Centro de Pesquisas René-Rachou, Minas Gerais: the first was isolated from Pernambuco and the second, similarly to SJ strain used in the present study, from the municipality of São José dos Campos.…”

Potential for shistosomiasis in a municipality of Rondônia, Brazilian Amazon

“…However, B. amazonica and B. occidentalis, which had been identified in the State of Rondônia by Paraense and Corrêa (1982), Coimbra Jr et al (1984), Coimbra Jr. and Santos (1986 were identified. The sites where these species were found possessed ecological conditions suitable for their development, including a favorable pH (6-7), sufficient aquatic vegetation, and a muddy substrate and with little or no water current (Coimbra Jr. and Santos 1986).…”

Malacological survey of Biomphalaria snails in municipalities along the Estrada Real in the southeast of the State of Minas Gerais, Brazil

“…In the southern region, between the rivers Grande and Preto, belonging to the Rio Grande and to the Rio Paraíba do Sul water basins, respectively, there are various collection dots for B. peregrina, but only one positive dot for B. tenagophila (Figure 1). [22][23][24][25][26] . B. tenagophila was present in 47.2% of the municipalities surveyed, B. glabrata in 33.3% and B. straminea in 8.3%.…”