Prairie State Wire

The Illinois Department of Public Health (IDPH) announced that the largest measles outbreak in Illinois since 1990 has been officially contained, with no new cases reported for over 42 days. The outbreak, which began on March 7, resulted in 67 confirmed cases, primarily linked to a Chicago shelter for new arrivals. The infection spread to suburban Cook County, DuPage, Lake, and Will counties but was swiftly contained.

“I applaud all of the public health, healthcare, emergency management and social service staffers who worked so diligently to cooperate across jurisdictional lines to contain this measles outbreak,” said IDPH Director Dr. Sameer Vohra. “Public health is a team sport founded on partnership, and this was no better exemplified than during this recent outbreak. Vaccination remains our most effective tool to prevent future outbreaks. Please reach out to your primary care provider this summer to ensure that you are up-to-date on the MMR vaccine and all other routine immunizations.”

During the outbreak, IDPH collaborated with the Illinois Department of Human Services (DHS) and Illinois Emergency Management Agency (IEMA) to support local public health efforts led by the Chicago Department of Public Health (CDPH). State-level epidemiological support was also provided to county health departments in Cook, DuPage, Lake, and Will counties.

Early intervention included activating Emerging Diseases funding for a DHS-run quarantine hotel-shelter in Chicago for vulnerable populations such as pregnant women, immunocompromised individuals, and young children. This initiative helped decompress the affected shelter.

IDPH expanded its laboratory capacity for expedited measles testing and coordinated educational sessions with clinicians and community leaders. Increased vaccination rates were observed as a result. The state also supported contact tracing efforts through DHS and reorganized mass events like job fairs to reduce super-spreader risks.

The IDPH vaccine team augmented vaccine supplies in Chicago and developed a school vaccine dashboard to assist local jurisdictions in managing vaccinations within schools. On-site clinical support included medical screening at shelters and infection control assessments at quarantine sites.

Most residents were vaccinated against measles during childhood; hence they were not at risk during this outbreak. According to the CDC, one dose of the MMR vaccine is 93% effective against measles while two doses are 97% effective.

As of May's end, there were 146 reported measles cases across 21 U.S. jurisdictions according to CDC data. IDPH emphasizes ensuring family members are current with their immunizations due to declining vaccination rates post-COVID-19 pandemic.

More information about the Illinois outbreak can be found by clicking HERE.

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