Research Article

The evaluation of potential global morbidity attributable to intestinal nematode infections

M. S. Chana1 p1, G. F. Medleya1 p2, D. Jamisona2 and D. A. P. Bundya1 p1

a1 WHO Collaborating Centre for the Epidemiology of Intestinal Parasitic Infections, Department of Biology, Imperial College, London SW7 2BB, UK

a2 School of Public Health, University of California at Los Angeles, Los Angeles, CA, USA


This paper presents a method of estimating the potential global morbidity due to human intestinal nematode infections (Ascaris lumbricoides, Trichuris trichiura and hookworms), based on the observed prevalence of infection. The method relies on the observed relationships between prevalence and intensity of infection, and between worm burden and potential morbidity. This approach is shown to be sensitive to the precision of the original prevalence estimates and, in particular, to the degree of spatial heterogeneity in levels of infection. The estimates presented here indicate that several tens of millions of children are likely to suffer developmental consequences from infection, and suggest that the global disease burden of geohelminthiasis may be significantly greater than was supposed.

(Received August 06 1993)

(Revised November 01 1993)

(Accepted February 09 1994)


p1 Present address: Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS.

p2 Present address: Ecosystems Analysis Management Group, Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.