Illinois Declares Downstate Measles Outbreak Over Amid National Surge

Even with a rise in measles cases nationally, the State of Illinois has declared that a downstate outbreak is over.

Rapid Response Contained Southern Illinois Cases

Following 42 days without a new reported case in southern Illinois, the Illinois Department of Public Health (IDPH) is confident the outbreak has been contained

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The outbreak began in April and totaled eight linked cases, according to the IDPH press release. Thanks to swift action by local health departments and the IDPH, there were no new infections after May 22.

National Measles Cases Reach 25-Year High

The Illinois outbreak is part of a national trend that has been concerning, with 1,288 measles cases in the U.S. in 2025, which is the highest number since 2000.

Measles was declared eliminated 25 years ago in the United States, and now 92 percent of new infections were either unvaccinated or had unknown vaccination status, according to the report.

Two Unrelated Cook County Cases Not Linked to Outbreak

Around the same time a southern Illinois outbreak ended, two additional measles cases were identified in Cook County. However, they were not connected to the downstate cluster of cases.

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According to the press release, no further spread of measles was detected, and there have been no new cases in over six weeks, so Illinois state officials confirm the threat has passed, at least for now.

IDPH Urges Residents to Get Vaccinated

Director of the Illinois Department of Public Health, Dr. Sameer Vohra, credited the end of the downstate outbreak to strong public health partnerships in the state and is urging all residents to stay current on vaccinations.

"The MMR vaccine is our most powerful defense," he said. With more hesitancy in getting vaccines since the COVID pandemic, health officials still conclude that being immunized is the key to future outbreaks.