Measles - Bangladesh

Measles is a highly contagious viral disease that affects susceptible individuals of all ages and remains one of the leading causes of death among young children globally. Measles can cause serious illness in at-risk groups, including children under 5 years of age, those who are malnourished especially those with vitamin A deficiency and people with weakened immune systems. Measles complications include hearing loss, diarrhoea, pneumonia and blindness. Severe complications of measles include encephalitis, brain damage, and death.

The current outbreak in Bangladesh is occurring in the context of suboptimal population immunity. A substantial proportion of cases occurred among children who were either unvaccinated or had received only one dose of measles-containing vaccine. In addition, some children were infected before reaching the age of eligibility for vaccination at 9 months. Most cases (91%) occurred among children aged 1 to 14 years, indicating substantial immunity gaps in this age group.

Before this outbreak, Bangladesh had made substantial progress towards measles elimination. Reported coverage with the first dose of measles-containing vaccine increased considerably between 2000 (89% - WUENIC) and 2016 (118% - WUENIC), while coverage with the second dose also improved between its nationwide introduction in 2012 (22% - WUENIC) and 2024 (121% - WUENIC). During the same period, confirmed measles incidence declined sharply. However, recent declines in MR1 and MR2 coverage due to nationwide stockout of MR vaccine between 2024-2025, combined with routine immunization gaps and the absence of regular nationwide supplementary measles-rubella campaigns since 2020, have increased the number of susceptible children and contributed to the current outbreak.

The risk at the national level is assessed as high due to ongoing transmission across multiple divisions, the large number of susceptible children, documented immunity gaps, and the occurrence of suspected measles-related deaths. The concentration of cases among unvaccinated and under-vaccinated children including infants too young to be vaccinated, raises concern for continued uninterrupted transmission and severe disease outcomes.

Overall, the outbreak suggests a reversal from Bangladesh's previous progress towards measles elimination and highlights increasing vulnerability to sustained transmission. Continued spread is likely unless urgent measures are implemented to strengthen surveillance, rapidly detect and respond to cases, and close immunity gaps through high-quality vaccination activities.

There are considerable risks of cross-border spread, facilitated by cross-border population movement, with major urban centres such as Dhaka, Chattogram, Sylhet, and Cox's Bazar being important international travel and transit hubs increasing the likelihood of national and international spread, particularly among unvaccinated or inadequately vaccinated travelers.

Measles is endemic across the South-East Asia region. The risk is assessed as high at regional level.

Bangladesh shares extensive land borders with India and Myanmar, and population mobility across these borders may facilitate continued transmission. In Myanmar there is a considerable number of unvaccinated/zero dose children. With ongoing conflict and humanitarian crisis, surveillance and response capacities are limited. India, despite achieving high vaccination coverage, has reported a rise in case count over the past six months. Cities with high incidence such as Jashore and Chapainawabganj (an identified hotspot) share busy land crossings with India, thereby increasing the risk of introduction across the border. Despite Bangladesh's progress towards measles elimination the current outbreak highlights the vulnerability of the population and underscores the fragility of immunization gains.