Test-to-Stay After Exposure to SARS-CoV-2 in K-12 Schools

SARS-CoV-2 Test-to-Stay in Daycare

BACKGROUND AND OBJECTIVES

Test-to-stay concepts apply serial testing of children in daycare after exposure to SARS-CoV-2 without use of quarantine. This study aims to assess the safety of a test-to-stay screening in daycare facilities.

METHODS

714 daycare facilities and approximately 50 000 children ≤6 years in Cologne, Germany participated in a SARS-CoV-2 Pool-polymerase chain reaction (PCR) screening from March 2021 to April 2022. The screening initially comprised post-exposure quarantine and was adapted to a test-to-stay approach during its course. To assess safety of the test-to-stay approach, we explored potential changes in frequencies of infections among children after the adaptation to the test-to-stay approach by applying regression discontinuity in time (RDiT) analyses. To this end, PCR-test data were linked with routinely collected data on reported infections in children and analyzed using ordinary least squares regressions.

RESULTS

219 885 Pool-PCRs and 352 305 Single-PCRs were performed. 6440 (2.93%) Pool-PCRs tested positive, and 17 208 infections in children were reported. We estimated that during a period of 30 weeks, the test-to-stay concept avoided between 7 and 20 days of quarantine per eligible daycare child. RDiT revealed a 26% reduction (Exp. Coef: 0.74, confidence interval 0.52-1.06) in infection frequency among children and indicated no significant increase attributable to the test-to-stay approach. This result was not sensitive to adjustments for 7-day incidence, season, SARS-CoV-2 variant, and socioeconomic status.

CONCLUSIONS

Our analyses provide evidence that suggest safety of the test-to-stay approach compared with quarantine measures. This approach offers a promising option to avoid use of quarantine after exposure to respiratory pathogens in daycare settings.

What is the specific role of schools and daycares in COVID-19 transmission? A final report from a living rapid review

Due to rapidly evolving conditions, the question of how to safely operate schools and daycares remained a top priority throughout the COVID-19 pandemic. In response to growing and changing evidence, the National Collaborating Centre for Methods and Tools in Canada maintained a living rapid review on the role of schools and daycares in COVID-19 transmission to guide evidence-informed decision making. This Review presents the final iteration of this living rapid review. 31 sources were searched until Oct 17, 2022. In the final version, eligible studies reported data from Jan 1, 2021 onward on transmission of COVID-19 in school or daycare settings, the effect of infection prevention and control measures on transmission, or the effect of operating schools or daycares on community-level COVID-19 rates. As a rapid review, titles and abstracts were screened by a single reviewer with artificial intelligence integrated into later versions. Full-text screening, data extraction, and critical appraisal were completed by one reviewer and checked by a second reviewer. The Johanna Briggs Institute tools were used for critical appraisal. The certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach, and results were synthesised narratively. Three citizen partners provided input for the final interpretation. This final update includes 73 primary studies. Secondary attack rates were low within school settings when infection prevention and control measures were in place (moderate certainty). Masks might reduce transmission, test-to-stay policies might not increase transmission risk compared with mandatory quarantine, cohorting and hybrid learning might make little to no difference in transmission (low certainty), and the effect of surveillance testing within schools remained inconclusive (very low certainty). Findings indicate that school settings do not substantially contribute to community incidence, hospitalisations, or mortality (low certainty). This living review provides a synthesis of global evidence for the role of schools and daycares during COVID-19, which might be helpful in future pandemics.

Secondary infections of COVID-19 in schools and the effectiveness of school-based interventions: a systematic review and meta-analysis

OBJECTIVES

This meta-analysis explored secondary infections of SARS-CoV-2 and the effectiveness of non-pharmaceutical interventions (NPIs) in school settings, with the aim of providing a reference to formulate scientific prevention and response strategies for similar major public health emergencies in specific settings.

STUDY DESIGN

This was a systematic review and meta-analysis.

METHODS

Systematic searches were conducted in PubMed, Web of Science and the Cochrane Library through to 1 August 2022 using the following key search terms: COVID-19, SARS-CoV-2, secondary attack rate, school, transmission, etc. The IVhet model was used for the meta-analysis, and the I2 index and Cochran's Q-test were used to assess heterogeneity. Publication bias was examined using Doi plot, Galbraith plots and Luis Furuya-Kanamori index. Prevalence Critical Appraisal Tool was used to assess the quality of the included articles, while Grading of Recommendations Assessment, Development, and Evaluation was used to rate the quality of the evidence. Subgroup analyses were conducted to explore the potential source of heterogeneity.

RESULTS

Thirty-four studies involving 226,727 school contacts and 2216 secondary cases were included in this study. The pooled secondary attack rates (SARs) of close contacts, staff contacts and student contacts were 0.67% (95% confidence interval [CI]: 0.11, 1.56), 0.79% (95% CI: 0.00, 6.72) and 0.50% (95% CI: 0.00, 4.48), respectively. Subgroup analysis suggested that multiple or specific combinations (e.g. the combination of contact restriction and hygiene action) of NPIs appeared to be associated with lower SARs.

CONCLUSIONS

The SAR of SARS-CoV-2 was low in schools. Multiple or specific combinations of prevention strategies appear to mitigate SARS-CoV-2 transmission in school settings. These findings provide a basis for continuous improvement of response strategies to major public health emergencies in the school environment.

Leveraging the Expertise of the CTSA Program to Increase the Impact and Efficiency of Clinical Trials

Importance

Multicenter clinical trials play a critical role in the translational processes that enable new treatments to reach all people and improve public health. However, conducting multicenter randomized clinical trials (mRCT) presents challenges. The Trial Innovation Network (TIN), established in 2016 to partner with the Clinical and Translational Science Award (CTSA) Consortium of academic medical institutions in the implementation of mRCTs, consists of 3 Trial Innovation Centers (TICs) and 1 Recruitment Innovation Center (RIC). This unique partnership has aimed to address critical roadblocks that impede the design and conduct of mRCTs, in expectation of accelerating the translation of novel interventions to clinical practice. The TIN's challenges and achievements are described in this article, along with examples of innovative resources and processes that may serve as useful models for other clinical trial networks providing operational and recruitment support.

Observations

The TIN has successfully integrated more than 60 CTSA institution program hubs into a functional network for mRCT implementation and optimization. A unique support system for investigators has been created that includes the development and deployment of novel tools, operational and recruitment services, consultation models, and rapid communication pathways designed to reduce delays in trial start-up, enhance recruitment, improve engagement of diverse research participants and communities, and streamline processes that improve the quality, efficiency, and conduct of mRCTs. These resources and processes span the clinical trial spectrum and enable the TICs and RIC to serve as coordinating centers, data centers, and recruitment specialists to assist trials across the National Institutes of Health and other agencies. The TIN's impact has been demonstrated through its response to both historical operational challenges and emerging public health emergencies, including the national opioid public health crisis and the COVID-19 pandemic.

Conclusions and Relevance

The TIN has worked to reduce barriers to implementing mRCTs and to improve mRCT processes and operations by providing needed clinical trial infrastructure and resources to CTSA investigators. These resources have been instrumental in more quickly and efficiently translating research discoveries into beneficial patient treatments.

Prevalence and Risk Factors for School-Associated Transmission of SARS-CoV-2

Importance

School-associated SARS-CoV-2 transmission is described as uncommon, although the true transmission rate is unknown.

Objective

To identify the SARS-CoV-2 secondary attack rate (SAR) in schools and factors associated with transmission.

Design, Setting, and Participants

This cohort study examined the risk of school-based transmission of SARS-CoV-2 among kindergarten through grade 12 students and staff in 10 Massachusetts school districts during 2 periods: fall 2020/spring 2021 (F20/S21) and fall 2021 (F21). School staff collected data on SARS-CoV-2 index cases and school-based contacts, and SAR was defined as the proportion of contacts acquiring SARS-CoV-2 infection.

Exposure

SARS-CoV-2.

Main Outcomes and Measures

Potential factors associated with transmission, including grade level, masking, exposure location, vaccination history, and Social Vulnerability Index (SVI), were analyzed using univariable and multivariable logistic regression models.

Results

For F20/S21, 8 school districts (70 schools, >33 000 students) were included and reported 435 index cases (151 staff, 216 students, and 68 missing role) with 1771 school-based contacts (278 staff, 1492 students, and 1 missing role). For F21, 5 districts (34 schools, >18 000 students) participated and reported 309 index cases (37 staff, 207 students, and 65 missing role) with 1673 school-based contacts (107 staff and 1566 students). The F20/S21 SAR was 2.2% (lower bound, 1.6%; upper bound, 26.7%), and the F21 SAR was 2.8% (lower bound, 2.6%; upper bound, 7.4%). In multivariable analysis, during F20/S21, masking was associated with a lower odds of transmission compared with not masking (odds radio [OR], 0.12; 95% CI, 0.04-0.40; P < .001). In F21, classroom exposure vs out-of-classroom exposure was associated with increased odds of transmission (OR, 2.47; 95% CI, 1.07-5.66; P = .02); a fully vaccinated vs unvaccinated contact was associated with a lower odds of transmission (OR, 0.04; 95% CI, 0.00-0.62; P < .001). In both periods, a higher SVI was associated with a greater odds of transmission.

Conclusions and Relevance

In this study of Massachusetts schools, the SAR for SARS-CoV-2 among school-based contacts was low during 2 periods, and factors associated with transmission risk varied over time. These findings suggest that ongoing surveillance efforts may be essential to ensure that both targeted resources and mitigation practices remain optimal and relevant for disease prevention.

Utilization and Impact of Symptomatic and Exposure SARS-CoV-2 Testing in K-12 Schools

OBJECTIVES

The Centers for Disease Control and Prevention recommend that schools can offer severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic (on-demand) testing for students and staff with coronavirus disease 2019 symptoms or exposures. Data related to the uptake, implementation, and effect of school-associated on-demand diagnostic testing have not been described.

METHODS

The Rapid Acceleration of Diagnostics Underserved Populations Return to School program provided resources to researchers to implement on-demand SARS-CoV-2 testing in schools. This study describes the strategies used and uptake among the different testing programs. Risk of positivity was compared for symptomatic and exposure testing during the δ and ο variant periods. We estimated the number of school absence days saved with school-based diagnostic testing.

RESULTS

Of the 16 eligible programs, 7 provided school-based on-demand testing. The number of persons that participated in these testing programs is 8281, with 4134 (49.9%) receiving >1 test during the school year. Risk of positivity was higher for symptomatic testing compared with exposure testing and higher during the ο variant predominant period compared with the δ variant predominant period. Overall, access to testing saved an estimated 13 806 absent school days.

CONCLUSIONS

School-based on-demand SARS-CoV-2 testing was used throughout the school year, and nearly half the participants accessed testing on more than 1 occasion. Future studies should work to understand participant preferences around school-based testing and how these strategies can be used both during and outside of pandemics.

Keeping kids in school: modelling school-based testing and quarantine strategies during the COVID-19 pandemic in Australia

Background

In 2021, the Australian Government Department of Health commissioned a consortium of modelling groups to generate evidence assisting the transition from a goal of no community COVID-19 transmission to 'living with COVID-19', with adverse health and social consequences limited by vaccination and other measures. Due to the extended school closures over 2020-21, maximizing face-to-face teaching was a major objective during this transition. The consortium was tasked with informing school surveillance and contact management strategies to minimize infections and support this goal.

Methods

Outcomes considered were infections and days of face-to-face teaching lost in the 45 days following an outbreak within an otherwise COVID-naïve school setting. A stochastic agent-based model of COVID-19 transmission was used to evaluate a 'test-to-stay' strategy using daily rapid antigen tests (RATs) for close contacts of a case for 7 days compared with home quarantine; and an asymptomatic surveillance strategy involving twice-weekly screening of all students and/or teachers using RATs.

Findings

Test-to-stay had similar effectiveness for reducing school infections as extended home quarantine, without the associated days of face-to-face teaching lost. Asymptomatic screening was beneficial in reducing both infections and days of face-to-face teaching lost and was most beneficial when community prevalence was high.

Interpretation

Use of RATs in school settings for surveillance and contact management can help to maximize face-to-face teaching and minimize outbreaks. This evidence supported the implementation of surveillance testing in schools in several Australian jurisdictions from January 2022.

Test-to-Stay in Kindergarten Through 12th Grade Schools After Household Exposure to Severe Acute Respiratory Syndrome Coronavirus 2

BACKGROUND

Test-to-stay (TTS) is a strategy to limit school exclusion following an exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We evaluated the use of TTS within universally masked kindergarten through 12th grade (K-12) school settings following household SARS-CoV-2 exposure.

METHODS

Three hundred twenty-two participants were enrolled. Serial rapid antigen testing was performed up to 15 days post-exposure. Analysis-eligible participants completed the 15-day testing protocol, tested positive any time during the testing window, or received a negative test on or after day 9. Primary outcomes included within-school tertiary attack rate (TAR) (test positivity among close contacts of positive TTS participants), and school days saved among TTS participants.

RESULTS

Seventy-three of 265 analysis-eligible participants tested positive for SARS-CoV-2 (secondary attack rate of 28% [95% CI: 16-63%]). Among 77 within-school close contacts, 2 were positive (TAR = 3% [95% CI: 1-5%]). Participant absences were limited to 338 days, resulting in 82% of 1849 school days saved.

IMPLICATIONS FOR SCHOOL HEALTH POLICY, PRACTICE, AND EQUITY

TTS facilitates continued in-person learning and can greatly reduce the number of missed school days.

CONCLUSIONS

Within universally masked K-12 schools, TTS is a safe alternative to school exclusion following household SARS-CoV-2 exposure.

Caregivers of Black and Latino/a/x Students and School Personnel Perspectives on School-Based SARS-CoV-2 Testing: Implications for Testing and Test-to-Stay Programs in K-12 Schools

BACKGROUND

"Test-to-stay" (TTS) is an effective approach for keeping students in school post-exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To prepare for school-based SARS-CoV-2 testing, we implemented formative research to gather perspectives on school-based testing among school personnel, as well as caregivers of Black and Latino/a/x students given systemic racism, existing school inequalities, and the disproportionate effect of COVID-19 on Black and Latino/a/x populations.

METHODS

We conducted in-depth interviews with caregivers of K-12 grade Black and Latino/a/x students and focus group discussions with K-12 school personnel. We described the forthcoming school-based SARS-CoV-2 testing program and explored potential benefits and concerns, including concerns about testing-related stigma and discrimination, particularly toward Black and Latino/a/x students, and implementation recommendations.

RESULTS

Perceived testing benefits included school community reassurance and preventing school outbreaks. Concerns included potential student anxiety, classroom disruption, inaccurate results, and limited information for caregivers. Some participants mentioned that testing-related stigma and discrimination could happen based on the testing selection process or results but not due to race or ethnicity. Participants provided numerous testing recommendations, including suggestions to prevent negative outcomes.

CONCLUSIONS

Participants believed that stigma and discrimination from SARS-CoV-2 testing is possible, although differential treatment based on race or ethnicity was not anticipated. Participants' narratives provide support for school-based testing and the testing component of TTS.

Test-to-Stay After SARS-CoV-2 Exposure: A Mitigation Strategy for Optionally Masked K-12 Schools

OBJECTIVES

We evaluated the impact of a test-to-stay (TTS) program on within-school transmission and missed school days in optionally masked kindergarten through 12th grade schools during a period of high community severe acute respiratory syndrome coronavirus 2 transmission.

METHODS

Close contacts of those with confirmed severe acute respiratory syndrome coronavirus 2 infection were eligible for enrollment in the TTS program if exposure to a nonhousehold contact occurred between November 11, 2021 and January 28, 2022. Consented participants avoided school exclusion if they remained asymptomatic and rapid antigen testing at prespecified intervals remained negative. Primary outcomes included within-school tertiary attack rate (test positivity among close contacts of positive TTS participants) and school days saved among TTS participants. We estimated the number of additional school-acquired cases resulting from TTS and eliminating school exclusion.

RESULTS

A total of 1675 participants tested positive or received at least 1 negative test between days 5 and 7 and completed follow-up; 92% were students and 91% were exposed to an unmasked primary case. We identified 201 positive cases. We observed a tertiary attack rate of 10% (95% confidence interval: 6%-19%), and 7272 (89%) of potentially missed days were saved through TTS implementation. We estimated 1 additional school-acquired case for every 21 TTS participants remaining in school buildings during the entire study period.

CONCLUSIONS

Even in the setting of high community transmission, a TTS strategy resulted in substantial reduction in missed school days in optionally masked schools.

Feasibility of At-Home Virological and Serological Testing for SARS-CoV-2 in Children

Longitudinal virological and serological surveillance is essential for understanding SARS CoV-2 transmission among children but requires increased test capacity. We assessed the uptake of serial at-home testing in children (2-17 years) via mailed SARS-CoV-2 antibody and molecular tests. Completion rates demonstrated feasibility and sustainability of at-home testing across age groups.