Preliminary report on the possibility of utilizing competition of larval schistosomes and other larval trematodes in the intermediate hosts for the biological control of schistosomiasis
Rysavý, B.; Ergens, R.; Groschaft, J.; Moravec, F.; Yousif, F.; el-Hassan, A.A.
Folia Parasitologica 20(4): 293-296
1973
ISSN/ISBN: 0015-5683 PMID: 4777759 Document Number: 68619
Cercariae and rediae of Echinostoma revolutum were found in 0.5 to 40% of snails examined along the Nile in Egypt; metacercariae were detected in Biomphalaria alexandrina, Bulinus truncatus, Physa acuta, Viviparus unicolor, and in the kidney of Rana esculenta. Cercariae and rediae of Echinoparyphium bioccalerouxi were also found in up to 60% of B. truncatus examined; metacercariae were found in B. truncatus, Biomphalaria alexandrina, P. acuta, Lanistes botteni, Cleopatra sp., Bithynia sp., Lymnaea caulliaudi and V. unicolor. Echinostomatid larvae were also found in Biomphalaria alexandrina from one locality. Feeding experiments showed that the first 2 trematodes developed well in domestic ducks, chickens, mice and rats; the 3rd trematode appears to be associated with wild water-birds. Preliminary studies of larval competition suggested that Echinostoma revolutum were antagonistic to Schistosoma mansoni in B. alexandrina and Echinoparyphium bioccalerouxi to S. haematobium in Bulinus truncatus. It is suggested that ducks may be suitable as definitive hosts for both these trematodes in the biological control of Schistosoma.r.