The US CDC on Friday reported 4,410 measles cases nationwide as of October 15, an increase of 330 from its last update a week ago, as an outbreak of the highly contagious disease continues.
Measles-related hospitalizations this year stand at 451, the Centers for Disease Control and Prevention said.
The state of Pennsylvania has reported five measles-related deaths.
The CDC has confirmed two measles-associated deaths in 2026, though it has not identified the states involved.
Pennsylvania has reported 1,222 measles cases this year as of October 14, with 225 disease-related hospitalizations, according to state health department data.
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.
The CDC said on Tuesday it would deploy more support to Pennsylvania to help investigate the outbreak.
Children and teenagers aged 5 to 19 were the largest group affected by the disease at 1,856, or 42% of cases, followed by adults aged 20 and older at 1,787 cases, or 41%, CDC data showed.
Earlier this month, the state of New York declared a disaster emergency for the measles outbreak, the first such declaration by a US state.
