Research scientist Ifakara Health Institute Bagamoyo, Dar es Salaam, Tanzania
Introduction
The human landing catch (HLC) measures human exposure to mosquito bites and evaluates the efficacy of vector control tools. However, it may expose volunteers to potentially infected mosquitoes. The mosquito electrocuting trap (MET) and BG-Sentineltraps (BGS) represent an alternative, exposure-free methods for sampling host-seeking mosquitoes. This study investigates whether these methods can be effectively used as alternatives to HLC for measuring the efficacy of transfluthrin against Aedes aegypti.
Method
HLC, MET and BGS were located 2 m from an experimental hut with transfluthrin emanator positioned 3 m on either side of them. For no choice experiment these methods were evaluated alone while for the choice experiment, a competitor HLC was included 10 m from the first collection point. One hundred laboratory-reared Ae. aegypti mosquitoes were released and collected for 3 hours.
Results
In the no-choice test, each method measured similar PE; HLC: 66% (95% confidence interval [CI]: 50–82), MET: 55% (95% CI: 48–63) and BGS: 64% (95% CI: 54–73). The proportion of mosquitoes recaptured was consistent between methods (20–24%) in treatment and varied (47–71%) in the control. However, in choice tests, the PE measured by each method varied; HLC: 37% (95% CI: 25–50%), MET: 76% (95% CI: 61–92) and BGS trap: 0% (95% CI: 0–100)
Conclusion
HLC, BGS, and MET can be used interchangeably if independence is ensured. BGS increases mosquito's bites to a volunteer sitting at 10 m.
