SARS-CoV-2 outbreaks in secondary school settings in the Netherlands during fall 2020; silent circulation

BMC Infectious Diseases

Research

Dirk Eggink¹  Harry Vennema¹  Matthijs R. A. Welkers²  Marion P. G. Koopmans³  Richard Molenkamp³  Robin C. Huisman³  Bas B. Oude Munnink³  Pieter L. A. Fraaij⁴  Kimberly J. Linde⁵  Wietske Dohmen⁵  Dick J. J. Heederik⁵  Inge M. Wouters⁵  Patricia C. J. L. Bruijning-Verhagen⁶  Lotte Jonker⁶  Marieke L. A. de Hoog⁶  Robin Sprado⁶ 

[1] Center for Infectious Disease Control, National Institute for Public Health and the Environment, Antonie Van Leeuwenhoeklaan 9, 3721 MA, Bilthoven, The Netherlands;Center for Infectious Disease Control, National Institute for Public Health and the Environment, Antonie Van Leeuwenhoeklaan 9, 3721 MA, Bilthoven, The Netherlands;Department of Medical Microbiology & Infection Prevention, Amsterdam University Medical Center, Meibergdreef 9, 1105AZ, Amsterdam, The Netherlands;Department of Viroscience, Erasmus Medical Center, Dr. Molewaterplein 50, 3015 GD, Rotterdam, The Netherlands;Department of Viroscience, Erasmus Medical Center, Dr. Molewaterplein 50, 3015 GD, Rotterdam, The Netherlands;Department of Pediatrics, Subdivision Infectious Diseases and Immunology, Erasmus Medical Center-Sophia Children’s Hospital, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands;Institute for Risk Assessment Sciences, Utrecht University, Yalelaan 2, 3584 CM, Utrecht, The Netherlands;Julius Center for Health Sciences and Primary Care, UMC Utrecht, Utrecht University, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands;

关键词: SARS-CoV-2;    Secondary schools;    Transmission;    Outbreak;    Air levels;   

DOI  :  10.1186/s12879-022-07904-3

 received in 2022-05-30, accepted in 2022-11-29,  发布年份 2022

来源: Springer

【 摘 要 】

BackgroundIn fall 2020 when schools in the Netherlands operated under a limited set of COVID-19 measures, we conducted outbreaks studies in four secondary schools to gain insight in the level of school transmission and the role of SARS-CoV-2 transmission via air and surfaces.MethodsOutbreak studies were performed between 11 November and 15 December 2020 when the wild-type variant of SARS-CoV-2 was dominant. Clusters of SARS-CoV-2 infections within schools were identified through a prospective school surveillance study. All school contacts of cluster cases, irrespective of symptoms, were invited for PCR testing twice within 48 h and 4–7 days later. Combined NTS and saliva samples were collected at each time point along with data on recent exposure and symptoms. Surface and active air samples were collected in the school environment. All samples were PCR-tested and sequenced when possible.ResultsOut of 263 sampled school contacts, 24 tested SARS-CoV-2 positive (secondary attack rate 9.1%), of which 62% remained asymptomatic and 42% had a weakly positive test result. Phylogenetic analysis on 12 subjects from 2 schools indicated a cluster of 8 and 2 secondary cases, respectively, but also other distinct strains within outbreaks. Of 51 collected air and 53 surface samples, none were SARS-CoV-2 positive.ConclusionOur study confirmed within school SARS-CoV-2 transmission and substantial silent circulation, but also multiple introductions in some cases. Absence of air or surface contamination suggests environmental contamination is not widespread during school outbreaks.

【 授权许可】

CC BY   
© The Author(s) 2022

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