Long-Standing B3 Variant Underpins Bangladesh Measles Outbreak

Genetic analysis conducted by two premier laboratories in Bangladesh has confirmed that the ongoing measles outbreak, affecting both children and adults, is being driven by a long-standing strain known as the B3 variant. Scientists and researchers have established that the virus did not originate from external sources, as the strain has been actively circulating within the country for many years.

The genome sequencing was carried out independently by the National Polio, Measles, and Rubella Laboratory at the Institute of Public Health (IPH) and the Institute of Epidemiology, Disease Control and Research (IEDCR). Both laboratories yielded identical results, identifying the B3 variant as the specific strain responsible for the current spike in infections across the nation.

Genetic Analysis and Strain History

The National Polio, Measles, and Rubella Laboratory at the IPH, which is accredited by the World Health Organisation (WHO), has been testing and tracking measles variants since 2014. Dr Khondker Mahbuba Jamil, a virologist at the institute, confirmed to our representative that genome sequencing of 35 samples collected between December 2025 and February 2026 explicitly identified the B3 variant. Data from these evaluations are routinely shared with the WHO. Furthermore, the IEDCR laboratory analysed an additional 38 samples in May, corroborating the definitive presence of the B3 strain.

Globally, 24 distinct genotypes of the measles virus have been identified. In Bangladesh, the B3 variant has historically been the dominant strain since it was first recorded in 2014. The only recent exception occurred during the 2017–2018 outbreak in Sitakunda, Chittagong, where the D8 variant was detected. Aside from that specific period, the B3 strain has consistently remained the primary cause of local infections. Dr Jamil noted that because this variant has been continuously circulating locally, claims suggesting the outbreak originated from Rohingya refugee camps are factually incorrect.

Fatality Toll and Epidemiological Data

According to a bulletin issued on Wednesday by the Integrated Control Centre of the Directorate General of Health Services (DGHS), 7 individuals died with measles symptoms during the preceding 24-hour reporting period (from 8:00 am Tuesday to 8:00 am Wednesday). This brought the cumulative death toll past the 600 mark.

Public health experts have pointed out that due to diagnostic limitations, many cases cannot be formally certified as measles, meaning the actual toll directly attributable to the disease is likely higher than official figures suggest. The fatalities began escalating at the start of March and continue to rise, with children under the age of five accounting for 80% of the recorded deaths.

Measles Outbreak Mortality and Variant Data:

Institutional Response and Operational Criticisms

Despite public debates and reported shortages concerning the measles vaccine, the health sector has struggled to curb the mortality rate among infected children. Public health professionals have alleged that management failures have severely hindered containment efforts since the onset of the outbreak. For instance, in early March, authorities at Rajshahi Medical College Hospital placed infected children in the same wards as general paediatric patients, despite being fully aware of the highly contagious nature of the virus.

The clinical progression of measles frequently leads to secondary complications such as diarrhoea, otitis media (ear infections), visual impairments, and severe pneumonia. The majority of recorded fatalities are caused by pneumonia. In response to the crisis, the Ministry of Health has implemented several emergency measures:

• Allocating additional mechanical ventilators to multiple hospitals.

• Instructing state-run hospitals to establish dedicated isolation wards for measles patients.

• Repurposing the DNCC Market Covid-19 Hospital in the Dhaka North City Corporation as a specialised treatment centre for measles.

• Expanding nationwide vaccination coverage to suppress further transmission.

Professor Zahid Raihan, Additional Director General (Administration) of the DGHS, stated to our representative that the mass vaccination campaign has successfully reduced overall infection rates, which is expected to lower the mortality rate subsequently. However, he cautioned that during this season, many children contract and succumb to standard pneumonia, meaning not every paediatric death can be automatically attributed to measles.

Conversely, Professor Be-Nazir Ahmed, former Director of Disease Control at the DGHS, criticised the institutional response, stating to our representative that a full-scale epidemic occurred without receiving the necessary strategic prioritisation or effective clinical management.