Activity of commerical fasciolicides in small laboratory mammals

The activity is reported of 6 commerical fasciolicides and disophenol administered at doses of effective in sheep, against 6- and 12-week-old Fasciola hepatica in rats and rabbits and 6-week-old flukes in guinea pigs. Tests in rats and rabbits do not give a reliable indication of the activity of fasciolicides in sheep, but results with guinea pigs were closer to those in sheep. A comparison of the effective dose in rats and sheep indicates that tests in rats usually underestimate activity in sheep. The use of a simple egg count procedure in sheep to provide information on potential fasciolicides is described.

Enzyme electrophoresis and speciation of Schistosoma intermediate hosts

1. Enzyme electrophoretic patterns from populations of snails, intermediate hosts of Schistosoma, have been examined.

2. Esterase patterns (α-naphthyl butyrate as substrate) have been used to differentiate snail populations of B. africanus and Biomph. pfeifferi.

3. Malate, β-hydroxybutyrate and α-glycerophosphate dehydrogenases may be of use in some cases to distinguish between species, e.g. B. africanus v. B. ugandae and Biomph. sudanica v. Biomph. pfeifferi.

Testes number in East African Schistosoma mansoni

One of the morphological features that has been considered of diagnostic value in distinguishing between different strains of Schistosoma spp. is the number of testes in the male worm. Hsu and Hsu (1957) demonstrated differences in testes number between different strains of Schistosoma japonicum, and Saoud (1966) subsequently showed differences between Schistosoma mansoni from Mwanza and S. mansoni from Egypt and Puerto Rico. Significant differences in testes numbers occurred between S. mansoni from Egypt and Wellcome strains if the worms were reared in hamsters, but not if they were reared in mice (Saoud, 1966).