Skip to main content Accessibility help
×
Home

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

  • R. F. Sturrock (a1), R. K. Klumpp (a2), J. H. Ouma (a3), A. E. Butterworth (a4), A. J. C. Fulford (a4), H. C. Kariuki (a3), F. W. Thiongo (a3) and D. Koech (a5)...

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.

Copyright

References

Hide All
Anon (1992). Praziquantel shows unexpected failure in recent schistosomiasis outbreak. TDR-News 41, 12.
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, 4152.
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.
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, 393408.
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.
Hairston, N. G. (1965). Statistical analysis of molluscicide field trials. Bulletin of the World Health Organization 32, 289–96.
Harrison, A. D. (1967). The effects of Bayluscid on gastropod snails and other aquatic fauna in Rhodesia. Hydrobiologia 32, 3784.
Hoffman, D. B. (1983). Schistosomiasis: The Strategic Plan. New York: Edna McConnell Clark Foundation.
Jordan, P. (1985). Schistosomiasis: The St Lucia Project. Cambridge: Cambridge University Press.
Jordan, P. & Webbe, G. (1993). Praziquantel shows unexpected failure in recent schistosomiasis outbreak. TDR-News 42, 10.
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.
Olivier, J. H. & Schneidermann, M. (1956). A method for estimating the density of aquatic snail populations. Experimental Parasitology 5, 109–17.
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.
Polderman, A. M. & Manshande, J. P. (1981). Failure of targeted mass chemotherapy to control schistosomiasis Lancet i, 27–8.
Prentice, M. A. (1984). A field-evolved differential filtration method for recovery of schistosome cercariae. Annals of Tropical Medicine and Parasitology 78, 117–27.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
Webbe, G. (1965). Natural trends in snail populations in relation to control of bilharziasis in East Africa. East African Medical Journal 42, 605–13.
Webbe, G. A. & Jordan, P. (1993). Epidemiology. In Human Schistosomiasis (ed. Jordan, P., Webbe, G. & Sturrock, R. F.), pp. 83158. Wallingford, CAB International.
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, 2935.
World Health Organization (1985). The control of schistosomiasis. WHO Technical Report Series No. 728, World Health Organization: Geneva.

Keywords

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed