The Missing Link in Dengue Prevention

Dengue prevention in Bangladesh has often been approached as a mosquito-control exercise. When cases rise, attention turns to fogging, insecticide spraying, larviciding and emergency hospital preparedness. These interventions are important. But the persistence and rapid expansion of dengue suggest that something fundamental is still missing from the way we approach prevention. That missing link is sustained, community-level prevention supported by local evidence and coordinated urban management.

The current situation in Chattogram makes the issue particularly relevant. According to the District Civil Surgeon’s Office, the district recorded 4,914 dengue cases and 21 deaths between January 1 and October 5, 2026. September alone accounted for 2,430 cases and 16 deaths. There were 1,202 cases in August, following 536 in July. The national picture is equally concerning. The Directorate General of Health Services reported 92,216 dengue hospitalisations and 289 deaths by October 7. The number of hospitalisations has continued to increase despite the end of the traditional monsoon period. These numbers should prompt more than another round of emergency mosquito-control campaigns. They should make us reconsider how dengue prevention is designed and implemented.

For years, fogging has remained one of the most visible forms of mosquito control. It is also one of the easiest interventions for citizens to recognise: a machine arrives, smoke fills the street, and people feel that something is being done. But visibility should not be confused with effectiveness. Fogging primarily targets adult mosquitoes. It does not eliminate the containers and locations where Aedes mosquitoes breed. If water remains in discarded containers, flowerpot trays, tyres, construction materials, rooftop spaces or other small receptacles, new mosquitoes can emerge after the spraying operation is completed. This is why dengue prevention cannot depend predominantly on reactive spraying.

Fogging primarily targets adult mosquitoes. It does not eliminate the containers and locations where Aedes mosquitoes breed. If water remains in discarded containers, flowerpot trays, tyres, construction materials, rooftop spaces or other small receptacles, new mosquitoes can emerge after the spraying operation is completed. This is why dengue prevention cannot depend predominantly on reactive spraying.

Aedes mosquitoes do not require large bodies of polluted water. Small quantities of stagnant water can be sufficient. This makes dengue fundamentally different from many public-health problems that can be addressed through large-scale infrastructure alone. The breeding site may be inside a house, on a rooftop, in a construction site, in a school compound or in a commercial establishment. This creates an important policy challenge: the government cannot physically inspect and clean every potential breeding site every day. That is where communities become essential. A sustainable dengue-control programme needs residents, landlords, building managers, schools, businesses, construction companies and local institutions to become part of routine vector surveillance and source reduction.

Yet community participation should not simply mean telling citizens to “be aware”. Awareness is only useful when it translates into specific behaviour. Instead of a generic message such as “prevent dengue”, people need practical instructions: inspect water-holding containers every week; empty or cover them; clean rooftop and drainage areas; remove discarded items that can collect rainwater; report persistent breeding sites; and seek appropriate medical advice when symptoms develop. The difference may appear small, but it represents a shift from awareness campaigns to behaviour-oriented prevention.

Another missing element is the use of local data. Dengue does not spread uniformly across a city. Chattogram City Corporation has already identified eight high-risk wards - 2, 3, 17, 18, 19, 32, 34 and 39 - based on a DGHS vector-density survey. A month-long special control programme was subsequently launched in those areas. This is a useful starting point. But risk mapping should not become a one-time exercise. Dengue surveillance should continuously bring together information on human cases, mosquito density, breeding sites, rainfall, environmental conditions and neighbourhood-level risk. Such information can help authorities determine where to inspect, where to conduct larval control, where to intensify community mobilisation and where health facilities may need additional preparedness.

Another issue is that dengue is often placed entirely within the health sector. But many of its determinants lie outside hospitals and even outside the conventional health system. Construction management, waste disposal, drainage, water storage, housing conditions and urban planning all influence the availability of mosquito breeding sites. A construction site with exposed containers and irregular water management is therefore not merely an environmental nuisance. It can become a public-health risk. Similarly, a household cannot be expected to control dengue effectively if its surrounding environment repeatedly accumulates stagnant water. This means city authorities need stronger coordination between health departments, city corporations, waste-management services, ward-level administration, construction regulators and community organisations. Dengue prevention is therefore not only a health-sector responsibility. It is an urban-governance responsibility.

There is another issue that deserves greater attention: how we involve communities. Too often, health communication follows a one-way model. Authorities issue instructions and residents are expected to follow them. But communities often know where problems actually occur: which building has standing water, which vacant plot remains neglected, where construction materials are stored, or which drainage point repeatedly becomes blocked. This local knowledge can strengthen surveillance if authorities create mechanisms to collect and act on it. Ward-level dengue committees, community volunteers, schools, resident associations and local health workers could play a role in identifying breeding sites and monitoring preventive actions.

Prevention needs to continue before cases begin rising. That means routine inspection of high-risk premises, regular monitoring of mosquito density, enforcement of construction-site requirements, removal of breeding sites and continuous community communication. It also means preparing health facilities before they become overwhelmed. The recent national experience demonstrates why this matters. By early October, Bangladesh had already recorded more than 90,000 dengue hospitalisations in 2026. Experts have warned that continued rainfall can sustain transmission because mosquito breeding and subsequent increases in human cases do not occur simultaneously; there is a time lag between favourable environmental conditions and rising infections. Therefore, waiting for hospital admissions to rise before intensifying prevention means responding after transmission has already expanded.

Chattogram has an opportunity to make that shift. The missing link in dengue prevention is not necessarily another machine, another campaign or another slogan. It is the connection between data, local government, urban management, health services and the everyday behaviour of communities. If we can build that connection before the next surge, dengue control can become a sustained public-health function rather than an annual emergency response. And that is ultimately the difference between responding to dengue and preventing it.