On August 20, 1897, Sir Ronald Ross demonstrated that female Anopheles mosquitoes transmit malaria. The discovery transformed our understanding of malaria and, importantly, gave public health a target: the mosquito. More than a century later, mosquitoes remain among the most important vectors of human disease. Malaria alone caused an estimated 282 million cases and 610,000 deaths in 2024 (WHO 2025 estimates). Dengue has expanded dramatically over the past decade, while chikungunya, Zika, yellow fever, and other arboviruses continue to emerge and spread across changing ecological and geographical landscapes.
For much of the history of vector control, interventions have been based on two complementary strategies: reducing mosquito populations and reducing human-mosquito contact. Insecticide-treated nets, indoor residual spraying, larval source management and topical repellents remain fundamental components of malaria and arbovirus control and have contributed substantially to reductions in disease transmission and mortality. However, the effectiveness and sustainability of these approaches are increasingly challenged by the adaptive capacity of mosquito populations. Widespread insecticide resistance, behavioural shifts that alter biting and resting patterns, and the emergence or expansion of vector species into previously unsuitable environments can reduce the impact of interventions designed around established vector biology. These challenges are prompting a broader conceptual shift in vector control-from viewing mosquitoes primarily as targets to be suppressed or avoided, to recognizing them as biological components of transmission that can themselves be modified to reduce pathogen transmission.
From Mosquito Control to Vector Control
A mosquito becomes a vector when it can acquire a pathogen, support its development, and transmit it to another host. This capacity, known as vector competence, is influenced by mosquito genetics, immunity, microbiota, environmental conditions and the pathogen itself. This provides several possible points of intervention. One of the clearest examples is Wolbachia, a naturally occurring bacterium that, when established in Aedes aegypti, reduces its ability to transmit several arboviruses. Rather than eliminating the mosquito, Wolbachia-based programmes establish the bacterium within mosquito populations, where it can persist and spread. By early 2026, Wolbachia-carrying mosquitoes had been deployed across 15 countries, with programmes reaching more than 16 million people. A randomised trial in Yogyakarta, Indonesia, reported a 77% reduction in dengue incidence and an 86% reduction in dengue hospitalisations, while large-scale deployments in Colombia have also reported substantial reductions in dengue (1). Independent re-analyses of some long-running sites have since questioned whether reported effect sizes fully account for background epidemiological trends; a reminder that even well-established interventions require ongoing, independent verification as programmes scale.
The Evolutionary Challenge of Vector Control
Mosquito control is an evolutionary process. Widespread insecticide resistance reflects selection for mosquitoes that survive chemical interventions, while behavioural changes-including shifts in biting times, resting sites and host-seeking-can further reduce intervention effectiveness. Evolutionary adaptation is also occurring in the pathogen: the WHO’s 2025 World Malaria Report confirmed partial artemisinin resistance in four African countries, with resistance suspected in four more. The geography of transmission is changing as well. Anopheles stephensi, an urban-adapted malaria vector, has now been detected in nine African countries, raising concerns about malaria transmission in urban settings. These challenges reinforce the need for integrated vector management while prompting a new question: rather than continually adapting interventions to the mosquito, can the mosquito itself be changed?
Genetic approaches are exploring two broad strategies: population suppression, by reducing fertility or reproductive success, and population modification, by reducing mosquitoes’ capacity to transmit pathogens while retaining reproductive ability. CRISPR technologies have accelerated research into genes involved in reproduction, immunity and pathogen interactions, while gene drives could, in principle, spread engineered traits through mosquito populations (2). Recent work through the Transmission Zero initiative, including development of the first transgenic mosquito strain generated on the African continent, demonstrates the progress of this field. However, these approaches remain experimental, and their ecological effects, unintended spread, genetic stability, regulatory requirements and community acceptance require careful evaluation. The challenge is therefore not simply to control mosquitoes, but to develop interventions that remain effective as mosquitoes and pathogens continue to evolve.
From Mapping Mosquitoes to Predicting Transmission
While laboratory research is expanding how we can intervene in mosquitoes, advances in surveillance are changing where and when we intervene. Mosquito populations respond to temperature, rainfall, land use, urbanisation and water-storage practices. Geographic information systems, remote sensing, epidemiological data and machine-learning approaches can bring these factors together to estimate where vector populations and transmission risk may increase (3). This predictive approach is increasingly relevant as climate and urban environments change, with the goal of identifying areas where conditions are becoming favourable for vectors and enabling earlier intervention.
What Does the Future of Mosquito Control Look Like?
The future of vector control is unlikely to depend on a single technology. Conventional vector-control measures, biological approaches such as Wolbachia, and emerging genetic and microbiome-based strategies may ultimately be integrated with increasingly precise surveillance and risk prediction. The broader direction is clear: from broadly reducing mosquito populations towards increasingly targeted strategies that disrupt pathogen transmission.
Written by ISID Emerging Leader, Tintu Varghese