A systematic review comparing at-home diagnostic tests for SARS-CoV-2: Key points for pharmacy practice, including regulatory information

School Absenteeism as a Marker for Community COVID-19 Rates

BACKGROUND

Reported community transmission rates of coronavirus disease 2019 (COVID-19) may not be accurate, particularly since at-home testing has become widely available. School absenteeism may serve as a marker of broader community COVID-19 transmission.

METHODS

We performed an observational study of North Carolina kindergarten through 12th grade schools participating in the ABC Science Collaborative that offered in-school instruction, and contributed severe acute respiratory syndrome coronavirus 2 data for at least 2 of 4 weeks monthly for the 2021-2022 academic year. Additionally, we analyzed publicly available databases including the North Carolina Department of Public Instruction, Centers for Disease Control and Prevention COVID-19 Data Repository, and National Center for Education Statistics. We described community and school COVID-19 infection rates compared with student monthly absenteeism rates to determine if the relationship between community COVID-19 infection rates and student absenteeism varied over time.

RESULTS

We included 500 192 students from 27 school districts. For the 2021-2022 academic year, the student and community COVID-19 infection rates did not show a significant difference (P > .05) across each month of comparison. Student absenteeism rates and community COVID-19 infection rates by month showed a similar trend across the academic year. For every 1% increase in community infection percentage, we found a 1.68% (1.12-2.25%) increase in absenteeism (P < .001); for every 1 month change in time, we found a 0.12% (0.01-0.24%) increase in absenteeism (P < .05).

CONCLUSIONS

Student absenteeism and infection rates may be a useful marker of COVID-19 community infection rates when testing frequency and results reporting are inconsistent.

A Call to Improve Usability, Accuracy, and Equity of Self-Testing for COVID-19 and Other Rapid Diagnostic Tests

The increasing availability of rapid diagnostic self-tests (RDSTs) for COVID-19 has played an important and increasing role during the pandemic. However, for many underserved communities, RDSTs potential benefits are offset by problems with usability, accuracy, and equity. Given the increased need for and interest in home testing for acute and chronic diseases, including COVID-19, this piece offers ways that regulatory agencies, federal public health agencies, and test developers should engage with diverse communities to ensure equity throughout test development, implementation, and evaluation. Such engagement will ensure maximum personal and public health benefits for current and future RDSTs under real-world conditions.

Daily SARS-CoV-2 Nasal Antigen Tests Miss Infected and Presumably Infectious People Due to Viral Load Differences among Specimen Types

In a recent household transmission study of SARS-CoV-2, we found extreme differences in SARS-CoV-2 viral loads among paired saliva, anterior nares swab (ANS), and oropharyngeal swab specimens collected from the same time point. We hypothesized these differences may hinder low-analytical-sensitivity assays (including antigen rapid diagnostic tests [Ag-RDTs]) by using a single specimen type (e.g., ANS) from reliably detecting infected and infectious individuals. We evaluated daily at-home ANS Ag-RDTs (Quidel QuickVue) in a cross-sectional analysis of 228 individuals and a longitudinal analysis (throughout infection) of 17 individuals enrolled early in the course of infection. Ag-RDT results were compared to reverse transcription-quantitative PCR (RT-qPCR) results and high, presumably infectious viral loads (in each, or any, specimen type). The ANS Ag-RDT correctly detected only 44% of time points from infected individuals on cross-sectional analysis, and this population had an inferred limit of detection of 7.6 × 106 copies/mL. From the longitudinal cohort, daily Ag-RDT clinical sensitivity was very low (<3%) during the early, preinfectious period of the infection. Further, the Ag-RDT detected ≤63% of presumably infectious time points. The poor observed clinical sensitivity of the Ag-RDT was similar to what was predicted based on quantitative ANS viral loads and the inferred limit of detection of the ANS Ag-RDT being evaluated, indicating high-quality self-sampling. Nasal Ag-RDTs, even when used daily, can miss individuals infected with the Omicron variant and even those presumably infectious. Evaluations of Ag-RDTs for detection of infected or infectious individuals should be compared with a composite (multispecimen) infection status to correctly assess performance. IMPORTANCE We reveal three findings from a longitudinal study of daily nasal antigen rapid diagnostic test (Ag-RDT) evaluated against SARS-CoV-2 viral load quantification in three specimen types (saliva, nasal swab, and throat swab) in participants enrolled at the incidence of infection. First, the evaluated Ag-RDT showed low (44%) clinical sensitivity for detecting infected persons at all infection stages. Second, the Ag-RDT poorly detected (≤63%) time points that participants had high and presumably infectious viral loads in at least one specimen type. This poor clinical sensitivity to detect infectious individuals is inconsistent with the commonly held view that daily Ag-RDTs have near-perfect detection of infectious individuals. Third, use of a combination nasal-throat specimen type was inferred by viral loads to significantly improve Ag-RDT performance to detect infectious individuals.

Metal-Organic Framework as a Fluorescent and Colorimetric Dual-Signal Readout Biosensor Platform for the Detection of a Genetic Sequence from the SARS-CoV-2 Genome

The quest for the development of high-accuracy, point-of-care, and cost-effective testing platforms for SARS-CoV-2 infections is ongoing as current diagnostics rely on either assays based on costly yet accurate nucleic acid amplification tests (NAAT) or less selective and less sensitive but rapid and cost-effective antigen tests. As a potential solution, this work presents a fluorescence-based detection platform using a metal-organic framework (MOF) in an effective assay, demonstrating the potential of MOFs to recognize specific targets of the SARS-CoV-2 genome with high accuracy and rapid process turnaround time. As a highlight of this work, positive detection of SARS-CoV-2 is indicated by a visible color change of the MOF probe with ultrahigh detection selectivities down to single-base mismatch nucleotide sequences, thereby providing an alternative avenue for the development of innovative detection methods for diverse viral genomes.

Experiences of Health Departments on Community Engagement and Implementation of a COVID-19 Self-testing Program

CONTEXT

Health departments (HDs) work on the front lines to ensure the health of their communities, providing a unique perspective to public health response activities. Say Yes! COVID Test (SYCT) is a US federally funded program providing free COVID-19 self-tests to communities with high COVID-19 transmission, low vaccination rates, and high social vulnerability. The collaboration with 9 HDs was key for the program distribution of 5.8 million COVID-19 self-tests between March 31 and November 30, 2021.

OBJECTIVE

The objective of this study was to gather qualitative in-depth information on the experiences of HDs with the SYCT program to better understand the successes and barriers to implementing community-focused self-testing programs.

DESIGN

Key informant (KI) interviews.

SETTING

Online interviews conducted between November and December 2021.

PARTICIPANTS

Sixteen program leads representing 9 HDs were purposefully sampled as KIs. KIs completed 60-minute structured interviews conducted by one trained facilitator and recorded.

MAIN OUTCOME MEASURES

Key themes and lessons learned were identified using grounded theory.

RESULTS

Based on perceptions of KIs, HDs that maximized community partnerships for test distribution were more certain that populations at a higher risk for COVID-19 were reached. Where the HD relied predominantly on direct-to-consumer distribution, KIs were less certain that communities at higher risk were served. Privacy and anonymity in testing were themes linked to higher perceived community acceptance. KIs reported that self-test demand and distribution levels increased during higher COVID-19 transmission levels.

CONCLUSION

HDs that build bridges and engage with community partners and trusted leaders are better prepared to identify and link high-risk populations with health services and resources. When collaborating with trusted community organizations, KIs perceived that the SYCT program overcame barriers such as mistrust of government intervention and desire for privacy and motivated community members to utilize this resource to protect themselves against COVID-19.

Advances in molecular infectious diseases testing in the time of COVID-19

The Coronavirus Disease of 2019 (COVID-19) pandemic has been a challenging event for laboratory medicine and diagnostics manufacturers. We have had to confront numerous unique and previously unthinkable issues on a daily basis in order to continue offering diagnostic testing for not only Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), but other testing that was significantly impacted by supply chain and staffing disruptions related to COVID-19. Out of this tremendously stressful and, at times, chaotic environment, decades of innovations and advances in testing methodologies and instrumentation became essential to handle the overwhelming volume of samples with clinically appropriate turn-around-time. Additionally, a number of novel testing approaches and technological innovations emerged to address laboratory and public health needs for widespread testing. In this review we consider both technological advances in infectious diseases testing and other innovations in sample collection, processing, automation, workflow, and testing that have embodied the laboratory response to the COVID-19 pandemic.

SARS-CoV-2 self-test uptake and factors associated with self-testing during Omicron BA.1 and BA.2 waves in France, January to May 2022

BackgroundFollowing the SARS-CoV-2 Omicron variant spread, the use of unsupervised antigenic rapid diagnostic tests (self-tests) increased.AimThis study aimed to measure self-test uptake and factors associated with self-testing.MethodsIn this cross-sectional study from 20 January to 2 May 2022, the case series from a case-control study on factors associated with SARS-CoV-2 infection were used to analyse self-testing habits in France. A multivariable quasi-Poisson regression was used to explore the variables associated with self-testing among symptomatic cases who were not contacts of another infected individual. The control series from the same study was used as a proxy for the self-test background rate in the non-infected population of France.ResultsDuring the study period, 179,165 cases who tested positive through supervised tests were recruited. Of these, 64.7% had performed a self-test in the 3 days preceding this supervised test, of which 79,038 (68.2%) were positive. The most frequently reported reason for self-testing was the presence of symptoms (64.6%). Among symptomatic cases who were not aware of being contacts of another case, self-testing was positively associated with being female, higher education, household size, being a teacher and negatively associated with older age, not French by birth, healthcare-related work and immunosuppression. Among the control series, 12% self-tested during the 8 days preceding questionnaire filling, with temporal heterogeneity.ConclusionThe analysis showed high self-test uptake in France with some inequalities which must be addressed through education and facilitated access (cost and availability) for making it a more efficient epidemic control tool.

A Comprehensive Overview of Sensors Applications for the Diagnosis of SARS-CoV-2 and of Drugs Used in its Treatment

During the COVID-19 process, determination-based analytical chemistry studies have had a major place at every stage. Many analytical techniques have been used in both diagnostic studies and drug analysis. Among these, electrochemical sensors are frequently preferred due to their high sensitivity, selectivity, short analysis time, reliability, ease of sample preparation, and low use of organic solvents. For the determination of drugs used in the SARS-CoV-2, such as favipiravir, molnupiravir, ribavirin, etc., electrochemical (nano)sensors are widely used in both pharmaceutical and biological samples. Diagnosis is the most critical step in the management of the disease, and electrochemical sensor tools are widely preferred for this purpose. Diagnostic electrochemical sensor tools can be biosensor-, nano biosensor-, or MIP-based sensors and utilize a wide variety of analytes such as viral proteins, viral RNA, antibodies, etc. This review overviews the sensor applications in SARS-CoV-2 in terms of diagnosis and determination of drugs by evaluating the most recent studies in the literature. In this way, it is aimed to compile the developments so far by shedding light on the most recent studies and giving ideas to researchers for future studies.

Combined Symptom Screening and At-Home Tests for COVID-19

BACKGROUND AND OBJECTIVE

At-home rapid antigen tests provide a convenient and expedited resource to learn about severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection status. However, low sensitivity of at-home antigen tests presents a challenge. This study examines the accuracy of at-home tests, when combined with computer-facilitated symptom screening.

METHODS

The study used primary data sources with data collected during 2 phases at different periods (phase 1 and phase 2): one during the period in which the alpha variant of SARS-CoV-2 was predominant in the United States and another during the surge of the delta variant. Four hundred sixty-one study participants were included in the analyses from phase 1 and 374 subjects from phase 2. Phase 1 data were used to develop a computerized symptom screening tool, using ordinary logistic regression with interaction terms, which predicted coronavirus disease-2019 (COVID-19) reverse transcription polymerase chain reaction (RT-PCR) test results. Phase 2 data were used to validate the accuracy of predicting COVID-19 diagnosis with (1) computerized symptom screening; (2) at-home rapid antigen testing; (3) the combination of both screening methods; and (4) the combination of symptom screening and vaccination status. The McFadden pseudo-R2 was used as a measure of percentage of variation in RT-PCR test results explained by the various screening methods.

RESULTS

The McFadden pseudo-R2 for the first at-home test, the second at-home test, and computerized symptom screening was 0.274, 0.140, and 0.158, respectively. Scores between 0.2 and 0.4 indicated moderate levels of accuracy. The first at-home test had low sensitivity (0.587) and high specificity (0.989). Adding a second at-home test did not improve the sensitivity of the first test. Computerized symptom screening improved the accuracy of the first at-home test (added 0.131 points to sensitivity and 6.9% to pseudo-R2 of the first at-home test). Computerized symptom screening and vaccination status was the most accurate method to screen patients for COVID-19 or an active infection with SARS-CoV-2 in the community (pseudo-R2 = 0.476).

CONCLUSION

Computerized symptom screening could either improve, or in some situations, replace at-home antigen tests for those individuals experiencing COVID-19 symptoms.

Knowledge about, acceptance of and willingness to use over-the-counter COVID-19 self-testing kits

Objectives

Early investments in new diagnostic technologies that allow for rapid and decentralized testing were critical in reducing SARS-CoV-2’s detrimental health and economic effects. This study evaluates public knowledge about, acceptance of and willingness to use COVID-19 self-testing kits.

Methods

An online descriptive cross-sectional questionnaire was used in this study. The final study population included all contacted national and resident adults, age 18 and over, who were willing to engage in the study. The survey was divided according to participants’ demographic information and 11 questions assessed the respondents’ understanding of and willingness to use COVID-19 self-testing kits. The statistical analysis was carried out using SPSS version 24. Multivariate linear regression models were used to identify the factors influencing respondents’ knowledge of and attitudes toward the acceptability of self-testing kits for COVID-19 and their willingness to use these kits.

Key findings

A total of 876 respondents participated in the study and completed the whole questionnaire. The average knowledge score on the acceptability of and willingness to use self-testing kits for COVID-19 was 70.2%, with a 95% confidence interval (CI) [69.1%, 71.4%]. Participants who were postgraduate, female and vaccinated against COVID-19, as well as employees and older participants, were jointly highly associated with higher levels of knowledge about, acceptance of and willingness to use self-testing kits for COVID-19. Moreover, participants who had been infected with COVID-19, were vaccinated against COVID-19 or were female, employees, older, Western or Arabic were jointly highly associated with positive attitudes about the acceptability of and willingness to use self-testing kits for COVID-19.

Conclusions

The majority of the respondents have acceptable levels of knowledge about, acceptance of and willingness to use self-testing kits for COVID-19. Nonetheless, future studies should consider the issues of pre- and post-test counselling, false negative results and the sale of unregulated testing kits. Additional information should be communicated so that people can make informed decisions and be protected from possible abuse of COVID-19 self-testing kits when they become available in pharmacies.

Advances in Sexually Transmitted Infection Testing at Home and in Nonclinical Settings Close to the Home

A commentary on recent successes and challenges for home STI specimen collection, for point-of-care test usage close to the home, and implications of COVID-19 self-tests for future STI self-test development.

Advances in nucleic acid amplification techniques (NAATs): COVID-19 point-of-care diagnostics as an example

Achieving superhigh sensitivity is the ultimate goal for bio-detection in modern analytical science and life science. Among variable signal amplification strategies, nucleic acid amplification technologies are revolutionizing the field of bio-detection, providing greater possibilities in novel diagnosis achieving high efficiency, specificity, and cost-effectiveness. Nucleic acid amplification techniques (NAATs), such as Polymerase Chain Reaction (PCR), Rolling Circle Amplification (RCA), Loop-Mediated Isothermal Amplification (LAMP), Recombinase Polymerase Amplification (RPA), CRISPR-related amplification, and others are dominating methods employed in research and clinical settings. They each provide distinctively unique features that can offer desirable performance in terms of sensitivity, specificity, simplicity, stability, and cost. NAATs are in unmet demand in molecular diagnosis, especially in point-of-care scenario. This review will discuss the principles and recent advancements of each NAAT, respectively, revealing their strengths and challenges in achieving rapid and accurate bio-detection with a focus on point-of-care diagnosis. Furthermore, this review will explore the application of each of the technologies through the contemporary COVID-19 pandemic, analyzing their ability in point-of-care diagnosis of the COVID-19 with high sensitivity to emphasize significance of developing NAATs based methods in battling COVID-19. Finally, advantages and potentials of each NAAT in enhancements of sensitivity and specificity in bio-detection from bench side to the bedside will be discussed, aiming for full exploitation of capability of each NAAT. This review will provide novel aspects in the selection and combination of usages of various NAATs based on their distinctive characteristics and limitations. A possible advancing direction of future accurate POCT is also proposed.