Rapid assessment of malaria risk using entomological techniques: taking an epidemiological snapshot

The pivotal role of mosquitoes in malaria epidemiology means that in practice, control efforts against the disease must include sustainable control of the vectors. This has fostered many careful and complex longitudinal studies designed to estimate the entomological inoculation rate (EIR) as a measure of risk of exposure to infection. Alternatives to this estimate - anti-circumsporozoite protein antibodies, conversion rates in non-immunes or re-infection rates - require sampling of blood from patients and have associated compliance and interpretation issues. Here, we describe how entomological techniques, which provide information on mosquito population densities, age structures and infection characteristics, allied with mapping and modelling approaches can provide a relative estimate of EIR within a few days of fieldwork. The information could be used to decide upon and track intervention measures, as well as to monitor disease outbreaks. Standardizing the techniques used for rapid assessment could enable comparison of malaria risk in different ecological and epidemiological settings.