Trapping and killing performance of a PermaNet 2.0 hybrid mosquito trapping bednet: an experimental hut evaluation

TL;DR

A new hybrid mosquito bednet design traps and kills more mosquitoes than existing nets, offering a promising solution to combat insecticide resistance in malaria-prone regions.

Contribution

The study introduces a hybrid-treated trapping bednet (T-LLIN) that combines insecticide-treated and insecticide-free compartments to enhance mosquito mortality.

Findings

The T-LLIN killed 89.2% of collected mosquitoes, with 46.75% of deaths occurring in the trap compartment.

The T-LLIN's killing effect was 52% higher than PermaNet 2.0 and outperformed other control nets.

The mechanical trapping effect significantly enhanced the net's overall performance in an insecticide resistance context.

Abstract

Background: Despite the huge global effort, there has been an increase in malaria morbidity and mortality in sub-Saharan Africa since 2015, from 212 million cases and 429,000 deaths in 2015 to 241 million cases and 627,000 deaths in 2020 mainly because of resistance to insecticide. Therefore, advancing innovative approaches is the only sustainable way to fight malaria.

Methods: Taking advantage of the behavior of mosquitoes around the net, which is almost 70–90% concentrated on the roof, we have developed a two-compartment mosquito bednet, the so-called T-Net for mass mosquito trapping and killing. In the current study, we investigated in an experimental hut trial, the efficacy of trapping-long-lasting insecticide-treated nets (T-LLINs) against
Anopheles gambiae s.l. in an insecticide resistance context. Five different arms have been considered in this study including three positive control arms e.g. PermaNet 2.0 LLIN, Tsara boost LLIN and Interceptor generation 2 (IG2) LLIN), one negative control arm using insecticide-free bednet, and one candidate arm using a hybrid-treated trapping bednet made with PermaNet 2.0 LLIN mounted with an insecticide-free compartment (T-LLIN).

Results: The highest average daily mortality was recorded with the T-LLIN. In total, 678 mosquitoes were killed by T-LLIN among the 760 collected, i.e. 89.2%. Out of these, 317 were found in the trap compartment, representing 46.75% of mortality directly attributable to the mechanical effect of this net. This added value made it possible to quantify the increased in the killing effect that this net would have over the positive control arms: this would be 52% higher than the killing effect of PN2.0, 25.2% higher than that of Tsara boost and 23% higher than that of IG2.

Conclusion: The current study shows potential to maximize the efficiency of the WHO-recommended LLINs by an addition of an insecticide-free trap compartment on top of the net.

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