Dengue: Stuck in pilots while the outbreak worsens

Bangladesh is currently experiencing another severe dengue outbreak. On September 21, 2025, the country recorded its worst single-day surge this year: 740 new hospitalizations and 12 deaths. So far, 2025 has already seen over 46,000 cases and 192 deaths -- a jump over 80% in infections and almost 50% in fatalities compared to last year.

This is not a new crisis. Dengue has become a deadly seasonal cycle. What is new is that Bangladesh today has scientific tools far more advanced than fogging machines, but they remain stuck in research and pilot stages.

What tools do we have? 

1. Wolbachia mosquitoes: These are Aedes aegypti mosquitoes infected with the bacterium Wolbachia, which blocks the transmission of the dengue virus. Large-scale trials in Indonesia and Brazil have slashed dengue incidence. 

In Bangladesh, icddr,b has developed Wolbachia-infected Dhaka strains with strong virus-blocking traits. However, they are still in the lab and pilot stages, not yet in citywide use.

1. Sterile insect technique (SIT): Supported by the IAEA, SIT involves releasing sterile male mosquitoes, which, over time, cause the population to collapse. Bangladesh is preparing pilots in a few areas of Dhaka. But again, no broad deployment.
2. Biological larvicides (Bti): Safer than chemicals, Bacillus thuringiensis israelensis is a biological control agent that kills larvae. Dhaka North imported and started using Bti in 2023, and Chittagong is currently using it. This is the only advanced tool that has somewhat mainstreamed, though it remains slightly patchy.
3. Lethal ovitraps. Ovitraps: Bangladeshi researchers used ovitraps in several Dhaka neighbourhoods, including Azimpur, Dhanmondi–Mohammadpur, Gulshan–Karail, Mirpur, Malibagh, and 
4. Uttara, to collect Aedes aegypti eggs for insecticide resistance studies.  These were surveillance traps, not lethal ones, meaning no ovitrap trials for active dengue control have yet been conducted in Bangladesh.
5. AI-based hotspot prediction: Bangladeshi researchers have built machine learning models to forecast dengue outbreaks using weather and hospital data. Yet authorities rely on manual inspections and reactive spraying. 

The message is stark: Bangladesh has the tools, but almost all are still trapped in the pilot stage.

What is being done now

Hospitals have been directed to open dedicated wards and specialized treatment teams for dengue, and medical staff across hospitals are being trained in managing dengue cases. Meanwhile, city corporations continue vector control activities, such as spraying and the use of larvicides. Public campaigns urge citizens to clear stagnant water.

However, when it comes to advanced solutions, Wolbachia remains confined to labs, SIT trials in neighbourhoods, ovitraps for small pilots, and AI applications in academic papers. Only Bti has seen real use, and even that is not systematic.

This fragmented approach cannot meet the scale of today’s crisis.

Where the main problem lies

The bottleneck is not science, but rather a failure to scale up.

• Fragmented action: City corporations, the health ministry, and researchers act in silos without an empowered national task force.
• Reactive timing: Fogging intensifies only after infections surge, although outbreaks are often predictable based on rainfall and weather data.
• Surveillance blind spots: Hospital data is incomplete, vector mapping is sparse, and predictive models are unused.
• Weak community enforcement: Mosquitoes breed in homes, construction sites, and on rooftops, but penalties and door-to-door checks are inconsistent.
• Policy inertia: Promising research has not translated into operational citywide programs.

In other words, Bangladesh is stuck in a pilot program while dengue spreads unchecked.

What must be done now

1. National Dengue Command Task Force: Establish a cross-sectoral body with genuine authority to unify health, urban development, environmental protection, and research.
2. Move beyond pilots: Deploy Wolbachia in high-incidence wards like Mirpur and Uttara; fast-track SIT expansion; mass-procure ovitraps; mainstream Bti as a permanent municipal practice.
3. Smart surveillance: Mandate daily digital reporting from hospitals and integrate predictive AI models to guide interventions.
4. Community enforcement: Penalize construction sites and households that harbour stagnant water; mobilize schools, mosques, and community groups for neighbourhood clean-ups.
5. Hospital readiness: Stockpile fluids and blood, train staff continuously, and ensure surge wards are prepared in Dhaka, Barishal, and Chittagong.
6. Long-term sustainability: Invest in drainage, enforce building codes, improve waste management, and prepare for the rollout of WHO -- prequalified dengue vaccines when national regulatory and advisory bodies approve them and ensure safety protocols are in place.

Bangladesh is experiencing one of its worst dengue outbreaks. The numbers are rising, the hospitals are full, and the disease is spreading nationwide. 

Yet the tools to fight back against Wolbachia, SIT, ovitraps, and AI are still locked in pilot projects.

If Indonesia and Brazil can scale Wolbachia, Bangladesh can too. If Brazil can mass-produce sterile mosquitoes, so can we. The difference is political urgency.

We must break free of the pilot stage. Otherwise, we will continue to count deaths every September while solutions gather dust in laboratories.

We cannot plead ignorance. The solutions are known, the pilots are running, and the warnings are clear. The only question is whether Bangladesh will act in time or face yet another outbreak, one we will have to admit was preventable.

Shaikh Afnan Birahim is a writer and analyst. He is a postgraduate student at the University of Glasgow.