Coronavirus outbreaks in L.A. schools increase, some tied to athletic activities

A nurse vaccinates a high school student in the gym.
A nurse vaccinates a student at Eagle Rock High School. Although coronavirus outbreaks moved upward at Los Angeles County schools last week, fewer students and staff were exposed to the virus. Public health officials encourage all who are eligible to get vaccinated.
(Allen J. Schaben / Los Angeles Times)

Los Angeles County recorded eight coronavirus outbreaks last week in its K-12 schools — up from three the previous week. The latest outbreaks led to 72 student infections, an increase from 40 the week before.

But in a sign that school-based COVID-19 safety measures are showing promise, fewer students and staff members were exposed to the coronavirus in these outbreaks: 211 people were exposed last week, down from 238 in the prior week — the week that classes began in the Los Angeles Unified School District, the second-largest in the nation.

“This most likely reflects improved understanding of who is exposed, and great work by schools working to mitigate exposures and unnecessary quarantine of students by using cohorting, distancing strategies and seating charts in their classrooms,” L.A. County Public Health Director Barbara Ferrer said.

Many of the outbreaks are tied to athletic activities or failures to follow COVID-19 protocols. An outbreak is defined by linked cases involving three or more people in which transmission probably occurred at schools or school activities.

Of 17 school outbreaks identified since the beginning of August, eight were tied to youth sports, and another eight to classrooms. The classroom outbreaks have resulted in the infections of 117 students and seven staff members; one person has been hospitalized, Ferrer said.

A graphic of COVID-19 outbreaks in L.A. County K-12 schools and programs in August by week

The risk factors for transmission in schools include inconsistent and incorrect mask use indoors, visibly sick people showing up to school, lack of ventilation measures and a lack of physical distancing in places including hallways, cafeterias, break rooms and playgrounds, as well as in classrooms, where distancing often isn’t possible due to a lack of space. State and county guidelines encourage but do not mandate physical distancing in classrooms.

“Findings from these outbreaks suggest that transmission risk is highest where there is close, unmasked contact with symptomatic people,” Ferrer said.

A list of best practices for reducing school transmission

Between Aug. 15 and Aug. 29, 5,207 coronavirus cases were reported among 1.5 million students, and 729 cases among 200,000 staff members.

But many of the coronavirus cases that are being identified are occurring at schools or sites where there are only one or two cases. Of 1,871 schools and related sites reporting coronavirus cases, 720 of them reported three or more cases.

New K-12 cases and investigations

L.A. Unified has launched an ambitious coronavirus testing program, which requires the screening of every student, teacher and staff member — more than half a million people — once a week for the foreseeable future. The effort is so vast that the number of tests done weekly through L.A. Unified’s program is equal to more than 50% of the county’s weekly test results, according to data provided by the Department of Public Health.

“The largest portion of these cases are identified through routine screening, and these are really people who are, in fact, asymptomatic,” Ferrer said.

Still, it’s important to identify these cases so that infected people are removed from the classroom until they recover and are no longer contagious, she said.

COVID-19 outbreaks in L.A. County K-12 schools and programs by week

Even as many schools in L.A. County have reopened, the overall number of new coronavirus infections countywide has actually declined.

Overall, L.A. County has reported an average of 2,596 new cases per day over the last week. That’s down 25% from two weeks ago, when many schools began to reopen.

The test positivity rate — a metric measuring the proportion of tests that confirm coronavirus infection — has also decreased notably, from 3.5% on Aug. 17 to 2.5% as of Tuesday.


Los Angeles County’s school-aged children remain in a better position than children in other parts of the country. There are some parts of the nation where pediatric COVID-19 hospitalization rates are at the highest point in the pandemic.

But in L.A. County, COVID-19 hospitalization rates for children are “nowhere near [what] they were during our winter surge,” Ferrer said.

Weekly rate of cases per 100,000 by pediatric age group

“This pattern may reflect the fact that many adults are vaccinated and that most people are wearing masks,” Ferrer said.

Still, the concern about the Delta variant has caused L.A. County health officials to retain a stricter quarantine standard in schools than required by California for at least a few more weeks.

L.A. County officials have ordered unvaccinated students who had “close contact” with an infected person for at least 15 minutes in one day while within six feet of that person to be sent home and quarantined for at least eight days.


The state, meanwhile, does not require a quarantine for the close contact if both the infected person and close contact were wearing masks during the entire time of exposure.

Ferrer said she wanted to see a couple more weeks of data before relaxing the quarantine standard, to be sure that “you’re not creating an unintended consequence of creating a lot of spread in schools.” COVID-19 vaccines are authorized only for those age 12 and older.

L.A. County health officials, however, did recently eliminate weekly testing requirements for all youth athletes or associated staff if they are fully vaccinated or have a documented coronavirus infection within the last 90 days. Also, weekly testing is no longer required for children younger than 12 if playing outdoors.

The Department of Public Health also removed a requirement that youth athletes and staff get a coronavirus test within 72 hours of a game.

Modified youth sports testing guidance

In the Wednesday briefing, Debra Duardo, the superintendent of the Los Angeles County Office of Education, said three L.A. County school districts have adopted vaccination mandates. Two of the three districts she named, ABC Unified and the Palmdale School District, said the information was incorrect and they do not have a student mandate. The third district, Culver City Unified, has approved a mandate for students, but it has not yet gone into effect.

A county spokesperson later corrected this information.

Duardo also named 13 districts that are considering vaccination mandates, but the spokesperson said this information is not confirmed and may have changed since an Aug. 19 school district survey.

But there are school systems exploring the option, including Los Angeles Unified and Santa Monica-Malibu Unified, according to officials in those districts.

The L.A. teachers union has called for mandating vaccinations for students.

Times staff writer Laura Newberry contributed to this report.