58 - Efficacy and User Acceptability of Novel Mosquito Repellent Formulations in Thailand
Tuesday, March 4, 2025
4:00 PM – 4:10 PM AST
Location: 202
Abstract: Background: This study focuses on the evaluation of novel mosquito repellent formulations targeting key malaria and dengue vectors, specifically Anopheles dirus, Aedes aegypti, and Aedes albopictus, under semi-field conditions in Thailand. By simulating near-real environmental conditions, the aim was to determine the effectiveness and user acceptability of these repellents, offering insights for optimizing vector control measures in endemic regions.
Methods: A semi-field experimental design was employed to evaluate the repellents’ efficacy in reducing mosquito landings, inhibiting blood-feeding, and assessing survival rates 24 hours post-exposure. Formulations included Nootkatone, Picaridin, and DEET, applied to human subjects. Additionally, a survey of 200 participants was conducted to assess user acceptability, focusing on demographics, satisfaction, and adverse effects of the repellents. Results: The results demonstrated a significant reduction in mosquito landings across all species (P < 0.001). DEET and Nootkatone were particularly effective in suppressing landings of An. dirus over a six-hour period. Blood-feeding inhibition varied by species, with DEET providing the highest level of protection for both An. dirus and Ae. aegypti. However, no significant variation was observed in mosquito survival rates after 24 hours, suggesting that while repellents reduced mosquito activity, they did not affect long-term survival. The user survey revealed that Picaridin had the highest satisfaction rating, though 10% of participants reported minor adverse reactions, including skin irritation and discomfort. Conclusion: This study underscores the potential utility of novel mosquito repellents for targeted vector control in endemic regions. The efficacy of repellents varied across mosquito species, with An. dirus showing greater susceptibility to DEET and Nootkatone formulations. Despite high user satisfaction, product improvements such as enhanced fragrance and prolonged efficacy are needed to increase public acceptability and adherence. These findings support the importance of continued development and refinement of repellent products to maximize their impact in real-world vector control programs.
