Early rains rising dengue risk
Bangladesh is entering the pre-monsoon dengue season with warning signs already visible, as repeated spells of heavy rainfall create fresh breeding grounds for Aedes mosquitoes weeks before the usual peak period.
Public health experts say the risk is no longer limited to Dhaka’s dense neighbourhoods. Expanding urbanisation, poor drainage, unmanaged waste, construction sites, discarded plastic containers and changing rainfall patterns are together creating conditions in which dengue can spread earlier and more widely than in previous years.
According to the Directorate General of Health Services, Bangladesh recorded 3,028 dengue hospitalisations and five deaths so far this year as of May 22, with 11 new hospitalised cases and no death reported in the latest 24-hour reporting period.
The official DGHS dashboard also shows that most hospitalised patients this year are outside city corporation areas, suggesting that dengue risk is spreading beyond the traditional urban hotspots.
The concern has grown after unusually wet weather. The Bangladesh Meteorological Department forecast rain in several divisions and moderately heavy to heavy rainfall in parts of Mymensingh and Sylhet until May 23.
Health experts say the next few weeks are crucial. Rain itself does not cause dengue, but it fills small containers, rooftop corners, flower tubs, open tanks, construction pits, tyres, plastic waste and clogged drains with stagnant water. These sites allow Aedes mosquitoes, the carrier of dengue, to breed close to homes, schools, markets and workplaces.
The danger is that Aedes mosquitoes do not need large pools of water. The US Centers for Disease Control and Prevention says female Aedes mosquitoes lay eggs on the inner walls of water-holding containers, and the eggs can survive dry conditions for months before hatching when water returns.
WHO Bangladesh also notes that Aedes mosquitoes breed in clean stagnant water found in old tyres, bottles, pots, broken appliances and plastic containers.
Health expert Dr. Kasedul Islam Nayan told The New Nation that early rainfall has already pushed mosquito-breeding indicators to risky levels. Based on recent field observations in 13 districts, he said the Breteau Index in urban areas has crossed 20, a threshold that signals increased dengue transmission risk. He advised immediate source management, meaning the removal or treatment of all water-holding containers before mosquito density rises further.
Bangladesh’s recent dengue history makes the warning harder to ignore. In 2023, the country recorded its deadliest dengue outbreak, with 321,179 cases and 1,705 deaths, according to research based on national data.
Although the current 2026 numbers are still far lower, specialists say early rainfall, high humidity and poor waste management can quickly change the situation if prevention is delayed.
Dengue patterns in Bangladesh have also shifted. Once seen mainly as a Dhaka-centred monsoon disease, it now appears in many districts and increasingly outside major city corporations.
A 2025 government-backed dengue action plan identified rapid urbanisation, population movement, weak vector control, poor waste management and climate change as major drivers behind the country’s recurring outbreaks.
The biggest challenge is coordination. Mosquito control is not only a health ministry task. City corporations, municipalities, local government bodies, schools, hospitals, housing societies, construction firms and households all control pieces of the dengue puzzle. Fogging alone cannot stop transmission if larvae remain active in containers and drains.
Experts recommend an early-season response built around four steps: daily destruction of breeding sources, rapid larval surveys in high-risk areas, proper use of larvicides where water cannot be removed, and public alerts before holidays or heavy-rain spells.
Households are advised to empty flower-pot trays, cover water tanks, clean rooftops and balconies, dispose of plastic waste, scrub water containers and avoid leaving buckets, tyres or bottles exposed to rain.
