Tracking: US measles outbreaks · Last checked 8 Oct, 16:52 UTC · 33 stories from listed outlets
US measles outbreaks 2026: latest status
Status: Outbreak growing Summary written
US measles cases exceed 3,800 as Pennsylvania and New York outbreaks expand
Is it spreading to new areas?
Spread confirmed
As of 8 October 2026, health officials reported four cases in Ontario County, New York, alongside recent case confirmations in Allegheny County and school districts in central Pennsylvania.
As of 8 October 2026, health officials in Pennsylvania reported 74 new measles cases, with state authorities indicating the outbreak shows no signs of slowing. Pennsylvania is contending with its largest outbreak since the early 1990s, having recorded over 1,000 cases since April.
In New York State, Governor Kathy Hochul declared a state disaster emergency following a concentration of cases in under-immunized communities across the Southern Tier and Finger Lakes regions. Federal health officials have offered federal support to assist New York with its emergency response.
Nationwide, reported measles cases in 2026 have approached 3,900, representing the highest annual US total since 1991 and drawing warnings from the CDC regarding further potential spread ahead of the travel season.
For official health guidance, consult your national health authority and the World Health Organization. The MMR vaccine is highly effective at preventing measles, and anyone unsure of their vaccination status should consult a doctor or local health department; this site does not provide medical advice.
Timeline
New York Governor Kathy Hochul declares a state disaster emergency, while Pennsylvania health officials confirm state cases exceeded 1,000.
Federal officials offer support to New York State, while elementary school students test positive for measles in central Pennsylvania and Lancaster County.
Original title: Pa. measles outbreak is nation’s worst, echoing deadly 1991 Philadelphia epidemic
Physicians who treated patients during the 1991 Philadelphia epidemic noted that Pennsylvania is again facing the nation's worst measles outbreak, according to The Philadelphia Inquirer.
Original title: Measles outbreak prompts state of emergency as Southern Tier, Finger Lakes report most cases in New York
A state of emergency was declared in New York State as health officials reported the highest concentration of measles cases in the Southern Tier and Finger Lakes regions.
Original title: Measles cases near 3,900 nationwide as Pennsylvania outbreak tops 1,000 and New York declares emergency
Nationwide measles cases approached 3,900 while Pennsylvania's outbreak exceeded 1,000 cases and New York declared an emergency, Spectrum News reported.
Original title: N.Y. state health officials mobilize following governor’s measles mandate
New York State health officials began mobilizing public health resources following an executive emergency declaration by the governor to address the measles outbreak, Spectrum News reported.