As dengue continues to burden Sri Lanka with tens of thousands of cases annually, public health experts are proposing biological control methods involving specially bred mosquitoes as a complement to traditional prevention efforts.
Dengue fever remains one of Sri Lanka's most entrenched public health crises, with the country recording over 80,000 cases in 2023 and surpassing 60,000 by mid-2024. The 2017 outbreak reached a historic peak of more than 186,000 cases, straining hospitals across multiple districts. According to public health analysis, densely populated areas including Colombo, Gampaha, Kandy, Kurunegala, and Batticaloa have consistently emerged as hotspots, driven by rapid urbanisation, inadequate waste management, and household water storage practices that create breeding grounds for the Aedes aegypti mosquito.
Traditional control methods—including fogging operations, community clean-up campaigns, and public awareness programmes—have proven insufficient to break the cycle of recurring outbreaks. The Aedes aegypti mosquito has demonstrated remarkable adaptability to Sri Lanka's warm, humid climate and urban environments, breeding in even the smallest containers of stagnant water. Its eggs can survive for months in dry conditions, allowing rapid population recovery despite intensive control efforts. Fogging targets only adult mosquitoes and cannot reach hidden breeding sites, while maintaining community compliance with preventive measures remains persistently challenging.
Scientific developments internationally have introduced a promising alternative: biological suppression using specially bred male mosquitoes carrying a trait that prevents their offspring from surviving to adulthood. These males do not bite and pose no risk to humans. When released into high-density areas, they mate with wild females, disrupting the reproductive cycle and causing significant population reduction. Field trials in several countries have demonstrated suppression rates exceeding 80 percent. Unlike chemical insecticides, this approach is species-specific and environmentally safe, requiring no reliance on perfect community compliance.
Sri Lanka possesses the institutional foundation to evaluate and implement such methods. The Epidemiology Unit and Medical Officer of Health offices maintain detailed surveillance systems identifying high-risk zones, while the country has prior experience with biological pest control in agriculture. Experts propose pilot projects in selected urban areas, with results informing potential nationwide expansion. Such biological methods would complement rather than replace existing prevention strategies, strengthening overall dengue control by reducing mosquito populations at their source. Success could significantly reduce hospitalisation pressure, economic burden on families, and school disruptions while demonstrating Sri Lanka's commitment to public health innovation.
