About 84 percent of fatal measles cases in a recent major outbreak at a migrant facility in Chicago are linked to Venezuelan immigrants, a new CDC report shows.
New information reveals that the spate of 57 cases at the Pilsen migrant shelter can be traced back to a one-year-old child who had only received one of two life-saving vaccines.
Most cases (72 percent) occurred among unvaccinated people, the CDC said.
The report cites overcrowding at the center as a cause of the rampant spread, with 500 people said to be crammed into a single room.
Chicago is at the epicenter of the measles outbreak in the US, with 64 cases recorded so far
Migrants photographed at a makeshift shelter in Chicago’s Pilsen neighborhood, where many are being transferred. There has been an outbreak of measles and tuberculosis linked to the shelter.
The first patient had arrived in the United States less than five months before becoming ill. He had received one dose of the MMR vaccine five weeks before his rash.
He had no recent travel history or known exposure to measles, and was taken to the hospital on February 27.
The Chicago Department of Public Health was notified of the case a few days later and hosted a vaccination event for shelter residents and staff members the next day.
Due to the highly infectious nature of measles, they considered anyone who had been inside the shelter between February 22 and 27 (the child’s infectious period) to have been exposed to measles.
Between February 26 and May 13, there were 57 confirmed cases linked to the shelter, including 52 among migrants housed at the shelter and three among staff members.
The average age of the infected migrants was three years and the majority were from Venezuela. Four were from Peru, two from Ecuador, one from Chile and one more whose country of origin was unknown.
Since August 2022, approximately 41,000 migrants have arrived in Chicago, Illinois, from the southern border of the United States.
Of them, 88 percent are from Venezuela, a country that has seen a recent decline in routine childhood vaccination coverage, including the measles vaccine.
The surge in immigrants comes as Chicago continues to pride itself on being a “sanctuary city,” or a place where people can ask city services for help without revealing their immigration status.
Officials also do not ask residents if they have a legal right to be in the United States.
About 30 of the 57 cases in the Pilsen center were women and 27 were men. Most patients were between six months and four years old, followed by those between 20 and 49 years old.
Measles usually starts with cold-like symptoms, before causing a rash made up of small red dots, some of which may feel slightly raised.
The Pilsen migrant shelter is the largest in Chicago and at the end of February it housed about 2,100 people, with more than 500 residing in some of the rooms.
Immigrants themselves have said that diseases are rampant in shelters due to overcrowding and unsanitary conditions.
About 130 Americans have been affected by measles this year, amid warnings that falling vaccination rates and increased immigration are leaving American children more vulnerable than ever to the disease.
The CDC says babies should receive their first dose of the measles vaccine between 12 and 15 months of age, and their second dose between the ages of four and six years.
Studies show that the first dose is 93 percent effective against the virus, while the second is 97 percent effective.
Vaccinated people can still get sick, doctors say, but they have a much milder infection because they already have immunity.
Dr Thomas Moore, an infectious disease expert, previously told DailyMail.com: “If you want to create a public health crisis, put people in overcrowded spaces.”
Overcrowding, unsanitary conditions and limited access to vaccines in immigrants’ home countries can lead to and exacerbate outbreaks in shelters, he said.
Measles was declared eliminated in the United States in 2000, meaning that the disease is no longer constantly present in the country.
Measles elimination status in the United States was threatened in 2019 due to two prolonged outbreaks among undervaccinated communities in New York.
According to the CDC, MMR vaccine coverage fell another two percent between the 2019-2021 school year and the 2022-2023 school year, meaning that approximately a quarter of a million kindergartens are at risk of contracting measles in all of the United States.
The 93.1 percent rate during the 2022-23 school year is lower than the 95 percent rate in the 2019-2020 school year, leaving measles coverage below the national goal of 95 percent for the third year consecutive.