Impacts of land use type on sampling methods for human and simian malaria vectors

Abstract

Background Malaria transmission to humans is increasing in complexity in Indonesia with simian malaria cases in humans increasing as human malaria incidence diminishes. Reliable, epidemiologically relevant, logistically feasible, and cost-effective collection methods are needed to define the transmission risk to humans and the efficacy of vector control for both simian and human malarias. Alternative and/or complementary representative mosquito sampling methods to the labour-intensive human landing collections (HLC) and animal-baited tent traps (ABT) currently used in Indonesia are needed. Methods Carbon dioxide gas from a compressed cylinder and from yeast/sugar fermentation were used as lures in Passive Box, CDC Light and BG Sentinel 2 mosquito traps and compared in Latin square trials to human landing catches (HLCs) and animal baited traps (ABTs) for sensitivity and specificity for anopheline vectors across three land use types (oil palm plantation, mixed-crop agricultural area and village) in North Sumatra. Results The ABT with cow as bait was the most sensitive sampling method for all anopheline species in a direct comparison to HLC and the BG-Sentinel 2 trap in North Sumatra. The Passive Box and CDC Light traps were not sensitive for anophelines regardless of the CO2 source. The HLC showed high specificity for members of the An. dirus complex, and also captured An. kochi, An. barbirostris complex, and An. maculatus Group mosquitoes.