Dengue is no longer a seasonal disease in Bangladesh, it has evolved into a year-round public health crisis. Over the past decade, the epidemiological pattern of dengue has changed significantly. Once confined between June and September, infections now extend from October to January.
According to official data, as of November 10, Bangladesh has recorded at least 79,722 dengue cases and 315 deaths in 2025. These figures indicate that the outbreak is still far from under control, and we anticipate that dengue transmission will continue throughout November.
Demographically, 65.2% of cases are male, while 34.8% are female. The most affected age group is 16-25 years, comprising mostly students and working urban youth. Death rates show 53.2% male and 46.8% female, with a worrying concentration among children aged 0–5 years and 11–15 years, revealing a clear child vulnerability trend. The Dhaka Division has reported the highest number of cases and deaths, driven by dense population, poor sanitation, and ineffective vector control operations.
Dengue transmission is directly linked to meteorological variables. Climate change has shifted rainfall patterns, and rain now often continues until late October, extending the breeding season of Aedes mosquitoes. These mosquitoes lay eggs in stagnant water; such as in flowerpots, buckets, drums, discarded tires, basement puddles, or under-construction sites. Late rainfall fills these breeding sites again, allowing larvae to develop into adult mosquitoes, thereby increasing the vector population even in the post-monsoon period.
In addition, November’s average temperature of around 20°C in Bangladesh remains ideal for dengue vector Aedes breeding, virus incubation, and survival. This altered climate context has created a “seasonal spillover effect,” extending dengue’s reach well beyond the traditional rainy season.
One major barrier to dengue control is the lack of an effective administrative framework. Local government institutions, particularly city corporations and municipalities, conduct mosquito control activities sporadically and seasonally, rather than systematically.
Larval surveillance and source reduction efforts are often inadequate, and fogging operations frequently use ineffective insecticides, applied at the wrong times and places. The shortage of trained entomologists and vector control specialists, coupled with poor planning and weak accountability, has made these programs largely ineffective, leading to residual mosquito breeding.
Studies of Jahangirnagar University show that 70-80% of Aedes breeding sites exist in private or residential areas, yet many citizens still believe mosquito control is solely the government’s responsibility.
Simple weekly practices, such as cleaning water containers, rooftops, garages, and flowerpots are still not part of most households’ routines. Given that Aedes mosquitoes complete their life cycle in just 5-7 days, weekly cleaning is critical. Unfortunately, public awareness campaigns remain reactive and seasonal instead of being proactive and continuous.
Many assume that dengue will subside in winter, but urban ecology tells a different story. Basements of high-rise buildings, car-washing areas, construction sites, and water storage drums in areas with water shortages act as dry-season refuges for Aedes mosquitoes.
These sources are not dependent on rainfall, which means mosquito breeding and consequently, dengue transmission, can persist even during cooler months. Observations show that active Aedes populations remain in Dhaka’s buildings throughout winter, sustaining viral transmission through December and January.
The first step toward effective control should be the establishment of year-round larval and adult surveillance systems based on scientific data. Each city corporation and municipality should conduct ward-based larval surveys and create hotspot maps to identify high-risk zones and periods.
Because changes in rainfall and temperature are reshaping dengue seasonality, prevention strategies must incorporate climate data and weather forecasts. An integrated Dengue Early Warning System should be developed jointly by the Meteorological Department and the Directorate General of Health Services (DGHS) to enable preemptive vector control in high-risk areas.
Mosquito control should be viewed as an integrated vector management (IVM) process, not merely fogging. This requires sufficient manpower, training, and modern equipment in city and municipal mosquito control departments. Each ward should form a Dengue Control Taskforce including health workers, sanitation officers, community leaders, and local representatives, with regular monitoring and accountability mechanisms.
Since over 80% of Aedes breeding occurs inside homes and workplaces, community engagement is indispensable. Every household should inspect and clean potential breeding sites weekly. Nationwide awareness campaigns should be revitalized, with schools, universities, mosques, temples, and community organizations actively participating in these drives.
Breaking misconceptions about dengue requires science-based education from the school level. The national curriculum should include chapters on dengue prevention, mosquito biology, and public hygiene. Additionally, year-round awareness campaigns through TV, radio, and social media should normalize dengue prevention as a daily habit, not a seasonal response.
During peak transmission, hospitals face overwhelming patient loads. Every district and upazila hospital must have dedicated dengue corners, sufficient beds, trained staff, and strict adherence to fluid management guidelines. Private hospitals must also follow National Guidelines of Clinical Management of Dengue to prevent mismanagement and overmedication.
Sustainable dengue control demands enhanced research in entomology, virology, and ecology. Collaborative efforts between universities, research institutes, and the health directorate should focus on studying mosquito genetics, viral serotype evolution, and insecticide resistance. Bangladesh should also explore pilot programs using innovative technologies for vector suppression.
Poor waste management create mosquito habitats. Urban authorities must enforce an Integrated Solid Waste Management Policy, mandatory drainage systems in construction projects, and include mosquito prevention guidelines in the national building code.
In the era of digitization, technology must play a central role. A GIS-based dengue monitoring platform can allow citizens to report mosquito breeding sites or dengue cases via mobile apps or web portals, facilitating rapid response and localized planning. All city corporations’ data should feed into a central database to guide national policy formulation.
Finally, dengue control must be embedded within a national public health policy, not treated as a temporary project. The national budget should allocate specific funds for control programs, research, awareness, and hospital preparedness. Both central and local authorities must establish accountability and performance evaluation systems. Within the next five years, every city corporation should be mandated to implement a dengue-free city action plan.
Dengue has become a permanent urban health crisis in Bangladesh. Combating it requires science-driven planning, citizen participation, and administrative accountability. As climate change reshapes our seasons, our response must be year-round, data-driven, and coordinated.
It is time to move from neglect to preparedness, and from reaction to prevention.
Prof Dr Kabirul Bashar is an Entomologist and Public Health Specialist, Department of Zoology, Jahangirnagar University
Email: professorkabirul@gmail.com.