Open access Protocol Study protocol for monitoring SARS-­ CoV-­2 infection and its determinants in Catalonia (Spain): an observational and participatory research approach in a Sentinel Network of Schools Anna Bordas ‍ ‍,1,2 Antoni Soriano-­Arandes,3 Maria Subirana,4,5 Rosina Malagrida,6 Juliana Maria Reyes-­Urueña ‍ ‍,1,7 Cinta Folch,1,2,7 Pere Soler-­Palacin,3 Mireia Gascón,5,8 Jordi Sunyer,5,9 Andres Anton,10 Ignacio Blanco,11 Jessica Fernández-­Morales,6 Andreu Colom-­Cadena,1,2 Alexis Sentís,1,12 Tomas Pumarola,10 Josep Basora,13 Jordi Casabona,1,2,7 Sentinel School Network Study Group of Catalonia To cite: Bordas A, Soriano-­ ABSTRACT Arandes A, Subirana M, et al. Strengths and limitations of this study Introduction Since the SARS-­CoV-­2 became of concern in Study protocol for monitoring January 2020, many preventive measures have been adopted SARS-­CoV-­2 infection and ► A multicentre study combining cross-­sectional and in educational settings to ensure the control of COVID-­19 its determinants in Catalonia longitudinal studies, collecting data from sentinel pandemic among children and staff in schools. This study (Spain): an observational schools throughout Catalonia. and participatory research aims to set up a school sentinel surveillance network with the ► Planned to consolidate the sentinel school surveil- approach in a Sentinel purpose of monitoring SARS-­CoV-­2 infection, seroprevalence lance network to monitor and evaluate the epidemi- Network of Schools. BMJ Open as well as to analyse the impact of preventive interventions ology of SARS-­CoV-­2 in school settings and assess 2022;12:e055649. doi:10.1136/ of SARS-­CoV-­2 in school settings. Additionally, we will assess the effectiveness of future preventive and control bmjopen-2021-055649 diverse screening strategies in a cohort of students and school measures, new diagnostic tests or vaccination. staff to monitor the screening acceptance and its potential ► Prepublication history for ► Transdisciplinary and participatory research, carried this paper is available online. impact. Altogether, we hope this study will enable the design out in collaboration with the education community To view these files, please visit of more effective strategies for the prevention of COVID-­19 to ensure that the prevention and control strategy the journal online (http://dx.doi.​ spread. for SARS-­CoV-­2 fits with the needs and expectations org/10.1136/bmjopen-2021-​ Methods and analysis The sentinel schools’ study of schools. 055649). is a cross-­sectional, school-­based project including ► The participating school population might not be 26 participating sentinel schools in Catalonia (Spain). representative of the entire Catalan school popula- AB, AS-­A, MS and RM are joint Children, adolescents and staff at the schools will be tion distributed across all the territory. first authors. invited to participate. This project will be carried out ► Participation in periodic screenings could be low due Received 20 July 2021 from January 2021 to June 2022 as follows: (1) twice to fear of testing the younger children or because of Accepted 05 January 2022 yearly serological testing and molecular SARS-­CoV-­2 pandemic fatigue due to the large number of tests detection and questionnaires covering SARS-­CoV-­2 being performed. symptoms, tests, health, knowledge, attitudes and behaviours; (2) an environmental evaluation carried out in different classrooms; (3) SARS-­CoV-­2 transmission dynamics and the impact of different variants among Findings will be disseminated at national and international confirmed cases and classmates; (4) a participatory conferences and published in peer-­reviewed journals. process by which the participants are invited to act © Author(s) (or their as coinvestigators to evaluate prevention strategies INTRODUCTION employer(s)) 2022. Re-­use and provide recommendations to improve COVID-­19 COVID-­19, first reported from Wuhan city, permitted under CC BY-­NC. No prevention in schools. Descriptive analysis will be commercial re-­use. See rights China, in December 2019,1 was declared a performed for the main variables collected. The and permissions. Published by Public Health Emergency of International incidence and seroprevalence will be calculated and the BMJ. Concern by the WHO on 30 January 2020 association with sociodemographic factors and school For numbered affiliations see characteristics will be determined using multivariate and defined as a pandemic on 11 March end of article. 2020. Although children were recognised logistic regression. Correspondence to Ethics and dissemination Ethical approval was obtained as contributing to only a small propor- Jordi Casabona; from the IDIAPJGol and the Hospital Universitari Vall d’Hebron tion of laboratory-­ confirmed COVID-­ 19 ​jcasabona@​iconcologia.​net ethics committees. A report will be generated quarterly. cases and rarely developing severe or fatal Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 1 Open access disease,2 3 their role in asymptomatic infection and trans- the authorisation for emergency use by the European mission, which is well described for other respiratory viral Medicines Agency and the Food and Drug Agency in the infections such as influenza, was uncertain at the point of USA.30 So far, teaching and non-­teaching staff and popu- these restrictions and is still under discussion. lation over 12 years are being vaccinated as defined in On the declaration of the global COVID-­19 pandemic, the Spanish vaccination strategy raising hopes for a better most countries closed their schools as part of their control of the epidemic inside school settings. In this national lockdown measures,4 5 with more than 1 billion context, there is a need to understand the epidemiology children and young people affected so far.6 The closure of SARS-­ CoV-­ 2 in children once the adult population of schools reduced the number of contacts within the has been vaccinated. The pandemic is moving very fast, population and, therefore, the subsequent transmis- and behaviours and attitudes may change in response sion.5 However, this measure can also cause considerable to the COVID-­19 pandemic. Understanding the drivers damage to children and their families with significant of vaccine acceptance will be crucial to the success of social and economic impacts, mainly on physical and COVID-­19 mass vaccination campaigns. mental health.7–11 However, most evidence from coun- Therefore, the use of periodical cross-­sectional surveys tries that have reopened schools or never closed them on the knowledge, attitude and practice associated with suggests that schools have not been associated with signif- COVID-­19 will allow rapid and adaptive monitoring of icant increases in community transmission.12–15 Thus, the demographics, preventive behaviours, knowledge and transmission of SARS-­CoV-­2 from paediatric patients both perceptions over time, among others, and can be useful at home and in schools has been an intensely topic since in order to identify misinformation as they emerge. the beginning of the COVID-­19 pandemic, also regarding This article reports the design and protocol of a school-­ the emergency of new variant scenarios.16–19 based study in several sentinel schools in Catalonia. The Since Catalan schools reopened in September 2020 study is part of the COVID-­19 monitoring and evaluation after 6 months of closure, there have been 83 911 accu- plan from the Ministry of Health of the Government of Cata- mulated positive COVID-­19 cases, of which 74 246 were lonia, and it is conceived as a participatory and transdisci- students (5.16%) and 8996 school staff (5.49%).20 Like- plinary research process where the students and school staff wise, a recent study that analysed the incidence dynamics will be invited to participate. The monitoring and evaluation of SARS-­CoV-­2 infection in children in the first term of provide practical information for making timely decisions, the school reopening shows that the infection rate among addressing community needs and identifying more effective children remained lower compared with the general strategies for the prevention of COVID-­19 spread and future population for preschool (3–6 years) and primary pupils infectious threats. In addition, the protocol could be highly (6–12 years) but was equal to it or higher in secondary useful for adaption into other educational settings for the students (12–18 years).21 Moreover, several studies have monitoring of the COVID-­19 pandemic. shown that in this pandemic very few cases infect many contacts (super-­spreaders), while most cases either infect nobody or very few people and this includes paediatric GENERAL OBJECTIVES index cases.22–26 Defining host-­related, viral and environ- 1. To describe over time the knowledge, attitudes and mental patterns that determine these super-­ spreading behaviours (KAB) of students and school staff (teach- situations is relevant to the tailoring of measures to mini- ing and non-­teaching staff) towards SARS-­CoV-­2 infec- mise the transmission of SARS-­CoV-­2 in schools.27 tion and its prevention as well as its impact in school Preventive interventions play an important role in settings. working together to gain control of the COVID-­ 19 2. To assess over time the prevalence of SARS-­CoV-­2 in- pandemic and also in schools. In this sense, the social fection and seroprevalence of antibodies against SARS-­ and behavioural sciences can provide valuable insights CoV-­2 and to identify associated sociodemographic, into managing the pandemic and its impacts.28 Non-­ biological, behavioural and environmental factors pharmacological preventive interventions in schools such among both children and staff. as physical distancing, hygiene, use of masks, restricting 3. To identify and describe multilevel determinants, bar- interactions to clusters of students in bubble groups, riers and needs of SARS-­CoV-­2 prevention related mea- massive microbiological testing and other safety measures sures in school settings over time. are essential to prevent transmission.29 These measures 4. To assess the secondary attack rate of SARS-­CoV-­2 chil- should be adapted to the setting and age group and dren index cases and its multilevel determinants and prevent transmission while providing children with an factors, both in school and family settings. optimal learning and social environment.4 Furthermore, 5. To analyse the impact of preventive and control mea- as it is known that SARS-­CoV-­2 transmission is via aerosols sures on the occurrence of SARS-­CoV-­2 in school set- and virus-­laden aerosols may easily accumulate in indoor tings. environments, a proper ventilation of indoor spaces can 6. To pilot alternative testing and screening technologies be a great preventive measure.29 Additionally, the first set and strategies to assess their acceptability, feasibility of COVID-­19 vaccines provided a pharmacological inter- and performance and the occurrence of SARS-­CoV-­2 vention in the last quarter of 2020 when they received infection among students and school staff. 2 Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 Open access 7. To analyse the impact of different SARS-­CoV-­2 vari- adults working in the educational settings such as ants’ transmission in school settings. extracurricular education instructors. 8. To facilitate a participatory process where the educa- tion community will act as coresearchers elaborating Informed consent recommendations to improve the prevention and con- Informed consent will be obtained from school staff, trol measures in the school environment. parents of children under 16 and pupils of 16 years old 9. To evaluate the impact on students’ learning, attitudes or older. Participants will be free to decline/withdraw and motivations of their participation in the research consent at any time without providing a reason and process and the teacher’s perspectives on this impact. without being subject to any resulting detriment. Study procedures METHODS AND ANALYSIS Summary information of questionnaires, biological Study design and setting samples and other information to be collected is provided The population of Catalonia was 7 619 494 in 2019. The in table 1. Catalan school system includes 1 582 466 students, 117 398 teaching staff and 5492 school centres.31 KAB questionnaires regarding COVID-19 and impact of preventive This project is based on sentinel schools defined as a and control measures network of schools representing the diversity of schools Each headteacher will send the study information pack (a and the scholar population in Catalonia and chosen study leaflet and the information sheet) and the link to using the following criteria: the online informed consent and the baseline question- ► Volunteering/commitment of both the school naires by email to the parents/guardians, school staff and management team and the teaching staff as well as the older students (when necessary, on paper). We will send children’s parents to participate in the project. follow-­ up questionnaires twice a year. Three different ► Representation of schools located in the different questionnaire models will be designed: for teachers and basic health areas (BHA) and territorial areas will be other school staff (questionnaire A); for students under ensured taking into account tertiles of SARS-­CoV-­2 16 years, which will be answered by parents/guardian accumulated incidence and tertiles of socioeconomic (questionnaire B) and for students over 16 years (ques- deprivation index32 tionnaire C). The variables included in the KAB survey ► Representation of schools with different will be mainly based on the WHO recommendations, as characteristics: described in WHO/Europe (2020).34 – Sociodemographic indicators. At least two-­ to-­five high complexity schools characterised by low socio- Prevalence of SARS-CoV-2 active infection and seroprevalence of economic level and specific educational needs. antibodies against SARS-CoV-2 33 – Some schools located in rural areas. Cross-­sectional study: a field team (FT) made up of three – Schools with all levels of education, small school nurses and a field coordinator will visit each school size and school centres with professional training equipped with personal protective equipment to collect courses. the samples for testing. They will schedule the number – Public, charter and private schools. of intervention days with each participating school The sentinel surveillance is carried out by means of depending on school size. The following samples in the serial cross-­sectional and longitudinal school-­ based baseline and the following cross sectionals (twice yearly) studies, direct observation, index case study and partic- will be collected from all participants: (1) nasal swabs ipatory research approach in children, adolescent and to perform a transcription-­mediated amplification assay school staff from the selected sentinel schools. In a subset (TMA) for detection of SARS-­CoV-­2 and (2) finger prick of schools (n=5), a cohort of students from first grade blood sample to assess with a quick anti SARS-­CoV-­2 IgM/ of secondary school to high school (12–>18 years) and IgG antibody test. school staff has been established in order to monitor the Longitudinal study: follow-­up interventions will be sched- COVID-­19 incidence and the feasibility and acceptability uled twice monthly during the school year as an alternative of different periodical screening practices for COVID-­19 testing strategy. In each intervention, the FT will collect saliva confirmation. All the study interventions will be carried and nasal specimens for the detection of SARS-­CoV-­2 by out in two academic years starting from January 2021 to molecular or antigenic tests, respectively. The cohort partici- June 2022, and the analysis will take place from June 2022 pants will fill in an additional online epidemiological survey until the end of 2022. with information related to SARS-­ CoV-­2 infection, their symptomatology, exposure and vaccine status. Study population (inclusion criteria) ► Students attending sentinel schools will be eligible for Secondary attack rate and SARS-CoV-2 variants the study, from preschool (3 years old) to high school This part of the study will be carried by the Paediatric (approximately 18 years old). Infectious Diseases and Immunodeficiencies Unit at ► School staff of the sentinel schools, including teachers, Hospital Universitari Vall d’Hebron (HUVH). Data on administrators, canteen and cleaning staff, and other COVID-­19 index cases will be collected with appropriate Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 3 Open access Table 1 Summary information of study procedures Type of intervention Determination Type of test Coordination Frequency Biobehavioural questionnaires CEEISCAT   ► Questionnaire A (teaching and non-­teaching   Once during 2020– staff) 2021 school year and ► Questionnaire B (parents or foster parents of twice during 2021– students under 16 years old) 2022 school year ► Questionnaire C (16 years old or older students) Biological sampling CEEISCAT   Baseline   ► Blood from finger prick Once during 2020– Ab anti-­SARS-­CoV-­2 LFA ► Nasal swab sample 2021 school year and Viral RNA (SARS-­CoV-­2) TMA Longitudinal study (> 1st grade of middle school and twice during 2021– Viral RNA (SARS-­CoV-­2) RT-­PCR school staff) 2022 school year SARS-­CoV-­2 Ag rapid test LFA ► Saliva sample Bi-­monthly ► Nasal swab sample Environmental and structural evaluation in each ISGlobal   sentinel school ► Environmental questionnaires (directors and   Once during 2020– teachers) Prevention measures (eg, 2021 school year and ► Structural and environmental evaluation by a ventilation practices) twice during 2021– field technician 2022 school year ► CO2, humidity and temperature measurements Transmissibility study HUVH   ► COVID-­19 index cases RT-­PCR   Viral coinfections ► Household and classmate contacts evaluation TMA/PCR Viral RNA (SARS-­CoV-­2) ► Secondary attack rate Whole-­genome   SARS-­CoV-­2 characterisations sequencing Viral load measurement Quantitative PCR assay Participatory research Living lab   (IRSICaixa) ► Scientific capital surveys   Once during 2020–2021 ► Focus groups school year and twice ► List of recommendations during 2021-­2022 ► Annual school conference school year Ab, antibodies; Ag, antigens; CEEISCAT, Centre for Epidemiological Studies of HIV/SIDA and STI of Catalonia; HUVH, Hospital Universitari Vall d’Hebron; LFA, lateral flow assay; TMA, transcription-­mediated amplification assay. social and geographical distribution. These cases will be evaluation by a field technician in at least one classroom detected by the routine data provided by the Catalan for each grade; (2) online twice yearly surveys addressed Public Health Department or detected during the study to teachers and headteachers regarding ventilation and interventions and analysed in depth from then on. Data other prevention practices; (3) twice yearly 15-­day assess- on demographic, social and clinical features, vaccina- ment of CO2, temperature and humidity—7 days assessed tion status, comorbidities and clinical outcome will be by the field technician and the remainder as an exper- collected. School and household contacts will also be imenting tool for students—in five to eight previously studied in depth to detect secondary cases. Samples from chosen classrooms. the index case and all COVID-­19 confirmed contacts will be sequenced using whole-­genome sequencing (WGS) Participatory research following the ARTIC Network protocol35 for the charac- The project is conceived as a collaborative and transdis- terisation of SARS-­CoV-­2 (lineage and mutations), molec- ciplinary research project where the education commu- ular tracing of sequences and measurement of the viral nity and families participate in different phases of the load in these respiratory samples to assess its role in the research process. They will act as coresearchers evalu- transmission dynamics. ating the prevention and control measure implementa- tion of SARS-­CoV-­2 infection in the school environment Environmental determinants and barriers with a systemic perspective, as well as elaborating their The environmental evaluation will be carried out by the recommendations to improve the prevention and control ISGlobal team to obtain information on the structural strategy. This approach will be implemented in collabora- characteristics of each participating sentinel school, tion with the EC funded project CONNECT, which aims ventilation practices and other environmental prevention to improve science learning and increase students’ moti- measures using the KKmoon carbon dioxide detector vation towards science careers by engaging schools, scien- device. This intervention will include: (1) a structural tists and families to solve local challenges. 4 Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 Open access Participation will entail discussion groups: (1) online Carlos III register. However, saliva samples with positive focus groups with teachers. Preliminary results of the SARS-­CoV-­2 results will be frozen and stored at the IGTP-­ biobehavioural surveys will be shared, and based on HUGTiP Biobank and conserved for 2 years. TMA/PCR these, they will be invited to analyse problems, opportuni- results will be uploaded by the microbiology laboratories ties and needs and to develop proposals for improvement to the electronic health record, and the participants and of prevention measures following a protocol; (2) teachers their general practitioners or paediatricians will be able conducting focus groups with their class group students to check them. and then families, reproducing a similar protocol; (3) Regarding the transmissibility study, nasopharyngeal the edited list of recommendations will be presented or nasal swab samples from index cases and positive by students to scientists and policy makers in an online secondary cases will be sent to the HUVH laboratory for conference; (4) elaboration of the final list of recommen- genetic SARS-­CoV-­2 characterisation, to measure the viral dations; (5) capital science survey: a preintervention and load and to detect other respiratory viruses. The genetic postintervention survey addressed to pupils regarding characterisation of SARS-­CoV-­2 will be performed through the science learning and students’ attitudes and motiva- WGS according to the ARTIC Network protocol35 by using tion, and a preintervention and postintervention survey MiSeq and NextSeq 2000 platforms (Illumina, California, addressed to teachers regarding the education process. USA). Other respiratory viruses will be detected by a real-­ time multiplex RT-­PCR assay (Allplex Respiratory Panel Sample management, microbiological analysis and test result Assay, Seegene); total nucleic acids will be extracted communication using NucliSENS EasyMAG (bioMérieux, Marcy l’Etoile, As described previously, diverse biological samples will be France) or Microlab STARlet System (Hamilton, Cali- collected during the study. fornia, USA) according to the manufacturer’s instruc- The finger prick blood collected at the baseline and the tions. Additionally, to measure the SARS-­CoV-­2 viral load, follow-­up will be processed at the time of collection to an in-­house quantitative RT-­PCR assay using the primer/ perform a quick SARS-­CoV-­2 serological test (COVID-­19 probe set targeting the nucleocapsid protein (N1) and IgG/IgM Rapid Test Kit, Lambra, Spain) with sensitivi- the human RNase P (housekeeping gene) from the CDC ties of 97.2% (IgG) and 87.9% (IgM), and specificities 2019-­nCoV Real-­ Time RT-­ PCR Diagnostic Panel will of 100% for both immunoglobulins as the manufacturers be carried out. The Ct values of the viral target will be describe. This approach will be used to assess the exposure normalised to a housekeeping gene based on the ΔCt to SARS-­CoV-­2 infection or vaccination by the presence of method (Ctsample − Cthousekeeping gene) in order antibodies. In addition, the nasal swab sample collected to minimise the variations due to the non-­standardised in the longitudinal study will be processed at the time collection of a heterogenous specimens. of collection for detection of SARS-­CoV-­2 antigen using the Panbio COVID-­19 Ag Rapid Test (Abbot, USA) with a Data management, data protection and patient confidentiality sensitivity of 93.3% (95% CI 83.8% to 98.2%) and speci- Informed consents and the different surveys will be ficity of 99.4% (95% CI 97.0% to 100%) as the manufac- designed and published by means of the EUSurvey turers describe. The nursing team will upload the rapid management system, an official online survey manage- test results on an online research database using elec- ment tool of the European Commission. For those partic- tronic tablets. These results will be introduced afterwards ipants for whom online access is not possible, printed to the electronic health record of all participants who will be able to consult them in the online patient health surveys will be distributed by the field team and afterwards portal (La Meva Salut app). In case of Ag positive with IgG digitalised. The periodical surveys from the cohort study negative, the COVID-­school manager, a new sanitary staff will be published by means of the OpenTIC software. role acting as a liaison between the primary care team and After giving their consent to participate (or allow the school centres, will activate the public health protocol their child to participate), each participant will be allo- established by the Catalan Ministry of Health.36 cated a unique participant ID number on enrolment to Nasal swabs and saliva samples will be maintained at 4°C the study. This unique identifier will serve as a link to during sampling procedures and transport to laboratory all the data needed for the study (questionnaires and facilities. A molecular assay based on the TMA (Procleix biological samples). The file that relates the identifier SARS-­ CoV-­2, Grifols) will be conducted in HUVH for or pseudonym to the personally identifiable data will be detection of SARS-­ CoV-­ 2 in nasal swabs, and RT-­ PCR encrypted, and the access to this file will be restricted to assay (Allplex SARS-­ CoV-­ 2/FluA/FluB/RSV, Werfen) a very small number of authorised persons (EM, YD, JA will be conducted at the Hospital Universitari Germans and LA). The process will comply with the General Data Trias i Pujol (HUGTiP) laboratories to determine SARS-­ Protection Regulation requirements. CoV-­2 infection in saliva specimens. If the TMA assay (HUVH) or RT-­PCR assay (HUGTiP) is positive, an active Study definitions infection will be confirmed. Once the nasal samples Given that all the participants attending the school have been tested, all positive specimens will be stored should be asymptomatic, a confirmed COVID-­19 case will in sample collection C.0001145 on the Instituto de Salud be defined as any individual testing SARS-­CoV-­2 positive Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 5 Open access by molecular assays (PCR or TMA-­based) or COVID-­19 ► Number of confined classrooms/total number of Ag Rapid Test (RAT) in a respiratory or saliva specimen.37 classrooms. A paediatric index case will be established when the child is the first confirmed COVID-­19 case in the class- Data analysis plan and sample size room noticed by health authorities or the research We estimate a participation of 50%–70% among the team.26 A secondary case will be defined as a classmate total of 11 000 individuals who are on the census at the or household contact subsequently testing positive for 26 sentinel schools since not all potential participants SARS-­CoV-­2 by molecular assay or RAT. Close contacts are aware of the public health concern and due to will be defined as all people who have shared space with other barriers. A descriptive analysis will be performed a positive COVID-­19 less than 2 m away, for more than for all the main aforementioned variables collected: 15 min, without protection and from the 48 hours prior to participant’s sociodemographic characteristics, SARS-­ the onset of symptoms. If the positive person has not had CoV-­ 2 infection characterisation, its associated factors, symptoms, onset will be defined as the date of performing behaviour information and other outcomes of interest. the diagnostic test. For quantitative variables, we will use measures of central tendency and dispersion (mean, SD, median, IQR and Variables collected 95% CI). For qualitative variables, we will calculate abso- Individual data lute frequencies and percentages. To estimate the statis- ► Sociodemographic and socioeconomic indicators: tical significance of time trends in SARS-­CoV-­2 laboratory age, gender, ethnic origin, household and career, confirmed cases, we will use multivariate logistic regres- economic status and job situation of their parents in sion analysis with robust SEs clustered at the individual the case of pupils. level and school level, adjusting for sociodemographic, ► Clinical data and infection by SARS-­CoV-­2: symptoms, environmental and school structural variables. COVID-­19 chronic symptoms, the duration of symp- In order to address the fourth objective related to toms, reinfection of COVID-­19, hospitalisation, expo- the transmissibility study, a descriptive analysis will be sure and contact with positive cases. performed for all cases and contacts identified in school ► Attitude, behaviour and knowledge regarding clusters. Analyses will include χ2 and independent COVID-­19 and preventive measures. sample t-­ test procedures to assess differences between ► Pandemic impact indicators such as changes on super-­spreaders and non-­spreaders for index cases and mental and physic health and the purchasing power secondary cases using sociodemographics, number of of parents and school staff. classmates and household contacts, clinical and environ- ► Vaccination data: manufacturer, number of doses, mental variables. Finally, we will use univariate and multi- date of doses, side effects of COVID-­19 vaccine and variate logistic regression models to assess the association refusal to vaccinate (date and reason). between transmission risk factors and SARS-­CoV-­2 infec- ► Attitude and usability of focus groups regarding scien- tion among index cases and close contacts. All models will tific contribution. be adjusted for gender, age, vaccination status, number of classmates and household contacts and whether or not Collective data the index cases are symptomatic. Number of classrooms, number of tables/classroom, Global data on the COVID-­19 epidemic in Catalonia number of pupils/m2, school surface, schoolyard surface, and the school BHA will be collected to contextualise the concentration of CO2, temperature and humidity in the current epidemic situation. Data will be provided globally classrooms. and stratified by age groups and collectives. These data will be provided by the Catalan Agency for Quality and Ecological data Health Assessment and SISAP. Analysis of the interrupted These data will be collected and provided by the Primary time series of SARS-­CoV-­2 seroprevalence and COVID-­19 Care Services Information System (SISAP) and the data confirmed cases will be performed to assess the public analytics programme for health research and innova- health implemented measures including vaccination tion (PADRIS) and will include data from different data programmes. The confirmed cases will be modelled sources in order to obtain the information mentioned as ARIMA processes to estimate the expected numbers further: to be compared with those observed and estimate the ► Number of new COVID-­19 confirmed cases or tested impact of the different analysed measures; to do this, positive for SARS-­CoV-­2 by TMA/PCR or RAT /total we will calculate absolute and relative changes between of residents. expected-­observed confirmed cases in each time point of ► Number of new COVID-­19 confirmed cases or tested the implemented measures. Analysis will be conducted in positive for SARS-­CoV-­2 by TMA/PCR or RAT/total R (R Core Team, 2014). of tested people. ► Number of new COVID-­19 confirmed cases or tested Patient and public involvement (PPI) positive for SARS-­CoV-­2 by TMA/PCR or RAT/total of We will convene a virtual PPI panel, who will contribute to suspected cases. the dissemination of findings. 6 Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 Open access 4 ETHICS AND DISSEMINATION Barcelona Institut for Global Health, IMIM-­Parc Salut Mar, Barcelona, Catalunya, The ethical aspects of the present study include: Spain 5 Universitat Pompeu Fabra, Barcelona, Catalunya, Spain ► Recruitment of participants with informed consent. 6 Living Lab for Health, IrsiCaixa AIDS Research Institute, Badalona, Catalunya, Spain ► Collection and storage of biological samples. 7 Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), ► Questionnaires with non-­anonymised data. Instituto de Salud Carlos III, Madrid, Comunidad de Madrid, Spain 8 ► Collection and storage of personal data. Centre for International Health Research (CRESIB), ISGlobal, Barcelona, Catalunya, The confidentiality of data and other ethical consid- Spain 9 IMIM-­Parc Salut Mar, ISGlobal, Barcelona, Catalunya, Spain erations will be managed in accordance with the recom- 10 Microbiology Department, Hospital Universitari Vall d'Hebron, Universitat mendations of the Spanish Law 14/2007 of 3 July, on Autònoma de Barcelona, Institut Català de la Salut, Barcelona, Catalunya, Spain Biomedical Research and the Spanish Royal Decree 11 Microbiology Department, Laboratori Clínic Metropolitana Nord, Hospital RD 1716/2011 of 18 November, which lays down the Universitari Germans Trias i Pujol, Institut D'Investigació en Ciències de La Salut basic requirements for the authorisation and operation Germans Trias I Pujol (IGTP), Institut Català de la Salut, Barcelona, Catalunya, Spain 12 Epiconcept SAS, Paris, Île-­de-­France, France of biobanks for purposes of biomedical research and 13 Foundation University Institute for Research in Primary Health Care Jordi Gol i the treatment of biological samples of human origin. Gurina (IDIAP Jordi Gol), Barcelona, Catalunya, Spain Informed consent is required for this project as is estab- lished in article 59 of the law. Twitter Antoni Soriano-­Arandes @tonisoriano66 The necessary measures will be taken to ensure the Collaborators Sentinel School Network Study Group of Catalonia* Principal protection of personal data and their confidentiality, in investigators: Jordi Casabona [Centre d’Estudis Epidemiològics sobre les accordance with EU Regulation 2016/679 of the Euro- Infeccions de Transmissió Sexual i Sida de Catalunya (CEEISCAT)-­CIBERESP], Josep Basora (Institut Universitari d’Investigació en Atenció Primària (IDIAP Jordi Gol). pean Parliament and of the Council of 27 April 2016 Project manager: Anna Bordas (CEEISCAT).Technical committee: Jordi Casabona on the protection of natural persons with regard to the (CEEISCAT), Jordi Sunyer (ISGlobal), Pere Soler-­Palacín (Hospital Universitari Vall processing of personal data and on the free movement of d’Hebron), Rosina Malagrida (Living lab for Health, IRSICaixa) as Work Package such data (General Data Protection Regulation (GDPR)), coordinators. Juliana Reyes-­Urueña, Cinta Folch, Pol Romano, Esteve Muntada, Anna Bordas, Andreu Colom-­Cadena i Jordi Casabona (CEEISCAT), Mireia Gascón, and in the Spanish Organic Law 3/2018 of 5 December, Maria Subirana, Jordi Sunyer (ISGlobal), Rosina Malagrida, Jessica Fernández for the protection of personal data and guarantee of (Living lab for Health), Antonio Soriano (Hospital Universitari Vall d’Hebron), Josep digital rights (in Spanish, LOPD-­GDD). Vidal (Gerència Territorial de la Catalunya Central, Institut Català de la Salut). The data protection office of the Ministry of Health of Microbiology laboratories: Tomàs Pumarola, Andrés Antón, Cristina Andrés, Juliana Esperalba, Albert Blanco (Hospital Universitari Vall d’Hebron), Ignacio Blanco, Pere-­ the Government of Catalonia has reached an agreement Joan Cardona, Maria Victoria González, Gema Fernández, Cristina Esteban (Hospital signed by all the organisations in the research team to Universitari Germans Trias i Pujol). Data Management and statistical analysis: Yesika align with all the ethical considerations mentioned above Díaz, Lucia Alonso, Jordi Aceiton, Marcos Montoro (CEEISCAT).Data Protection and recommended by the same office. Officer and Technical Support: Esteve Muntada (CEEISCAT). Communication manager: Pol Romano (CEEISCAT).Field team: Maria Subirana (ISGlobal), Jessica The data and results provided by this project will be Fernández (Living Lab for Health, IRSICaixa), Andreu Colom-­Cadena, Isabel Martínez, valuable in the current context of the public health emer- Marina Herrero, Alba García, Juan Rus (CEEISCAT). Community Paediatricians: gency of international concern declared by the WHO Esperança Macià i Silvia Burgaya (CAP Manlleu), Mª Teresa Riera-­Bosch, Elisabet for the COVID-­19 pandemic and taking into account the Sola (EAP Vic Nord), Lidia Aulet, Maria Mendoza, Lidia Busquets (EAP Vic Sud), Xavier Perramon, Júlia Sebastià (EAP Eixample Dret), Ana Moreno (Cap Ripollet), urgent need for information coming from COVID-­ 19 Xavier Duran, Belen Pérez (EAP Can Gibert del Pla), Anna Gatell (Equip Territorial de studies. Pediatria Alt Penedès), Maria Coma (Hospital Universitari Joan XXIII). Department The research team will generate a quarterly report with of Health: Ariadna Mas (Direcció Assistencial Atenció Primària, Institut Català de la qualitative and quantitative data to give feedback to the Salut), Maria Antònia Llopis (Coordinació dels laboratoris de l’Institut Català de la Salut), Sandra Pequeño and Jacobo Mendioroz (Subdirecció general de Vigilància i stakeholders. Findings from this study will be dissemi- Resposta a Emergències de l’Agència de Salut Pública de Catalunya, Departament nated at national and international conferences, reported de Salut), Carmen Cabezas (Agència de Salut Pública de Catalunya, Departament on the public webpage of the project and published in de Salut). peer-­reviewed journals. Contributors All authors have read, reviewed and agreed to the finalised This study involves human participants and was submitted version of the manuscript. Conceptualisation: JC. Design study: JC, CF, approved by Ethical approval from Foundation Univer- AS, AB, JMR-­U, JS, PS-­P, AS-­A and MG. Operational procedures: JC, JMR-­U, AB, CF, AC, JS, MG, AA, TP, IB, JF-­M, RM, PS-­P, AS-­A, MS and JB. Resources: RF, JM, JMA, sity Institute for Research in Primary Health Care Jordi CC and JB. Writing and draft preparation: AB, CF, AC, AS-­A, MS and RM. Writing, Gol i Gurina (IDIAPJGol) ethics committee with code review and edition: all authors. 20/192-­ PCV on 17 December 2020 and the Hospital Funding This work will be supported by Ministry of Health from Government of Universitari Vall d’Hebron ethics committee with code Catalonia with no grant number. PR(AMI)668/2020. Participants gave informed consent Disclaimer This funding source had no role in the design of this study and will not to participate in the study before taking part. have any role during its execution, analyses, interpretation of the data or decision to submit result. Author affiliations Competing interests None declared. 1 Centre for Epidemiological Studies of HIV/SIDA and STI of Catalonia (CEEISCAT), Patient and public involvement Patients and/or the public will be involved in the Health Department, Generalitat de Catalunya, Badalona, Catalunya, Spain design, or conduct, or reporting, or dissemination plans of this research. Refer to 2 Institute for Health Science Research Germans Trias i Pujol (IGTP), Badalona, Spain the Methods section for further details. 3 Pediatric Infectious Diseases and Immunodeficiencies Unit, Vall d’Hebron Institut de Recerca, Universitat Autònoma de Barcelona, Hospital Vall d'Hebron, Barcelona, Patient consent for publication Consent obtained directly from patient(s). Catalunya, Spain Provenance and peer review Not commissioned; externally peer reviewed. Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649 7 Open access Open access This is an open access article distributed in accordance with the 16 Esposito S, Principi N. School closure during the coronavirus disease Creative Commons Attribution Non Commercial (CC BY-­NC 4.0) license, which 2019 (COVID-­19) pandemic: an effective intervention at the global permits others to distribute, remix, adapt, build upon this work non-­commercially, level? JAMA Pediatr 2020;174:921–2. 17 Posfay-­Barbe KM, Wagner N, Gauthey M, et al. COVID-­19 in and license their derivative works on different terms, provided the original work is children and the dynamics of infection in families. Pediatrics properly cited, appropriate credit is given, any changes made indicated, and the use 2020;146:e20201576. is non-­commercial. See: http://creativecommons.org/licenses/by-nc/4.0/. 18 Lee B, Raszka WV. COVID-­19 transmission and children: the child is not to blame. Pediatrics 2020;146:e2020004879. ORCID iDs 19 Somekh E, Gleyzer A, Heller E, et al. The role of children in the Anna Bordas http://orcid.org/0000-0001-5640-8433 dynamics of intra family coronavirus 2019 spread in densely Juliana Maria Reyes-­Urueña http://orcid.org/0000-0002-3122-6518 populated area. Pediatr Infect Dis J 2020;39:e202–4. 20 Dades sobre La covid-­19 ALS centres educatius. Traçacovid. Available: http://educacio.gencat.cat/ca/actualitat/escolasegura/​ tracacovid/dades-covid19-centres/#/ 21 Perramon A, Soriano-­Arandes A, Pino D, et al. Schools as a REFERENCES framework for COVID-­19 epidemiological surveillance of children 1 Emergencies preparedness, response. novel coronavirus – Republic in Catalonia, Spain: a population-­based study. Front Pediatr of Korea (ex-­China). Available: https://www.who.int/csr/don/21-​ 2021;9:754744. january-2020-novel-coronavirus-republic-of-korea-ex-china/en/ 22 Zhang J, Litvinova M, Liang Y, et al. Changes in contact patterns [Accessed 17 Dec 2020]. shape the dynamics of the COVID-­19 outbreak in China. Science 2 Pollán M, Pérez-­Gómez B, Pastor-­Barriuso R, et al. Prevalence of 2020;368:1481–6. SARS-­CoV-­2 in Spain (ENE-­COVID): a nationwide, population-­based 23 Mizumoto K, Omori R, Nishiura H. Age specificity of cases and seroepidemiological study. Lancet 2020;396:535–44. attack rate of novel coronavirus disease (COVID-­19). medRxiv 2020. 3 Hildenwall H, Luthander J, Rhedin S, et al. Paediatric COVID-­19 24 Bi Q, Wu Y, Mei S, et al. Epidemiology and transmission of COVID-­19 admissions in a region with open schools during the two first months in 391 cases and 1286 of their close contacts in Shenzhen, China: a of the pandemic. Acta Paediatr 2020;109:2152–4. retrospective cohort study. Lancet Infect Dis 2020;20:911–9. 4 European Centre for Disease Prevention and Control. COVID-­19 in 25 Heavey L, Casey G, Kelly C, et al. No evidence of secondary children and the role of school settings in COVID-­19 transmission, 6 transmission of COVID-­19 from children attending school in Ireland, August 2020. Stockholm: ECDC, 2020. 2020. Euro Surveill 2020;25:2000903. 5 Viner RM, Russell SJ, Croker H, et al. School closure and 26 Soriano-­Arandes A, Gatell A, Serrano P, et al. Household severe management practices during coronavirus outbreaks including acute respiratory syndrome coronavirus 2 transmission and children: COVID-­19: a rapid systematic review. Lancet Child Adolesc Health a network prospective study. Clin Infect Dis 2021;73:e1261–9. 2020;4:397–404. 27 COVID-­19. IFRC, UNICEF and WHO issue guidance to protect 6 United Nations Educational, Scientific and Cultural Organization children and support safe school operations. Geneva: World Health (UNESCO). Education: from disruption to recovery. Available: https://​ organization. available at. Available: https://www.unicef.org/press-​ en.unesco.org/covid19/educationresponse [Accessed 3 Jan 2020]. releases/covid-19-ifrc-unicef-and-who-issue-guidance-protect-​ 7 López-­Bueno R, López-­Sánchez GF, Casajús JA, et al. Health-­ children-and-support-safe-school [Accessed 26 May 2020]. Related behaviors among school-­aged children and adolescents 28 Bavel JJV, Baicker K, Boggio PS, et al. Using social and behavioural during the Spanish Covid-­19 confinement. Front Pediatr 2020;8:573. science to support COVID-­19 pandemic response. Nat Hum Behav 8 López-­Bueno R, Calatayud J, Ezzatvar Y, et al. Association between 2020;4:460–71. current physical activity and current perceived anxiety and mood 29 Kuehn BM. Fewer COVID-­19 cases in schools with masks and in the initial phase of COVID-­19 confinement. Front Psychiatry improved ventilation. JAMA 2021;326:125. 2020;11:729. 30 COVID-­19 vaccines. Available: https://www.ema.europa.eu/en/​ 9 Wilson OWA, Holland KE, Elliott LD, et al. The impact of the human-regulatory/overview/public-health-threats/coronavirus-​ COVID-­19 pandemic on us college students' physical activity and disease-covid-19/treatments-vaccines/vaccines-covid-19/ mental health. J Phys Act Health 2021;18:272–8. [Accessed 14 Apr 2021]. 10 Cohen ZP, Cosgrove KT, DeVille DC, et al. The impact of 31 Alumnes i professors. Per nivells educatius. Available: https://www.​ COVID-­19 on adolescent mental health: preliminary findings from a idescat.cat/pub/?id=aec&n=734 [Accessed 1 Mar 2021]. longitudinal sample of healthy and at-­risk adolescents. Front Pediatr 32 Colls C, Mias M, García-­Altés A. Un índice de privación para reformar 2021;9:622608. El modelo de financiación de la atención primaria en Cataluña. Gac 11 Lee J, Solomon M, Stead T, et al. Impact of COVID-­19 on the mental Sanit 2020;34:44–50. health of US college students. BMC Psychol 2021;9:95. 33 Domínguez i Amorós M, Monllor i Rico, N and Simó i Solsona, 12 WHO. Considerations for school-­related public health measures M. Món rural i joves. Realitat juvenil i polítiques de joventut ALS in the context of COVID-­19: annex to considerations in adjusting municipis rurals de Catalunya 2010. public health and social measures in the context of COVID-­19. WHO, 34 World Health Organization Europe. Monitoring knowledge, risk 2020: 6. perceptions, preventive behaviours and trust to inform pandemic 13 Macartney K, Quinn HE, Pillsbury AJ, et al. Transmission of SARS-­ outbreak response 2020. CoV-­2 in Australian educational settings: a prospective cohort study. 35 ARTIC Network Protocol. Available: https://www.protocols.io/view/​ Lancet Child Adolesc Health 2020;4:807–16. ncov-2019-sequencing-protocol-v3-locost-bh42j8ye 14 Brandal LT, Ofitserova TS, Meijerink H, et al. Minimal transmission of 36 Gestió de casos de COVID-­19 ALS centres educatius. available at:. SARS-­CoV-­2 from paediatric COVID-­19 cases in primary schools, Available: https://canalsalut.gencat.cat/web/shared/continguts_per_​ Norway, August to November 2020. Euro Surveill 2021;26:2002011. compartir/ENS/salut-escola/documentacio/escoles/gestio-casos-​ 15 Zimmerman KO, Akinboyo IC, Brookhart MA, et al. Incidence and centres-educatius.pdf secondary transmission of SARS-­CoV-­2 infections in schools. 37 Case definition. Available: https://www.ecdc.europa.eu/en/covid-19/​ Pediatrics 2021;147:e2020048090. surveillance/case-definition [Accessed 5 Jan 2021]. 8 Bordas A, et al. BMJ Open 2022;12:e055649. doi:10.1136/bmjopen-2021-055649