Innovative sterile male release strategies for Aedes mosquito control: progress and challenges in integrating evidence of mosquito population suppression with epidemiological impact

Abstract

Background Aedes mosquitoes pose a significant global threat as vectors for several debilitating arboviruses, including dengue, Zika, yellow fever, and chikungunya. Their unique breeding habits, behavior, and daytime activity complicate control efforts, prompting the search for innovative solutions. The sterile insect technique (SIT) and incompatible insect technique (IIT) are promising new techniques under investigation. This review synthesizes findings from field trials on SIT and/or IIT for Aedes mosquito control. Methods A scoping review was conducted through comprehensive searches on Scopus, Web of Science, MEDLINE, PubMed, and preprint repositories up to April 25, 2024. Studies were initially screened for relevance based on their titles and abstracts, followed by a full-text review conducted by two independent extractors. Only field trials with control groups were included, with the final assessment focusing on trials reporting epidemiological outcomes. Data were abstracted into templates, emphasizing study design, intervention details, and outcomes. The review adhered to the PRISMA-ScR guidelines. Results The search identified 21 field trials in various countries against Aedes mosquitoes. These trials employed diverse methodologies and mosquito release strategies, achieving varying levels of mosquito population suppression. Notably, two SIT and two Wolbachia-based IIT trials reported epidemiological outcomes, including reductions in dengue incidence and associated risk ratios. However, the reliance on national surveillance data for assessing dengue incidence suggests caution due to the potential underreporting of subclinical cases. Conclusions The review underscores the promise of SIT and IIT for controlling Aedes mosquito populations, citing successful reductions in mosquito densities and dengue transmission. However, it calls for more rigorous study designs and standardized methodologies, as well as the adoption of comprehensive frameworks to accurately assess the effectiveness of these interventions. Future research should focus on bridging gaps in real-world effectiveness by addressing factors such as feasibility, acceptability, scalability, and cost, which are crucial for guiding their successful large-scale deployment in any country.