Does school reopening affect SARS-CoV-2 seroprevalence among school-age children in Milan?

Generalizability of anti-SARS-CoV-2 seroprevalence estimates to the Montréal pediatric population: a comparison between 2 weighting methods

Seroprevalence studies of SARS-CoV-2 infections often have been based on study populations with nonrandom and nonrepresentative samples, limiting the generalizability of their results. In this study, the representativity and the generalizability of the baseline estimate (data collected from October 16, 2020, to April 18, 2021) of a pediatric seroprevalence study based in Montréal were investigated. The change in the estimates of seroprevalence were compared between 2 different weighting methods: marginal standardization and raking. The target population was the general pediatric population of Montréal, based on 2016 Canadian census data. Study results show variation across the multiple weighting scenarios. Although both weighting methods performed similarly, each possesses its own strengths and weaknesses. However, raking was preferred for its capacity to simultaneously weight for multiple underrepresented study population characteristics.

Environmental predictors of SARS-CoV-2 infection incidence in Catalonia (northwestern Mediterranean)

Numerous studies have explored whether and how the spread of the SARS-CoV-2, the causative agent of coronavirus disease 2019 (COVID-19), responds to environmental conditions without reaching consistent answers. Sociodemographic factors, such as variable population density and mobility, as well as the lack of effective epidemiological monitoring, make it difficult to establish robust correlations. Here we carry out a regional cross-correlation study between nine atmospheric variables and an infection index (Ic ) estimated from standardized positive polymerase chain reaction (PCR) test cases. The correlations and associated time-lags are used to build a linear multiple-regression model between weather conditions and the Ic index. Our results show that surface pressure and relative humidity can largely predict COVID-19 outbreaks during periods of relatively minor mobility and meeting restrictions. The occurrence of low-pressure systems, associated with the autumn onset, leads to weather and behavioral changes that intensify the virus transmission. These findings suggest that surface pressure and relative humidity are key environmental factors that may be used to forecast the spread of SARS-CoV-2.

SARS-CoV-2 in Mozambican primary school-aged children at Maputo City and Province: a cross-sectional study from a low-income country

BACKGROUND

Seroprevalence studies provide information on the true extent of infection and capture demographic and geographic differences, indicating the level of immunity against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). We sought to provide local evidence of SARS-CoV-2 exposure in school-aged children during in-class teaching in Maputo City and Province, Mozambique.

METHODS

Between August and November 2022, we performed a cross-sectional study in school-aged children in four schools in rural, peri-urban, and urban areas of Maputo City and Province. A point-of-care test was used to evaluate SARS-CoV-2 antigens and anti-SARS-CoV-2-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies. Descriptive statistics were used to estimate the prevalence of the antigens and antibodies. Multiple logistic regression models were used to estimate the adjusted odds ratio (AOR) for the factors associated with anti-SARS-CoV-2 antibodies.

RESULTS

A total of 736 school-aged children were analyzed. The prevalence of the SARS-CoV-2 antigen was 0.5% (4/736). The prevalence of SARS-CoV-2 antigens was 0.0% (0/245), 0.8% (2/240) and 0.8% (2/251), in the rural, peri-urban and urban areas respectively. The overall seroprevalence of the anti-SARS-CoV-2 antibodies (IgG or IgM) was 80.7% (594/736). In rural area anti-SARS-CoV-2 IgG or IgM antibodies were detected in 76.7% (188/245), while in peri-urban area they were detected in 80.0% (192/240) and in urban area they were detected in 85.3% (214/251). In the adjusted logistic regression model, school-aged children from the urban area were more likely to have anti-SARS-CoV-2 IgG or IgM antibodies than were school-aged children from the rural area (adjusted odds ratio: 1.679; 95% CI: 1.060-2.684; p-value = 0.028).

CONCLUSIONS

During the in-class teaching period, active SARS-CoV-2 cases in school-aged children were observed. More than half of the school-aged children were exposed to SARS-CoV-2, and SARS-CoV-2 was significantly more common in the schools at the urban area than in the school in the rural area at Maputo City and Province.

General infection prevention, mitigation, and control procedures implemented in the university education during the COVID-19 pandemic to achieve classroom attendance: a successful community case study

Introduction

The COVID-19 pandemic entailed confinement and elimination of face-to-face university classes in Spain. The Francisco de Vitoria University in Madrid (UFV by its Spanish acronym) implemented risk management systems to enable on-campus university activity to avoid a negative impact on students, teachers, and faculties.

Methods

A tracking/registry system was implemented to collect data, identify COVID-19-related cases, implement containment measures, and do follow-up in the UFV community (administration/services personnel [ASP], teaching/research personnel [TRP], and students), from September 2020 to April 2022. In addition, a prevention plan was implemented on campus to avoid COVID-19 spreading. Satisfaction with these measures was assessed through an online questionnaire.

Results

A total of 7,165 suspected COVID-19 cases (84.7% students, 7.7% ASP, 6.5% TRP) were tracked (62.5% female cases, mean age (±SD) 24.8 years (±9.2 years)), and 45% of them confirmed (82% symptomatic/16% asymptomatic), being the student group that with the highest percentage (38.3% total tracked cases). The source of infection was identified in 50.6% of the confirmed cases (90.2% located off-campus). Nineteen COVID-19 outbreaks were registered (inside-10/outside-9). COVID-19 incidence rates were similar or lower than those reported in the Community of Madrid, except in the last wave, corresponding to Omicron variant. The degree of satisfaction (scale 1-6) with the implemented measures was high (scores 4.48-5.44).

Conclusion

During the COVID-19 pandemic, UFV control measures, periodic monitoring, and the effectiveness of the tracking system have contributed to maintaining classroom teaching, guaranteeing health and safety. UFV has adapted to a new reality as an example of good practice for future pandemics or emergency situations.

Measuring the clustering effect of the SARS-CoV-2 transmission in a school population: a cross-sectional study in a high incidence region

Since the beginning of the pandemic, there has been a great deal of controversy regarding the role of schools in the spread of SARS-CoV-2 infection, and the relative contribution of students, teachers, and others. To quantify the clustering effect of SARS-CoV-2 infection within classes and schools considering the seroprevalence of specific antibodies among students and school staff (teachers and non-teachers) evaluated in schools located in the Northern region of Portugal. 1517 individuals (1307 students and 210 school staff) from 4 public and 2 private schools, comprising daycare to secondary levels, were evaluated. A rapid point-of-care test for SARS-CoV-2 specific IgM and IgG antibodies was performed and a questionnaire was completed providing sociodemographic and clinical information. We calculated the seroprevalence of IgM and IgG antibodies and estimated the Median Odds Ratio (OR) and 95% confidence interval (CI) to assess the clustering effect, using a multilevel (school and class) logistic regression. SARS-CoV-2 seroprevalence (IgM or IgG) was 21.8% and 23.8% (p = 0.575) in students and school staff, respectively. A total of 84 (8.6%) students and 35 (16.7%) school staff reported a previous molecular diagnosis. Among students, those who reported high-risk contacts only at school (OR = 1.13; 95% CI 0.72-1.78) had a seroprevalence similar to those without high-risk contacts; however, seroprevalence was significantly higher among those who only reported a high-risk contact outside the school (OR = 6.56; 95% CI 3.68-11.72), or in both places (OR = 7.83; 95% CI 5.14-11.93). Similar associations were found for school staff. The median OR was 1.00 (95% CI 1.00, 1.38) at the school-level and 1.78 (95% CI 1.40, 2.06) at the class-level. SARS-CoV-2 seroprevalence was similar between students and staff, without a clustering effect observed at the school level, and only a moderate clustering effect documented within classes. These results indicate that the mitigation measures in the school environment can prevent the spread of class outbreaks to the remaining school community.

Lessons from inter-disciplinary collaboration to mitigate SARS-CoV-2 transmission in schools, Ireland, 2020/2021, to inform health systems and multisectoral recovery

Introduction

School closures associated with the COVID-19 pandemic resulted in the loss of educational and social supports for up to 1,000,000 students in Ireland and disproportionately affected students from lower socio-economic backgrounds. For the 2020/2021 school year, multisectoral and interdisciplinary "Schools Teams" were established within Public Health departments to maintain in-person education by minimizing transmission of SARS-CoV-2 in schools. This study aimed to describe this model and explore the experiences of Schools Team members in the East of Ireland to identify factors that influenced effective working that can be sustained in the context of health systems and multisectoral recovery.

Methods

Schools Teams were comprised of multidisciplinary staff from regional Public Health departments and redeployed staff from the Education sector. Governance rested with Public Health departments. All staff operated to nationally agreed protocols following training. The experiences of the East Schools Team members were explored through an online survey and semi-structured interviews.

Results

The survey response rate was 53/70 (75.7%). Participants reported clear channels of communication within the team (44, 83.0%), feeling comfortable in their role following training (43, 82.7%) and a positive team culture (51, 96.2%) as key facilitators of effective inter-disciplinary working. Insufficient administrative support and mixed messaging to schools were identified as barriers to efficient team collaboration.

Discussion

The Schools Team model illustrates the potential for multisectoral partnerships to effectively address complex public health priorities and contribute toward health system resilience to health threats. By recognizing and leveraging the ability of allied sectors such as the education sector, to contribute to public health goals, countries can move toward the kind of whole-of-government approach to health recognized as key to health system resilience. The strong links between the education and public health sectors developed through this collaboration could be extended and strengthened to more effectively pursue public health priorities in school settings. More broadly, mechanisms to support multisectoral working should be developed, expanding beyond reactive interventions to proactively address key health priorities and build resilience across health systems and communities. Such collaborations would promote healthier populations by promoting and encouraging a public health perspective among other sectors and embedding "health in all policies".

Increasing ventilation reduces SARS-CoV-2 airborne transmission in schools: A retrospective cohort study in Italy's Marche region

Introduction

While increasing the ventilation rate is an important measure to remove inhalable virus-laden respiratory particles and lower the risk of infection, direct validation in schools with population-based studies is far from definitive.

Methods

We investigated the strength of association between ventilation and SARS-CoV-2 transmission reported among the students of Italy's Marche region in more than 10,000 classrooms, of which 316 were equipped with mechanical ventilation. We used ordinary and logistic regression models to explore the relative risk associated with the exposure of students in classrooms.

Results and discussion

For classrooms equipped with mechanical ventilation systems, the relative risk of infection of students decreased at least by 74% compared with a classroom with only natural ventilation, reaching values of at least 80% for ventilation rates >10 L s-1 student-1. From the regression analysis we obtained a relative risk reduction in the range 12%15% for each additional unit of ventilation rate per person. The results also allowed to validate a recently developed predictive theoretical approach able to estimate the SARS-CoV-2 risk of infection of susceptible individuals via the airborne transmission route. We need mechanical ventilation systems to protect students in classrooms from airborne transmission; the protection is greater if ventilation rates higher than the rate needed to ensure indoor air quality (>10 L s-1 student-1) are adopted. The excellent agreement between the results from the retrospective cohort study and the outcome of the predictive theoretical approach makes it possible to assess the risk of airborne transmission for any indoor environment.

Epidemiology of SARS-CoV-2 infection among staff and students in a cohort of English primary and secondary schools during 2020-2021

Background

There remains uncertainty about the epidemiology of SARS-CoV-2 among school students and staff and the extent to which non-pharmaceutical-interventions reduce the risk of school settings.

Methods

We conducted an open cohort study in a sample of 59 primary and 97 secondary schools in 15 English local authority areas that were implementing government guidance to schools open during the pandemic. We estimated SARS-CoV-2 infection prevalence among those attending school, antibody prevalence, and antibody negative to positive conversion rates in staff and students over the school year (November 2020-July 2021).

Findings

22,585 staff and students participated. SARS-CoV-2 infection prevalence among those attending school was highest during the first two rounds of testing in the autumn term, ranging from 0.7% (95% CI 0.2, 1.2) among primary staff in November 2020 to 1.6% (95% CI 0.9, 2.3) among secondary staff in December 2020. Antibody conversion rates were highest in the autumn term. Infection patterns were similar between staff and students, and between primary and secondary schools. The prevalence of nucleoprotein antibodies increased over the year and was lower among students than staff. SARS-CoV-2 infection prevalence in the North-West region was lower among secondary students attending school on normal school days than the regional estimate for secondary school-age children.

Interpretation

SARS-CoV-2 infection prevalence in staff and students attending school varied with local community infection rates. Non-pharmaceutical interventions intended to prevent infected individuals attending school may have partially reduced the prevalence of infection among those on the school site.

Funding

UK Department of Health and Social Care.

Asymptomatic SARS-CoV-2 seropositivity: patients with childhood-onset rheumatic diseases versus healthy children

OBJECTIVE

We aimed to find out the asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence among pediatric patients with rheumatic diseases and healthy children and to compare them with each other.

METHODS

Patients with familial Mediterranean fever (FMF), juvenile idiopathic arthritis (JIA), and juvenile systemic lupus erythematosus (jSLE) and healthy children as healthy control (HC) group who remained asymptomatic during the pandemic are examined by ELISA immunoglobulin (Ig) A and IgG tests in this cross-sectional study.

RESULTS

Overall, 149 subjects (90 females) were included in the study. While IgA was positive in 15 subjects (10%) (HC: 8, jSLE: 3, FMF: 2, JIA: 2; p = 0.196), IgG was positive in 14 subjects (9.4%) (HC: 7, JIA: 5, FMF: 1, jSLE: 1; p = 0.156). Nineteen subjects (12.75%) were IgA or IgG positive (HC: 8, JIA: 5, jSLE: 3, FMF: 3; p = 0.644). Although not significant, seropositivity was more often in HC group. Both IgA and IgG positivity were not found to be related to age, sex, underlying rheumatic diseases, and received treatments of the patients.

CONCLUSION

We revealed that patients with childhood-onset rheumatic diseases, even if they receive immunosuppressive medication such as biologic or conventional disease-modifying anti-rheumatic drugs, might have an asymptomatic SARS-CoV-2 infection, similarly to their healthy peers. Key points • Although it has been already known that children are most likely to have asymptomatic SARS-CoV-2 infection, there is a lack of data on the disease course of children with rheumatic disease. • There was no significant difference regarding the asymptomatic SARS-CoV-2 seropositivity rates between healthy children and the patients with childhood-onset rheumatic diseases. • Patients with childhood-onset rheumatic diseases, even if they receive immunosuppressive medication, might have asymptomatic SARS-CoV-2 infection, similarly to their healthy peers.

SARS-CoV-2 Circulation in the School Setting: A Systematic Review and Meta-Analysis

The contribution of children to viral spread in schools is still debated. We conducted a systematic review and meta-analysis of studies to investigate SARS-CoV-2 transmission in the school setting. Literature searches on 15 May 2021 yielded a total of 1088 publications, including screening, contact tracing, and seroprevalence studies. MOOSE guidelines were followed, and data were analyzed using random-effects models. From screening studies involving more than 120,000 subjects, we estimated 0.31% (95% confidence interval (CI) 0.05–0.81) SARS-CoV-2 point prevalence in schools. Contact tracing studies, involving a total of 112,622 contacts of children and adults, showed that onward viral transmission was limited (2.54%, 95% CI 0.76–5.31). Young index cases were found to be 74% significantly less likely than adults to favor viral spread (odds ratio (OR) 0.26, 95% CI 0.11–0.63) and less susceptible to infection (OR 0.60; 95% CI 0.25–1.47). Lastly, from seroprevalence studies, with a total of 17,879 subjects involved, we estimated that children were 43% significantly less likely than adults to test positive for antibodies (OR 0.57, 95% CI 0.49–0.68). These findings may not applied to the Omicron phase, we further planned a randomized controlled trial to verify these results.

The role of schools in driving SARS-CoV-2 transmission: Not just an open-and-shut case

Keeping schools open without permitting COVID-19 spread has been complicated by conflicting messages around the role of children and schools in fueling the pandemic. Here, we describe methodological limitations of research minimizing SARS-CoV-2 transmission in schools, and we review evidence for safely operating schools while reducing overall SARS-CoV-2 transmission.

Variation in SARS-CoV-2 seroprevalence in children in the region of Asturias, Northern Spain

BACKGROUND

Updated seroprevalence estimates are important to describe the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) landscape and to guide public health decisions. The aims are to describe longitudinal changes in seroprevalence in children in a region in Northern Spain and to analyze factors associated with SARS-CoV-2 seropositivity.

METHODS

Prospective multicenter longitudinal study with subjects recruited from July to September 2020. Children (up to 14 years old) were included and followed up until September 2021. Venous blood samples were collected every six months during three testing rounds and were analyzed for SARS-CoV-2 antibodies. The data regarding epidemiological features, contact tracing, symptoms, and virological tests were collected. The evolution of SARS-CoV-2 seroprevalence during the study and the differences between children with positive and negative SARS-CoV-2 antibody tests were analyzed.

RESULTS

Two hundred children were recruited (50.5% girls, median age 9.7 years). The overall seroprevalence increased from round 1 [1.5%, 95% confidence interval (CI) 0.3%-4.3%] to round 2 (9.1%, 95% CI 4.6%-12.7%) and round 3 (16.6%, 95% CI 9.5%-19.6%) (P < 0.001). Main changes occurred in children aged zero to four years (P = 0.001) who lived in urban areas (P < 0.001). None of the children who were previously positive became seronegative. Following multivariable analysis, three variables independently associated with SARS-CoV-2 seropositivity were identified: close contact with coronavirus disease 2019 (COVID-19) confirmed or suspected cases [odds ratio (OR) = 3.9, 95% CI 1.2-12.5], previous positive virological test (OR = 17.1, 95% CI 3.7-78.3) and fatigue (OR = 18.1, 95% CI 1.7-193.4).

CONCLUSIONS

SARS-CoV-2 seroprevalence in children has remarkably increased during the time of our study. Fatigue was the only COVID-19-compatible symptom that was more frequent in seropositive than in seronegative children.

SARS-CoV-2 PCR and antibody positivity among school staff at the beginning and end of the first school term

Background

There is controversy regarding the role of in-person attendance in schools and transmission of the SARS-CoV-2 pandemic. Several studies have demonstrated no increase in transmission, while some have reported large outbreaks with in-person attendance. We determined the incidence and risk factors for SARS-CoV-2 infection among school staff after one school term.

Methods

Nasopharyngeal swabs (NPS) for SARS-CoV-2 RT-PCR and blood for SARS-CoV-2 antibody testing were obtained from staff at a large international school in Qatar at the beginning of the 2020–2021 school year and repeated at the end of the first term.

Results

A total of 376 staff provided samples for testing. At the beginning of the 2020–2021 school year, the PCR positivity for SARS-CoV-2 was 13%, while seropositivity was 30.1%. A majority of those who tested positive either by PCR or serologically, were non-teaching staff. At the end of the first school term four months later, only 3.5% of the initially antibody-negative staff had seroconverted. In multivariable logistic regression analysis, male gender (OR 11.48, 95%CI 4.77–27.64), non-teaching job category (OR 3.09, 95%CI 1.10–8.64), contact with a confirmed case (OR 20.81, 95%CI 2.90–149.18), and presence of symptoms in the preceding 2 weeks [1–2 symptoms OR 4.82, 95%CI 1.79–12.94); ≥3 symptoms OR 42.30, 95%CI 3.76–476.43) independently predicted SARS-CoV-2 infection in school staff before school starting.

Conclusion

Male gender, non-teaching job, presence of symptoms, and exposure to a confirmed case were associated with higher risk of infection. These data can help policymakers in determining the optimal strategy for school reopening.