Hostname: page-component-7479d7b7d-k7p5g Total loading time: 0 Render date: 2024-07-09T15:34:22.186Z Has data issue: false hasContentIssue false
  • English
  • Français

Shell Abnormalities in Biomphalaria glabrata Infected with Schistosoma mansoni and their Significance in Field Transmission Studies

Published online by Cambridge University Press:  05 June 2009

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

Extract

1. A distortion of the shell aperture of Biomphalaria glabrata infected with Schistosoma mansoni reported in earlier work was found to be due to a reversal from ventral to dorsal of the deflection found in uninfected snails.

2. The most sensitive way of measuring this distortion was to record the height of the dorsal deflection. The difference in this figure from uninfected and infected snails of the same diameter is termed the relative distortion.

3. A longitudinal study showed that the relative distortion first appeared at about the time when cercarial shedding started, and that it increased in size linearly as the infection progressed.

4. Temperatures between 20 and 30°C. controlled the length of the prepatent period and thus the first appearance of the relative distortion, but they did not significantly alter its subsequent rate of development.

5. Histological changes were observed in the mantle collar in the region where the relative distortion was most pronounced.

6. Possible mechanisms causing the development of the distortion are discussed.

7. Relative distortions were observed in some naturally infected field snails and the laboratory results were used to estimate how long these snails had been shedding cercariae.

8. Naturally infected St. Lucian snails appeared to have shed cercariae for an average of less than three weeks in the field.

9. A survival curve was drawn up for one collection of field snails, based on the frequency among them of relative distortions of different sizes. Another curve was obtained from an independent technique. The similarity of the two curves gives confidence in both methods.

10. The findings in St. Lucia are discussed in relation to similar studies elsewhere in the world.

Type
Research Article
Information
Journal of Helminthology , Volume 45 , Issue 2-3 , June 1971 , pp. 201 - 210
Copyright
Copyright © Cambridge University Press 1971

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

Barbosa, F.S., 1963.—“Survival in the field of Australorbis glabrata infected with Schistosoma mansoni.” J. Parasit., 49, 149.Google Scholar
Chu, K.Y., and Dawood, I.K., 1970.—“Cercarial transmission seasons of Schistosoma mansoni in the Nile delta.” Bull. Wld Hlth Org., 42, 575.Google ScholarPubMed
Foster, R., 1964.—“The effect of temperature on the development of Schistosoma mansoni Sambon, 1907 in the intermediate host.” J. trop. Med. Hyg., 67, 289.Google Scholar
Grieg-Smith, P., 1964.—Quantitative plant ecology. London, Butterworths.Google Scholar
Pan, C-T., 1958.—“The general histology and topographic microanatomy of Australorbis glabratus.” Bull. Mus. comp. Anat., 119, 237.Google Scholar
Pan, C-T., 1963.—“Generalised and focal tissue responses in the snail Australorbis glabratus infected with Schistosoma mansoni.” Ann. N.Y. Acad. Sci., 113, 475.CrossRefGoogle ScholarPubMed
Pan, C-T., 1965.—“Studies on the host-parasite relationship between Schistosoma mansoni and the snail Australorbis glabratus.” Amer. J. trop. Med. Hyg., 14, 931.CrossRefGoogle ScholarPubMed
Slobodkin, L.B., 1961.—Growth and regulation of animal populations. Holt, Rinehart and Winston, Inc., New York, U.S.A.Google Scholar
Snedecor, W.G., and Cochran, W.G., 1967.—Statistical Methods. The Iowa State University Press, Ames, Iowa, U.S.A.Google Scholar
Sturrock, R.F., 1963.—“Observations on the use of Trichostrongylus colubriformis (Nematoda) infections of guineapigs for laboratory experiments.” Parasitology, 53, 189.Google Scholar
Sturrock, R.F., 1965.—“Studies on the biology of Biomphalaria angulosa MandahlBarth and on its ability to act as an intermediate host for Schistosoma mansoni.” Ann. trop. Med. Parasit., 59, I.CrossRefGoogle ScholarPubMed
Sturrock, B.M., and Sturrock, R.F., 1970.—“Laboratory studies of the hostparasite relationship of Schistosoma mansoni and Biomphalaria glabrata from St. Lucia, West Indies.” Ann. trop. Med. Parasit., 64, 357.CrossRefGoogle ScholarPubMed
Sturrock, R.F., and Webbe, G., 1971.—“The application of catalytic models to schistosomiasis in snails.” J. Helminth., 45.CrossRefGoogle ScholarPubMed