Evaluation of Chemical and Physical-morphological Factors as Potential Determinants of Biomphalaria pfeifferi (Krauss, 1848) Distribution

Memórias do Instituto Oswaldo Cruz

Jürg Utzinger¹  Charles Mayombana¹  Konstanze Mez¹  Marcel Tanner¹ 

关键词: Biomphalaria pfeifferi;    physical-morphological factors;    schistosomiasis;    Tanzania;    water chemistry;   

DOI  :  10.1590/S0074-02761997000300004

来源: SciELO

【 摘 要 】

This study was carried out in five sites along a small perennial river system in south-central Tanzania, which had been identified as the focus for transmission of intestinal schistosomiasis in the area. Malacological surveys preceding the study showed a focal distribution of Biomphalaria pfeifferi, intermediate host snail of Schistosoma mansoni, the snails being present in three sites but absent from the other two sites. The objective of this study was to evaluate to what extent chemical and/or physical-morphological factors determine the distribution of B. pfeifferi between these five sites.It was found that none of the chemical constituents in the waters examined were outside the tolerance range of B. pfeifferi snails. Moreover, the composition of water from B. pfeifferi-free sites was not different from that in those sites where snails occurred. Furthermore, none of the physical-morphological constituents seemed likely to be a determinant for the absence of B. pfeifferi.In view of these findings, and those of previous studies, it is concluded that the focal distribution of B. pfeifferi cannot be associated with a single environmental factor and is rather the result of more complex interactions of habitat factors

【 授权许可】

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