Using non-insecticidal traps indoors can complement insecticide-treated nets to target insecticide-resistant malaria...

Area of Science:

• Vector control
• Medical entomology
• Public health

Background:

• Insecticide-treated nets (ITNs) are crucial for malaria vector control, offering insecticidal and physical protection.
• Insecticide resistance in malaria vectors compromises ITN efficacy, necessitating complementary control strategies.
• Evaluating non-insecticide-based tools integrated with ITNs is vital for sustained malaria control.

Purpose of the Study:

• To assess the effectiveness of the Host Decoy Trap (HDT) as a complementary tool to standard ITNs against insecticide-resistant Anopheles gambiae s.l.
• To evaluate the integrated approach in experimental hut trials under WHO Phase II guidelines.

Main Methods:

• Field-collected An. gambiae mosquitoes from Benin Republic were tested against HDT combined with permethrin or deltamethrin-treated nets.
• Effectiveness was measured by mosquito mortality, blood-feeding rates, and exophily (exit rates).
• Insecticide susceptibility tests were conducted prior to trials to confirm pyrethroid resistance.

Main Results:

• The combination of HDT and ITNs achieved significantly higher An. gambiae mortality (80.18-99.78%) compared to ITNs alone.
• Combined HDT-ITN use resulted in lower blood-feeding rates (0-10.83%) than ITNs alone (0-16.93%).
• The integrated approach significantly reduced the exophily of insecticide-resistant mosquitoes compared to ITNs alone.

Conclusions:

• The Host Decoy Trap (HDT) combined with ITNs significantly reduces vector-host contact for insecticide-resistant Anopheles gambiae.
• This integrated strategy effectively lowers live mosquito populations, blood-feeding rates, and the potential for mosquitoes to re-enter the environment.
• Findings support the integration of non-insecticidal trapping devices with ITNs for future malaria vector control strategies.