Feasibility of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen self-testing in school and summer camp attendees

Background SARS-CoV-2 screening is one of the pillars of non-pharmaceutical preventive strategies to early identify and isolate infected individuals and therefore decrease community incidence. Methods We assessed the feasibility of severe acute respiratory syndrome coronavirus 2 self-testing with antigen-detecting rapid diagnostic tests in attendees of educational settings. Results A total of 305 students (88.15%) and 41 staff (11.85%) from 9 to 56 years old participated in the self-testing procedure and answered the survey at the end of the study. 91.3% (n = 313) did not need help, 96.1% of participants reported the same outcome as the healthcare workers. 94.5% strongly or slightly agree with the statement “I would repeat the experience”. Conclusion The study demonstrates that self-testing is acceptable and usable in children, adolescents and adults when the epidemiological situation may require a systematic screening of these populations, although supervision by health care or previously trained personnel is recommended for younger age groups.


Introduction
Since the emergence of SARS-CoV-2 in December 2019 governments have implemented various measures to control the spread of the virus.Schools were severely affected and initially closed in many countries, including Spain, despite uncertainty if school closures were an effective containment measure, with a negative impact on the education of children and adolescents (1).
However, data from different countries showed that reopening or never closing schools was not necessarily associated with a significant increase in child-to-child or community transmission in children under 14 years of age (2).
Measures must be adapted to each setting to prevent transmission of the virus (3).An important strategy to minimize SARS-CoV-2 transmission is the rapid identification of infected people, symptomatic or not.Nonpharmaceutical preventive interventions such as screening asymptomatic people for SARS-CoV-2, have been shown to decrease incidence at the community level (3).Antigen detection rapid diagnostic tests (Ag-RDTs) have been proposed as suitable for point-of-care screening of potentially exposed people.Advantages of Ag-RDTs include: low price, absence of referral to a high-tech laboratory, short turnaround time for results and identification of people with potential to transmit their SARS-CoV-2 infection (3) However, taking into account that rapid tests are often developed and marketed when outbreaks are already advanced, should be considered as a medium to long term measure.Making Ag-RDTs available in educational centers could reduce care school closures, costs, response time and eventually SARS-CoV-2 transmission.
As nasal Ag-RDT self-testing is considered to be reliable and feasible in adults (4,5), the main objective of this study was to assess whether it is acceptable and usable in younger ages, by focusing on students and staff in schools and summer camps during the fifth wave caused by the Delta B.1.617.2 variant of SARS-CoV-2 in Catalonia (Spain).

Study population and period
The research took place between April and August 2021 in 2 schools [one from COVID-19 Sentinel Schools Network of Catalonia (6) and other school from ESCORAT project] and 4 summer camps in Catalonia, Spain.Thus, here students over 9 years old were invited to participate and staff were included only in summer camps.In one school (School A) a prospective cohort was established (testing weekly for 8 weeks) while a cross-sectional study was done in School B and summer camps.The field team consisted of between 2 and 4 healthcare workers (nurses and nursing assistants).

Material delivery and data collection
After signing the informed consent, participants received a sampling kit including: paper-based schematic and illustrated instructions for the self-testing procedure, a printed feasibility survey, ID labels and the SARS-CoV-2 Ag-RDT Kit [test cassette, nasal swab, empty tube and plug, Pasteur pipette and buffer solution; Panbio™ COVID-19 Ag Rapid Test Device (Abbot Laboratories, Chicago, US)].Additionally, the self-test procedure was recorded on video and distributed to participating schools.
Tests were performed in accordance with biosecurity measures (well-ventilated area, separation between participants of >1.5 m, table disinfection with alcohol before and after the procedures).Subsequently, acceptability surveys were entered into the EUSurvey platform by the research team.
All test results were validated.In School B and summer camps, participants read the test result themselves, and the healthcare team validated the reliability, while in School A previously trained older pupils (15-16 years old) supervised the sampling procedure and read the results.
Ag-RDT Positive cases were referred to the health center for a Reverse Transcription-PCR (RT-PCR) with nasal swab to confirm the results.

Feasibility evaluation
We assessed the acceptability and usability of the intervention among participants based on a conceptual validated framework adapted from previous studies (7).Here, acceptance and use of SARS-CoV-2 Ag-RDT self-testing was adapted and divided into the following subdomains: Learnability, Willingness, Suitability, Satisfaction and Efficacy (see Table 1).
A semi-structured interview was conducted with trained pupils who read the test results (School A) to assess the acceptability and usability of the experience, this was recorded and later transcribed for analysis.

Data analysis
A descriptive analysis of the sample was carried out and the percentages of the categorical variables were calculated for each Reasons for those who need help or did not succeed on sampling are included as a text in the results section of the manuscript.c The Efficacy subdomain is not included in the table because is defined as the ability to create a network with the main actors of the local health and education system -primary care, epidemiological surveillance service, educational community, local political agents-, correct communication of results, management of positive cases according to governmental protocols, and appropriate waste management, and results are presented in the aforementioned section.
different outcome to the healthcare workers.Of these, 9 students (81,1%) indicated a negative result when the healthcare worker said positive, and 2 students (18,2%) answered that they don't know the result, when healthcare worker recorded a negative result.
In terms of Efficacy, there was a rapid response and proper management of positive cases, both at the educational and public health levels.
Through the semi-structured interview, the students of School A reported a positive feeling about the research project; that the study helps to have a safer school and that a weekly test is acceptable.However, trained students highlighted the heavy workload, with loss of class hours, and suggested involvement of more students in the future.
analysis.ACC and HMR: were responsible for writing the original draft.All authors contributed to the article and approved the submitted version.

Funding
This work was supported by the Ministry of Health of the Government of Catalonia with no grant number.This funding source had no role in the design of this study and any role during its execution, analyses, interpretation of the data or decision to submit results.

TABLE 1
category, stratifying by age group in accordance with the educational stages of Catalonia based on Law 12/2009 of 10 July 2009 on education.The p-value was obtained by means Acceptability and usability subdomains results by age groups.