Dengue used to be confined to main cities but transmission has been widespread since 2023 Mosquito control measures hindered by July-August unrest and regime change DHAKA: Bangladesh’s dengue fever outbreak this year is its second deadliest on record, raising concerns over widespread transmission as infection rates show no signs of slowing. Each year, dengue fever becomes a major health concern in Bangladesh during the monsoon season between July and October, with thousands of people contracting the potentially deadly virus transmitted by the Aedes mosquito. The incidence of the disease has increased dramatically since the early 2000s, with the worst outbreak claiming 1,705 lives last year. This year, the dengue toll is already the second worst in history, with 69,922 people hospitalized and 342 dengue-related deaths, according to Directorate General of Health Services data as of Saturday. While previous outbreaks would normally end in October, this year it saw the highest infection numbers, with more than 30,870 people admitted to hospital. “This trend of dengue infection will probably continue till next January. We can expect a decline in the infection rate in some two weeks from now, but it will still be higher in comparison with November and December in the previous years,” Prof. Kabirul Bashar, an entomologist from Jahangirnagar University in Dhaka, told Arab News. “There are various reasons for the rise of dengue outbreak this year. Among them, the impact of climate change is very prominent here. It has created a suitable environment for the breeding of the Aedes mosquitoes. Also, there are many dengue patients — they, too, are the virus’s carriers.” While dengue outbreaks in Bangladesh have usually been confined to urban areas, with cities such as Dhaka reporting most of the cases, since last year, the virus has been reported in every district, even reaching remote and previously unaffected rural areas. Rising global temperatures have accelerated the spread of the Aedes mosquito, the primary carrier of the virus, while heavy rainfall has created an ideal environment for the insects to breed. An additional problem faced by Bangladesh this year was the lack of dengue control campaigns, with efforts disrupted by the sudden regime change in the country amid unrest in July and August that led to the ouster of the previous administration. “The impacts of climate change and insufficient mosquito control measures by authorities have been key factors driving the increase in the dengue outbreak,” Bashar said. “The most worrying issue is the high death rate. No other country has such high mortality. Our health authorities need to consider this issue very seriously.” Deaths during the current outbreak are mostly occurring as patients come to hospitals at a late stage, often after a long time traveling, as most specialist and testing facilities are available only in major urban centers. Since last year, many patients have contracted the virus for a second or third time — some even with multiple strains, which decreases their chances of survival. “There are four strains of dengue. Last year, we also found patients infected with all of them. This year, too,” said Dr. Khondoker Mahbuba Jamil, virologist laboratory head of the Institute of Public Health in Dhaka. “The disease becomes more severe when someone is infected for the second time, leading to immunological complications ... And when someone is infected with a different strain for the second time, their immunological response becomes excessive. That’s what is happening this time.”