Oogram pattern, egg load and hatchability of eggs in mixed infection of Schistosoma mansoni and Schistosoma haematobium in hamster

Laboratory bred hamsters, weight 125-185 g each, were examined in this study and classified into three groups. In the first group, 15 hamsters were exposed simultaneously to 100 cercariae of S. Mansoni and 100 cercariae of S. haematobium. Experimentally infected hamsters and their controls were scarified at 7 and 10 weeks postinfection. In the second group, 20 hamsters were exposed each to 100 cercariae of S. mansoni for 7 weeks then superinfected with 100 cercariae of S. haematobium and scarified 25 days later. Their controls were 20 hamsters exposed to 100 cercariae of S. mansoni. In the third group, 20 hamsters exposed each to 100 cercariae of S. Haematobium for 10 weeks, then superinfected each with 100 cercariae of S. Mansoni and scarified 21 days post challenge infection. Their controls infected with 100 cercariae of S. Haematobium. In mixed infection with Schistosoma mansoni and S. haematobium in hamsters, either simultaneously or after the full maturation of an initial infection with either schistosome species, a high level of acquired resistance was observed. The degree of immunity was magnified by the significant reduction in the number of eggs per gram tissue and hatchability of mature eggs. Some disturbance was also observed in the oogram pattern

Biological and morphological changes in worms in mixed infection of Schistosoma mansoni and Schistosoma in hamsters

Hamsters infected with Schistosoma mansoni and S. Haematobium either simultaneously or after the maturation of an initial infection with either schistosome species were examined to estimate the biological and morphological changes under mixed infection conditions. The results indicated a high level of acquired resistance. The degree of immunity was evidenced by the significant reduction in the worm load as well as in the size of mature worms. Some disturbance was observed in the worm distribution. The results were important for epidemiological and immunological uses as well as in the development of a vaccine from one species that might be effective against both species