Effectiveness of Vector Control Interventions in Preventing Dengue Outbreaks: A Systematic Review and Meta-analysis

Abstract

Background: Dengue fever is one of the most widespread vector-borne viral infections globally, transmitted primarily by Aedes aegypti and Aedes albopictus mosquitoes. In the absence of an effective universal vaccine, vector control remains the cornerstone of dengue prevention. However, the relative effectiveness of different vector control interventions-chemical, environmental, biological, or integrated approaches-in reducing dengue incidence and preventing outbreaks remains uncertain.

Objectives: To systematically review and quantitatively assess the effectiveness of vector control interventions in reducing dengue incidence and outbreak occurrence, and to compare the impact of novel biological strategies such as Wolbachia deployment with conventional methods.

Methods: Following PRISMA 2020 guidelines, a comprehensive search of PubMed, Embase, Cochrane CENTRAL, Scopus, Web of Science, and WHO databases was conducted up to June 2025. Eligible studies included randomized controlled trials, quasi-experimental, and observational designs reporting dengue incidence, outbreak occurrence, or entomological indices. Two reviewers independently screened studies, extracted data, and assessed bias using Cochrane RoB 2 and ROBINS-I tools. Pooled relative risks (RRs) were estimated using a random-effects model (DerSimonian-Laird), and certainty of evidence was evaluated using GRADE.

Results: Twelve studies (4 RCTs, 8 quasi-experimental/observational) with clinical outcomes and 23 with entomological data met inclusion criteria. Wolbachia-based biological control interventions demonstrated the greatest effectiveness, yielding a pooled RR = 0.25 (95 % CI 0.17-0.37; I² = 54 %), corresponding to a 75 % reduction in dengue incidence. Integrated vector management (IVM) and community-based environmental control achieved moderate reductions (RR = 0.61 (95 % CI 0.40-0.92)), whereas chemical control (fogging and residual spraying) had minimal effect (RR = 0.87 (95 % CI 0.65-1.16)). Overall pooled RR across all interventions was 0.68 (95 % CI 0.51-0.91), with moderate heterogeneity. Funnel plot and Egger’s test indicated no significant publication bias. Certainty of evidence was moderate for Wolbachia and low for other interventions.

Conclusions: Vector control interventions collectively reduce dengue incidence, but effectiveness varies widely by strategy. Biological control through Wolbachia-infected Aedes aegypti offers the most robust and sustainable reduction in dengue transmission, while multi-component IVM programs provide additional benefit when community engagement is high. Conventional chemical control alone remains insufficient for outbreak prevention. Future research should emphasize high-quality cluster-randomized trials, standardized dengue outcome measures, and cost-effectiveness evaluations to optimize integrated dengue prevention strategies.