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Studies on the effects of cercarial concentration and length of exposure on the infection of mice by St Lucian Schistosoma mansoni cercariae in a natural running-water habitat

Published online by Cambridge University Press:  06 April 2009

Edward Suchart Upatham
Edward Suchart Upatham
Affiliation:
Research and Control Department, Castries, St Lucia, West Indies
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Extract

The effects of cercarial concentration and length of exposure on the infection of mice by St Lucian Schistosoma mansoni cercariae were investigated in a running-water habitat.

For all exposure times, mice exposed to cercarial concentrations from 2·5 to 40 cercariae per mouse acquired no infections. At higher concentrations, infection rates and worm burdens of mice increased in direct proportion to cercarial concentrations and exposure times. The highest infection rate (57·9 %) and worm burden (46 worms) were obtained in mice exposed for 256 mm to 1280 cercariae per mouse.

Cercarial concentrations are low in St Lucian running waters, a fact suggesting that the risk of persons becoming infected while fording, collecting domestic water, washing clothes and swimming in habitats with reasonable flows is very low. It appears that most infected individuals acquire a low worm burden over a rather long period of time.

Type
Research Article
Information
Parasitology , Volume 68 , Issue 2 , April 1974 , pp. 155 - 159
Copyright
Copyright © Cambridge University Press 1974

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References

REFERENCES

Crossland, N. O. (1967). Field trials to evaluate the effectiveness of the molluscicide N. tritylmorpholine in irrigation systems. Bulletin of the World Health Organization 37, 23–42.Google ScholarPubMed
Radke, M. G., Ritchie, L. S. & Rowan, W. B. (1961). Effects of water velocities on worm burdens of animals exposed to Schistosoma mansoni cercariae released under laboratory and field conditions. Experimental Parasitology 11, 323–31.CrossRefGoogle ScholarPubMed
Radke, M. G., Berrios-Duran, L. A. & Moran, K. (1961). A perfusion procedure (Perf-O-Suction) for recovery of schistosome worms. Journal of Parasitology 47, 366–8.CrossRefGoogle ScholarPubMed
Sandt, D. G. (1973). Direct filtration for recovery of Schistosoma mansoni cercariae in the field. Bulletin of the World Health Organization 48, 27–34.Google ScholarPubMed
Smithers, S. R. & Terry, R. J. (1965). The infection of laboratory hosts with cercariae of Schistosoma mansoni and the recovery of the adult worms. Parasitology 55, 695–700.CrossRefGoogle ScholarPubMed
Upatham, E. S. (1972). Exposure of caged Biomphalaria glabrata (Say) to investigate dispersion of miracidia of Schistosoma mansoni Sambon in simulated field and field habitats in St Lucia, West Indies. Journal of Helminthology 46, 297–306.CrossRefGoogle Scholar
Upatham, E. S. (1974 a). Dispersion of St Lucian Schistosoma mansoni cercariae in natural standing and running waters determined by cercariometry and mouse exposure. Annals of Tropical Medicine and Parasitology (in the Press).CrossRefGoogle Scholar
Upatham, E. S. (1974 b). Infectivity of Schistosoma mansoni cercariae in natural St Lucian habitats. Annals of Tropical Medicine and Parasitology (in the Press).CrossRefGoogle Scholar
Upatham, E. S. & Sturrock, R. F. (1973). Studies on the effects of cercarial concentration and length of exposure on the infection of mice by Schistosoma mansoni cercariae. Parasitology 67, 219–28.CrossRefGoogle Scholar
Warren, K. S. (1973). Regulation of the prevalence and intensity of schistosomiasis in man: immunology or ecology? Journal of Infectious Diseases 127, 595–609.CrossRefGoogle ScholarPubMed
Webbe, G. (1965). Transmission of bilharziasis. 2. Production of cercariae. Bulletin of the World Health Organization 33, 155–62.Google ScholarPubMed
Webbe, G. (1966). The effect of water velocities on the infection of animals exposed to Schistosoma mansoni cercariae. Annals of Tropical Medicine and Parasitology 60, 78–84.CrossRefGoogle ScholarPubMed