Measles cases in US top 4,000 nationwide, CDC reports

U.S. measles cases have officially surpassed 4,000, marking a historic and alarming milestone in the nation's worst resurgence in decades.

According to data released by the Centers for Disease Control and Prevention (CDC), infections have now spread across 45 states and Washington, D.C.

The US CDC on Friday reported 4,080 confirmed measles cases in the country as of October 8, up 193 from a week earlier.

Pennsylvania has emerged as a primary epicentre, logging over 1,000 cases in what has become the largest single-state outbreak in 30 years.

Public health officials report that approximately 95% of all infected individuals are completely unvaccinated or have an unknown immunization history.

26 cases were identified among international visitors,

According to the CDC (Centers for Disease Control and Prevention), measles-related hospitalizations this year stand at 414, or 10% of cases, compared with 244 hospitalizations in 2025.

The CDC has confirmed two measles-associated deaths in 2026, though it has not identified the states involved, compared with three deaths in 2025.

Separately, Pennsylvania health officials have reported five deaths linked to the state’s measles outbreak this year.

Last month, the CDC shifted to using mortality data from the National Center for Health Statistics for measles-related deaths, rather than relying on state health departments, a change that has drawn scrutiny.

Children and teenagers aged 5 to 19 accounted for the largest share of cases at 1,716, or 42% of infections, followed by adults aged 20 and older at 1,635 cases, or 40%.

Earlier this week, New York declared a statewide disaster emergency over a measles outbreak after reporting 108 cases this year through October 3, including 92 cases since July 15.

Experts attribute the sharp surge primarily to declining routine childhood vaccination rates over recent school years, which have steadily eroded herd immunity and left communities vulnerable to the highly contagious virus.

In response, local governments and state leaders are ramping up containment protocols, localized emergency declarations, and catch-up vaccination drives.

The CDC continues to stress that the measles, mumps, and rubella (MMR) vaccine remains exceptionally safe and effective, urging parents and healthcare providers to ensure that all eligible children receive their immunizations immediately to halt further community transmission.