New school year in San Diego, already new cases of COVID on campuses Parents at Hilltop High in Chula Vista said they recently received a letter letting them know about multiple cases of COVID-19 on campus. Author: Steve Price (Reporter) Updated: 7:17 PM PDT July 28, 2021 SAN DIEGO COUNTY, Calif. — The San Diego County Office of Education confirmed several schools that recently returned to in-person learning have already had at least one positive COVID-19 case on their campuses. Parents at one of those schools, Hilltop High School in Chula Vista, said they recently received a letter letting them know about multiple cases.