Mosquitoes vs mosquitoes: a systematic review of mass release strategies for the control of Aedes-borne diseases

Background. Aedes-borne arboviruses have emerged or re-emerged worldwide, driving the development and implementation of mosquito mass-release strategies aimed at reducing vector populations or their ability to transmit viruses. These strategies include the sterile insect technique (SIT), the incompatible insect technique (IIT), combined and boosted-SIT/IIT approaches, and Wolbachia-based population replacement strategies (PRS). Yet, despite their increasing implementation worldwide, the strength of evidence supporting their effectiveness has rarely been critically assessed across techniques and outcome measures. Methodology/Principal Findings. To address this gap, semi-field and field studies were systematically reviewed and a weight-of-evidence framework was applied to evaluate the strength and consistency of the entomological and epidemiological evidence across these strategies. Seventy-nine studies conducted across 22 countries or territories met the inclusion criteria. Most studies evaluated entomological outcomes, whereas relatively few assessed disease incidences. For SIT, evidence consistently demonstrated induced sterility, reflected by reduced egg hatch rates. However, evidence for adult population suppression remained limited whereas epidemiological evidence was absent. For IIT and combined SIT-IIT, the evidence showed that mosquito populations were more consistently suppressed, and a few studies also reported reductions in dengue incidence. The strongest epidemiological evidence concerned PRS. Across diverse geographical settings, stable establishment of Wolbachia in local Aedes aegypti populations was consistently associated with substantial reductions in dengue incidence. Conclusions/Significance. Mosquito mass-release strategies should not be considered as a single class of interventions. Rather, they differ markedly in the strength of evidence supporting their entomological and epidemiological effectiveness. This review