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Observations on the effects of different chemotherapy strategies on the transmission of Schistosoma mansoni in Machakos District, Kenya, measured by long-term snail sampling and cercariometry

Published online by Cambridge University Press:  06 April 2009

R. F. Sturrock ,
R. K. Klumpp ,
J. H. Ouma ,
A. E. Butterworth ,
A. J. C. Fulford ,
H. C. Kariuki ,
F. W. Thiongo  and
D. Koech
R. F. Sturrock
Affiliation:
Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, Keppel Street (Gower Street), London WCIE 7HT, UK
R. K. Klumpp
Affiliation:
147 Laurel Street, Atherton, California 94027, USA
J. H. Ouma
Affiliation:
Division of Vector-Borne Diseases, Ministry of Health, Nairobi, Kenya
A. E. Butterworth
Affiliation:
Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
A. J. C. Fulford
Affiliation:
Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
H. C. Kariuki
Affiliation:
Division of Vector-Borne Diseases, Ministry of Health, Nairobi, Kenya
F. W. Thiongo
Affiliation:
Division of Vector-Borne Diseases, Ministry of Health, Nairobi, Kenya
D. Koech
Affiliation:
Kenyan Medical Research Institute, Nairobi, Kenya
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Summary

Transmission of Schistosoma mansoni was monitored by routine snail sampling for Biomphalaria pfeifferi and by supplementary cercariometric measurements in 4 neighbouring study areas in Machakos District, Kenya. After 1 year, extensive, population-based chemotherapy with a single dose of praziquantel was given in 3 areas, but only minimal treatment in the fourth. In the year preceding treatment, seasonal transmission of S. mansoni and other non-human trematodes occurred in all 4 areas, despite some ecological differences and the effects of earlier treatment campaigns in 1 of the study areas. After treatment of all infected subjects in one area in which there had been earlier chemotherapy campaigns, S. mansoni transmission remained very low. It was reduced for at least 2 years after chemotherapy targeted at either all heavily infected subjects or all infected school children, but it was unaffected in an area where treatment was restricted to those few very heavily infected cases at risk of developing, disease. Nowhere was transmission entirely eliminated by chemotherapy and that of non-human trematodes continued unabated. The snail data correspond well with the human, parasitological data. Targeting school children was as effective as more extensive campaigns, but chemotherapy alone never stopped S. mansoni transmission: reinfection was inevitable, at rates determined by ecological factors affecting snail populations.

Keywords

Schistosoma mansoniBiomphalaria pfeifferisnailscercariatransmissionmass chemotherapy strategies
Type
Research Article
Information
Parasitology , Volume 109 , Issue 4 , November 1994 , pp. 443 - 453
Copyright
Copyright © Cambridge University Press 1994

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References

REFERENCES

Anon (1992). Praziquantel shows unexpected failure in recent schistosomiasis outbreak. TDR-News 41, 1–2.Google Scholar
Barbosa, F. S., Costa, D. & Pessoa, P. (1982). A long-term schistosomiasis control project with molluscicide in a rural area of Brasil. Annals of Tropical Medicine and Parasitology 75, 41–52.CrossRefGoogle Scholar
Butterworth, A. E., Dalton, P. R., Dunne, D. W., Mugambi, M., Ouma, J. H., Richardson, B. A., Siongok, T. K. & Sturrock, R. F. (1984). Immunity after treatment of human schistosomiasis mansoni. I. Study design, pretreatment observations and the results of treatment. Transactions of the Royal Society of Tropical Medicine and Hygiene 78, 108–23.CrossRefGoogle ScholarPubMed
Butterworth, A. E., Capron, M., Cordingly, J. S., Dalton, P. R., Kariuki, H. C., Koech, D., Mugambi, M., Ouma, J. H., Prentice, M. A., Richardson, B. A., Siongok, T. K., Sturrock, R. F. & Taylor, D. W. (1985). Immunity after treatment of human schistosomiasis mansoni. II. Identification of resistant individuals and analysis of their immune responses. Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 393–408.CrossRefGoogle ScholarPubMed
Butterworth, A. E., Sturrock, R. F., Ouma, J. H., Mbugua, G. G., Fulford, A. J. C., Kariuki, H. C. & Koech, D. (1991). Comparison of different chemotherapy strategies against Schistosoma mansoni in Machakos District, Kenya. 1. Effects on human infection and morbidity. Parasitology 103, 339–55.CrossRefGoogle Scholar
Hairston, N. G. (1965). Statistical analysis of molluscicide field trials. Bulletin of the World Health Organization 32, 289–96.Google Scholar
Harrison, A. D. (1967). The effects of Bayluscid on gastropod snails and other aquatic fauna in Rhodesia. Hydrobiologia 32, 37–84.Google Scholar
Hoffman, D. B. (1983). Schistosomiasis: The Strategic Plan. New York: Edna McConnell Clark Foundation.Google Scholar
Jordan, P. (1985). Schistosomiasis: The St Lucia Project. Cambridge: Cambridge University Press.Google Scholar
Jordan, P. & Webbe, G. (1993). Praziquantel shows unexpected failure in recent schistosomiasis outbreak. TDR-News 42, 10.Google Scholar
Mahmoud, A. A. F., Siongok, T. K., Ouma, J. H., Houser, H. B. & Warren, K. S. (1983). Effect of targeted mass treatment on intensity and morbidity in schistosomiasis mansoni. Lancet 1, 849–51.CrossRefGoogle ScholarPubMed
Olivier, J. H. & Schneidermann, M. (1956). A method for estimating the density of aquatic snail populations. Experimental Parasitology 5, 109–17.CrossRefGoogle ScholarPubMed
Ouma, J. H., Sturrock, R. F., Klumpp, R. K. & Kariuki, H. C. (1989). A comparative evaluation of snail sampling and cercariometry to detect Schistosoma mansoni transmission in a large-scale, longitudinal field study in Machakos, Kenya. Parasitology 94, 349–55.CrossRefGoogle Scholar
Polderman, A. M. & Manshande, J. P. (1981). Failure of targeted mass chemotherapy to control schistosomiasis Lancet i, 27–8.CrossRefGoogle Scholar
Prentice, M. A. (1984). A field-evolved differential filtration method for recovery of schistosome cercariae. Annals of Tropical Medicine and Parasitology 78, 117–27.CrossRefGoogle ScholarPubMed
Prentice, M. A. & Barnish, G. (1981). Snail infestations following chemotherapy of Schistosoma mansoni in St Lucia, West Indies. Transactions of the Royal Society of Tropical Medicine and Hygiene 75, 713–14.CrossRefGoogle Scholar
Prentice, M. A. & Ouma, J. H. (1984). Field comparison of mouse immersion and cercariometry for assessing the transmission potential of water containing cercariae of Schistosoma mansoni. Annals of Tropical Medicine and Parasitology 78, 169–72.CrossRefGoogle ScholarPubMed
Ritchie, L. S., Radke, M. G. & Ferguson, F. F. (1962). Population dynamics of Australorbis glabratus in Puerto Rico. Bulletin of the World Health Organization 27, 171–81.Google ScholarPubMed
Sato, K., Shimada, M., Noda, S., Muhoho, N. D., Katsumata, T., Sato, A. & Aoka, Y. (1988). Efficacy of metrifonate in a highly endemic area of urinary schistosomiasis in Kenya. American Journal of Tropical Medicine and Hygiene 38, 81–5.CrossRefGoogle Scholar
Savioli, L., Dixon, H., Kisumu, U. M. & Mott, K. E. (1989). Control of morbidity due to Schistosoma haematobium on Pemba Island; selective population chemotherapy of school children with haematuria to identify high risk localities. Transactions of the Royal Society of Tropical Medicine and Hygiene 83, 805–10.CrossRefGoogle ScholarPubMed
Sleigh, A. C., Mott, K. E., Franca Silva, J. T., Muniz, T. M., Mota, E. A., Barretto, M. L., Hoff, R., Lehman, J. S. & Sherlock, I. (1981). A three year follow up of chemotherapy in a Brazilian community with endemic schistosomiasis mansoni. Transactions of tile Royal Society of Tropical Medicine and Hygiene 75, 234–8.CrossRefGoogle Scholar
Sturrock, R. F. (1973). Field studies on the transmission of Schistosoma mansoni and on the bionomics of its intermediate host, Biomphalaria glabrata, on St Lucia, West Indies. International Journal for Parasitology 3, 175–94.CrossRefGoogle Scholar
Sturrock, R. F. (1975). Distribution of the snail Biomphalaria glabrata, intermediate host of Schistosoma mansoni, within a St Lucian field habitat. Bulletin of the World Health Organization 52, 267–72.Google ScholarPubMed
Sturrock, R. F., Bensted-Smith, R., Butterworth, A. E., Dalton, P. R., Kariuki, H. C., Koech, D., Mugambi, M., Ouma, H. H. & Siongok, T. K. (1987). Immunity after treatment of human schistosomiasis mansoni. III. Long-term effects of treatment and retreatment. Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 303–14.CrossRefGoogle ScholarPubMed
Sturrock, R. F., Kinanjui, H., Thiongo, F. W., Tosha, S., Ouma, J. H., King, C. H., Koech, D., Siongok, T. K. & Mahmoud, A. A. F. (1990). Chemotherapy-based control of schistosomiasis haematobia. 3. Snail studies monitoring the effect of Chemotherapy on transmission in the Msambweni area, Kenya. Transactions of the Royal Society of Tropical Medicine and Hygiene 84, 257–61.CrossRefGoogle ScholarPubMed
Webbe, G. (1965). Natural trends in snail populations in relation to control of bilharziasis in East Africa. East African Medical Journal 42, 605–13.Google ScholarPubMed
Webbe, G. A. & Jordan, P. (1993). Epidemiology. In Human Schistosomiasis (ed. Jordan, P., Webbe, G. & Sturrock, R. F.), pp. 83–158. Wallingford, CAB International.Google Scholar
Wilkins, H. A., Blumenthal, U. J., Hagan, P., Hayes, R. J. & Tulloch, S. (1987). Resistance to reinfection after treatment of urinary schistosomiasis. Transactions of tile Royal Society of Tropical Medicine and Hygiene 81, 29–35.CrossRefGoogle ScholarPubMed
World Health Organization (1985). The control of schistosomiasis. WHO Technical Report Series No. 728, World Health Organization: Geneva.Google Scholar