Updated : 12 October 2026, 01:42
Tuhin Shubhra Adhikary
While dengue cases have surged across much of the country this year, Sylhet and Rangpur divisions have remained relatively less affected, a trend epidemiologists and health officials attribute to environmental, demographic and urbanisation factors.
Once largely concentrated in Dhaka and other major cities, dengue has spread nationwide in recent years, with coastal divisions such as Khulna and Barishal reporting increasing cases.
However, Sylhet and Rangpur have consistently recorded fewer cases and deaths.
With the country’s dengue caseload approaching one lakh and deaths exceeding 300 this year, Rangpur has reported 1,061 cases and no deaths, while Sylhet has recorded 426 cases and two deaths, according to the Directorate General of Health Services (DGHS).
In 2023, when Bangladesh recorded its highest-ever dengue caseload and death toll, with 3,21,179 cases and 1,705 deaths, Sylhet reported 1,435 cases and one death, while Rangpur recorded 5,540 cases and 10 deaths.
Experts cite rainfall, lower urbanisation, fewer Aedes mosquitoes and limited population movement
In 2025, the country recorded 102,861 cases and 413 deaths, including 426 cases and two deaths in Sylhet and 1,061 cases and no deaths in Rangpur. A similar trend was observed in 2024.
Mahbubul Alam, Sylhet divisional director of DGHS, attributed the division’s lower dengue burden to heavy rainfall, mosquito-control programmes and the near absence of Aedes aegypti mosquitoes.
Sylhet receives around 5,500mm of annual rainfall, which keeps water flowing and reduces stagnation and mosquito breeding, he said.
He said most dengue patients admitted to Sylhet hospitals had travelled to Dhaka, suggesting they contracted the disease there.
He also credited city corporations’ cleaning and mosquito-control drives with limiting mosquito populations.
Entomologist GM Saifur Rahman, an associate professor in the Department of Zoology at the National University of Bangladesh, said Rangpur’s relatively low urbanisation, limited industrial development and lower population movement could explain its lower dengue burden.
“Urbanisation and dengue transmission are closely linked. In urban areas, sites with stagnant water are more common, which create ideal environment for mosquito breeding,” he said.
“This can explain Rangpur’s lower dengue burden compared to neighbouring Rajshahi division, where urbanisation is increasing,” he added.
Wazed Ali, Rangpur divisional director of DGHS, cited limited travel between Rangpur and dengue hotspots such as Dhaka, along with lower Aedes mosquito density, as possible reasons.
In contrast, Saifur said coastal areas such as Khulna and Barishal offered more favourable conditions for Aedes mosquito breeding.
Salinity often forces households to store water in containers and tanks, creating potential breeding sites, particularly in large containers that are difficult to clean regularly, he said.
High humidity and rainfall also favour mosquito breeding in coastal areas, he added.
This year, Khulna recorded the second-highest caseload and death toll after Dhaka, while Barishal ranked fourth in both categories.