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The Effect of Sublethal Doses of the Molluscicide (N-tritylmorpholine) on the Development of Schistosoma mansoni in Biomphalaria glabrata (Say)

Published online by Cambridge University Press:  18 November 2009

J. Massoud
Affiliation:
London School of Hygiene and Tropical Medicine
G. Webbe
Affiliation:
London School of Hygiene and Tropical Medicine

Extract

1. The effects of a sublethal concentration (0·0165 p.p.m.) of N-tritylmorpholine on the development of S. mansoni in B. glabrata are described.

2. A total of 160 snails were infected with S. mansoni and then divided into 4 groups. Each group was treated separately with N-tritylmorpholine for a period of 24 hours.

3. The first group was treated 10 days after infection (early prepatent stage); the second group 20 days after infection (late prepatent stage); the third group 42 days after infection (patent stage); and the fourth group was left untreated and kept as an infected but untreated control group.

4. Three groups of uninfected snails were treated simultaneously with the infected groups, and a fourth uninfected group was left untreated and maintained as an uninfected and untreated control group.

5. In the early and late prepatent groups treated with N-tritylmorpholine a relatively short incubation period was observed compared with those in the patent and untreated infected groups.

6. No significant difference was observed between the cercarial infection rates of the 4 infected groups of snails (x2 = 0·744; p > 0·5).

7. In all infected groups peak cercarial production was observed about 15–20 days after the emergence of cercariae was first noted, after which numbers declined. No significant difference was observed between the total cercarial production of the early prepatent, late prepatent or patent groups and that of the untreated infected control group (p > 0·4).

8. The mortality rate of snails in the patent group was significantly higher than in the corresponding uninfected control group (x2 = 6·04; p <0·02).

9. Treated infected snails in all three groups ultimately had a lower survival rate than did treated uninfected snails.

10. The survival rate of untreated infected snails while initially as good as that of the untreated and uninfected group, was ultimately much poorer.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1969

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References

Boyce, C. B. C., Tieze-Dagevos, J. W. and Larman, V. N., 1967.—“The susceptibility of B. glabrata, through its life-history to N-tritylmorpholine.” Bull. Wld Hlth Org., 37, 1321.Google Scholar
Boyce, C. B. C., Tyssul Jones, T. W. and Van Tongeren, A., 1967.—“The molluscicidal activity of N-tritylmorpholine.” Bull. Wld Hlth Org., 37, 111.Google ScholarPubMed
Boyce, C. B. C., and Williams, D. A., 1967.—“The influence of exposure time on the susceptibility of B. glabrata to N-tritylmorpholine.” Ann. trop. Med. Parasit., 61, 1520.Google Scholar
Chernin, E., 1964.—“Maintenance in vitro of larval Schistosoma mansoni in tissues from the snail Australorbis glabratus.” J. Parasit., 50, 531545.CrossRefGoogle ScholarPubMed
Chu, K. Y., Sabbaghian, H. and Massoud, J., 1966.—“Host-parasite relationship of Bulinus truncatus and S. haematobium in Iran. 2. Effect of exposure dosage of miracidia on the biology of the snail host and the development of the parasites.” Bull. Wld Hlth Org., 34, 121130.Google ScholarPubMed
Claugher, D., 1960.—“The transport and laboratory culture of snail intermediate hosts of S. haematobium.” Ann. trop. Med. Parasit., 54, 333337.Google Scholar
Crossland, N. O., 1967.—“Field trials to evaluate the effectiveness of the molluscicide N-tritylmorpholine in irrigation systems.” Bull Wld. Hlth Org., 37, 2342.Google Scholar
Etges, C. J., 1963.—“Effect of S. mansoni infection upon fecundity in Australorbis glabratus.” J. Parasit., 49, suppl. 26.Google Scholar
Hoff, D. J. and Muller, R. L., 1962.—“Laboratory breeding and testing of Australorbis glabratus for mollusciciding screening.” Bull. Wld Hlth Org., 27, 783789.Google Scholar
McClelland, W. F. J., 1965.—“The production of cercariae by S. mansoni and S. haematobium, and methods for stimulating the number of cercariae in suspension.” Bull. Wld Hlth Org., 33, 270275.Google Scholar
Paulini, E. and Pellegrino, J., 1956.—“Observaçoes sôbre a biologia do Australorbis glabratus. I. Influencia da infestacão pelo S. mansoni sôbre a susceptibilidade ao pentaclorophenato de sodio.” Revta bras. Malar. Doenç. trop., 8, 551554.Google Scholar
Paulini, E. and Pellegrino, J., 1957.—“Influence of infection with S. mansoni on the susceptibility of Australorbis glabratus to copper sulphate.” Trans. R. Soc. trop. Med. Hyg., 51, 283284.CrossRefGoogle Scholar
Schreiber, F. G. and Schubert, M., 1949 a.—“Experimental infection of the snail Australorbis glabratus with the trematode S. mansoni and the production of cercariae.” J. Parasit., 35, 91100.CrossRefGoogle Scholar
Schreiber, F. G. and Schubert, M., 1949 b.—“Result of the exposure of Australorbis glabratus to varying numbers of miracidia of S. mansoni.” J. Parasit., 35, 590592.Google Scholar
Standen, O. D., 1952.—.“Experimental infection of Australorbis glabratus with S. mansoni. I. Individual and mass infection of snails and the relationship of infection of snails and the relationship of infection to temperature and season.” Ann. trop. Med. Parasit., 46, 4853.Google Scholar
Stirewalt, M. A., 1954.—“Effect of snail maintenance temperatures on development of S. mansoni.” Expl Parasit., 3, 504516.Google Scholar
Sturrock, R. F., 1965.—“Studies on the biology of Biomphalaria angulosa (Mandahl-barth) and on its ability to act as an intermediate host of S. mansoni.” Ann. trop. Med. Parasit., 59, 116.CrossRefGoogle Scholar
Sturrock, R. F., 1966.—“The effect of sublethal doses of molluscicide (Bayluscide) on the development of S. mansoni in Biomphalaria sudanica tanganyicensis.” Bull. Wld Hlth Org., 34, 277283.Google Scholar
Warren, K. S. and Weisberger, A. S., 1966.—“Suppression of Schistosomiasis in snails by Chioramphenicol.” Nature, Lond., 209, 422423. (Correspondence).Google Scholar
Webbe, G., 1962.—“The transmission of Schistosoma haematobium in an area of Lake Province, Tanganyika.” Bull. Wld Hlth Org., 27, 5985.Google Scholar
Webbe, G., and Jordan, P., 1966.—“Recent advances in knowledge of schistosomiasis in East Africa.” Trans. R. Soc. trop. Med. Hyg., 60, 279306.Google Scholar
Webbe, G., Jordan, P., and Sturrock, R. F., 1964.—“Laboratory tests of some new molluscicides in Tanganyika.” Ann. trop. Med. Parasit., 58, 234239.CrossRefGoogle ScholarPubMed