Transmission patterns and the epidemiology of hookworm infection

Background. This paper presents a suite of models of hookworm transmission dynamics which vary the mixing patterns and rates of contamination and infection between children and adults. In this context mixing refers to the degree of epidemiological communication between children and adults, for example, whether adults are likely to get infected from infective material passed by children. Methods. Three models are described which represent random mixing, no mixing and restricted mixing respectively. Child, adult and population targeted chemotherapy programmes are examined and compared between these models. Data from a hookworm control programme in Zimbabwe were analysed with respect to their fit to the various models. Results. The analysis suggests that some mixing does occur and that in this study location, the sites where adults deposit faeces are more likely to lead to subsequent contamination than the sites children use. Conclusions. Mixing patterns may have a profound effect on transmission dynamics and should be considered in relation to design of control programmes.