An Illinois church camp for teenagers and an affiliated men’s conference that did not mandate masks or require attendees to be vaccinated or tested for the coronavirus have been linked to at least 180 infections, according to new report from the Centers for Disease Control and Prevention.

The investigation, published Tuesday in the Morbidity and Mortality Weekly Report, shows that a five-day overnight summer camp and a two-day men’s conference held in June, both of which were sponsored by a church, led to scores of coronavirus cases across three states. The summer camp outbreak occurred at the Crossing Camp in Rushville, Ill., which is affiliated with The Crossing, a nondenominational Christian church with locations in Illinois, Missouri and Iowa, according to the Chicago Tribune.

No deaths have been reported from the outbreak, but five people were hospitalized, the CDC said, noting that all of the hospitalizations involved unvaccinated patients. Twenty-nine people who were vaccinated ended up getting infected in the outbreak, according to the CDC. Health officials pointed to the highly transmissible delta variant as a catalyst for an outbreak that eventually exposed more than 1,100 people in four states to the virus.

“The high rate of transmission was likely driven by the number of persons infected with the SARS-CoV-2 Delta variant,” the report says.

Messages left for the camp and The Crossing were not immediately returned Wednesday.

The report comes at the end of a roller-coaster summer in which covid restrictions and guidance at camps were initially loosened before the delta variant began to ravage states nationwide. It also underscores the continued threat of the virus among young people at a time when officials are stressing why it’s important for teens to get vaccinated. About 47 percent of people ages 12 to 17 are at least partially vaccinated, according to data compiled by The Washington Post.

Illinois reported nearly 4,900 new infections Tuesday, and more than 2,200 people are hospitalized for the virus. About 51 percent of the state is fully vaccinated. Gov. J.B. Pritzker (D) reinstated the state’s mask mandate this week, requiring residents over the age of 2 to wear face coverings in indoor public settings. The governor said Illinois is “running out of time as our hospitals run out of beds.”

The central Illinois summer camp held between June 13 and 17, which did not require teens to be vaccinated, tested or masked, had groups of about 100 people sleep in “large, shared boarding facilities,” according to the CDC. The camp made no mention of masks in the “What to Bring” section of its website, but it urged campers to bring items such as water shoes, a pen and the Bible.

A camper left early on June 16 with “fever and respiratory symptoms” and later tested positive for the virus, the report says. Then at least six of the staff members who eventually tested positive left camp to attend the affiliated men’s conference at a different location on June 18 and 19.

In late June, the Illinois Department of Public Health announced that more than 80 teens and adults at the camp had tested positive, with officials saying they knew of “only a handful of campers and staff receiving the vaccine.” Ngozi Ezike, director of the Health Department, noted in a statement that the majority of the coronavirus cases at the camp were among teens.

“The perceived risk to children may seem small, but even a mild case of covid-19 can cause long-term health issues,” Ezike said at the time. “Additionally, infected youth who may not experience severe illness can still spread the virus to others, including those who are too young to be vaccinated or those who don’t build the strong expected immune response to the vaccine.”

More than a quarter of the 335 campers and staff members ended up having confirmed or probable coronavirus cases, the CDC said.

Last month, the CDC found that at least 35 cases were linked to the men’s conference. The CDC later identified at least 58 additional secondary cases stemming from close contacts of camp or conference attendees, the report says.

The CDC stressed that the 180 total cases stemming from the church camp and conference are believed to be an underestimate of the true number, because health officials have not had access to camp rosters. The agency said not everyone participated in contact tracing.

Health officials noted at least 21 outbreaks had been reported at Illinois overnight camps as of Aug. 7. The CDC report says the news of camp outbreaks across the state is “reinforcing the importance of covid-19 prevention measures at these camps, including identifying infected people through prearrival and screening testing programs and consistent implementation of other prevention efforts, including vaccination, masking, and physical distancing.”

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