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The CDC sent a team of experts to Chicago to assess a measles outbreak at a migrant shelter and help minimize community spread. darekm101/Getty Images
  • The CDC sent a team of experts to Chicago on March 12 to assess a measles outbreak and help minimize the risk of community spread.
  • As of March 12, eight measles cases in Chicago were reported in children and adults, seven of which occurred in a migrant shelter in the Pilsen neighborhood.
  • Experts continue to express concern about low vaccination rates that have led to measles outbreaks in Europe and around the U.S.

A team of experts from the Centers for Disease Control and Prevention (CDC) arrived in Chicago on March 12 to help manage a measles outbreak.

The Chicago Department of Public Health (CDPH) confirmed additional measles cases at a new arrivals shelter in Pilsen in Chicago’s Lower West Side. The latest confirmed cases bring the total number of measles cases in the third-largest city in the United States to eight.

On March 10, CDPH announced a confirmed measles case in a young child at the Halsted Street migrant shelter in Pilsen. The child is hospitalized, but in good condition, city health officials said. Another child staying at the shelter contracted measles but has recovered and is no longer infectious. Two measles cases were also identified in adults who CDPH said were in stable condition.

Another measles case was confirmed in an elementary student attending a Chicago public school who was staying at the Pilsen shelter. That child was hospitalized on Monday but is in good condition.

On March 7, CDPH announced a measles case in a Chicago resident, the first measles case identified in a Chicagoan since 2019. The case was unrelated to the Pilsen shelter outbreak.

Pilsen shelter residents who have been vaccinated against measles are permitted to enter and exit the shelter, while those who have not been vaccinated or have been recently vaccinated must quarantine for 21 days (from the date of vaccination) and monitor any symptoms, CDPH said.

“We have advised all unvaccinated and newly vaccinated residents of the quarantine period but some of those residents have left the shelter, and I want to acknowledge that,” said CDPH Commissioner Dr. Olusimbo Ige, MPH, in a public health announcement.

“That is why we so strongly advise the unvaccinated to get the vaccine and to immediately quarantine if you have had contact with anyone with measles.”

At the request of city and state officials, the CDC deployed a team of experts to Chicago to help manage the outbreak.

Chicago health officials are working with the CDC to contain the measles outbreak and prevent further spread.

CDPH and healthcare professionals are also mobilizing at the Pilsen shelter to screen residents for measles symptoms and encourage vaccination.

“Groups at high risk of contracting measles are those who are unvaccinated, and migrant groups may have variable vaccination rates,” Dr. Monica Gandhi, MPH, professor of medicine at the University of California, San Francisco, told Healthline.

“As immigrants come into the U.S., we have to make a concerted effort to catch migrant children up with their routine childhood vaccinations,” Gandhi said.

The CDC team will help identify at-risk individuals who may have been exposed to the disease. They will provide clinical guidance for managing active measles cases and educate the community through a targeted vaccination campaign at a number of schools, shelters, and congregate settings.

The CDC will also provide extra vaccines to the Chicago HealthDepartment and surrounding jurisdictions to help maintain supply for children and adults.

“CDC continues to recommend the safe and effective MMR vaccination as part of the routine immunizations schedule for all children and adults, with special guidance for international travel,” the public health agency said in a statement shared with Healthline. ‘We will continue to provide updates as more information becomes available.”

The CDPH will continue to urge vaccination for new arrivals and Chicagoans to protect against infectious diseases and minimize community transmission.

“The majority of Chicagoans are vaccinated against measles and therefore are not at high risk but we are strongly urging those who aren’t vaccinated to do so as soon as possible, new arrivals and all Chicagoans. It is by far the best protection against measles, which for the first time in years is in our city,” Ige said on March 10.

“Because of how contagious measles is, I anticipate seeing more cases. Should you be exposed to someone who has measles, if you are not vaccinated you need to immediately quarantine and call a health provider. If you are not sure of your vaccination status, stay home and call your health provider as soon as possible,” Ige continued.

Recent measles outbreaks in Europe and around the U.S. have raised concern among health officials amid low childhood vaccination rates for measles, mumps, and rubella (MMR) and other infectious diseases.

The CDC issued an alert about rising measles cases in January, indicating that most confirmed cases were among children and adolescents who had not been vaccinated against measles, even if they were age-eligible.

Clusters of cases have since been reported in several northeastern states, Washington DC, Florida, Washington state, and most recently, in Northern California, where an unvaccinated child contracted measles and may have exposed upward of 300 people.

Health experts have tied the recent outbreaks to low childhood vaccine rates.

A recent CDC report shows that childhood vaccination exemption rates among kindergarteners are at an all-time high, fueling outbreaks that could have otherwise been prevented. According to the report, low vaccine rates reflect lingering COVID-era barriers to vaccination and ongoing vaccine hesitancy.

Of the 288 schools within the Chicago Public Schools system, for instance, some schools have a vaccination rate as low as 12%, including some early childhood students, CBS found.

Measles is a highly contagious disease causing serious respiratory infection, rash, and high fever. In severe cases, measles may lead to pneumonia and other complications.

Young children, particularly unvaccinated young children, are most at risk for serious illness from contracting measles, which is spread through air droplets and contaminated surfaces.

Once declared eradicated in the U.S., measles is recirculating and putting unvaccinated people of all ages at risk for infection. The risk of infection among vaccinated individuals or reinfection among people who’ve had measles remains rare, however.

“Members of the public are at risk if they have not been vaccinated (which usually happens in childhood), so the larger population need not be concerned if vaccinations are kept up to date,” Gandhi said.

“However, population immunity will decline if childhood vaccination rates in the U.S. do not improve. The U.S. is at risk of losing its status as having eliminated measles with these recent cases. Young children should receive two doses, and adults may require booster vaccination prior to international travel, prior to college, prior to pregnancy, or during outbreaks,” Gandhi noted.

The CDC sent a team of experts to Chicago to help manage a measles outbreak and prevent further community spread.

At least eight measles cases have been confirmed, seven of which occurred at a migrant shelter, with an additional, unrelated case occurring in a Chicago resident.

Recent clusters of measles outbreaks around the world and in the U.S. due to low vaccination rates have sounded alarm among health officials.

Experts continue to say following routine immunization schedules, especially during early childhood, is the best way to protect the spread of infectious diseases.