| schistosome infection rates in field snails: schistosoma mansoni in biomphalaria pfeifferi from kenya. | six collections of biomphalaria pfeifferi were made in the nairobi and machakos areas of kenya. individual cercarial shedding (method a) showed that 6.9% (65/938) of the snails had mature 'patent' schistosoma mansoni infections (range 3.1--34% in the six collections). crushing (method b) about one-third of the remaining snails detected no additional mature infections but yielded 1.4% (four snails from one collection) with secondary sporocysts from immature 'prepatent' infections. weekly shedding ... | 1979 | 496488 |