Feasibility of large-scale population testing for SARS-CoV-2 detection by self-testing at home

Evaluation of COVID-19 antigen rapid diagnostic tests for self-testing in Lesotho and Zambia

INTRODUCTION

The use of antigen rapid tests (Ag-RDTs) for self-testing is an important element of the COVID-19 control strategy and has been widely supported. However, scale-up of self-testing for COVID-19 in sub-Saharan Africa is still insufficient and there is limited evidence on the acceptability of self-testing and agreement between Ag-RDT self-testing and Ag-RDT testing by professional users. A joint collaboration (Botnar Research Centre for Child Health-European & Developing countries Clinical Trials Partnership)was established between Lesotho and Zambia to address these gaps in relation to Ag-RDT self-testing and contribute to increasing its use in the region.

METHODS

A cross-sectional study was conducted with qualitative and quantitative data analysis. Firstly, 14 in-depth cognitive interviews (5 in Zambia and 9 in Lesotho) were performed to assess the participants' understanding of the instructions for use (IFU) for self-testing. In a second step, evaluation of test agreement between Ag-RDT self-testing and Ag-RDT testing by professional user using SD Biosensor STANDARD Q COVID-19 Ag-RDT was performed. In Zambia, usability and acceptability of self-testing were also assessed.

RESULTS

Cognitive interviews in Lesotho and Zambia showed overall good understanding of IFU. In Zambia, acceptability of self-testing was high, though some participants had difficulties in conducting certain steps in the IFU correctly. Agreement between Ag-RDT self-test and Ag-RDT by professional users in Lesotho (428 participants) and Zambia (1136 participants) was high, 97.3% (403/414, 95% CI: 95.3-98.7) and 99.8% (1116/1118, 95% CI: 99.4-100) respectively.

CONCLUSION

Findings from this study support the use of Ag-RDT self-testing within COVID-19 control strategies in sub-Saharan Africa, contributing to increase the testing capacity and access in hard-to reach settings.

Knowledge and willingness toward SARS-CoV-2 rapid antigen testing among older adults in China: a nationwide cross-sectional study

BACKGROUND AND AIMS

The end of the zero-COVID-19 policy placed a large number of older adults in China at increased risk of COVID-19 infection. SARS-CoV-2 rapid antigen testing (RAT) is a promising tool for scaling up testing and ensuring that patient management and public health measures can be implemented without delay. We aimed to understand the knowledge and willingness of RAT, and its correlates among older adults in China.

METHODS

A nationwide cross-sectional survey on knowledge and willingness about RAT among older adults in China was conducted between January 14 and 28, 2023, shortly after the end of the zero-COVID-19 policy. An online questionnaire was used to collect information on sociodemographic characteristics, health characteristics, sources to access RAT information, and attitudes toward COVID-19 and its RAT. Logistic regression was used to assess correlates of knowledge of RAT and willingness to take RAT among older adults.

RESULTS

A total of 1030 older adults (494 women and 536 men, mean age 68.7 ± 7.0 years) were recruited. 49.4% of the participants had a high level of RAT knowledge. After adjusting for sociodemographic characteristics, chronic diseases (0.70, 0.49-0.99), learning RAT from new media (5.46, 3.48-8.68) and traditional media (3.35, 2.13-5.34), and perceiving RAT as convenient (4.03, 2.80-5.85) were associated with levels of RAT knowledge. 53.3% of the participants were willing to take RAT. After adjusting for sociodemographic characteristics, learning RAT from new media (8.46, 5.26-14.0) and traditional media (1.63, 1.04-2.55), perceiving RAT as convenient (2.97, 2.10-4.22), and worrying about (re)infection with COVID-19 (2.12, 1.55-2.92) were associated with willingness to take RAT.

CONCLUSION

The levels of RAT knowledge and willingness to take RAT among older adults in China may hinder the scale-up of RAT. Health education about RAT should be strengthened among older adults. Special efforts should be made to integrate traditional and new media to promote RAT among older adults, specifically, for virus susceptibility and the convenience of RAT. Given the reopening of society, our study could inform our response to future novel infectious diseases and aid in the timely scale-up of RAT.

Point of care detection of SARS-CoV-2 antibodies and neutralisation capacity-lateral flow immunoassay evaluation compared to commercial assay to inform potential role in therapeutic and surveillance practices

Introduction

As the COVID-19 pandemic moves towards endemic status, testing strategies are being de-escalated. A rapid and effective point of care test (POCT) assessment of SARS-CoV-2 immune responses can inform clinical decision-making and epidemiological monitoring of the disease. This cross-sectional seroprevalence study of anti-SARS-CoV-2 antibodies in Irish healthcare workers assessed how rapid anti-SARS-CoV-2 antibody testing can be compared to a standard laboratory assay, discusses its effectiveness in neutralisation assessment and its uses into the future of the pandemic.

Methods

A point of care lateral flow immunoassay (LFA) detecting anti-SARS-CoV-2 spike (S)-receptor binding domain (RBD) neutralising antibodies (Healgen SARS-CoV-2 neutralising Antibody Rapid Test Cassette) was compared to the Roche Elecsys/-S anti-SARS-CoV-2 antibody assays and an in vitro surrogate neutralisation assay. A correlation between anti-spike (S), anti-nucleocapsid (N) titres, and in vitro neutralisation was also assessed.

Results

1,777 serology samples were tested using Roche Elecsys/-S anti-SARS-CoV-2 assays to detect total anti-N/S antibodies. 1,562 samples were tested using the POC LFA (including 50 negative controls), and 90 samples were tested using an in vitro ACE2-RBD binding inhibition surrogate neutralisation assay. The POCT demonstrated 97.7% sensitivity, 100% specificity, a positive predictive value (PPV) of 100%, and a negative predictive value (NPV) of 61% in comparison to the commercial assay. Anti-S antibody titres determined by the Roche assay stratified by the POC LFA result groups demonstrated statistically significant differences between the "Positive" and "Negative" LFA groups (p < 0.0001) and the "Weak Positive" and "Positive" LFA groups (p < 0.0001). No statistically significant difference in ACE2-RBD binding inhibition was demonstrated when stratified by the LFA POC results. A positive, statistically significant correlation was demonstrated between the in vitro pseudo-neutralisation assay results and anti-S antibody titres (rho 0.423, p < 0.001) and anti-N antibody titres (rho = 0.55, p < 0.0001).

Conclusion

High sensitivity, specificity, and PPV were demonstrated for the POC LFA for the detection of anti-S-RBD antibodies in comparison to the commercial assay. The LFA was not a reliable determinant of the neutralisation capacity of identified antibodies. POC LFA are useful tools in sero-epidemiology settings, pandemic preparedness and may act as supportive tools in treatment decisions through the rapid identification of anti-Spike antibodies.

Dynamics of SARS-CoV-2 seroassay sensitivity: a systematic review and modelling study

BackgroundSerological surveys have been the gold standard to estimate numbers of SARS-CoV-2 infections, the dynamics of the epidemic, and disease severity. Serological assays have decaying sensitivity with time that can bias their results, but there is a lack of guidelines to account for this phenomenon for SARS-CoV-2.AimOur goal was to assess the sensitivity decay of seroassays for detecting SARS-CoV-2 infections, the dependence of this decay on assay characteristics, and to provide a simple method to correct for this phenomenon.MethodsWe performed a systematic review and meta-analysis of SARS-CoV-2 serology studies. We included studies testing previously diagnosed, unvaccinated individuals, and excluded studies of cohorts highly unrepresentative of the general population (e.g. hospitalised patients).ResultsOf the 488 screened studies, 76 studies reporting on 50 different seroassays were included in the analysis. Sensitivity decay depended strongly on the antigen and the analytic technique used by the assay, with average sensitivities ranging between 26% and 98% at 6 months after infection, depending on assay characteristics. We found that a third of the included assays departed considerably from manufacturer specifications after 6 months.ConclusionsSeroassay sensitivity decay depends on assay characteristics, and for some types of assays, it can make manufacturer specifications highly unreliable. We provide a tool to correct for this phenomenon and to assess the risk of decay for a given assay. Our analysis can guide the design and interpretation of serosurveys for SARS-CoV-2 and other pathogens and quantify systematic biases in the existing serology literature.

Direct-to-consumer testing - benefits for consumers, people with disease and public health

Direct-to-consumer (DTC) tests can be defined as any in-vitro diagnostic (IVD) test or, more broadly, any medical test using an IVD or medical device, that is marketed directly to consumers without involvement of a health care provider (HCP). Examples are pregnancy tests, alcohol breath tests, blood pressure measurements (medical device), coagulation tests (INR), self-monitoring of blood glucose, continuous glucose monitoring (medical device), HIV tests, HPV tests, SARS-CoV-2 antigen tests, or genetic tests. DTC tests fulfil various customer needs such as making rapid decisions (e.g. glucose monitoring for insulin dosing, SARS-CoV-2 antigen test, hormone test identifying fertile days, alcohol test), monitoring chronic conditions between consultations (e.g. diabetes, lipidaemia, hypertension), saving time and reducing consultations (e.g. INR, SARS-CoV-2 antigen test, blood pressure monitoring), screening for disease when no symptoms are present (e.g. occult blood, cholesterol, triglycerides, SARS-CoV2 antigen test), or maintaining privacy (e.g. pregnancy test, HIV test, HPV test, certain genetic tests). Further, DTC tests can reduce cost and expand access to care in countries with limited resources and can support healthcare systems in extraordinary circumstances such as a pandemic. Valid concerns about DTC testing need to be described, addressed and resolved with the help of authorities and regulators in collaboration with HCP and should not detract from the advantages DTC tests can provide. HCP should play a more prominent role in educating the public through mass media and social media on the proper use of DTC tests and help to pinpoint problem areas.

Knowledge of SARS-CoV-2 antigen detection and proper use of rapid diagnostic self-test among Shanghai residents in China

Objectives

To assess and evaluate the knowledge of Shanghai, China, residents on the use of SARS-CoV-2 antigen detection and rapid diagnostic self-test.

Methods

A cross-sectional electronic survey using a self-administered questionnaire was sent via the online platform, Sojump, to general individuals. Multiple linear regression analysis was performed to determine the variables associated with knowledge of self-test.

Results

A total of 283 participants were recruited between July 1, 2022 and July 20, 2022 through an online survey. The mean score of knowledge on the tests was 14.33 ± 2.85 (out of 21). The questions concerning the depth of swab insertion and minimum number of swab rotations in the nostril, necessity of bilateral sampling, necessity of rotating and squeezing the swab for 10 times in the extraction buffer tube, and waiting time for the results showed the highest rate of incorrect responses. In the multiple regression analysis model, sex, social status, and source of information were associated with the knowledge on the self-test kits.

Conclusion

Immediate health education programs should be made available and the kits could be improved appropriately to ensure adequate knowledge. The use of technology should be fully leveraged to achieve accurate self-diagnosis and correct interpretation of the results.

A qualitative study exploring experiences, attitudes, and wellbeing of university students of a period of restricted movement and self-testing during COVID-19 “Incoming Student Wellbeing and Benefits of Serial COVID-19 testing (ISWAB)” study

Background: As part of Ireland’s response to the COVID-19 pandemic, travellers to Ireland were required to restrict movements on arrival. Worldwide compliance with measures such as quarantine and testing vary and are influenced by factors including an individual’s knowledge of trust in, and attitudes towards these measures. The aim of this study was to explore student experiences of restricted movements after entering Ireland from abroad and to assess the acceptability and feasibility of self-administered SARS-CoV-2 tests. Methods: The Incoming Student Wellbeing and the Acceptability and Benefits of serial COVID-19 testing (ISWAB) study recruited university students who travelled into Ireland and were required by national public health guidance to restrict their movements. As part of the study, students were provided with SARS-CoV-2 self-test kits. This qualitative study explored the students’ attitudes to self-testing and restricted movements using focus groups and interviews. Ethical approval was obtained. Interviews were conducted until data saturation was reached. Interview transcripts were thematically analysed. Results: Of 41 ISWAB participants, 32 agreed to participate in a follow-up qualitative study providing written consent. One focus group, two group interviews and three individual interviews were conducted in August 2021, on Microsoft Teams. Among the 11 (seven male, four female) students interviewed, self-testing was considered feasible and acceptable. Facilitators of adherence to restrictions included: support with grocery shopping and study periods coinciding with quarantine. Barriers to well-being included: living alone, being an individual who leads a social lifestyle, and the number of days of quarantine completed. Conclusions: This qualitative study demonstrated high levels of compliance with restriction of movement guidelines and self-testing, with limited impact on general well-being. Self-testing for SARS-CoV-2 was found to be practical and achievable for at home use by participants in this study. The findings of this study may inform future self-testing initiatives.

Lateral Flow Immunoassays for SARS-CoV-2

The continued circulation of SARS-CoV-2 virus in different parts of the world opens up the possibility for more virulent variants to evolve even as the coronavirus disease 2019 transitions from pandemic to endemic. Highly transmissible and virulent variants may seed new disruptive epidemic waves that can easily put the healthcare system under tremendous pressure. Despite various nucleic acid-based diagnostic tests that are now commercially available, the wide applications of these tests are largely hampered by specialized equipment requirements that may not be readily available, accessible and affordable in less developed countries or in low resource settings. Hence, the availability of lateral flow immunoassays (LFIs), which can serve as a diagnostic tool by detecting SARS-CoV-2 antigen or as a serological tool by measuring host immune response, is highly appealing. LFI is rapid, low cost, equipment-free, scalable for mass production and ideal for point-of-care settings. In this review, we first summarize the principle and assay format of these LFIs with emphasis on those that were granted emergency use authorization by the US Food and Drug Administration followed by discussion on the specimen type, marker selection and assay performance. We conclude with an overview of challenges and future perspective of LFI applications.

Feasibility of home-based ELISA capillary blood self-testing for anti-SARS-CoV-2 antibodies

Objectives

Serological assays for the presence of anti-SARS-CoV-2 antibodies are crucially needed for research and monitoring of the SARS-CoV-2 pandemic. Antibodies are reliability detected in capillary blood, a minimally invasive and cost-effective alternative to venous blood testing. However, there is a limited knowledge on feasibility of capillary blood self-sampling. This study compared the feasibility of capillary blood self-testing in people aged less than 65 vs. people aged 65 or more. A secondary aim was to investigate the performance of the Hem-Col® (no additive) device compared to venous blood testing.

Design and methods

Data were collected in a prospective study in Switzerland (n = 106). Capillary blood was collected using the Hem-Col® (no additive) device. Feasibility was assessed using 1) collecting the recommended amount of capillary blood and 2) achieving all steps of capillary blood collection. A sample of 5 ml of venous blood was also collected.

Results

For the primary objective, 86.2%/62.1% of patients aged less than 65 collected the recommended amount of capillary blood/achieved all steps vs. 62.5%/39.6% of patients aged 65 or more (p = .006/p = .022). For the secondary objective, the correlation between capillary and venous blood was r = 0.992 and kappa = 1.

Conclusions

Capillary blood self-testing appeared as a feasible and reliable alternative to venous blood testing. Such alternative would improve access to serological testing and spare health care resources. However, the difference between age groups should be considered when using self-sampling devices. Help should be developed for older people, such as phone counseling or encouraging asking younger family members for help.

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Evidence of the feasibility of capillary blood self-testing is scarce.

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Capillary blood self-testing appeared as reliable and feasible alternative.

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Older people (aged 65 or more) were more likely to fail than younger people.

SARS-CoV-2 and Liver Transplant: How Has It Behaved in This Sixth Wave?

BACKGROUND

Since the declaration of a new variant of concern (VOC), Omicron, by the World Health Organization in November 2021, a quick spread has been documented worldwide, being the main VOC in the sixth wave in Spain. The Omicron variant has more transmissibility, lower virulence, and less risk of severe disease than previously described VOC. Here we analyze the current wave of severe acute respiratory syndrome coronavirus 2 infection in liver transplant recipients (LTRs).

METHODS

A retrospective observational study of 355 LTRs was conducted in La Rioja and Cantabria regions of Spain. Epidemiological and clinical parameters were gathered on the basis of clinical records and telephone interviews.

RESULTS

In the current wave of infection, a higher number of LTRs have been found to be infected than the sum of the previous 5 waves (30 versus 16 LTRs). Of the 30 infected LTRs, 29 (96.6%) had received 3 vaccine doses (mRNA based), in a median of 93 d (interquartile range, 86-108) before infection. Eight of 30 LTRs (24.0%) were asymptomatic and 21 LTRs (67.8%) were with mild symptoms with a mean duration of 4.6 d (interquartile range, 2.5-7), whereas in the unvaccinated LTRs, the symptoms were fever, nausea, vomiting, and diarrhea. Moreover, in the sixth wave, intrafamiliar transmission was the main route of infection (17/30; 56.6%), and nosocomial transmission was confirmed in 2 LTRs (6.6%).

CONCLUSIONS

In our series, increased transmissibility of the Omicron variant was confirmed, including nosocomial infection, with a lower risk of severe disease in LTRs. These findings could be supported by the universal vaccination of LTRs and less virulence of the Omicron variant.

Good ingredients from foods to vegan cosmetics after COVID-19 pandemic

Background

New changes are taking place in the beauty and cosmetology market due to changes in daily life due to coronavirus disease‐19 (COVID‐19) and environmental alteration caused by the spread of live commerce.

Purpose

This study technically investigated the future value and direction of vegan cosmetics from food to cosmetics by focusing on good ingredients after COVID‐19 pandemic and changing the needs of consumers in the beauty and cosmetics industry.

Methods

This review paper is a critical literature review, and a narrative review approach has been used for this study. A total of 300–400 references were selected using representative journal search websites such as PubMed, Google Scholar, Scopus, RISS, and ResearchGate, which a total of 45 papers were selected in the final stage based on 2009 to 2022.

Result

As environmental problems increased after the COVID‐19 pandemic, we tried to understand the needs of consumers for vegan cosmetics, which are good ingredients and good cosmetics. Therefore, this narrative review clearly shows the need for beauty and cosmetics industry consumers to pursue good consumption due to the global COVID‐19 pandemic.

Conclusion

Accordingly, this literature review will need to identify consumer needs for vegan cosmetics that started from vegan foods and develop the applications for the development of customized inner beauty products, customized vegan inner beauty products and/or customized vegan cosmetics using customized cosmetics. This is expected to be used as important marketing materials for the global vegan cosmetics market that confirms new changes in the cosmetics market.

Evaluation of Knowledge, Attitudes and Practices Related to Self-Testing Procedure against COVID-19 among Greek Students: A Pilot Study

The COVID-19 pandemic has had a major impact on health, economy, society and education. In the effort to return to normalcy, according to the instructions of the Greek Government for the resumption of the operation of schools, a screening Rapid Antigen Detection Test with the method of self-testing is required for students twice per week, for the early identification and isolation of positive cases. We aimed to pivotally investigate the knowledge, attitudes and practices related to self-testing procedures against COVID-19 among Greek students. A questionnaire was distributed to a convenient sample of students in the region of Athens. Information about the vaccination coverage against SARS-CoV-2 was also obtained. Our study included 1000 students, with 70% of them having an average grade at school. Most of the participants were aware of coronavirus (98.6%) and the self-test (95.5%). The vast majority of students (97%) performed self-testing twice per week, with the 70% them being assisted by someone else. Nearly one sixth of the participants had been infected by COVID-19 (14%) while 36% of them have already been vaccinated against SARS-CoV-2. In conclusion, we report high compliance with the COVID-19 self-testing procedure among students in Attica, Greece. Older age adolescents are more likely to not comply with the regulations of self-testing. Consequently, tailored interventions targeted at older age adolescents are warranted in order to increase the acceptability of self-testing.

Assessment of the Field Utility of a Rapid Point-of-Care Test for SARS-CoV-2 Antibodies in a Household Cohort

Point-of-care (POC) tests to detect SARS-CoV-2 antibodies offer quick assessment of serostatus after natural infection or vaccination. We compared the field performance of the BioMedomics COVID-19 IgM/IgG Rapid Antibody Test against an ELISA in 303 participants enrolled in a SARS-CoV-2 household cohort study. The rapid antibody test was easily implemented with consistent interpretation across 14 users in a variety of field settings. Compared with ELISA, detection of seroconversion lagged by 5 to 10 days. However, it retained a sensitivity of 90% (160/177, 95% confidence interval [CI] 85-94%) and specificity of 100% (43/43, 95% CI 92-100%) for those tested 3 to 5 weeks after symptom onset. Sensitivity was diminished among those with asymptomatic infection (74% [14/19], 95% CI 49-91%) and early in infection (45% [29/64], 95% CI 33-58%). When used appropriately, rapid antibody tests offer a convenient way to detect symptomatic infections during convalescence.

Usability of an At-Home Anterior Nares SARS-CoV-2 RT-PCR Sample Collection Kit: Human Factors Feasibility Study

Background

Readily available testing for SARS-CoV-2 is necessary to mitigate COVID-19 disease outbreaks. At-home collection kits, in which samples are self-collected without requiring a laboratory or clinic visit and sent to an external laboratory for testing, can provide convenient testing to those with barriers to access. They can prevent unnecessary exposure between patient and clinical staff, increase access for patients with disabilities or remote workers, and decrease burdens on health care resources, such as provider time and personal protective equipment. Exact Sciences developed an at-home collection kit for samples to be tested to detect SARS-CoV-2 that includes an Instructions for Use (IFU) document, which guides people without prior experience on collecting a nasal swab sample. Demonstrating successful sample collection and usability is critical to ensure that these samples meet the same high-quality sample collection standards as samples collected in clinics.

Objective

The aim of this study was to determine the usability of a SARS-CoV-2 at-home nasal swab sample collection kit.

Methods

A human factors usability study was conducted with 30 subjects without prior medical, laboratory, or health care training and without COVID-19 sample self-collection experience. Subjects were observed while they followed the IFU for the at-home sample collection portion of the SARS-CoV-2 test in a setting that simulated a home environment. IFU usability was further evaluated by requiring the subjects to complete a survey, answer comprehension questions, provide written feedback, and respond to questions from the observer about problems during use.

Results

All 30 subjects successfully completed the sample collection process, and all 30 samples were determined by reverse transcription–polymerase chain reaction (RT-PCR) testing to meet quality standards for SARS-CoV-2 testing. The subjects’ written feedback and comments revealed several recommendations to improve the IFU.

Conclusions

The study demonstrated the overall usability of an at-home SARS-CoV-2 collection kit. Various feedback mechanisms provided opportunities to improve the wording and graphics for some critical tasks, including placing the label correctly on the tube. A modified IFU was prepared based on study outcomes.