The cost-effectiveness of Wolbachia-based biocontrol interventions for dengue: A scoping review of the available evidence

Background: Dengue incidence has increased sharply worldwide, placing nearly half of the global population at risk. In response, various innovative technologies and interventions, including biocontrol strategies that deploy Wolbachia-infected mosquitoes, are being explored. These can be used to either replace the existing mosquito population with one that is less likely to transmit infection or to suppress the existing mosquito population. We conducted a scoping review of economic evaluations of Wolbachia-based interventions for dengue control, aimed at summarising assumptions and results of existing studies. Methodology/Principal Findings: A scoping review of the published literature was conducted on the 29th of April 2024 using the MEDLINE (via OVID), Embase Classic+Embase (via OVID), Global Health - OVID, PubMed, and Econ Lit electronic databases. No date or language restrictions were applied to the searches. We identified nine studies that reported the results of economic evaluations of Wolbachia-based interventions for dengue control. The majority (eight out of nine studies) investigated Wolbachia replacement-based programmes. Overall, the results were supportive for the use of replacement-based programmes in large urban settings, with the intervention likely to generate cost savings from a societal perspective. Conclusions/Significance.: The available economic evaluations consistently suggest that Wolbachia-based replacement interventions can be cost-effective for dengue control when targeted to densely populated urban areas, and several studies indicate that they can generate substantial long‑term cost savings from a societal perspective. Further research is needed to understand how heterogeneity in epidemiological effectiveness influences long-term projected cost‑effectiveness and to investigate the combination of Wolbachia-based interventions with other dengue control/prevention measures (such as vaccination). To support more robust and comparable analyses, we provide recommendations for future studies in this area, emphasising the importance of reporting results disaggregated by cost and outcome components, and making important underlying assumptions related to the intervention more explicit. Author summary: Dengue poses a growing global health threat, with nearly half the world’s population at risk. Among emerging control strategies, Wolbachia-infected mosquitoes offer a promising biocontrol approach—either by replacing local mosquito populations with less infectious ones or by suppressing mosquito numbers. We conducted the first scoping review of economic evaluations of Wolbachia-based interventions for dengue control, identifying nine studies published up to 29th of April 2024. Most focused on replacement strategies, particularly in large urban settings, and found these interventions to be cost-effective from a societal perspective. Our review highlights that the available economic evaluations consistently suggest that Wolbachia‑based replacement programmes are highly cost‑effective in high‑burden areas, where the intervention has the potential to generate substantial long‑term cost savings from a societal perspective in many settings. We also identify key drivers of variation across studies and provide recommendations to guide future economic evaluations in this field, emphasising the importance of reporting results in a disaggregated manner and making all underlying assumptions explicit.