Bangladesh warns dengue outbreak could worsen after deadly September

Bangladesh entered October facing a worsening dengue outbreak after its deadliest month of the year, with experts warning that weather conditions could fuel further transmission and add pressure to hospitals already battling the world’s worst measles outbreak.

The resurgence of dengue, which causes fever and muscle and joint pain, follows the country’s deadliest outbreak in 2023 and is placing further strain on a healthcare system in which measles has killed more than 1,100 children this year.

“I was lucky to get a bed, but many dengue patients are still struggling to find one,” said police sergeant Shafiqur Islam, 30, who was discharged from hospital this week after receiving a blood transfusion.

“Many of my colleagues have also been infected. We spend our days serving the public, but often neglect our own health.”

Experts said recent rainfall and changing weather patterns could sustain dengue transmission through October, traditionally one of the peak months for the disease.

“Our forecasting model indicates that the dengue situation will worsen further in October,” said medical entomologist Kabirul Bashar of Jahangirnagar University, who called for targeted mosquito-control measures and stronger household prevention.

Disease becomes a nationwide challenge

The spread of the dengue-carrying Aedes mosquito beyond major cities has turned the disease into a nationwide challenge, Bashar said, warning that pesticide fogging alone would not be sufficient unless mosquito breeding sites were eliminated.

September’s rainfall could continue to drive infections through October because of a 45- to 60-day lag between rainfall and dengue transmission, he added.

At least 245 people have died and 79,620 dengue patients have been admitted to hospital since January, according to the health ministry. September recorded 148 deaths, sharply higher than the 43 deaths in August and 36 in July.

On Wednesday, six more people died and 1,948 new dengue patients were hospitalised, while 5,485 patients were receiving treatment nationwide.

There is no specific treatment for dengue. Doctors generally recommend rest, adequate fluids and painkillers such as paracetamol, while severe cases require hospital monitoring to prevent complications.

Climate adds uncertainty

Climate change is also adding uncertainty to dengue transmission patterns.

A Bangladesh-focused study covering the 22 years to 2022 found that temperature and rainfall in preceding months were closely associated with dengue transmission. Researchers said changing weather patterns could affect both mosquito populations and disease transmission.

Bashar said shifts in rainfall and humidity patterns were changing the seasonal behaviour of Aedes mosquitoes, allowing them to remain active for longer and extending breeding periods.

The findings are consistent with conclusions from the World Health Organization.

Experts call for stronger prevention

Public health specialists say prevention must extend beyond government campaigns, with eliminating stagnant water among the most effective ways to reduce mosquito breeding. Residents in many neighbourhoods, however, say breeding sites remain a concern despite mosquito-control efforts.

“There are a lot of mosquitoes in our area, but we haven't seen any initiative to control or eliminate them,” said Zahid Hasan, 32, whose four-year-old son recently recovered from dengue. Zahid has since developed a fever himself.

Prevention is essential to easing pressure on hospitals dealing with multiple outbreaks, said Mahmudur Rahman, a former director of the Institute of Epidemiology, Disease Control and Research.

“The health system has limited capacity to cope with simultaneous outbreaks,” he said. “Preventing infections by reducing mosquito breeding is critical.”

Government figures show that 21,520 measles cases have been confirmed since March 15, while more than 190,000 people have sought medical care for suspected measles or similar symptoms.