MARIN COUNTY (CBS SF) – More than 50 eighth graders from Marin County tested positive for COVID-19 following a spring break trip to Washington, DC last week, health officials said Wednesday.

According to Marin County Public Health, several groups of 8th grade students across the county took part in the annual field trip to the nation’s capital. This particular outbreak involved students from two schools that returned on Sunday.

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Before classes resumed on Monday, 22 students from the group tested positive for COVID-19. In response, health officials issued guidance to all middle schools urging all participants to test prior to returning to class and to mask in indoor public spaces for five days.

Participants were allowed to return to school unless symptomatic for COVID-19 or test positive for the virus. By Tuesday, 56 students had tested positive.

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Health officials said the students have either mild or no symptoms. No students have been hospitalized.

Boasting one of the highest COVID-19 vaccination rates in the state, officials reported that 90% of 8th graders are fully vaccinated, while over half have received their booster shot.

The outbreak comes amid rising COVID-19 cases in the Washington, DC area and the East Coast. Several high-profile lawmakers, including Speaker Nancy Pelosi, have tested positive in recent days.

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Officials did not disclose which schools were involved.

Source: sanfrancisco.cbslocal.com.