DENV-3 dominance raises alarm

Dengue infections are rising rapidly in Bangladesh, with three more deaths and 1,463 new hospital admissions reported in the latest 24 hours. The growing dominance of DENV-3 has raised fresh concerns about the severity of the outbreak, as experts warn that people previously infected with another dengue serotype may face a greater risk of severe disease.

The latest Directorate General of Health Services (DGHS) data show that 46,938 dengue patients have been hospitalised and 133 have died this year as of Wednesday morning. Of the deaths, 13 occurred in June, 36 in July, 43 in August and 36 during the first nine days of September.

Hospital admissions rose sharply from 2,907 in June to 9,206 in July and 20,536 in August. Another 11,092 patients were admitted during the first nine days of September.

Experts warn of a difficult period ahead 

The Institute of Epidemiology, Disease Control and Research (IEDCR) said DENV-3 was detected in around 91.5 percent of the dengue samples tested this year.

IEDCR collected samples from 1,097 dengue patients at nine hospitals �" six in Dhaka and three outside the capital �" in late July and early August. Of the 71 samples that have so far undergone serotyping, DENV-3 was detected in 65, while the remaining six contained DENV-2.

DENV-3 BECOMES DOMINANT
IEDCR surveillance shows a significant shift in circulating dengue serotypes in recent years. In 2024, DENV-2 accounted for 73.2 percent of detected infections, followed by DENV-3 at 20.2 percent, DENV-4 at 7.7 percent and DENV-1 at 1.9 percent.
In 2025, DENV-2 declined to 48.5 percent while DENV-3 increased to 35 percent. DENV-4 accounted for 9.2 percent and DENV-1 for 7.4 percent.

In 2026, DENV-3 has become overwhelmingly dominant, accounting for more than 90 percent of tested cases.
Virologists say the shift is epidemiologically significant because people previously infected with DENV-2 may be more vulnerable to severe secondary infection with DENV-3.

The World Health Organisation says dengue has four serotypes �" DENV-1, DENV-2, DENV-3 and DENV-4. Infection with one serotype provides long-term immunity against that type but limited protection against the others, meaning a subsequent infection with a different serotype can increase the risk of severe disease and death.

IEDCR Director Dr Quazi Ahmed Zaki told The Daily Observer that the identification of DENV-3 is based on the samples collected so far. He said people previously infected with one serotype face a greater risk of severe dengue when infected with another, particularly if treatment is delayed. He urged collective efforts to prevent the spread of the disease.

WARNING AHEAD OF PEAK PERIOD
State Minister for Health and Family Welfare Dr AMA Muhith warned at a programme on Wednesday that the dengue situation could become severe unless effective preventive measures were taken in time. He said infections could increase from the last week of September through October.

Health officials said infections have increased slightly over the past two weeks compared with the same period last year, although the fatality situation remains under control.

Speaking to reporters on Wednesday after an urgent consultation meeting on National Dengue Prevention Day, State Minister for Local Government, Rural Development and Cooperatives Mir Shahe Alam announced a three-month-long “Nationwide Dengue Prevention and Cleanliness Drive-2026”, beginning on September 12. Prime Minister Tareq Rahman will inaugurate the programme.

The government’s primary objective is to destroy Aedes mosquito breeding grounds and ensure cleanliness. Five beds have also been kept ready for dengue patients at district hospitals.

Dr AMA Muhith said preparations had been made to prevent shortages of hospital beds, saline and testing kits during the peak period. Adequate testing kits and saline are currently available, while designated dengue beds have been activated at government hospitals. Additional beds will be rearranged if necessary.

DENGUE SPREADS BEYOND URBAN AREAS
Public health expert Dr Zakia Ferdousi Khanom told The Daily Observer that dengue is no longer confined to urban areas.
She said unplanned urbanisation, increased use of canned and packaged food and indiscriminate waste disposal are creating Aedes mosquito breeding grounds across the country. 

Water shortages are also encouraging water storage, while stagnant water in holes, containers and discarded single-use cups and plastic items is creating breeding sites in hilly areas.

With hospital admissions climbing and DENV-3 now overwhelmingly dominant, health authorities face a critical period as Bangladesh heads towards the expected peak of dengue infections.