A new study from the Centers for Disease Control and Prevention reveals how quickly COVID-19 can spread, even among young people.
A single ninth grader, who attended a summer school retreat in Wisconsin, likely caused more than 100 other people to get sick, the CDC said.
That ninth grader tested negative one week before the retreat. But shortly after he got there, he started showing symptoms, and tested positive.
The students did not wear masks at the retreat, and they shared dorms with beds close together and sat in outdoor classrooms.
As a result, 76% of the students and staff were diagnosed with COVID-19. Those who became ill were between 14 and 24 years old. They had prolonged contact and shared sleeping quarters.
All attendees were required to provide documentation of having antibodies within the last three months or a negative coronavirus test less than seven days before travel. They were also asked to self-quarantine in their homes for seven days before travel.
The high school boys' camp took place between July 2 and Aug. 11.