Research Article

Estimating the number of multiple-species geohelminth infections in human communities

M. Bootha1 p1 and D. A. P. Bundya1

a1 Imperial College of Science Technology and Medicine, Department of Biology, Prince Consort Road, London SW7 2BB


Infections with Ascaris lumbricoides, Triclmris trichiura and the hookworm species are often found in the same communities and individuals. Hosts infected by more than one species are potentially at risk of morbidity associated with each infection. This paper describes the use of a probabilistic model to predict the prevalence of multiple-species infections in communities for which only overall prevalence data exist. The model is tested against field data, using log-linear analysis, and is found to be more effective at estimating the numbers of multiple infections involving hookworms than those involving only A. lumbricoides and T. trichiura. This latter combination of infections is found, in half the communities examined, to be more common than expected by chance. An age-stratified analysis reveals that the degree of interaction between these two infections does not alter significantly with age in the child age classes of a Malaysian population.

(Received January 13 1995)

(Revised May 05 1995)

(Accepted May 05 1995)


p1 Present address and address for reprint requests: Department of Public Health and Epidemiology, Swiss Tropical Institute, Socinstrasse 57, CH-4051 Basel Switzerland


† Centre for the Epidemiology of Infectious Disease, University of Oxford, South Parks Road, Oxford OX1 3PS, UK