The ongoing measles outbreak in Bangladesh is being fuelled by suboptimal population immunity, with most deaths occurring among the unvaccinated children under two years of age, according to the latest Disease Outbreak News released by the World Health Organization.
The WHO on Friday said that gaps in routine immunisation had created pockets of susceptible populations, allowing the highly contagious virus to spread rapidly across the country.
Since mid-March, the outbreak has expanded to a large part of the country, with transmission reported from most districts and thousands of suspected and confirmed cases recorded.
Young children, particularly those aged between six months and five years, have been the most affected, with a significant proportion of deaths reported among infants who were either unvaccinated or under-vaccinated.
According to the WHO, measles is one of the most contagious viral diseases and it warned that even small gaps in immunisation coverage could trigger large-scale outbreaks.
To control the situation, the agency recommended maintaining at least 95 per cent vaccination coverage with both doses of the measles-containing vaccine across all areas, ensuring that no communities are left behind.
It also urged the authorities to strengthen integrated epidemiological surveillance for measles and rubella to ensure early detection and rapid response to suspected cases across all healthcare facilities.
Meanwhile, the Directorate General of Health Services reported a continued rise in infections and deaths.
According to the DGHS, at least four suspected measles deaths and 1,215 new infections were recorded in the 24 hours until 8:00am on Friday.
During the same period, the health authorities confirmed three additional deaths and 172 new laboratory-confirmed cases.
With the latest official figures, the total number of suspected deaths has reached 198, while suspected infections have risen to 29,549. Among them, 4,231 cases have been laboratory-confirmed, including 42 confirmed deaths.
However, experts believe that all the deaths were because of measles as per the WHO definition.
A measles-related death is defined as a death in an individual with clinically, laboratory, or epidemiologically confirmed measles, occurring within 30 days of the rash onset, provided it is not due to an unrelated cause.
According to the WHO guidelines, deaths from secondary infections or complications (like pneumonia or diarrhoea) following measles are also counted as measles deaths
One person infected by measles can generate up to 18 secondary infections.
Public health experts say that the resurgence of measles reflects declining routine immunisation coverage in recent years, compounded by disruptions in vaccination services and uneven access to healthcare.
Although Bangladesh had previously achieved high vaccination coverage and made significant progress in reducing measles-related deaths, recent gaps have reversed those gains, they further say.
The outbreak, the WHO noted, is occurring in the context of ‘suboptimal population immunity’, meaning that a large proportion of the children are not protected, allowing the virus to circulate.
Experts warned that children infected at an early age faced a higher risk of severe complications, including pneumonia, encephalitis, and long-term disabilities, in addition to death.
In response to the outbreak, the government, with support from the WHO, UNICEF and Gavi, has launched an emergency measles-rubella vaccination campaign targeting children aged six months to five years in high-risk areas, with plans for nationwide expansion.
Health officials said that the campaign aimed to rapidly increase immunity among vulnerable children and interrupt transmission chains.
However, experts cautioned that emergency campaigns alone would not be sufficient without strengthening routine immunisation systems and ensuring sustained high coverage across all regions.
They stressed that achieving uniform vaccination coverage, improving surveillance and addressing barriers to access are critical to preventing future outbreaks.
The WHO reasserts that measles is entirely preventable through vaccination and that maintaining high immunisation coverage remains the most effective way to protect children and eliminate the disease.
In Bangladesh, health experts said, the current outbreak underscores the urgent need to reinforce routine vaccination programmes and ensure that no child is missed.
