The data about Schistosomiasis in the São Paulo State, Brazil, shows that the disease is now here at an expansive stage. To conclude by this, are the discorvery of new active foci in counties where it had been found before and its recrudescence very year producing new autochthonous case. The detection, at the beginning, of other active foci, it is very suggestive too. This was obtained by collecting naturally infected planorbids at places where no autochthonous cases was announced up […]

The occurrence of 90 Biomphalaria straminea shells displaying marked deformation in their last whorl, is reported. The referred to planorbid population originates from a strain collected, about three years ago, in Curvelo, MG (Brazil), and which has been kept in laboratory glass aquarium.

Experimental data of the developing of S. mansoni cercariae of two strains (Belo Horizonte, MG and S. José dos Campos, SP), penetrating through the tails of Mus musculus, were analysed. The data led to conclude that there is no numerical difference, in the two strains, as for development from cercariae to adult worm.

Two strains of Schistosoma mansoni (Belo Horizonte, MG and S. José dos Campos, SP, Brazil) are morphologically studied. Some numerical characteristics are found to be different between the strains. These differences are as follows: lenght, distance from the oral sucker until the ventral sucker, distance between the anterior pole of the worm and the distal part of the gonads and finally the number of testes.

The susceptibility of Biomphalaria glabrata from Ourinhos, São Paulo, to strains of Schistosoma mansoni from Belo Horizonte, Minas Gerais and S. José dos Campos, S. Paulo, was studied. It was conclude that the molluscs has a high susceptibility to both strains of Schistosoma mansoni.

Among laboratory-bred Biomphalaria glabrata, a live snail in an anomalous shell was found. The anomaly consisted in changes of level in the whorls. The specimen was isolated for a study on its biological behaviour. Afterwards, another specimen displaying a similar anomaly was joined to it. The results obtained showed their biological functions to be normal, their anomaly being of genetic character. In F1 embryos, the anomaly observed was 0.01%. In a 25-month period of investigation, 13 anomalous embryos were isolated. […]

Some effects of a sugar-rich diet and of the aloxanic diabetes in albino mice (Mus musculus) infected with Schistosoma mansoni were considered. The results showed: 1. the number of granulomata for the aloxane treated animals was significantly lower than the number for untreated animals. 2. one may, then, surmise that the aloxane treatment generates conditions that inhibits the development and oviposition of S. mansoni.

Some of the behavioral aspects of the Minas Gerais and S. Paulo states’ strains Schistosoma mansoni, concerning the penetration capability of cercariae of each strain and the relationship between hepatic granulomata and worms, were studied. The Minas Gerais’ strain cercariae present more penetration capability and the ratio between the numbers of hepatic granulomata and number of worms varied inversely with the number of infecting worms per mouse, in both strains.

Descendents of Biomphalaria tenagophila from Minas Gerais, Brazil were experimentally infected with the Schistosoma mansoni. B. glabrata from Belo Horizonte was used as control. The “LE” strain of S. mansoni used in both cases was isolated in Belo Horizonte. B. tenagophila from Itajubá was shown, for the first time, to be susceptible to the strain of S. mansoni adapted to B. glabrata from Belo Horizonte. A 3.3% infection rate was observed, i.e., 5 of the 149 specimen which survived until […]

In the region of Baldim, MG (Brazil) – a well-known Schistosoma mansoni endemic area where transmission control had already been unsuccessfully attempted through molluscicide, sanitary education and clinical treatment – 5,421 specimens of Pomacea haustrum (Prosobranchia, Pilidae) were introduced into 5 brooks and 2 ditches where Biomphalaria glabrata (primarily) and B. straminea (secondarily) predominated. From 1968 to 1971, the infection rate of B. glabrata by S. mansoni ranged from 2.1% to 11.9%. None of the B. straminea specimens collected, however, […]