Impact of Wolbachia -infected Aedes aegypti on dengue incidence in endemic regions: a systematic review and meta-analysis

Dengue remains a major public health challenge in endemic regions, and conventional vector-control strategies have shown limited long-term effectiveness. The release of Wolbachia-infected Aedes aegypti mosquitoes has emerged as a novel biocontrol strategy to reduce dengue transmission. We conducted a systematic review and meta-analysis to evaluate the effectiveness of Wolbachia deployments in reducing dengue incidence. We searched PubMed, Embase, and the Cochrane Library until 30 April 2025 for randomized controlled trials and quasi-experimental studies conducted in dengue-endemic settings. Population-level effectiveness was assessed using pooled incidence rate ratios (IRRs), and individual-level protective efficacy using pooled odds ratios (ORs). Random-effects meta-analysis with restricted maximum likelihood with Hartung-Knapp adjustment was applied. Subgroup analyses examined geographic region and deployment coverage. Nine studies involving >8 million individuals were included. Wolbachia deployment was associated with a substantial reduction in dengue incidence (pooled IRR 0.15, 95% CI 0.05-0.39), corresponding to an estimated 85% reduction. Full-area deployments demonstrated greater reductions (IRR 0.046, 95% CI 0.038-0.055) than partial-area deployments (IRR 0.22, 95% CI 0.07-0.74). Exploratory individual-level analyses yielded a pooled OR of 0.29 (95% CI 0.01-8.41) with substantial heterogeneity (I² = 86.5%).