Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.

<h4>Background</h4>The role of school contacts in the spread of the virus and the effectiveness of school closures in controlling the epidemic is still debated. We aimed to quantify the risk of transmission of SARS-CoV-2 in the school setting by type of school, characteristics of the ind...

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Main Authors: Olivera Djuric, Elisabetta Larosa, Mariateresa Cassinadri, Silvia Cilloni, Eufemia Bisaccia, Davide Pepe, Massimo Vicentini, Francesco Venturelli, Laura Bonvicini, Paolo Giorgi Rossi, Patrizio Pezzotti, Alberto Mateo Urdiales, Emanuela Bedeschi, Reggio Emilia Covid-19 Working Group
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2022-01-01
Series:PLoS ONE
Online Access:https://doi.org/10.1371/journal.pone.0275667
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author Olivera Djuric
Elisabetta Larosa
Mariateresa Cassinadri
Silvia Cilloni
Eufemia Bisaccia
Davide Pepe
Massimo Vicentini
Francesco Venturelli
Laura Bonvicini
Paolo Giorgi Rossi
Patrizio Pezzotti
Alberto Mateo Urdiales
Emanuela Bedeschi
Reggio Emilia Covid-19 Working Group
author_facet Olivera Djuric
Elisabetta Larosa
Mariateresa Cassinadri
Silvia Cilloni
Eufemia Bisaccia
Davide Pepe
Massimo Vicentini
Francesco Venturelli
Laura Bonvicini
Paolo Giorgi Rossi
Patrizio Pezzotti
Alberto Mateo Urdiales
Emanuela Bedeschi
Reggio Emilia Covid-19 Working Group
author_sort Olivera Djuric
collection DOAJ
description <h4>Background</h4>The role of school contacts in the spread of the virus and the effectiveness of school closures in controlling the epidemic is still debated. We aimed to quantify the risk of transmission of SARS-CoV-2 in the school setting by type of school, characteristics of the index case and calendar period in the Province of Reggio Emilia (RE), Italy. The secondary aim was to estimate the speed of implementation of contact tracing.<h4>Methods</h4>A population-based analysis of surveillance data on all COVID-19 cases occurring in RE, Italy, from 1 September 2020, to 4 April 2021, for which a school contact and/or exposure was suspected. An indicator of the delay in contact tracing was calculated as the time elapsed since the index case was determined to be positive and the date on which the swab test for classmates was scheduled (or most were scheduled).<h4>Results</h4>Overall, 30,184 and 13,608 contacts among classmates and teachers/staff, respectively, were identified and were recommended for testing, and 43,214 (98.7%) underwent the test. Secondary transmission occurred in about 40% of the investigated classes, and the overall secondary case attack rate was 4%. This rate was slightly higher when the index case was a teacher but with almost no differences by type of school, and was stable during the study period. Speed of implementation of contact tracing increased during the study period, with the time from index case identification to testing of contacts being reduced from seven to three days. The ability to identify the possible source of infection in the index case also increased.<h4>Conclusions</h4>Despite the spread of the Alpha variant during the study period in RE, the secondary case attack rate remained stable from school reopening in September 2020 until the beginning of April 2021.
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spelling doaj.art-007bdef77bc1482993cf32eb0311a4e62022-12-22T04:06:16ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-011710e027566710.1371/journal.pone.0275667Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.Olivera DjuricElisabetta LarosaMariateresa CassinadriSilvia CilloniEufemia BisacciaDavide PepeMassimo VicentiniFrancesco VenturelliLaura BonviciniPaolo Giorgi RossiPatrizio PezzottiAlberto Mateo UrdialesEmanuela BedeschiReggio Emilia Covid-19 Working Group<h4>Background</h4>The role of school contacts in the spread of the virus and the effectiveness of school closures in controlling the epidemic is still debated. We aimed to quantify the risk of transmission of SARS-CoV-2 in the school setting by type of school, characteristics of the index case and calendar period in the Province of Reggio Emilia (RE), Italy. The secondary aim was to estimate the speed of implementation of contact tracing.<h4>Methods</h4>A population-based analysis of surveillance data on all COVID-19 cases occurring in RE, Italy, from 1 September 2020, to 4 April 2021, for which a school contact and/or exposure was suspected. An indicator of the delay in contact tracing was calculated as the time elapsed since the index case was determined to be positive and the date on which the swab test for classmates was scheduled (or most were scheduled).<h4>Results</h4>Overall, 30,184 and 13,608 contacts among classmates and teachers/staff, respectively, were identified and were recommended for testing, and 43,214 (98.7%) underwent the test. Secondary transmission occurred in about 40% of the investigated classes, and the overall secondary case attack rate was 4%. This rate was slightly higher when the index case was a teacher but with almost no differences by type of school, and was stable during the study period. Speed of implementation of contact tracing increased during the study period, with the time from index case identification to testing of contacts being reduced from seven to three days. The ability to identify the possible source of infection in the index case also increased.<h4>Conclusions</h4>Despite the spread of the Alpha variant during the study period in RE, the secondary case attack rate remained stable from school reopening in September 2020 until the beginning of April 2021.https://doi.org/10.1371/journal.pone.0275667
spellingShingle Olivera Djuric
Elisabetta Larosa
Mariateresa Cassinadri
Silvia Cilloni
Eufemia Bisaccia
Davide Pepe
Massimo Vicentini
Francesco Venturelli
Laura Bonvicini
Paolo Giorgi Rossi
Patrizio Pezzotti
Alberto Mateo Urdiales
Emanuela Bedeschi
Reggio Emilia Covid-19 Working Group
Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.
PLoS ONE
title Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.
title_full Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.
title_fullStr Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.
title_full_unstemmed Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.
title_short Surveillance, contact tracing and characteristics of SARS-CoV-2 transmission in educational settings in Northern Italy, September 2020 to April 2021.
title_sort surveillance contact tracing and characteristics of sars cov 2 transmission in educational settings in northern italy september 2020 to april 2021
url https://doi.org/10.1371/journal.pone.0275667
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