COVID-19 Case Rates in Transitional Kindergarten Through Grade 12 Schools and in the Community - Los Angeles County, California, September 2020-March 2021.

Sherry Yin,Kaitlin Barnes,Dawn Terashita,Andrea A Kim,Rebecca Fisher

doi:10.15585/mmwr.mm7035e3

Abstract

In-person instruction during the COVID-19 pandemic concerns educators, unions, parents, students, and public health officials as they plan to create a safe and supportive learning environment for children and adolescents (1). Los Angeles County (LAC), the nation's largest county, has an estimated population of 10 million, including 1.7 million children and adolescents aged 5-17 years (2). LAC school districts moved to remote learning for some or all students in transitional kindergarten* through grade 12 (TK-12) schools during the 2020-21 school year (3). Schools that provided in-person instruction were required by LAC Health Officer orders to implement prevention measures such as symptom screening, masking, physical distancing, cohorting, and contact tracing (4). This analysis compares COVID-19 case rates in TK-12 schools among students and staff members who attended school in person with LAC case rates during September 2020-March 2021.

Highlights

Los Angeles County (LAC) schools are required to report all laboratory-confirmed COVID-19 cases in persons who were on campus during their incubation or infectious period to the LAC Department of Public Health (DPH).† School-associated cases were defined as cases among students and staff members who were on campus for any length of time from 14 days before symptom onset or testing until isolation
Student and staff member case rates were calculated using the number of school-associated cases reported to DPH, assigned to a month by episode date, and divided by monthly attendance
Community case rates among children and adolescents aged 5–17 years and adults aged 18–79 years were calculated using the number of reported cases in LAC divided by the 2019 county population.§ Standard errors were calculated for school-associated rates

Summary

Introduction

Student and staff member case rates were calculated using the number of school-associated cases reported to DPH, assigned to a month by episode date, and divided by monthly attendance. Community case rates among children and adolescents aged 5–17 years and adults aged 18–79 years were calculated using the number of reported cases in LAC divided by the 2019 county population.§ Standard errors were calculated for school-associated rates. During September 1, 2020–March 31, 2021, a total of 463 school-associated cases were reported among students attending public TK–12 schools in person and 3,927 among staff members working on-site.

Results

Conclusion