As dengue infections and deaths in the country remain at an alarming level, the government and the two city corporations in the capital have intensified cleanliness drives, mosquito control, public awareness campaigns and medical preparedness to prevent the spread of the disease.
However, experts have said that spraying insecticides or conducting cleanliness drives alone is not enough to control dengue. They emphasised the need to identify and destroy actual Aedes mosquito breeding grounds, assess the effectiveness of insecticides and increase regular surveillance in high-risk areas.
According to the Directorate General of Health Services (DGHS), 116,990 dengue patients had been hospitalised in the country up to 21 October this year, while 364 had died of the disease.
Entomologist Dr Kabirul Bashar, a professor in the Department of Zoology at Jahangirnagar University, told BSS that the dengue situation could remain alarming throughout October and November.
"Although the outbreak may decline somewhat in November, it may be necessary to wait until December for significant improvement," he said.
Prof Bashar said field-level surveillance needed to be strengthened alongside ongoing preventive measures to control infections.
He said the first step in controlling dengue was to identify Aedes mosquito breeding grounds. He suggested regular monitoring to determine where mosquitoes were breeding, which types of places contained the most larvae and how effective the insecticides used for mosquito control were.
Indiscriminate use of insecticides without identifying breeding grounds could not produce the desired results, the entomologist said.
Aedes mosquitoes do not breed only in drains or along roads. They can also breed inside homes, in buildings under construction, in basements and parking areas, in containers left on rooftops and verandas, in flowerpots and water tanks, and in stagnant clear water accumulated in other places.
Water collecting in hidden areas of buildings or between two buildings can also become breeding grounds, Prof Bashar said, adding that such places often remain outside regular cleanliness drives.
"As a result, even if roads and drains are cleaned, mosquitoes can spread again from breeding grounds inside buildings," he said.
Since taking office in February this year, the present government has taken various measures to tackle dengue.
The Ministry of Health and Family Welfare has announced a three-month awareness programme. Around 3,000 doctors have also received refresher training in dengue patient management. Initiatives have been taken to ensure adequate hospital beds, testing kits and saline supplies at government hospitals across the country.
Dhaka North City Corporation (DNCC) has intensified mosquito control and cleanliness activities in the capital. It is regularly conducting larviciding, fogging and larva destruction, and taking necessary measures after identifying mosquito breeding grounds and hotspots.
Cleanliness drives, public awareness rallies and mobile court operations to destroy Aedes mosquito larvae are also being conducted in different areas.
The DNCC has opened several mobile phone numbers for emergency health advice, information on mosquito control and communication regarding larva testing amid the dengue outbreak. The numbers are 01716-063425, 01773-393276 and 01715-238754.
DNCC Administrator Md Safiqul Islam Khan told BSS that various initiatives had been taken alongside regular larviciding and fogging to control dengue.
Public awareness activities are being conducted with the participation of members of the Bangladesh National Cadet Corps (BNCC) and Bangladesh Scouts, he said. Views-exchange meetings have also been held with imams and khatibs of mosques and the heads and principals of schools, colleges and madrasahs.
Noting that public awareness was the most important factor in controlling dengue, the DNCC administrator urged people not to allow water to accumulate on rooftops or verandas of their homes.
Meanwhile, Dhaka South City Corporation (DSCC) is conducting integrated cleanliness activities by dividing its 75 wards into 10 zones. It plans to continue the programme for the next three months, with special drives every Saturday.
In its pre-monsoon survey, 63 of the 75 wards were identified as dengue-prone. Based on the findings, mosquito control activities have been intensified in high-risk areas.
Speaking to BSS, DSCC Administrator and valiant freedom fighter Md Abdus Salam said dengue had become a national crisis.
"The Prime Minister has given the highest priority to dengue prevention and treatment and issued directives accordingly," he said. However, he added, the disease could not be prevented through government initiatives alone; people also needed to be aware and act responsibly.
Public health expert Dr Mushtaq Husain, a former chief scientific officer at the Institute of Epidemiology, Disease Control and Research (IEDCR), said that merely spraying smoke with fogging machines or conducting seasonal inspections and collecting fines was not enough.
"Regular measures must be taken to destroy larvae in various places, including under-construction buildings, abandoned vehicles, water accumulated on rooftops, open drums, flowerpots and broken containers," he said.
The expert said many people in coastal areas stored rainwater for long periods. In such cases, it was essential to train people and provide them with the necessary materials to use safe larvicides or water purification technologies, he added.
The spread of dengue could be reduced if preventive activities were intensified immediately after rainfall, Dr Mushtaq said.
According to the World Health Organization (WHO), more than 2.2 million people in 97 countries and territories worldwide were infected with dengue between January and August this year, with around 1,200 deaths.
The Pan American Health Organization reported around 1.6 million suspected cases in different parts of the Americas this year, with more than 500 deaths.
Although several countries, including Brazil and Colombia, continue to face pressure from infections, the number of cases in the region has declined somewhat compared with last year.
Meanwhile, dengue infections continue in several Southeast Asian countries, including Vietnam, Indonesia, Malaysia, Cambodia and Thailand.
According to data cited by the European Centre for Disease Prevention and Control, more than 1.5 million infections and over 500 deaths were reported worldwide across more than 90 countries up to July.
Dr Mushtaq said climate change, urbanisation, rainfall patterns and the breeding conditions of Aedes mosquitoes were contributing to the spread of dengue.
He stressed the need to strengthen coordinated efforts to identify infected people early, ensure timely treatment for patients with severe dengue and destroy mosquito breeding grounds.
Prof Bashar emphasised the importance of regularly assessing insecticide quality, application methods and field-level results to determine the effectiveness of mosquito control activities.
Before repeatedly applying the same type of insecticide, he said, it was essential to test whether it remained effective in killing mosquitoes.
Prof Bashar said greater information-sharing between the Health Services Division and local government institutions would make it easier to identify areas at risk of infection and take effective measures.
The experts said public participation was essential alongside government initiatives to prevent dengue.
They observed that a coordinated approach combining cleanliness drives, science-based mosquito control, effective medical services and public awareness could play an important role in preventing the spread of the disease.