{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,9]],"date-time":"2025-11-09T03:50:29Z","timestamp":1762660229474,"version":"3.40.5"},"reference-count":28,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2022,7,12]],"date-time":"2022-07-12T00:00:00Z","timestamp":1657584000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Background<\/jats:title>\n<jats:p>In February 2021, the spread of a new variant of SARS-CoV-2 in the Lombardy Region, Italy caused concerns about school-aged children as a source of contagion, leading local authorities to adopt an extraordinary school closure measure. This generated a debate about the usefulness of such an intervention in light of the trade-off between its related benefits and costs (e.g. delays in educational attainment, impact on children and families\u2019 psycho-physical well-being). This article analyses the epidemiological impact of the school closure intervention in the Milan metropolitan area.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>Data from the Agency for Health Protection of the Metropolitan City of Milan allowed analysing the trend of contagion in different age classes before and after the intervention, adopting an interrupted times series design, providing a quasi-experimental counterfactual scenario. Segmented Poisson regression models of daily incident cases were performed separately for the 3\u201311-year-old, the 12\u201319-year-old, and the 20+-year-old age groups, examining the change in the contagion curves after the intervention, adjusting for time-varying confounders. Kaplan-Meier survival curves and Cox regression were used to assess the equality of survival curves in the three age groups before and after the intervention.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>Net of time-varying confounders, the intervention produced a daily reduction of the risk of contagion by 4% in those aged 3\u201311 and 12\u201319 (IRR = 0\u00b796) and by 3% in those aged 20 or more (IRR = 0\u00b797). More importantly, there were differences in the temporal order of contagion decrease between the age groups, with the epidemic curve lowering first in the school-aged children directly affected by the intervention, and only subsequently in the adult population, which presumably indirectly benefitted from the reduction of contagion among children.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusion<\/jats:title>\n<jats:p>Though it was not possible to completely discern the effect of school closures from concurrent policy measures, a substantial decrease in the contagion curves was clearly detected after the intervention. The extent to which the slowdown of infections counterbalanced the social costs of the policy remains unclear.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0271404","type":"journal-article","created":{"date-parts":[[2022,7,12]],"date-time":"2022-07-12T17:29:15Z","timestamp":1657646955000},"page":"e0271404","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":8,"title":["The impact of school closure intervention during the third wave of the COVID-19 pandemic in Italy: Evidence from the Milan area"],"prefix":"10.1371","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5363-3691","authenticated-orcid":true,"given":"David","family":"Consolazio","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Simone","family":"Sarti","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1072-2923","authenticated-orcid":true,"given":"Marco","family":"Terraneo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Corrado","family":"Celata","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5681-5861","authenticated-orcid":true,"given":"Antonio Giampiero","family":"Russo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2022,7,12]]},"reference":[{"key":"pone.0271404.ref001","article-title":"New variant of SARS-CoV-2 in UK causes surge of COVID-19","author":"T. 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Townsend","year":"2020","journal-title":"Child and Adolescent Mental Health"},{"key":"pone.0271404.ref006","doi-asserted-by":"crossref","DOI":"10.1007\/s11159-020-09860-z","article-title":"The impact of lockdown on the learning gap: family and school divisions in times of crisis","volume":"66","author":"X Bonal","year":"2020","journal-title":"International Review of Education"},{"key":"pone.0271404.ref007","doi-asserted-by":"crossref","DOI":"10.1001\/jama.2020.14348","article-title":"Association between Statewide School Closure and COVID-19 Incidence and Mortality in the US.","volume":"324","author":"KA Auger","year":"2020","journal-title":"JAMA\u2014Journal of the American Medical Association."},{"key":"pone.0271404.ref008","article-title":"The Effectiveness of School Closures and Other Pre-Lockdown COVID-19 Mitigation Strategies in Argentina, Italy, and South Korea.","author":"G Neidh\u00f6fer","year":"2020","journal-title":"SSRN Electronic Journal"},{"key":"pone.0271404.ref009","doi-asserted-by":"crossref","DOI":"10.3390\/fi13050109","article-title":"How schools affected the covid-19 pandemic in Italy: Data analysis for Lombardy region, Campania region, and Emilia region.","volume":"13","author":"D Tosi","year":"2021","journal-title":"Future Internet"},{"key":"pone.0271404.ref010","doi-asserted-by":"crossref","DOI":"10.1093\/cid\/ciaa855","article-title":"Asymptomatic Transmission and the Infection Fatality Risk for COVID-19: Implications for School Reopening","volume":"72","author":"SH Vermund","year":"2021","journal-title":"Clinical infectious diseases: an official publication of the Infectious Diseases Society of America"},{"key":"pone.0271404.ref011","doi-asserted-by":"crossref","DOI":"10.1016\/j.lanepe.2021.100092","article-title":"A cross-sectional and prospective cohort study of the role of schools in the SARS-CoV-2 second wave in Italy","volume":"5.","author":"S Gandini","year":"2021","journal-title":"The Lancet Regional Health\u2014Europe"},{"key":"pone.0271404.ref012","article-title":"School closure and management practices during coronavirus outbreaks including COVID-19: a rapid systematic review","author":"RM Viner","year":"2020","journal-title":"The Lancet Child and Adolescent Health"},{"key":"pone.0271404.ref013","article-title":"Do school closures reduce community transmission of COVID-19? A systematic review of observational studies","author":"S Walsh","year":"2021","journal-title":"medRxiv"},{"key":"pone.0271404.ref014","first-page":"223","article-title":"Outdoor Transmission of SARS-CoV-2 and Other Respiratory Viruses: A Systematic Review","author":"TC Bulfone","year":"2021","journal-title":"The Journal of infectious diseases"},{"key":"pone.0271404.ref015","first-page":"198","article-title":"Simple quantitative assessment of the outdoor versus indoor airborne transmission of viruses and COVID-19","author":"BR Rowe","year":"2021","journal-title":"Environmental Research"},{"key":"pone.0271404.ref016","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1016\/j.jclinepi.2018.05.026","article-title":"A methodological framework for model selection in interrupted time series studies","volume":"103","author":"J Lopez Bernal","year":"2018","journal-title":"Journal of Clinical Epidemiology"},{"key":"pone.0271404.ref017","doi-asserted-by":"crossref","first-page":"dyw098","DOI":"10.1093\/ije\/dyw098","article-title":"Interrupted time series regression for the evaluation of public health interventions: a tutorial.","author":"J Lopez Bernal","year":"2016","journal-title":"Int J Epidemiol"},{"key":"pone.0271404.ref018","doi-asserted-by":"crossref","first-page":"2082","DOI":"10.1093\/ije\/dyy135","article-title":"The use of controls in interrupted time series studies of public health interventions","volume":"47","author":"J Lopez Bernal","year":"2018","journal-title":"International Journal of Epidemiology"},{"key":"pone.0271404.ref019","doi-asserted-by":"crossref","DOI":"10.1186\/s13643-021-01648-y","article-title":"The incubation period during the pandemic of COVID-19: a systematic review and meta-analysis.","author":"W Dhouib","year":"2021"},{"key":"pone.0271404.ref020","doi-asserted-by":"crossref","DOI":"10.1136\/bmjopen-2020-039652","article-title":"Incubation period of COVID-19: A rapid systematic review and meta-analysis of observational research","volume":"10","author":"C McAloon","year":"2020","journal-title":"BMJ Open"},{"key":"pone.0271404.ref021","doi-asserted-by":"crossref","DOI":"10.3855\/jidc.14025","article-title":"Estimation of incubation period and serial interval for SARS-CoV-2 in Jiangxi, China, and an Updated Meta-Analysis","volume":"15","author":"T Zhang","year":"2021","journal-title":"Journal of Infection in Developing Countries"},{"key":"pone.0271404.ref022","article-title":"Seasonal Modelling of Fourier Series with Linear Trend.","volume":"5","author":"IA Iwok","year":"2016","journal-title":"International Journal of Statistics and Probability"},{"key":"pone.0271404.ref023","doi-asserted-by":"crossref","DOI":"10.3390\/jcm9020538","article-title":"Incubation Period and Other Epidemiological Characteristics of 2019 Novel Coronavirus Infections with Right Truncation: A Statistical Analysis of Publicly Available Case Data","volume":"9","author":"N Linton","year":"2020","journal-title":"Journal of Clinical Medicine"},{"volume-title":"Flexible parametric survival analysis using Stata: beyond the Cox model","year":"2011","author":"P Royston","key":"pone.0271404.ref024"},{"key":"pone.0271404.ref025","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1080\/20469047.2020.1781356","article-title":"Human and novel coronavirus infections in children: a review.","volume":"41","author":"N Rajapakse","year":"2021","journal-title":"Paediatrics and International Child Health"},{"key":"pone.0271404.ref026","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.immuni.2022.01.014","article-title":"SARS-CoV-2 infections in children: Understanding diverse outcomes","volume":"55","author":"P. 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Pfefferbaum","year":"2021","journal-title":"Curr Psychiatry Rep"},{"key":"pone.0271404.ref028","doi-asserted-by":"crossref","first-page":"189","DOI":"10.2174\/1745017902016010189","article-title":"School Closure and Children in the Outbreak of COVID-19.","volume":"16","author":"DR Petretto","year":"2020","journal-title":"Clin Pract Epidemiol Ment Health."}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0271404","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,7,12]],"date-time":"2022-07-12T17:29:40Z","timestamp":1657646980000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0271404"}},"subtitle":[],"editor":[{"given":"Hao","family":"Xue","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2022,7,12]]},"references-count":28,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2022,7,12]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0271404","relation":{},"ISSN":["1932-6203"],"issn-type":[{"type":"electronic","value":"1932-6203"}],"subject":[],"published":{"date-parts":[[2022,7,12]]}}}