MARIN COUNTY, Calif. - When Marin County 8th graders returned from their field trip to Washington D.C. last week, two dozen of them immediately tested positive for COVID-19, Marin County Public Health said.
That number soon swelled to at least 56 on Tuesday, officials said.
They were all part of a group of 77 students from two schools who made the annual trip to the nation's capital and then returned from the trip on Sunday.
County health officials said they had tested positive before returning to school the next day. Marin County Public Health issued an advisory to all middle schools offering guidance on Monday.
Public health officials said all the infected students have reported mild or no symptoms and none are hospitalized.
A total of 90% of Marin County 8th graders are fully vaccinated with over half of them having received their booster shot, officials said.
Washington D.C. is currently undergoing a high-profile coronavirus surge with Rep. Rashida Tlaib announcing on Monday that she is among a wave of Washington leaders who have tested positive.
Marin County Public Health recommended that students and staff who participated in the Washington field trip may return to class unless they have tested positive for COVID or are symptomatic. They should also test for COVID prior to returning to class and continue testing for five days after their return or sooner if they experience symptoms.
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Participants in the field trip should wear a mask indoors in school and in public for five days upon returning from the trip if anyone within the group they traveled with tested positive for COVID.