World’s worst measles outbreak a ‘warning’ to other nations

Measles is a highly contagious infectious disease. The article identifies its classic symptoms as high fever, cough and a telltale rash. It matters because infection can be fatal, especially among young children and people living with malnutrition. The WHO says measles usually kills two or three people in every 1000 cases.

The disease spreads through infectious particles released when an infected person coughs or breathes. Because people can pass it to others before communities identify every case, vaccination is the main protection. Two vaccine doses help capture children who do not develop immunity after one dose. That is why very high coverage is necessary.

Bangladesh’s outbreak shows the danger of losing that protection. First-dose coverage fell to 90 percent in 2025, while second-dose coverage fell to 86 percent. The result was a large outbreak, with 94 percent of reported deaths occurring among children under five. Prevention is safer and cheaper than emergency response.

Bangladesh’s measles outbreak became the largest reported anywhere in 2025. From its start in mid-March through October 9, the country recorded 202,000 suspected cases. Laboratory testing confirmed 22,000 of them. The scale overwhelmed the picture of a country that had recently been close to maintaining protective vaccination levels.

The outbreak also became deadly. The WHO reported 1,147 deaths. Children under five accounted for 94 percent of reported fatalities. In poorer settings, measles can kill more often because malnutrition makes illness more dangerous. Families described deaths after children arrived at hospitals, including two unvaccinated children in the Sylhet region.

The crisis was still active in September. Bangladesh reported an average of 1,198 new measles cases each day, the highest daily total since May. An emergency campaign vaccinated almost 20 million children in April and May, but later data showed that millions had been missed. The government was trying to end the outbreak, but weak coverage and incomplete data continued to impede control.

Measles cases rose because Bangladesh lost the population protection built through earlier vaccination success. The WHO says coverage around 95 percent is needed to prevent outbreaks. In 2025, estimated first-dose coverage fell to 90 percent and second-dose coverage to 86 percent. Those gaps left more children without effective immunity.

The decline followed political turmoil after protests ended Sheikh Hasina’s 15-year rule. Health workers went on strike, vaccine orders were delayed, and follow-up vaccinations were disrupted. These interruptions weakened routine protection. When measles appeared in mid-March, the virus found more children who could become infected and pass it onward.

An emergency drive initially slowed cases after almost 20 million children were vaccinated in April and May. However, a June routine health intervention listed four million more children than the measles campaign for the same age group. That revealed the campaign had missed children. New cases then remained high, averaging 1,198 daily in September, showing that the outbreak was not under control.

Emergency vaccination failed to reach millions because Bangladesh’s planning and outreach systems were incomplete. The campaign’s target list was smaller than another routine intervention’s list for the same age group. In June, that comparison showed four million children were missing from the measles campaign’s count. Weak data made it difficult to know who had actually been vaccinated.

Distance and communication also mattered. In remote Sylhet villages, families said health workers did not arrive in time or explain the emergency program. Amin Mia said workers came only after his two-year-old son died. Humayun Rashid said no worker told his family that the vaccination age had been lowered to six months, leaving his nine-month-old daughter unvaccinated.

The government said it had covered every child aged six months to five years, and nearly 20 million children received a dose in April and May. But reported cases rose again, reaching a daily average of 1,198 in September. The gap between official targets and families’ experiences exposed the need for better records and stronger local outreach.

Falling vaccination rates remove the community protection that stops measles outbreaks. The WHO says coverage below 95 percent creates conditions in which outbreaks can occur. More susceptible children allow transmission to continue, especially where families are hard to reach and health records are incomplete. The result is not only more illness, but also a heavier emergency response.

Bangladesh shows the human cost. In Sylhet, two-year-old Arman Hossain died unvaccinated, while his four-year-old sister survived. His family sold its three-wheeled auto rickshaw to pay for hospital treatment. In another Sylhet town, nine-month-old Labiba Akter died unvaccinated, although an emergency program had made her eligible for vaccination.

By October 9, Bangladesh had recorded 202,000 suspected cases and 1,147 deaths. Ninety-four percent of reported deaths were children under five. The article also says measles can be more deadly in poorer nations because of malnutrition. Mark Jit warned that preventing outbreaks through vaccination is easier, cheaper and safer than responding after transmission begins.

Bangladesh had recently been a vaccination success story, with 96 percent first-dose and 93 percent second-dose coverage estimated for 2024. Then protests ended Sheikh Hasina’s 15-year rule, creating political turmoil. Health workers went on strike, vaccine orders were delayed, and follow-up vaccinations linked to routine programs were disrupted. Coverage fell sharply in 2025.

The emergency response inherited those weaknesses. Health data left out millions of children, and campaign records did not match another intervention covering the same age group. The June program listed four million more children than the measles campaign. That made it harder to identify missed children and plan visits. Poor and remote families also reported that health workers did not reach them or explain changed eligibility.

The government initially slowed cases after vaccinating almost 20 million children in April and May. Yet cases climbed again, averaging 1,198 per day in September. The experience shows how political disruption can damage both prevention and crisis response. Better preparation, complete data and reliable local outreach are essential before the next outbreak begins.

Herd immunity is community protection created when enough people are immune that an infection struggles to spread. It helps shield people who are not immune, including children who have not yet been vaccinated or who did not respond fully to a dose. The WHO says measles requires about 95 percent vaccination coverage to prevent outbreaks.

The reason is measles’ exceptional contagiousness. If coverage falls, each infected person can encounter more susceptible people. Transmission then continues through schools, families and communities instead of stopping. Bangladesh’s two-dose estimates illustrate the risk: coverage fell from 96 percent for the first dose and 93 percent for the second in 2024 to 90 and 86 percent in 2025.

Those figures were several points below the level needed for herd immunity. Bangladesh then reported 202,000 suspected cases and 1,147 deaths by October 9. The second dose is important because it reaches the small percentage of children who do not develop immunity after one shot. High, reliable coverage prevents outbreaks more safely than emergency campaigns.