The United States has recorded its highest annual measles total in 35 years, with 5,182 confirmed cases reported as of 5 November, days before a regional commission meets to review whether the country and Mexico should retain their measles elimination status.
The US Centers for Disease Control and Prevention (CDC) reported more than twice the 2,289 cases recorded in 2025. The latest total is the highest since 1991, with cases reported by 47 jurisdictions and 562 patients admitted to hospital.
The Pan American Health Organization (PAHO) will hold its review in Washington from 10 to 13 November. A loss of elimination status would formally recognise a reversal of a public health achievement and place the United States among countries where measles spreads continuously. The outcome has not yet been decided.
US cases rise as death counts differ
The CDC said 96 per cent of confirmed US cases involved people who were either unvaccinated or whose vaccination status was unknown. Those categories are reported together, so the figure does not establish how many patients were known to be unvaccinated.
Hospital admissions account for 11 per cent of reported cases. Pennsylvania is the worst-hit state, with 1,487 confirmed infections and a sixth measles-associated death reported this week. An infant in Wisconsin is also among the deaths reported by state health departments.
The national and state death totals differ. The CDC records four measles-associated deaths, while state health departments have reported at least eight. The supplied figures do not explain that difference, and neither total should be presented as though it matches the other.
The CDC’s case count includes 18 infections among international visitors. Those cases form part of the wider US total, rather than an additional group to be added to the 5,182 confirmed infections.
The figures show both the scale of the increase and its geographical reach. The 2026 total has already exceeded the full-year count for 2025 by 2,893 cases, although the latest reporting date is still several weeks before the end of the year.
Mexico and Guatemala dominate regional totals
PAHO’s latest regional situation report recorded 57,666 confirmed measles cases across 17 countries and territories up to 31 October. That was 4.7 times the figure for 2025, with five countries accounting for almost all reported infections.
Guatemala had the largest total, with 34,748 cases, followed by Mexico with 13,761. PAHO recorded 4,852 cases in the United States at its reporting cut-off, alongside 2,862 in Peru and 1,126 in Canada.
The lower US figure in the regional report should not be confused with the CDC’s more recent total. PAHO’s report covers the period up to 31 October, while the CDC’s 5,182 cases were reported as of 5 November. They are different reporting snapshots.
PAHO recorded 81 measles deaths across the region: 53 in Guatemala, 23 in Mexico, three in the United States, and one each in Peru and Bolivia. Its US death figure also differs from the later CDC count and the totals reported by state health departments.
Mexico enters the elimination review with the region’s second-largest case total and 23 reported deaths. The commission’s consideration of Mexico and the United States therefore comes against a much wider regional increase, rather than a rise confined to either country.
Vaccination coverage falls before Washington review
The CDC also reports a decline in coverage for the measles, mumps and rubella vaccine, known as MMR, among kindergarten children. Coverage fell from 95.2 per cent in the 2019-20 school year to 92.4 per cent in 2025-26.
That fall of 2.8 percentage points leaves about 280,000 children at risk, according to the CDC. The school vaccination figures provide important context for the case totals, although they measure a particular age group rather than vaccination coverage across the whole US population.
The issue extends beyond national borders because measles can travel with unvaccinated people. Falling kindergarten vaccination coverage in the United States and Canada is an underlying driver identified in the background to the regional increase. The 18 US cases among international visitors also underline the international dimension of the figures.
PAHO’s regional monitoring and re-verification commission is due to assess the elimination status of the United States and Mexico during its four-day Washington meeting. The review had been scheduled for April before being postponed.
That review is the next formal step. For now, the confirmed developments are a US annual total at its highest level since 1991, a sharp regional increase and declining US kindergarten vaccination coverage. Whether either country loses elimination status remains to be determined.
