Mosquito war: Bangladesh spends more, but dengue persists
Dhaka’s two city corporations alone have allocated more than Tk1,037 crore for mosquito control over the past decade, with their combined allocation reaching Tk242 crore in FY26
Highlights:
- Dhaka has spent over Tk1,037 crore on mosquito control in a decade.
- Insecticide resistance and ineffective spraying undermine Bangladesh's mosquito-control efforts.
- Dengue deaths reached 294, while treatment costs burden families nationwide.
- Wolbachia technology has reduced dengue cases by over 75% in some countries.
- Bangladesh has no decision yet on introducing the Qdenga dengue vaccine.
- Experts advocate integrated mosquito management combining surveillance, breeding-site removal, chemicals and biological solutions.
Once, Dhaka's war on mosquitoes was so aggressive that helicopters were deployed to spray insecticides over the city. The campaign, led by then East Pakistan health minister Habibullah Bahar Chowdhury, was credited with making Dhaka's mosquito-infested nights bearable for years.
More than six decades later, the mosquito war continues – but with diminishing returns. City authorities are spending heavily on insecticides, fogging and other control measures, while dengue and other mosquito-borne diseases continue to spread.
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Dhaka's two city corporations alone have allocated more than Tk1,037 crore for mosquito control over the past decade, with their combined allocation reaching Tk242 crore in FY26. Yet a pre-monsoon survey found Aedes larvae density above the acceptable threshold in 63 of Dhaka South's 75 wards, including 27 considered highly vulnerable to dengue transmission.
The problem is no longer confined to Dhaka.
Dengue has become a national health burden, while Bangladesh's mosquito-control system remains heavily dependent on chemical insecticides despite growing resistance among local Aedes mosquitoes. Officials say the mosquitoes have developed resistance to most of the standard public-health chemicals used in the country.
Almost all countries dealing with malaria or dengue still use insecticides for mosquito control. Indonesia and Brazil remain among the largest aggregate consumers of insecticides globally. In South Korea, roughly 72% to 94% of its vector-control budget is spent on chemicals and insecticides.
A 2024 study published in National Library of Medicine suggests invasive Aedes aegypti and Aedes albopictus mosquitoes transmit viruses that cause dengue, chikungunya and Zika, posing a huge public health burden, estimated at $94.7 billion at minimum.
The vector control market is rising rapidly. Vector control is a public health strategy and set of methods that involve a combination of biological control (predators), chemical control (insecticides), and personal protection (repellents/bed nets).
The broader vector control market is valued at approximately $23.42 billion, with chemical controls dominating nearly 60% of the insect pest management sector.
A 2020 estimate suggests that Bangladesh spends at least Tk5,476 crore, government and household expenses put together, to control mosquitoes using repellents, bats and nets, as well as insecticides sprayed by city authorities.
Industry insiders say the market for mosquito repellents in Bangladesh has been growing at a rate of 18 to 20 percent annually for the last few years with dengue and chikungunya surging.
According to an industry estimate from 2020, the annual market for mosquito coils was worth around Tk1,480 crore, aerosols Tk200 crore, vapourisers Tk14 crore and mosquito bats Tk50 crore. Non-branded mosquito coils widely used in rural areas were not included in the estimate.
Authorities in two major cities – Dhaka and Chattogram – keep aside a substantial amount in their annual budgets for mosquito control drives which include pesticide procurement and spraying.
Dhaka city authorities in 2023 sent teams to Germany and France to learn how to properly use fogging machines. A similar initiative of Chattogram City Corporation was cancelled earlier this year after Prime Minister Tarique Rahman did not approve a proposal to send a team to the USA to study mosquito-control technologies and biological larvicide production.
Various such efforts however did not so far bring much relief to city people, as mosquitoes continued breeding and spreading diseases.
A pre-monsoon survey of Aedes larvae conducted by Dhaka South in May found mosquito density above the acceptable threshold in 63 of its 75 wards, of which 27 were considered highly vulnerable to dengue transmission.
Residents in most of the port city's 41 wards say they see no respite from mosquito bites as fogging machine operators are rarely seen.
Dengue's rising cost to families
Dengue is no longer an urban health issue, it has grown into a bigger national health problem with a growing number of cases found beyond Dhaka. The death toll from dengue reached 294 this year as of Thursday, with nearly 1,900 admitted to hospitals on average daily across the country last week.
Though spread of Aedes mosquitoes beyond the capital is driving infections, treatment capacity and experienced personnel remain mostly concentrated in Dhaka, forcing critical patients, mainly children, to be referred to Dhaka, overstressing the capital's healthcare facilities.
Faruk Ahmed's four-and-half year child, though tested dengue-negative, was referred from Feni to Dhaka's Shishu Hospital for better care. He said he was lucky to get his son admitted on Wednesday morning.
Longer stay in hospitals sends treatment cost mounting, making it unaffordable for most families.
Mohammad Liton, a tea-stall owner in Dhaka, has his three-year old daughter, Lisa, admitted in a public hospital in Dhaka, but he had to get some tests done in a private clinic spending Tk3,600. Hospitalisation and frequent blood tests cost him Tk15,000, while he had to keep his small shop shut.
For 13-year Arhaan Safwat, who required ICU facilities, the expense was far bigger, costing the family Tk1.40 lakh for four days' stay at a private facility, his mother Salma Afrose said.
Dr Syed Abdul Hamid, professor at the Institute of Health Economics, University of Dhaka told TBS, cited a 2023 study suggesting that treatment cost of a dengue patient ranged from Tk7000 to Tk12,000 for a family in a public hospital, which might go up to Tk50,000-Tk1 lakh in private facilities.
He suggested creation of a national health fund to support hospitals to provide medicine, saline and tests free of costs for patients.
Moving away from insecticides?
While city authorities are taking the blame for the failure in mosquito control drives, entomologists complain about unscientific approach, irregular spraying of insecticide and the absence of an entomology-based strategy for the programme's poor results.
This is a worldwide scenario. Despite massive public and private spending on insecticides, larvicides, and household repellents, studies show that global management investments are heavily outpaced by the actual damages and medical costs resulting from vector-borne diseases.
The world is gradually shifting away from relying solely on insecticides and exploring innovative ways to control mosquitoes to keep vector-borne diseases in check. Countries are reducing their reliance on chemical insecticides because mosquitoes are rapidly developing widespread resistance, creating a costly "pesticide treadmill" that harms the environment and human health.
Apart from insecticide residence, constant reapplication of the same traditional method becomes progressively more expensive and less effective, with chemicals harming non-target wildlife like honeybees and posing direct public health risks. These exposures are among reasons for countries trying safer and more effective alternatives to fight mosquitoes.
How Wolbachia works
Some nations are experimenting with eco-friendly biological solutions, such as releasing male mosquitoes treated with the bacterium [Wolbachia] or using sterile insect techniques (SIT) managed by organizations.
The World Mosquito Program is campaigning Wolbachia in more than a dozen countries. It says the method is safe for humans and the environment. Evidence shows that virus transmission is significantly reduced in areas where Wolbachia is maintained at a high level.
The World Health Organization has recognized that the Wolbachia method demonstrates public health value against dengue.
Under this method, scientists release Aedes aegypti mosquitoes infected with natural Wolbachia bacteria which compete with the dengue virus inside the mosquito, preventing the virus from multiplying and spreading to humans.
The WHO says this "self-sustaining method" is active in countries such as Brazil, Singapore, Indonesia, Australia, and Colombia, protecting millions and lowering dengue cases by over 75%. Singapore sees even more success, with lab-bred male Wolbachia mosquitoes helping the mosquito population drop up to 90%.
This is not about eradicating mosquitoes, but making them less capable of spreading disease.
A vaccine-for-all not yet available
There is a growing public health need for effective preventive interventions against dengue, a disease caused by four viruses, termed serotypes 1-4.
Currently, only one vaccine is available for dengue prevention. WHO recommends the use of Q-denga® (TAK-003) in children aged 6–16 years in settings with high intensity of dengue transmission. The vaccination course consists of two injections given 3 months apart.
Manufactured by Japan's Takeda Pharma, Q-denga has been authorized for use in more than 40 countries, including Argentina, Brazil, Indonesia, and Thailand. It is not recommended for use in the United States.
Several other dengue vaccines or dengue vaccine models are being evaluated in clinical trials and ongoing research studies.
On 20 July 2026, India approved QDENGA as its first dengue vaccine. It is expected to launch commercially in the first half of 2027, with the two-dose course estimated to cost ₹6,000-12,000.
However, Bangladesh has not yet taken any decision about the dengue vaccine.
Should Bangladesh go for Wolbachia or vaccines?
Entomologists point to irregular spraying, an unscientific approach and the absence of an entomology-based strategy, making mosquito control drives less effective and progressively expensive.
Other countries are therefore experimenting with alternatives, including biological methods such as Wolbachia and sterile insect techniques.
But Bangladesh may not have to choose between insecticides, Wolbachia and vaccines. As medical entomologist Khabirul Bashar points out, such tools should form part of an integrated vector-management strategy rather than be treated as stand-alone solutions.
He also cites Kolkata's experience, where sustained "search and destroy", breeding-source management, larvicide use and community engagement helped control mosquitoes without relying on Wolbachia.
That suggests that one new technology alone will not help win the mosquito war. Mosquito control needs to become more scientific, targeted and integrated — combining surveillance, breeding-source elimination, appropriate chemical use, community participation and, where evidence supports it, newer biological tools. Mosquitoes are here to stay. Worldwide, researchers are now trying to make them less dangerous.
After decades of spending on fogging and insecticides, Bangladesh cannot afford to keep measuring success by how much chemical it sprays. The real test is whether fewer mosquitoes breed, fewer people fall sick and families spend less treating preventable disease.
