Mosquito populations have jumped by more than 40 percent in parts of Dhaka within weeks, triggering public health concerns, as experts warn that poor sanitation and chemical resistance are weakening control efforts.
Vector-borne diseases account for more than 17 percent of infectious illnesses globally and claim over 700,000 lives each year.
In Bangladesh, residents report a sudden spike in mosquito activity that is disrupting daily life and increasing disease risks. In Shukrabad, resident Neamul Hasan said even indoor spaces no longer offer relief.
“Even inside our home, mosquitoes find a way in. It feels like there is no safe space anymore,” he said.
In Khilgaon, resident Rezwan Sohan said the change has been noticeable in recent weeks. “The number of mosquitoes has risen so quickly that we now close windows much earlier in the evening,” he said. “Even stepping outside briefly means getting bitten.”
A joint monitoring initiative by Jahangirnagar University’s zoology department and Dhaka North City Corporation (DNCC) across five locations confirmed the rise.
Researchers using 24-hour traps collected 17,159 mosquitoes between 16 and 20 January. The figure climbed to 22,362 between 30 January and 3 February.
The sites included a park in Uttara Sector 4, the DNCC store office in Mirpur 2, the old store office in Gulshan 1, the Ward 10 community centre in Mirpur 1, and the DNCC regional office in Mohammadpur.
More than 90 percent of the samples were identified as Culex mosquitoes.
Public health expert and former World Health Organization consultant Mohammad Mushtuq Husain said that while Aedes mosquitoes — which transmit more serious diseases — breed in clean stagnant water during the rainy season, the current surge is largely driven by Culex, which thrive in polluted water.
He said Culex populations typically rise during winter and warmer spells. Though rarely fatal, their bites cause irritation, discomfort and sleep disturbance.
“The dirtier a city, the higher the Culex population,” Husain said.
“City cleaning alone is not enough. Residents must also keep homes, markets and shared spaces clean.”
Entomologists say conventional measures such as fogging are failing to deliver lasting results.
Entomologist and Jahangirnagar University Professor Golam Mostafa told TIMES of Bangladesh that unhygienic surroundings and poorly functioning drainage systems are central to the surge.
He also questioned the effectiveness of chemical control.
“Spraying alone is insufficient, particularly as mosquitoes are developing resistance,” he said.
He added that monitoring insecticide quality and expiry dates is often inadequate, stressing that larval control is essential for sustained impact.
With temperatures rising, experts warn that the window for preventive action is narrowing. While Culex currently dominate, the risk of Aedes-borne diseases is expected to escalate with the onset of the rainy season.
Professor Mostafa urged the government to adopt a coordinated strategy, including expert panels and national-level guidance. “Experts must be consulted and their recommendations systematically monitored to strengthen mosquito control,” he said.
He stressed that lasting solutions require coordinated action between authorities and citizens to maintain cleanliness in both public and private spaces.
