Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-24T12:24:15.503Z Has data issue: false hasContentIssue false
  • English
  • Français

Studies on the effects of cercarial concentration and length of exposure on the infection of mice by Schistosoma mansoni

Published online by Cambridge University Press:  06 April 2009

E. S. Upatham  and
R. F. Sturrock
E. S. Upatham
Affiliation:
Research and Control Department, Castries, St Lucia, West Indies
R. F. Sturrock
Affiliation:
Research and Control Department, Castries, St Lucia, West Indies
Get access Rights & Permissions [Opens in a new window]

Extract

Groups of mice were exposed to Schistosoma mansoni cercariae in a large volume of water. A factorial design was used to investigate the effects of cercarial concentration and length of exposure on infection rates and worm burdens. Low exposure times and cercarial concentrations gave no infections, but prolonged exposure to high concentrations gave high infection rates and worm burdens. Prolonged exposure to low concentrations gave low worm burdens and moderate infection rates: short exposure to high concentrations gave moderate infection rates and worm burdens. Statistical analysis showed that both infection rates and mean worm burdens were significantly related to the two main factors, but the relationship was complicated in each case by curvilinear effects and by a significant interaction between the main factors. Field cercarial concentrations are generally low on St Lucia, a fact suggesting that brief human water contacts, such as fording and filling domestic water containers, play little part in transmission. Prolonged contact during swimming, bathing and washing clothes may produce significant infection rates accompanied by low worm burdens. However, on the rare occasions when high cercarial concentrations occur, even the briefest exposure may produce significant infection rates and moderate worm burdens.

Type
Research Article
Information
Parasitology , Volume 67 , Issue 2 , October 1973 , pp. 219 - 228
Copyright
Copyright © Cambridge University Press 1973

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Cook, J. A, Warren, K. S., & Jordan, P., (1972). Passive transfer of immunity in human schistosomiasis mansoni: attempt to prevent infection by repeated injections of hyperimmune antischistosome gamma globulin. Transactions of the Royal Society of Tropical Medicine and Hygiene 66, 777–80.CrossRefGoogle ScholarPubMed
Radke, M. G., Berrios-Duban, L. A., & Moran, K., (1961). A perfusion procedure (Perf-OSuction) for recovery of schistosome worms. Journal of Parasitology 47, 366–8.CrossRefGoogle ScholarPubMed
Rowan, W. B., (1958). Daily periodicity of Schistosoma mansoni cercariae in Puerto Rican waters. American Journal of Tropical Medicine and Hygiene 7, 374–81.CrossRefGoogle ScholarPubMed
Sandt, D. G., (1973). Direct filtration for recovery of Schistosoma mansoni cercariae in the field. Bulletin of the World Health Organization (in the Press).Google ScholarPubMed
Smithers, S. R., & Terry, R. J., (1965). The infection of laboratory hosts with the cercariae of Schistosoma mansoni and the recovery of adult worms. Parasitology 55, 695–700.CrossRefGoogle ScholarPubMed
Snedecor, G. W., & Cochran, W. G., (1967). Statistical Methods. Ames: The Iowa State University Press.Google Scholar
Stirewalt, M. A., (1953). The influence of previous infection of mice with Schistosoma mansoni on a challenging infection with the homologous parasite. American Journal of Tropical Medicine and Hygiene 2, 867–82.CrossRefGoogle ScholarPubMed
Stirewalt, M. A., (1956). Penetration of host skin by cercariae of Schistosoma mansoni. I. Observed entry into skin of mouse, hamster, rat, monkey and man. Journal of Parasitology 42, 565–80.CrossRefGoogle Scholar
Sturrock, R. F., (1973). Field studies on the transmission of Schistosoma mansoni Sambon by the snail Biomphalaria glabrata (Say) on the West Indian island of St Lucia. International Journal of Parasitology 3, 175–94.CrossRefGoogle Scholar
Upatham, E. S., (1972 a). Exposure of caged Biomphalaria glabrata (Say) to investigate dispersion of miracidia of Schistosoma mansoni Sambon in outdoor habitats in St Lucia. Journal of Helminthology 46, 297–306.CrossRefGoogle ScholarPubMed
Upatham, E. S., (1972 b). The effects of some physico-chemical factors on the infection of Biomphalaria glabrata (Say) by miracidia of Schistosoma mansoni Sambon in St Lucia, West Indies. Journal of Helminthology 46, 307–15.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
Warren, K. S., & Peters, P. A., (1967). Quantitative aspects of exposure time and cercarial dispersion on penetration and maturation of Schistosoma mansoni in mice. Annals of Tropical Medicine and Parasitology 61, 294–300.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