Fulltext

Aggregation in schistosomiasis: comparison of the relationships between prevalence and intensity in different endemic areas

Guyatt, H. L. ; Smith, T. ; Gryseels, B. ; Lengeler, C. ; Mshinda, H. ; Siziya, S. ; Salanave, B. ; Mohome, N. ; Makwala, J. ; Ngimbi, K. P. ; Tanner, M.

In: Parasitology, 1994, vol. 109, no. 1, p. 45-55

Add to personal list
    Title
    • Aggregation in schistosomiasis: comparison of the relationships between prevalence and intensity in different endemic areas
    Author
    • Guyatt, H. L.. Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, Basel CH-4002, Switzerland
    • Smith, T.. Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, Basel CH-4002, Switzerland
    • Gryseels, B.. Department of Parasitology, University of Leiden, P.B. 9605, 2300 RC Leiden, The Netherlands
    • Lengeler, C.. Tropical Health and Epidemiology Unit, London School of Hygiene and Tropical Medicine, Keppel Street, London WCIE 7HT, UK
    • Mshinda, H.. Ifakara Centre, PO Box 53, Ifakara, Tanzania
    • Siziya, S.. Tropical Diseases Research Center, POB 71 769 Ndola, Zambia
    • Salanave, B.. IFORD, B.P. 1556, Yaoundé, Cameroon
    • Mohome, N.. OCEAC, B.P. 288, Yaoundé, Cameroon
    • Makwala, J.. Département de Démographie, Université de Kinshasa, Zaire
    • Ngimbi, K. P.. Département de Démographie, Université de Kinshasa, Zaire
    • Tanner, M.. Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, Basel CH-4002, Switzerland
    Document Type
    • Postprint
    OAI-PMH Identifier
    • oai:doc.rero.ch:293712
    Summary
    Distributions of the intensities of helminth infections within their host populations are invariably aggregated. In the case of the intestinal nematodes, the degrees of aggregation have been shown to be species specific, and constant for any given species despite geographical variation in study sites. This species-specific aggregation can be quantified and used as a tool in planning control interventions. One practical application is that the prevalence of infection can be used to predict the prevalence of heavy infection and thus the risks of morbidity. This paper investigates the patterns of aggregation in schistosome egg counts in different endemic areas in Africa (data sets were obtained from Burundi, Cameroon, Tanzania, Zambia and Zaire). The analysis demonstrates that the degree of parasite aggregation, for both Schistosoma mansoni and S. haematobium, differs amongst the different study localities. This is probably due to area-specific differences in host exposure and immunity. This implies that for these schistosome species, it is not possible to predict egg count distributions or morbidity levels from prevalence data alone