Pens down: An outbreak of the B.1.617.2 SARS-CoV-2 variant in an Australian high school, August 2021
DOI:
https://doi.org/10.33321/cdi.2022.46.44Keywords:
COVID-19, SARS-CoV-2, schools, risk factors, outbreak, contact tracing, adolescent, child, transmission, classroomAbstract
Background
Little is known about the transmission dynamics of the B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children and young adolescents. We investigated an outbreak in an Australian high school, with limited public health mitigation measures in place, to understand the school activities associated with transmission, and the role of young adolescents in spreading SARS-CoV-2.
Methods
All 1,164 school attendees were monitored for SARS-CoV-2 infection through their mandated 14-day quarantine period. A cohort study design was used to investigate the effect of contact with the index case in different classes on the transmission of SARS-CoV-2, and the effect of vaccination among household contacts on becoming infected by SARS-CoV-2.
Results
There were 48 outbreak cases, including 14 students and one teacher who likely acquired their infection at the school. Attack rates among students in the index case’s classes ranged from 0% to 45%. The greatest risk of infection for students in the same grade attending a class with the index case were from the drama class (risk ratio, RR: 111.6; 95% confidence interval (95% CI): 14.88–837.19) and the personal development, health, and physical education class (RR: 7.45: 95% CI: 2.27–24.44). The overall household attack rate was 57%, and household contacts who were not fully vaccinated were 2.9 times more likely (95% CI: 1.07–7.87) to become cases than were effectively-vaccinated household contacts.
Conclusion
Children can play an important role in the transmission of the Delta variant of SARS-CoV-2 within schools and at home. Transmission in this outbreak was largely associated with active, practical lessons that had close contact between students. This study demonstrates that the absence of public health and social measures in a low-incidence context resulted in the rapid spread of coronavirus disease 2019 (COVID-19) within an educational setting. These findings reinforce the role of public health and social measures and vaccinations to reduce airborne transmission and to enable a safe face-to-face learning environment.
Downloads
References
Australian Capital Territory Government (ACT Government), ACT Legislation Register. Public Health (Lockdown Restrictions) Emergency Direction 2021 (No 1). ((ACT) NI2021-480). [Legislation.] Canberra: ACT Government; 12 August 2021. Available from: https://www.legislation.act.gov.au/ni/2021-480/.
ACT Government. COVID-19 vaccine bookings open for 16–29 year old Canberrans. [Internet.] Canberra: ACT Government; 1 September 2021. Available from: https://www.covid19.act.gov.au/news-articles/covid-19-vaccine-bookings-open-for-16-29-year-old-canberrans.
Australian Government Department of Health. Coronavirus Disease 2019 (COVID-19). CDNA National guidelines for public health units. Version 4.7. [Internet.] Canberra: Australian Government Department of Health; 2021. Available from: https://www1.health.gov.au/internet/main/publishing.nsf/Content/cdna-song-novel-coronavirus.htm.
ACT Government, ACT Legislation Register. Public Health (Diagnosed People and Close Contacts) Emergency Direction 2021 (No 1). ((ACT) NI2021–421). [Legislation.] Canberra: ACT Government; 9 July 2021. Available from: https://www.legislation.act.gov.au/ni/2021-421/.
Harris PA, Taylor R, Minor BL, Elliott V, Fernandez M, O’Neal L et al. The REDCap consortium: building an international community of software platform partners. J Biomed Inform. 2019;95:103208. doi: https://doi.org/10.1016/j.jbi.2019.103208.
Harris PA, Taylor R, Thielke R, Payne J, Gonzalez N, Conde JG. Research electronic data capture (REDCap)—a metadata-driven methodology and workflow process for providing translational research informatics support. J Biomed Inform. 2009;42(2):377–81. doi: https//doi.org/10.1016/j.jbi.2008.08.010.
Baumgarte S, Hartkopf F, Hölzer M, von Kleist M, Neitz S, Kriegel M et al. Investigation of a limited but explosive COVID-19 outbreak in a German secondary school. Viruses. 2022;14(1):87. doi: https://doi.org/10.3390/v14010087.
Gettings JR, Gold JAW, Kimball A, Forsberg K, Scott C, Uehara A et al. SARS-CoV-2 transmission in a Georgia school district – United States, December 2020–January 2021. Clin Infect Dis. 2022;74(2):319–26. doi: https://doi.org/10.1093/cid/ciab332.
Gold JAW, Gettings JR, Kimball A, Franklin R, Rivera G, Morris E et al. Clusters of SARS-CoV-2 infection among elementary school educators and students in one school district – Georgia, December 2020–January 2021. MMWR Morb Mortal Wkly Rep. 2021;70(8):289–92. doi: https://doi.org/10.15585/mmwr.mm7008e4.
Jehn M, McCullough JM, Dale AP, Gue M, Eller B, Cullen T et al. Association between K–12 school mask policies and school-associated COVID-19 outbreaks – Maricopa and Pima Counties, Arizona, July–August 2021. MMWR Morb Mortal Wkly Rep. 2021;70(39):1372–3. doi: https://doi.org/10.15585/mmwr.mm7039e1.
Lam-Hine T, McCurdy SA, Santora L, Duncan L, Corbett-Detig R, Kapusinszky B et al. Outbreak associated with SARS-CoV-2 B.1.617.2 (Delta) variant in an elementary school – Marin County, California, May–June 2021. MMWR Morb Mortal Wkly Rep. 2021;70(35):1214–9. doi: https://doi.org/10.15585/mmwr.mm7035e2.
Schoeps A, Hoffmann D, Tamm C, Vollmer B, Haag S, Kaffenberger T et al. Surveillance of SARS-CoV-2 transmission in educational institutions, August to December 2020, Germany. Epidemiol Infect. 2021;149:e213. doi: https://doi.org/10.1017/S0950268821002077.
Stein-Zamir C, Abramson N, Shoob H, Libal E, Bitan M, Cardash T et al. A large COVID-19 outbreak in a high school 10 days after schools’ reopening, Israel, May 2020. Euro Surveill. 2020;25(29):2001352. doi: https://doi.org/10.2807/1560-7917.ES.2020.25.29.2001352.
Torres JP, Piñera C, De La Maza V, Lagomarcino AJ, Simian D, Torres B et al. Severe acute respiratory syndrome coronavirus 2 antibody prevalence in blood in a large school community subject to a coronavirus disease 2019 outbreak: a cross-sectional study. Clin Infect Dis. 2021;73(2):e458–65. doi: https://doi.org/10.1093/cid/ciaa955.
Atherstone C, Siegel M, Schmitt-Matzen E, Sjoblom S, Jackson J, Blackmore C et al. SARS-CoV-2 transmission associated with high school wrestling tournaments – Florida, December 2020–January 2021. MMWR Morb Mortal Wkly Rep. 2021;70(4):141–3. doi: https://doi.org/10.15585/mmwr.mm7004e4.
Zimmerman KO, Brookhart MA, Kalu IC, Boutzoukas AE, McGann KA, Smith MJ et al. Community SARS-CoV-2 surge and within-school transmission. Pediatrics. 2021;148(4). doi: https://doi.org/10.1542/peds.2021-052686.
Pray IW, Gibbons-Burgener SN, Rosenberg AZ, Cole D, Borenstein S, Bateman A et al. COVID-19 outbreak at an overnight summer school retreat – Wisconsin, July-August 2020. MMWR Morb Mortal Wkly Rep. 2020;69(43):1600–4. doi: https://doi.org/10.15585/mmwr.mm6943a4.
Vishnu Prasad S, Mukherjee G, Bobdey S, Kaushik SK, Yadav AK, Teli P et al. Epidemiological analysis of SARS-COV-2 B.1.617.2 (delta variant) transmission in an educational institute. Med J Armed Forces India. 2022. doi: https://doi.org/10.1016/j.mjafi.2022.02.008.
Brandal LT, Ofitserova TS, Meijerink H, Rykkvin R, Lund HM, Hungnes O et al. Minimal transmission of SARS-CoV-2 from paediatric COVID-19 cases in primary schools, Norway, August to November 2020. Euro Surveill. 2021;26(1):2002011. doi: https://doi.org/10.2807/1560-7917.ES.2020.26.1.2002011.
Macartney K, Quinn HE, Pillsbury AJ, Koirala A, Deng L, Winkler N et al. Transmission of SARS-CoV-2 in Australian educational settings: a prospective cohort study. Lancet Child Adolesc Health. 2020;4(11):807–16. doi: https://doi.org/10.1016/S2352-4642(20)30251-0.
National Centre for Immunisation Research and Surveillance (NCIRS), New South Wales Government Department of Health (NSW Health). COVID-19 in schools – the experience in NSW: 18 October 2021 to 17 December 2021. Sydney: NCIRS, NSW Health; 18 February 2022. Available from: https://www.ncirs.org.au/sites/default/files/2022-02/NCIRS_NSW_Schools_COVID_Summary_Term_4_2021_Report%20-%2024-02-2022_Final.pdf.
Otte Im Kampe E, Lehfeld AS, Buda S, Buchholz U, Haas W. Surveillance of COVID-19 school outbreaks, Germany, March to August 2020. Euro Surveill. 2020;25(38):2001645. doi: https://doi.org/10.2807/1560-7917.ES.2020.25.38.2001645.
Hwang H, Lim JS, Song SA, Achangwa C, Sim W, Kim G et al. Transmission dynamics of the Delta variant of SARS-CoV-2 infections in South Korea. J Infect Dis. 2021;225(5):793–9. doi: https://doi.org/10.1093/infdis/jiab586.
Li YF, Fan W, Wang WH et al. A school cluster outbreak of COVID-19 caused by SARS-CoV-2 Omicron variant. Chin J Public Health. 2022;38(5):614–8. doi: https://doi.org/10.11847/zgggws1138512.
Lorthe E, Bellon M, Berthelot J, Michielin G, L’Huillier AG, Posfay-Barbe KM et al. A SARS-CoV-2 omicron (B.1.1.529) variant outbreak in a primary school in Geneva, Switzerland. Lancet Infect Dis. 2022;S1473-3099(22)00267-5. doi: https://doi.org/10.1016/S1473-3099(22)00267-5.
Grant R, Charmet T, Schaeffer L, Galmiche S, Madec Y, Von Platen C et al. Impact of SARS-CoV-2 Delta variant on incubation, transmission settings and vaccine effectiveness: results from a nationwide case-control study in France. Lancet Reg Health Eur. 2022;13:100278. doi: https://doi.org/10.1016/j.lanepe.2021.100278.
Assaker R, Colas AE, Julien-Marsollier F, Bruneau B, Marsac L, Greff B et al. Presenting symptoms of COVID-19 in children: a meta-analysis of published studies. Br J Anaesth. 2020;125(3):e330–2. doi: https://doi.org/10.1016/j.bja.2020.05.026.
Forrest CB, Burrows EK, Mejias A, Razzaghi H, Christakis D, Jhaveri R et al. Severity of acute COVID-19 in children <18 years old March 2020 to December 2021. Pediatrics. 2022;149(4):e2021055765. doi: https://doi.org/10.1542/peds.2021-055765.
Meuris C, Kremer C, Geerinck A, Locquet M, Bruyère O, Defêche J et al. Transmission of SARS-CoV-2 after COVID-19 screening and mitigation measures for primary school children attending school in Liège, Belgium. JAMA Netw Open. 2021;4(10):e2128757. doi: https://doi.org/10.1001/jamanetworkopen.2021.28757.
Shoji K, Akiyama T, Tsuzuki S, Matsunaga N, Asai Y, Suzuki S et al. Comparison of the clinical characteristics and outcomes of COVID-19 in children before and after the emergence of Delta variant of concern in Japan. J Infect Chemother. 2022;28(4):591–4. doi: https://doi.org/10.1016/j.jiac.2022.01.009.
Viner RM, Ward JL, Hudson LD, Ashe M, Patel SV, Hargreaves D et al. Systematic review of reviews of symptoms and signs of COVID-19 in children and adolescents. Arch Dis Child. 2020. doi: https://doi.org/10.1136/archdischild-2020-320972.
Yasuhara J, Kuno T, Takagi H, Sumitomo N. Clinical characteristics of COVID-19 in children: a systematic review. Pediatr Pulmonol. 2020;55(10):2565–75. doi: https://doi.org/10.1002/ppul.24991.
Chudasama DY, Tessier E, Flannagan J, Leeman D, Webster H, Demirjian A et al. Surge in SARS-CoV-2 transmission in school-aged children and household contacts, England, August to October 2021. Euro Surveill. 2021;26(48):2101019. doi: https://doi.org/10.2807/1560-7917.ES.2021.26.48.2101019.
Dougherty K, Mannell M, Naqvi O, Matson D, Stone J. SARS-CoV-2 B. 1.617. 2 (Delta) variant COVID-19 outbreak associated with a gymnastics facility—Oklahoma, April–May 2021. MMWR Morb Mortal Wkly Rep. 2021;70(28):1004. doi: https://doi.org/10.15585/mmwr.mm7028e2.
Goldstein E, Lipsitch M, Cevik M. On the effect of age on the transmission of SARS-CoV-2 in households, schools, and the community. J Infect Dis. 2020;223(3):362–9. doi: https://doi.org/10.1093/infdis/jiaa691.
Madewell ZJ, Yang Y, Longini IM, Halloran ME, Dean NE. Household transmission of SARS-CoV-2: a systematic review and meta-analysis. JAMA Netw Open. 2020;3(12):e2031756. doi: https://doi.org/10.1001/jamanetworkopen.2020.31756.
Peng J, Liu J, Mann SA, Mitchell AM, Laurie MT, Sunshine S et al. Estimation of secondary household attack rates for emergent spike L452R SARS-CoV-2 variants detected by genomic surveillance at a community-based testing site in San Francisco. Clin Infect Dis. 2022;74(1):32–9. doi: https://doi.org/10.1093/cid/ciab283.
Tanaka H, Hirayama A, Nagai H, Shirai C, Takahashi Y, Shinomiya H et al. Increased transmissibility of the SARS-CoV-2 Alpha variant in a Japanese population. Int J Environ Res Public Health. 2021;18(15):7752. doi: https://doi.org/10.3390/ijerph18157752.
Published
How to Cite
License
Copyright (c) 2022 Communicable Diseases Intelligence

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
