US Measles Cases Reach 4,852, Up 264 in a Week, as PAHO Elimination Review Opens Nov. 10

Since the CDC's Oct. 22 update put the 2026 total at 4,588 cases, the count has risen to 4,852 confirmed cases as of Oct. 29, an increase of 264 in one week. That is more than double the 2,289 cases recorded in all of 2025, with two months of the year left.

It is the 12th consecutive week of triple-digit national increases. All but 18 cases this year were locally acquired. The 18 involved international visitors.

Pennsylvania and Wisconsin lead the climb

Pennsylvania remains the hot spot. The state Department of Health reported 1,426 cases and 268 hospitalizations as of Oct. 30, up from 1,398 cases and 265 hospitalizations two days earlier. Another 88 cases were added in the latest weekly count.

Lancaster County is the epicenter with 493 cases. Mifflin County has 205, Chester 93 and Jefferson 88.

Unlike the national pattern, adults make up 67% of Pennsylvania's cases.

Wisconsin is close behind in weekly growth. The state added 82 cases for a total of 392. Of those, 336 (86%) are in four southwestern counties: Grant, Iowa, Lafayette and Vernon.

Health and Human Services Secretary Robert F. Kennedy Jr. said two weeks ago that he would bring the Pennsylvania outbreak to "a quick close." Case counts have kept rising since. The Associated Press reported Oct. 30 that more Pennsylvania residents, including some in hard-hit Amish communities, are open to vaccination.

Who is getting sick

The CDC's national breakdown by age:

• Ages 5 to 19: 2,010 cases
• Adults 20 and older: 1,996 cases
• Children under 5: 812 cases

Hospitalizations total 511, or 11% of cases, matching the 2025 rate. The CDC says the rate is 16% among preschoolers and 14% among adults.

About 96% of 2026 cases are in people who are unvaccinated or whose vaccination status is unknown, up from 93% in 2025. The CDC counts 43 new outbreaks this year, against 48 in all of 2025, and 96% of cases (4,666 of 4,852) are tied to outbreaks. Of those, 1,384 come from outbreaks that began in 2025.

The CDC notes that its figures include only confirmed cases that jurisdictions have reported. It says it is aware of additional probable cases.

The death count does not match

The CDC acknowledges three measles deaths this year and has not said where they occurred. CDC Director Dr. Erica Schwartz confirmed the third death in an Oct. 21 interview.

The Pennsylvania Department of Health has reported five measles-associated deaths. It had reached five by Oct. 7. A sixth death in the state is under investigation.

One of the Pennsylvania deaths was in Franklin County. The coroner's office said it was the county's first in many years involving a patient with a recent measles diagnosis, and that it met the state health department's definition of a measles-associated death. The gap between the state and federal counts may reflect differing definitions, but neither agency has publicly explained it.

The elimination review

The U.S. gained measles elimination status in 2000. The Pan American Health Organization's Measles and Rubella Elimination Regional Monitoring and Re-Verification Commission will hold its sixth annual meeting Nov. 10 to 13. PAHO announced the dates on Oct. 14.

The commission is an independent body of epidemiologists, virologists, pediatricians and immunization experts. It will examine data from 2025 and the first half of 2026. That includes vaccination coverage, surveillance quality, laboratory and molecular evidence, outbreak response and transmission chains.

PAHO says "no single source of evidence determines the final classification of a country's elimination status." The announcement does not name the United States or predict an outcome.

Outside experts are less cautious. Dr. Amesh Adalja of the Johns Hopkins Center for Health Security said: "The U.S. has effectively lost elimination status. The November PAHO review will make this formal." CIDRAP, the University of Minnesota's infectious disease news service, wrote that the country "will very likely lose" the status in the coming month.

The precedent is Canada. The commission concluded a year ago that endemic measles transmission had been re-established there, and the Americas region lost its measles-free status in 2025. Canada is currently the only country in the region classified as endemic. All others retain elimination status.

The commission's ruling is expected after the Nov. 10 to 13 meeting. Pennsylvania is still adding dozens of cases a week and has a sixth death under investigation.