Comparison of different chemotherapy strategies against Schistosoma mansoni in Machakos District, Kenya: effects on human infection and morbidity | Parasitology | Cambridge Core (original) (raw)

Extract

A comparison was made of the long-term impact of different methods of administration of chemotherapy (oxamniquine, 30 mg/kg in divided doses; or praziquantel, 40 mg/kg) on prevalence and intensity of Schistosoma mansoni infection in four areas in Kangundo Location, Machakos District, Kenya. In Area A, treatment was offered in October 1983 and again in April 1985 to all infected individuals. In Area H, treatment was offered in April 1985 to individuals excreting ≥ 100 eggs per gram (epg) of faeces. In Area H, treatment was offered in April 1985 to all infected school children, within the framework of the primary schools. In the witness area, Area W, treatment was given in April 1985, for ethical reasons, to a small number of individuals excreting ≥ 800 epg. Prevalence and intensities of infection were subsequently monitored at yearly intervals for three complete post-treatment years. In the Area S schools, clinical examination was also carried out at yearly intervals. Treatment of all infected individuals on two occasions (Area A) was the most effective and long-lasting way of reducing prevalence and intensity of infection. In this area, however, some earlier interventions had been carried out and pre-treatment intensities were lower than in the other areas. Treatment only of infected schoolchildren (Area S) also had a marked and prolonged effect, comparable to or better than treatment of individuals with heavy infections (Area H). Treatment of infected schoolchildren also caused a persistent reduction in the prevalence of hepatomegaly, and there was suggestive evidence from intensities of infection in community stool surveys (but not from incidence rates) of an effect on transmission. In all study areas, reinfection was most rapid and most intense among children. These findings are discussed in the light of theoretical considerations and of results from other studies, both on schistosomiasis and on intestinal helminths. We conclude that, in areas of low morbidity such as Kangundo, chemotherapy of schoolchildren only, at intervals of up to 3 years, is a satisfactory way of producing a long-term reduction in both intensity of infection and morbidity.

References

Anderson, R. M. & May, R. M. (1982). Population dynamics of human helminth infections: control by chemotherapy. Nature, London 297, 557–63.CrossRefGoogle ScholarPubMed

Anderson, R. M. & May, R. M. (1985 a). Herd immunity to helminth infection and implications for parasite control. Nature, London 315, 493–6.CrossRefGoogle ScholarPubMed

Anderson, R. M. & May, R. M. (1985 b). Helminth infections of humans: mathematical models, population dynamics and control. Advances in Parasitology 24, 1–101.CrossRefGoogle ScholarPubMed

Anderson, R. M. & Medley, G. F. (1985). Community control of helminth infections of man by mass and selective chemotherapy. Parasitology 90, 629–60.CrossRefGoogle Scholar

Arap Siongok, T. K., Mahmoud, A. A. F., Ouma, J. H., Warren, K. S., Muller, A. S., Hander, A. K. & Houser, H. B. (1976). Morbidity in schistosomiasis mansoni in relation to intensity of infection: study of a community in Machakos, Kenya. American Journal of Tropical Medicine and Hygiene 25, 273–84.CrossRefGoogle ScholarPubMed

Bensted-Smith, R., Anderson, R. M., Butterworth, A. E., Dalton, P. R., Kariuki, H. C., Koech, D., Mugambi, M., Ouma, J. H., ArapSiongok, T. K. Siongok, T. K. & Sturrock, R. F. (1987). Evidence for predisposition of individual patients to reinfection with Schistosoma mansoni after treatment. Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 651–4.CrossRefGoogle ScholarPubMed

Brinkmann, U. K., Werler, C., Traore, M. & Korte, R. (1988). Experiences with mass chemotherapy in the control of schistosomiasis in Mali. Tropical Medicine and Parasitology 39, 167–74.Google ScholarPubMed

Bulsara, M. K., Sukwa, T. Y. & Wurapa, F. K. (1985). Risks of liver and spleen enlargement in schistosomiasis mansoni infection in a rural Zambian community. Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 535–6.CrossRefGoogle Scholar

Bundy, D. A. P. & Cooper, E. S. (1988). The evidence for predisposition to trichuriasis in humans: comparison of institutional and community studies. Annals of Tropical Medicine and Parasitology 82, 251–6.CrossRefGoogle ScholarPubMed

Bundy, D. A. P., Cooper, E. S., Thompson, D. E., Didier, J. M. & Simmons, I. (1988). Effect of age and initial infection intensity on rate of reinfection with Trichuris trichuria after treatment. Parasitology 97, 469–76.CrossRefGoogle Scholar

Bundy, D. A. P., Wong, M. S., Lewis, L. L. & Horton, J. (1990). Control of geohelminths by delivery of targeted chemotherapy through schools. Transactions of the Royal Society of Tropical Medicine and Hygiene 84, 115–20.CrossRefGoogle ScholarPubMed

Butterworth, A. E. (1988). Control of schistosomiasis in man. In The Biology of Parasitism (ed. Englund, P. T. & Sher, A.), p. 43. New York: Alan R. Liss, Inc.Google Scholar

Butterworth, A. E., Dalton, P. R., Dunne, D. W., Mugambi, M., Ouma, J. H., Richardson, B. A., ArapSiongok, T. K. 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., Cordingley, J. S., Dalton, P. R., Dunne, D. W., 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., Fulford, A. J. C., Dunne, D. W., Ouma, J. H. & Sturrock, R. F. (1988). Longitudinal studies on human schistosomiasis. Philosophical Transactions of the Royal Society of London, B 321, 495–511.Google ScholarPubMed

Butterworth, A. E., Corbett, E. L., Dunne, D. W., Fulford, A. J. C., Gachuhi, R. K., Klumpp, R., Mbugua, G., Ouma, J. H., ArapSiongok, T. K. Siongok, T. K. & Sturrock, R. F. (1989). Immunity and morbidity in human schistosomiasis. In New Strategies in Parasitology (ed. McAdam, K. P. W. J.), p. 193. Edinburgh: Churchill Livingstone.Google Scholar

Chen, M. G. & Mott, K. E. (1988). Progress in assessment of morbidity due to Schistosoma mansoni infection. Tropical Diseases Bulletin 85, R1–R56.Google Scholar

Cook, J. A. (1987). Strategies for control of human schistosomiasis. In Schistosomiasis (ed. Mahmoud, A. A. F.), Bailliere's Clinical Tropical Medicine and Communicable Diseases, Vol. 2, No. 2, pp. 449–63. London: Baillière Tindall.Google Scholar

Cook, J. A., Baker, S. T., Warren, K. S. & Jordan, P. (1974). A controlled study of morbidity of schistosomiasis mansoni in St. Lucian children, based on quantitative egg excretion. American Journal of Tropical Medicine and Hygiene 23, 625–33.CrossRefGoogle Scholar

Elkins, D. B., Haswell-Elkins, M. & Anderson, R. M. (1986). The epidemiology and control of intestinal helminths in the Pulicat Lake region of Southern India. I. Study design and pre- and post-treatment observations on Ascaris lumbricoides infection. Transactions of the Royal Society of Tropical Medicine and Hygiene 80, 774–92.CrossRefGoogle Scholar

Forrester, J. E., Scott, M. E., Bundy, D. A. P. & Golden, M. H. N. (1990). Predisposition of individuals and families in Mexico to heavy infection with Ascaris lumbricoides and Trichuris trichiura. Transactions of the Royal Society of Tropical Medicine and Hygiene 84, 272–6.CrossRefGoogle ScholarPubMed

Fulford, A. J. C., Mbugua, G. G., Ouma, J. H., Kariuki, H. C., Sturrock, R. F. & Butterworth, A. E. (1991). Differences in the rate of hepatomegaly due to Schistosoma mansoni infection between two areas in Machakos District, Kenya. Transactions of the Royal Society of Tropical Medicine and Hygiene (in the Press.)CrossRefGoogle ScholarPubMed

Gryseels, B. (1988). The morbidity of schistosomiasis mansoni in the Rusizi Plain (Burundi). Transactions of the Royal Society of Tropical Medicine and Hygiene 82, 582–7.CrossRefGoogle ScholarPubMed

Gryseels, B. (1990). Morbidity and morbidity control of schistosomiasis mansoni in subsaharan Africa. Ph.D. thesis, University of Leiden. CIP-Gegevens Koninklijke Bibliotheek den Haag.Google Scholar

Gryseels, B. & Polderman, A. M. (1987). The morbidity of schistosomiasis mansoni in Maniema (Zaire). Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 202–9.CrossRefGoogle ScholarPubMed

Gryseels, B. & Nkulikyinka, L. (1989). Two year follow-up of Schistosoma mansoni infection and morbidity after treatment with different regimens of oxamniquine and praziquantel. Transactions of the Royal Society of Tropical Medicine and Hygiene 82, 219–28.CrossRefGoogle Scholar

Hairston, N. G. (1965). An analysis of age prevalence data by catalytic models. Bulletin of the World Health Organization 33, 163–75.Google ScholarPubMed

Haswell-Elkins, M. R., Elkins, D. B. & Anderson, R. M. (1987). Evidence for predisposition in humans to infection with Ascaris, hookworm, Enterobius and Trichuris in a South Indian fishing community. Parasitology 95, 323–37.CrossRefGoogle Scholar

Holland, C. V., Asaolu, S. O., Crompton, D. W., Stoddart, R. C., Macdonald, R. & Torimiro, S. E. (1989). The epidemiology of Ascaris lumbricoides and other soil-transmitted helminths in primary school children from Ile-life, Nigeria. Parasitology 99, 275–85.CrossRefGoogle ScholarPubMed

Jordan, P. (1985). Schistosomiasis – the St. Lucia project. Cambridge: Cambridge University Press.Google Scholar

Jordan, P., Bartholomew, R. K., Grist, E. & Auguste, E. (1982). Evaluation of chemotherapy in the control of Schistosoma mansoni in Marquis Valley, St. Lucia. I. Results in humans. American Journal of Tropical Medicine and Hygiene 31, 103–10.CrossRefGoogle ScholarPubMed

Jordan, P. & Webbe, G. (1982). Schistosomiasis – Epidemiology, Treatment and Control. London: William Heinemann Medical Books Ltd.Google Scholar

Kloetzel, K. & Schuster, N. H. (1987). Repeated mass treatment of schistosomiasis mansoni: experience in hyperendemic areas of Brazil. I. Parasitological effects and morbidity. Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 365–70.CrossRefGoogle Scholar

Lehman, J. S., Mott, K. E., Morrow, R. H., Muniz, T. M. & Boyer, M. H. (1976). The intensity and effects of infection with Schistosoma mansoni in a rural community in northeast Brazil. American Journal of Tropical Medicine and Hygiene 25, 285–94.CrossRefGoogle Scholar

Machado, P. A. (1982). The Brazilian program for schistosomiasis control, 1975–1979. American Journal of Tropical Medicine and Hygiene 31, 76–86.CrossRefGoogle ScholarPubMed

Mahmoud, A. A. F., Arap Siongok, T. K., Ouma, J. H., Houser, H. B. & Warren, K. S. (1983). Effect of targeted mass treatment on intensity of infection and morbidity in schistosomiasis mansoni. Lancet 1, 849–51.CrossRefGoogle ScholarPubMed

Ouma, J. H., Wijers, D. J. B. & Siongok, T. K. (1985). The effect of targeted mass treatment on the prevalence of schistosomiasis mansoni and the intensity of infection in Machakos, Kenya. Annals of Tropical Medicine and Parasitology 79, 431–8.CrossRefGoogle ScholarPubMed

Ouma, J. H. (1987). Transmission of Schistosoma mansoni in an endemic area of Kenya with special reference to the role of human defaecation behaviour and sanitary practices. Ph.D. thesis, University of Liverpool.Google Scholar

Polderman, A. M. (1984). Cost-effectiveness of different ways of controlling intestinal schistosomiasis: a case study. Social Science and Medicine 19, 1073–80.CrossRefGoogle ScholarPubMed

Polderman, A. M. & Manshande, J. P. (1981). Failure of targeted mass treatment to control schistosomiasis. Lancet 1, 27–8.CrossRefGoogle ScholarPubMed

Sleigh, A. C., Mott, K. E., FrancaSilva, J. T. Silva, J. T., Muniz, T. M., Mota, E. A., Barreto, M. L., Hoff, R., Maguire, J. H., Lehman, J. S. & Sherlock, I. (1981). A three year follow-up of chemotherapy with oxamniquine in a Brazilian community with endemic schistosomiasis mansoni. Transactions of the Royal Society of Tropical Medicine and Hygiene, 75, 234–8.CrossRefGoogle Scholar

Sleigh, A. C., Hoff, R., Mott, K. E., Maguire, J. H. & Da Franca Silva, J. T. (1986). Manson's schistosomiasis in Brazil: 11-year evaluation of successful disease control with oxamniquine. Lancet 1, 635–7.CrossRefGoogle ScholarPubMed

Smith, D. H., Warren, K. S. & Mahmoud, A. A. F. (1979). Morbidity in schistosomiasis mansoni in relation to intensity of infection: study of a community in Kisumu, Kenya. American Journal of Tropical Medicine and Hygiene 28, 220–9.CrossRefGoogle ScholarPubMed

Sturrock, R. F., Butterworth, A. E. & Houba, V. (1976). Schistosoma mansoni in the baboon (Papio anubis): parasitological responses of Kenyan baboons to different exposures of a local parasite. Parasitology 73, 239–52.CrossRefGoogle ScholarPubMed

Sturrock, R. F., Kimani, R., Cottrell, B. J., Butterworth, A. E., Seitz, H. M., Siongok, T. A. & Houba, V. (1983). Observations on possible immunity to reinfection among Kenyan schoolchildren after treatment for Schistosoma mansoni. Transactions of the Royal Society of Tropical Medicine and Hygiene 77, 363–71.CrossRefGoogle ScholarPubMed

Sturrock, R. F., Bensted-Smith, R., Butterworth, A. E., Dalton, P. R., Kariuki, H. C., Koech, D., Mugambi, M., Ouma, J. H. & Arap 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

Sukwa, T. Y., Bulsara, M. K. & Wurapa, F. K. (1986). The relationship between morbidity and intensity of Schistosoma mansoni infection in a rural Zambian community. International Journal of Epidemiology 15, 248–51.CrossRefGoogle Scholar

Sukwa, T. Y., Boatin, B. A. & Wurapa, F. K. (1988). A three year follow-up of chemotherapy with praziquantel in rural Zambian community endemic for schistosomiasis mansoni. Transactions of the Royal Society of Tropical Medicine and Hygiene 82, 258–60.CrossRefGoogle ScholarPubMed

Warren, K. S. & Mahmoud, A. A. F. (1976). Targeted mass treatment: a new approach to the control of schistosomiasis. Transactions of the American Association of Physicians 89, 195–202.Google Scholar