Sri Lanka Deploys Drones to Combat Mosquitoes as Dengue Deaths Mount

July 2, 2026 5 min read

Sri Lankan health authorities have begun deploying drone technology to combat an escalating dengue fever outbreak, with cases climbing sharply across multiple districts including Colombo, Kandy, and Galle. The aerial spraying initiative targets breeding grounds in urban areas where standing water has allowed mosquito populations to thrive during the monsoon season. Officials say the measure represents a significant shift in how the country tackles its annual dengue crisis, which claimed dozens of lives in the first quarter alone.

Rising caseload strains healthcare system

The health ministry reported that hospital admissions for dengue patients reached their highest levels since 2017, overwhelming facilities in the western province where transmission rates remain most acute. Medical staff at Colombo's National Hospital confirmed that wards were operating at or above capacity throughout February, forcing some patients to be treated in temporary overflow tents. The spike follows above-average rainfall in December and January, creating ideal conditions for the Aedes aegypti mosquito that carries the virus.

Local authorities in Kandy district launched parallel ground-level fumigation campaigns, deploying teams to manually spray areas where drone access proved difficult. The district medical officer told reporters that workers focused on schools, markets, and residential areas within a 500-metre radius of confirmed cases. Hospital data showed that children under 15 accounted for a substantial proportion of those hospitalised, echoing patterns seen in previous outbreaks.

Drone technology targets breeding grounds

The agriculture ministry partnered with a local technology firm to operate the drone fleet, which began spraying larvicide over waterlogged areas, rooftop containers, and construction sites that human crews cannot easily reach. Footage released by the health ministry showed one of the drones dispersing chemical agents over the densely populated suburb of Wattala, just north of Colombo. Each drone can cover approximately 10 hectares per hour, a rate officials say would take ground teams the better part of a day to match.

The larvicide being deployed, temefos, has been approved by the World Health Organization for use in dengue control programmes across South and Southeast Asia. A ministry spokesperson stated that the chemical poses minimal risk to humans and animals when applied according to guidelines. However, residents in several neighbourhoods raised concerns about the smell and potential skin exposure, prompting authorities to issue public advisories about staying indoors during spraying operations.

Cost and accessibility challenges

The drone programme carries a price tag that has drawn scrutiny from opposition lawmakers, who question whether the investment will deliver results commensurate with the expense. A senior finance ministry official told reporters that the initial contract valued the operation at roughly $1.2 million for the first three months. Proponents counter that the cost of treating dengue patients, including extended hospital stays and potential complications, frequently exceeds what preventive measures would require. The treasury is expected to review funding levels in April, according to officials familiar with the matter.

Historical context of dengue in Sri Lanka

Dengue fever has become a recurrent public health challenge for Sri Lanka since the first major recorded outbreak in the 1960s. The country experienced its worst crisis in 2017, when more than 185,000 cases and 295 deaths were logged throughout the year. Subsequent outbreaks in 2019 and 2022 each fell short of those figures but still placed considerable strain on district hospitals. Climate experts have warned that rising temperatures and shifting rainfall patterns linked to climate change are extending the mosquito's active season beyond traditional months.

The virus presents with high fever, severe headache, and muscle pain that can progress to a potentially fatal form known as dengue haemorrhagic fever. There is no dedicated antiviral treatment for the disease, making vector control the primary tool available to health authorities. Sri Lanka's national dengue control unit has run seasonal awareness campaigns for years, urging households to eliminate standing water in flowerpots, tyres, and gutters.

Community response and compliance issues

Health workers conducting doorto-door inspections have found that compliance with prevention guidelines remains inconsistent across affected areas. In Colombo's Fort zone, inspectors discovered active breeding sites in nearly one in five premises checked during January surveys. The figure dropped to roughly one in twelve in more affluent suburbs where residents reported greater awareness of prevention measures. Officials say the disparity underscores the challenge of reaching lower-income communities where cramped living conditions and limited waste management create ideal mosquito habitat.

Some community leaders in Kandy have called for stricter enforcement against property owners who fail to maintain their land, arguing that individual negligence undermines collective prevention efforts. The police have been authorised to issue fines under public health legislation, though officials acknowledge that prosecution remains rare. A district secretariat meeting in February produced commitments from local government officials to increase inspections of construction sites, which frequently become dengue hotspots due to accumulated standing water.

Looking ahead: the road to containment

Health officials have set a target of reducing mosquito density by 50 percent in high-risk districts before the northeast monsoon arrives in October. Achievement of that goal will depend partly on sustained funding for the drone programme and partly on whether community compliance improves during the coming dry spell in April and May. The national dengue control unit plans to release updated case figures in six weeks, which will serve as a benchmark for evaluating whether current measures are having the desired effect.

Regional health authorities in Bangladesh and Thailand have expressed interest in Sri Lanka's drone approach, according to officials at the health ministry. Those countries are also grappling with rising dengue transmission, and international health agencies have encouraged South Asian nations to share lessons learned from pilot programmes. Sri Lanka's experience over the next several months will likely influence whether drones become a standard component of vector control strategies across the region.