CDC reports more than ۵,۰۰۰ measles cases, highest number in ۳۵ years

Children and teenagers make up almost ۶۰ percent of confirmed cases.

A total of ۵,۱۸۲ confirmed measles cases have been reported in the United States to date in ۲۰۲۶, according to data released by the Centers for Disease Control and Prevention (CDC).

The figure for the highly contagious but vaccine-preventable disease is the highest number reported by the CDC since ۱۹۹۱.

Children below the age of five make up ۱۸ percent of cases, while children between ages five and ۱۹ account for ۴۱ percent of cases.

In total, children and teenagers account for about ۵۹ percent of confirmed cases.

The majority of cases, a total of ۴,۹۹۳, were outbreak-associated.

The outbreak comes as vaccination coverage among US kindergarteners has decreased from ۹۵.۲ percent during the ۲۰۱۹-۲۰۲۰ school year to ۹۲.۴ percent in the ۲۰۲۵-۲۰۲۶ school year.

The number of confirmed cases by November ۲۰۲۶ is more than double the ۲,۲۸۹ confirmed measles cases reported in ۲۰۲۵.

Dispute over death toll

According to CDC data, four people have died due to measles in ۲۰۲۶.

However, the agency’s national death toll is lower than the number of measles-related deaths reported by state officials, particularly in Pennsylvania, the state hardest hit by the outbreak.

Pennsylvania’s Department of Health reported six deaths and ۱,۴۸۷ cases this year.

The federal count has been at the centre of a dispute between Pennsylvania Governor Josh Shapiro and US Health Secretary Robert F Kennedy Jr over how measles deaths are classified.

Pennsylvania reports “measles-associated” deaths after a person with confirmed measles dies within ۳۰ days of developing symptoms, unless the death resulted from an unrelated event.

In August, Pennsylvania reported that two unvaccinated people died of measles. The CDC initially included the deaths in its national tally but subsequently removed them after Kennedy, a vaccine sceptic, questioned whether measles had caused or contributed to the fatalities.

The CDC has said it is working with the US Council of State and Territorial Epidemiologists to establish a standardised definition for measles deaths.

Infectious disease experts warn that the dispute over how to classify the deaths puts the CDC at odds with a longstanding approach to tracking the consequences of measles.

Epidemiologists have told Al Jazeera that tracking “measles-associated” deaths has long been a standard used by the World Health Organization and the CDC.

The US declared the virus eliminated more than two decades ago. Measles cases have also increased globally, particularly in communities that are vaccine-sceptical or where there are gaps in healthcare access.

Experts warn that declining vaccination rates in one geographic location can leave people thousands of miles away vulnerable, making measles prevention a shared global responsibility.