PA measles outbreak tops 1,000 cases, largest since disease was eliminated

What happened

That contains 12 cases in January and March, with the remaining 1,066 cases since April , when the current outbreak began. The tally contains 145 cases recorded in the last seven days and 74 identified since the previous update on Monday.

Pennsylvania reported 1,066 outbreak-linked cases on Wednesday. Pennsylvania's explosive measles outbreak is now the largest the US has seen since the highly infectious virus was declared eliminated in 2000. Pennsylvania's health officials reported 1,078 measles cases in all of 2026 as of this afternoon.

Key facts

• The tally — includes: 145 cases recorded in the last seven days and 74 identified since the previous update on Monday