Measles cases surge to highest level in three decades

Children are disproportionately affected, with those under five accounting for 18 percent of cases and those between five and 19 representing 41 percent, totaling approximately 59 percent of all confirmed cases.

A significant majority, 4,993 cases, are linked to ongoing outbreaks.

Vaccination rates among kindergarteners have decreased, dropping from 95.2 percent in the 2019-2020 school year to 92.4 percent in the 2025-2026 school year.

The current number of cases significantly exceeds the 2,289 reported throughout 2025.

Four deaths have been attributed to measles in 2026 according to the CDC, though this figure is lower than the number reported by state officials, particularly in Pennsylvania, which has experienced 1,487 cases this year.

A disagreement has arisen between Pennsylvania Governor Josh Shapiro and US Health Secretary Robert F Kennedy Jr regarding the classification of measles-related deaths.

Pennsylvania’s Department of Health defines “measles-associated” deaths as those occurring within 30 days of symptom onset unless the death is due to an unrelated cause. Two unvaccinated individuals were reported as measles-associated deaths in August, initially included in the CDC’s national count but later removed following Kennedy’s questioning.

The CDC is collaborating with the US Council of State and Territorial Epidemiologists to establish a consistent definition for measles deaths, a move infectious disease experts caution may undermine established tracking practices.

Experts note that tracking measles-associated deaths is a standard practice employed by the World Health Organization and the CDC.

The virus was previously declared eliminated in the United States, but measles cases are increasing globally, particularly in areas with vaccine hesitancy or limited healthcare access, highlighting the need for global collaboration in prevention efforts.