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Heritability of human hookworm infection in Papua New Guinea

Published online by Cambridge University Press:  21 October 2008

Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, UK
Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK
Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK
*Corresponding author: Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, UK. Tel: +44 113 3432824. Fax: +44 113 3432835. E-mail:


Hookworms infect approximately 740 million humans worldwide and are an important cause of morbidity. The present study examines the role of additive genetic effects in determining the intensity of hookworm infection in humans, and whether these effects vary according to the sex of the host. Parasitological and epidemiological data for a population of 704 subjects in Papua New Guinea were used in variance components analysis. The ‘narrow-sense’ heritability of hookworm infection was estimated as 0·15±0·04 (P<0·001), and remained significant when controlling for shared environmental (household) effects. Allowing the variance components to vary between the sexes of the human host consistently revealed larger additive genetic effects in females than in males, reflected by heritabilities of 0·18 in females and 0·08 in males in a conservative model. Household effects were also higher in females than males, although the overall household effect was not significant. The results indicate that additive genetic effects are an important determinant of the intensity of human hookworm infection in this population. However, despite similar mean and variance of intensity in each sex, the factors responsible for generating variation in intensity differ markedly between males and females.

Original Articles
Copyright © 2008 Cambridge University Press

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