Screening Students and Staff for Asymptomatic Coronavirus Disease 2019 in Chicago Schools

• Published in: The Journal of pediatrics 2021-12, Vol.239, p.74-80.e1
• Main Authors: Edward, Priya R., Reyna, Megan E., Daly, Mary Kate, Hultquist, Judd F., Muller, William J., Ozer, Egon A., Lorenzo-Redondo, Ramon, Seed, Patrick C., Simons, Lacy M., Sheehan, Karen, Staples, Jacinta, Kociolek, Larry
• Format: Article
• Language: English
• Subjects: asymptomatic; Asymptomatic Diseases - epidemiology; Chicago - epidemiology; coronavirus disease 2019; COVID-19 - diagnosis; COVID-19 - epidemiology; COVID-19 - prevention & control; COVID-19 Testing; Faculty; Humans; Mass Screening; Original; Prospective Studies; SARS-CoV-2; Schools; screening; Students
• ISSN: 0022-3476; 1097-6833
• DOI: 10.1016/j.jpeds.2021.08.017

To assess rates of asymptomatic severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) positivity in K-8 schools with risk mitigation procedures in place, and to evaluate SARS-CoV-2 transmission in school and household contacts of these positive individuals. In this prospective observational study, screening testing for SARS-CoV-2 was performed by oropharyngeal swabbing and polymerase chain reaction (PCR) analysis in students and staff at K-8 private schools in high-risk Chicago ZIP codes. New coronavirus disease 2019 (COVID-19) diagnoses or symptoms among participants, household contacts, and nonparticipants in each school were queried. Among 11 K-8 private schools across 8 Chicago ZIP codes, 468 participants (346 students, 122 staff members) underwent screening testing. At the first school, 17 participants (36%) tested positive, but epidemiologic investigation suggested against in-school transmission. Only 5 participants in the subsequent 10 schools tested positive for an overall 4.7% positivity rate (1.2% excluding school 1). All but 1 positive test among in-person students had high PCR cycle threshold values, suggesting very low SARS-CoV-2 viral loads. In all schools, no additional students, staff, or household contacts reported new diagnoses or symptoms of COVID-19 during the 2 weeks following screening testing. We identified infrequent asymptomatic COVID-19 in schools in high-risk Chicago communities and did not identify transmission among school staff, students, or their household contacts. These data suggest that COVID-19 mitigation procedures, including masking and physical distancing, are effective in preventing transmission of COVID-19 in schools. These results may inform future strategies for screening testing in K-8 schools.