New tools for surveillance of adult yellow fever mosquitoes: comparison of trap catches with human landing rates in an urban environment

Abstract

A novel mosquito trapping system, the BG-Sentinel trap, was evaluated as a monitoring tool for adult Aedes aegypti in field tests in the city of Belo Horizonte, Brazil. Human landing/biting collections, a gas-powered CO2 trap, and a Fay-Prince trap with only visual cues serving as references to evaluate the efficacy of the new trap. The BG-Sentinel is a simple suction trap that uses upward-directed air currents as well as visual cues to attract mosquitoes. The trap was tested with a new dispenser system (BG-Lure) that releases artificial human skin odors and needs no CO2. In comparison with the two other traps, the BG-Sentinel caught significantly more Ae. aegypti. Although human landing rates were the highest, there was no significant difference between human landing rates and the capture rates of the BG-Sentinel trap. The finding indicates that the trap can be considered as an acceptable alternative to human landing/biting collections in the surveillance of adult host-seeking dengue vectors. The addition of BG-Lure to the gas-powered CO2 trap greatly increased its efficacy. This combination, however, was not significantly more effective than the BG-Sentinel without CO2. In a 6-month comparison between the BG-Sentinel and a sticky ovitrap for gravid females, the BG-Sentinel proved to be a far more efficient and sensitive tool to measure the density of Ae. aegypti populations.