The Illinois Department of Public Health (IDPH) announced the largest measles outbreak to affect Illinois since 1990 is officially contained as no new cases have been reported for more than two incubation periods spanning 42 days.

A total of 67 measles cases were reported during the outbreak since March 7, officials said.

A vast majority of these cases were linked to a Chicago shelter for new arrivals, but cases were eventually reported in suburban Cook, DuPage, Lake and Will counties.

All cases were rapidly contained in all these other locations.

“I applaud all of the public health, health care, 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.”

Throughout the outbreak, IDPH, the Illinois Department of Human Services (DHS), and Illinois Emergency Management Agency (IEMA) mobilized resources to support local public health partners and provided epidemiological support for county public health departments for Cook, DuPage, Lake and Will counties.

IDPH also expanded its laboratory capacity to expedite measles testing and provided results back faster than any commercial lab.

State and local partners convened educational and awareness sessions with clinicians, community leaders and school personnel which led to increased vaccinations, testing and rapid reporting of cases.

In addition, the state galvanized its public service sector through DHS to assist with contact tracing of those who had left the shelter system and re-organized mass events such as job fairs to minimize the risk of super-spreader events.

Most residents of Chicago and Illinois were vaccinated for measles routinely in childhood and therefore were not at risk during the outbreak.

IDPH stresses the importance of ensuring everyone in your family is up to date on their immunizations.

Since the COVID-19 pandemic, vaccination rates in the United States have dropped, increasing the likelihood of more cases of vaccine-preventable diseases.

Individuals can protect themselves and their communities by doing their part and ensuring their families are up to date on all recommended vaccines.