Experimental Infection of Bulinus truncatus with Schistosoma haematobium

Abstract

Methods of maintaining and feeding B. truncatus under laboratory conditions are outlined and discussed. Preliminary attempts to infect B. truncatus with S. haematobium yielded poor results. The exposure procedures, no. of miracidia and age of the snails exposed were varied. A compilation of data obtained from 3 yrs. experience of attempting to produce laboratory infections in the snails showed a total of 507 snails exposed; 178 of these snails or 35.1% survived for at least 45 days and only 18 or 10.1% of the surviving snails shed cercariae. The present study is concerned with the relationships of the age of the snails to their susceptibility to infection. Methods of exposing and maintaining very young snails are given. A total of 398 snails 1-7 days of age were exposed to 5-10 miracidia each; 317 or 79.6% of these snails survived for at least 43 days and 160 or 50.4% of the surviving snaiis shed cercariae. An avg. of 39 days elapsed from exposure to first shedding. A total of 389 snails from 1.5-5 weeks of age were exposed to 10 miracidia each; 312 or 80.2% of these snails survived at least 46 days and 62 or 19.8% of the surviving snails shed cercariae. An avg. of 41 days elapsed from exposure to first shedding.