The Brentwood Union School District returned to campus last week, and after three days of class, the district is reporting 18 positive COVID-19 cases.
As other districts prepare to return in the coming weeks, concerns continue to grow about the Delta variant.
The district superintendent of schools initially reported Saturday that there were 15 positive cases among staff and students and spread out across the system's 11 campuses. That number was updated to 18 on the district's COVID-19 tracker online.
Seventeen of those cases are students, according to the tracker.
A parent who didn't want to speak on camera, shared a letter sent by the principal at Edna Hill Middle School, advising them that the campus had one of the positive cases.
According to that letter, the person who tested positive for COVID-19 at Edna Hill Middle School was last on campus on July 29.
The school nurse and other staff are currently conducting contact tracing and may soon be reaching out to people who were in close proximity of that person, who tested positive.
The Brentwood Union School District has elementary and middle schools. Most of the students in the district are not old enough to be vaccinated.
The schools are in Contra Costa County Board of Supervisors President Diane Burgis' district.
“As we go forward, particularly here in East Contra Costa, where the vaccination rate is low and the spread has been high recently. We're seeing that we're going to have more, probably, outbreaks or exposures,” she said.
One parent, who didn't want to use her name, told NBC Bay Area’s Sergio Quintana that she has a son who attends one of the district’s elementary schools.
“It's expected. I just didn't, so soon? It's kind of soon. and early. But I understand like, we just got off break, so people are coming from vacation and getting tested,” the parent told NBC Bay Area.
Vanessa Rojas has a daughter that just started preschool. She told NBC Bay Area Saturday that she’s concerned about the rest of the school year.
“I think they're going to shut down again. Especially, with this delta variant that is coming out,” she said.
Both parents that NBC Bay Area talked to said they've already had COVID-19 and they don't plan on getting vaccinated.
“I'm not anti-vaccine. I'm just not so sure right now,” the first parent told NBC Bay Area.
Rojas was asked if she would get her shots to try to protect her daughter.
“So far, I'm going to say no to it,” she said.
The district adds that there’s no evidence that any of the 18 cases were contracted on school campuses.