The rate of COVID-19 transmission in New South Wales (NSW) educational settings was extremely limited during the first wave of COVID-19, research findings have shown. Researchers from the National Centre for Immunisation Research and Surveillance (NCIRS) and the University of Sydney released their preliminary findings from this work from January to April 2020.
The study contains detailed analysis on COVID-19 spread in 25 educational settings (15 schools and 10 childcare settings) in Term 1. Additional data from Term 2 and 3 are also available today. Lead author Professor Kristine Macartney said the study showed transmission rates in NSW schools and early childhood education and care (ECEC) services were minimal, particularly between children and from children to adults.
"This is the first comprehensive population-based assessment of coronavirus transmission in educational settings worldwide," Macartney said.
"COVID-19 transmission in schools appears to be considerably less than that seen for other respiratory viruses, such as influenza. This supports the previous findings that COVID-19 transmission in educational settings can be kept low and manageable in the context of an effective pandemic response that includes contact tracing and quarantine, and temporary school closures for cleaning if someone is found to be infected.
"It is also consistent with other data that show lower rates, and generally milder disease, in children than in adults. However, it is important to view these findings in the context of the NSW outbreak. Higher rates of transmission may occur in areas with higher levels of virus transmission in the community or with less rigorous public health and community response."
In Term 1 and 2 there have been 33 initial cases of COVID-19 confirmed at 31 of NSW's 7700 schools and ECEC services, with 25 sites in Term 1 and six during Term 2 affected. In Term 1 and 2, a total of 16 students and 17 adult staff were the first cases who tested positive for the virus.
Out of 1333 close contacts in primary and high schools, just five (0.4%) possible secondary infections were recorded across Terms 1 and 2: one primary student, two high school students, one primary teacher and one high school teacher.
Initial cases were also seen in 11 ECEC services across Term 1 and 2, with 13 possible secondary infections recorded out of 636 close contacts.
All 13 secondary cases (7 children and 6 staff) were linked to an outbreak at a single ECEC service early in Term 1 that started initially in staff members. No secondary cases were identified in the other 10 ECEC services.
This observational study is continuing in Term 3 in NSW (July-September). Data for Term 3 is preliminary but as at 3 August, there have been 11 cases (3 staff members and 8 students) with two secondary infections being recorded in one primary school and one ECEC service.
"We know anyone of any age can be infected and potentially spread the virus," Macartney said.
"But understanding how the virus spreads in our context will assist modellers, policymakers, healthcare providers, and the public to understand the risk of COVID-19 in educational settings and help in decision making around school closures and re-openings."
Abstract
Background: School closures have occurred globally during the COVID-19 pandemic. However, empiric data on transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children and in educational settings are scarce. In Australia, most schools have remained open during the first epidemic wave, albeit with reduced student physical attendance at the epidemic peak. We examined SARS-CoV-2 transmission among children and staff in schools and early childhood education and care (ECEC) settings in the Australian state of New South Wales (NSW).
Methods: Laboratory-confirmed paediatric (aged ≤18 years) and adult COVID-19 cases who attended a school or ECEC setting while considered infectious (defined as 24 h before symptom onset based on national guidelines during the study period) in NSW from Jan 25 to April 10, 2020, were investigated for onward transmission. All identified school and ECEC settings close contacts were required to home quarantine for 14 days, and were monitored and offered SARS-CoV-2 nucleic acid testing if symptomatic. Enhanced investigations in selected educational settings included nucleic acid testing and SARS-CoV-2 antibody testing in symptomatic and asymptomatic contacts. Secondary attack rates were calculated and compared with state-wide COVID-19 rates.
Findings: 15 schools and ten ECEC settings had children (n=12) or adults (n=15) attend while infectious, with 1448 contacts monitored. Of these, 633 (43·7%) of 1448 had nucleic acid testing, or antibody testing, or both, with 18 secondary cases identified (attack rate 1·2%). Five secondary cases (three children; two adults) were identified (attack rate 0·5%; 5/914) in three schools. No secondary transmission occurred in nine of ten ECEC settings among 497 contacts. However, one outbreak in an ECEC setting involved transmission to six adults and seven children (attack rate 35·1%; 13/37). Across all settings, five (28·0%) of 18 secondary infections were asymptomatic (three infants [all aged 1 year], one adolescent [age 15 years], and one adult).
Interpretation: SARS-CoV-2 transmission rates were low in NSW educational settings during the first COVID-19 epidemic wave, consistent with mild infrequent disease in the 1·8 million child population. With effective case-contact testing and epidemic management strategies and associated small numbers of attendances while infected, children and teachers did not contribute significantly to COVID-19 transmission via attendance in educational settings. These findings could be used to inform modelling and public health policy regarding school closures during the COVID-19 pandemic.
Funding: NSW Government Department of Health.
Authors
Kristine Macartney, Helen E Quinn, Alexis J Pillsbury, Archana Koirala, Lucy Deng, Noni Winkler, Anthea L Katelaris, Matthew V N O'Sullivan, Craig Dalton, Nicholas Wood, D Brogan, C Glover, N Dinsmore, A Dunn, A Jadhav, R Joyce, R Kandasamy, K Meredith, L Pelayo, L Rost, G Saravanos, S Bag, S Corbett, M Staff, K Alexander, S Conaty, K Leadbeater, B Forssman, S Kakar, D Dwyer, J Kok, K Chant
[link url="https://www.sydney.edu.au/news-opinion/news/2020/08/04/covid-19-study-confirms-low-transmission-in-educational-settings.html"]University of Sydney material[/link]
[link url="https://www.thelancet.com/journals/lanchi/article/PIIS2352-4642(20)30251-0/fulltext"]The Lancet Child & Adolescent Health abstract[/link]