Application of a Serial Antigen Based Testing Strategy for SARS-CoV-2 and Student Adherence in a University Setting, Wisconsin — October–November 2020

Abstract Background Serial SARS-CoV-2 testing has been implemented at institutions of higher education (IHEs) and other settings. Testing strategies can include algorithms specifying confirmatory reverse transcription polymerase chain reaction (RT-PCR) testing after an antigen test. It is unknown how testing strategies perform detecting SARS-CoV-2, including individual adherence to serial testing requirements. Methods Student serial testing adherence was defined as completing ≥80% of weekly tests from October 5–November 14, 2020 and evaluated using logistic regression. Medical records were reviewed for all positive antigen test encounters and 10% of daily negative antigen test encounters during October 19–November 30, 2020. Results were used to estimate the proportion of individuals requiring only antigen tests, requiring and completing RT-PCR testing, and associated costs of tests. Results Two-thirds (66.5%; 1,166/1,754) of eligible on-campus students adhered to weekly testing; female students were more adherent (adjusted odds ratio [aOR]:2.07, 95% CI:1.66–2.59) than male students. Of all antigen test encounters, 11.5% (1,409/12,305) reported >1 COVID-19 symptoms. Of non-COVID-19 exposed antigen test encounters, 88% (10,386/11,769) did not require confirmatory RT-PCR testing. Only 28% (390/1,387) of testing encounters had an associated recommended confirmatory RT-PCR test performed. We estimated the testing strategy captured 61% (235/389) of predicted RT-PCR positive specimens. Conclusions At this IHE, most students voluntarily adhered to serial testing. The majority of antigen test results did not require confirmatory RT-PCR testing, but when required, most students did not obtain it. Including strategies to increase the proportion of individuals obtaining indicated confirmatory testing might improve the testing program’s performance.

Download Full-text

Diagnostic performance of a novel digital immunoassay (RapidTesta SARS-CoV-2): a prospective observational study with 1,127 nasopharyngeal samples

10.1101/2021.07.26.21261162 ◽

2021 ◽

Author(s):

Hiromichi Suzuki ◽

Yusaku Akashi ◽

Atsuo Ueda ◽

Yoshihiko Kiyasu ◽

Yuto Takeuchi ◽

...

Keyword(s):

Diagnostic Performance ◽

Prospective Observational Study ◽

Test Results ◽

Antigen Test ◽

Rt Pcr ◽

Asymptomatic Patients ◽

Pcr Method ◽

Antigen Tests ◽

Positive Line ◽

Test Cassette

Introduction: Digital immunoassays are generally regarded as superior tests for the detection of infectious disease pathogens, but there have been insufficient data concerning SARS-CoV-2 immunoassays. Methods: We prospectively evaluated a novel digital immunoassay (RapidTesta SARS-CoV-2). Two nasopharyngeal samples were simultaneously collected for antigen tests and RT-PCR. Real-time RT-PCR for SARS-CoV-2, using a method developed by the National Institute of Infectious Diseases, Japan, served as the reference RT-PCR method. Results: During the study period, 1,127 nasopharyngeal samples (symptomatic patients: 802, asymptomatic patients: 325) were evaluated. For digital immunoassay antigen tests, the sensitivity was 78.3% (95% CI: 67.3%-87.1%) and the specificity was 97.6% (95% CI: 96.5%-98.5%). When technicians visually analyzed the antigen test results, the sensitivity was 71.6% (95% CI: 59.9%-81.5%) and the specificity was 99.2% (95% CI: 98.5%-99.7%). Among symptomatic patients, the sensitivity was 89.4% (95% CI; 76.9%-96.5%) with digital immunoassay antigen tests, and 85.1% (95% CI; 71.7%-93.8%) with visually analyzed the antigen test, respectively. Conclusions: The findings indicated that RapidTesta SARS-CoV-2 analysis with the DIA device had sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal samples. When positive DIA results are recorded without a visually recognizable red line at the positive line location on the test cassette, additional RT-PCR evaluation should be performed.

Download Full-text

High Sensitivity and NPV for BinaxNOW Rapid Antigen Test in Children at a Mass Testing Site During Prevalent Delta Variant

10.1101/2022.01.05.22268788 ◽

2022 ◽

Author(s):

Kristie J Sun ◽

Mary Jane E Vaeth ◽

Matthew L Robinson ◽

Maryam Elhabashy ◽

Ishaan Gupta ◽

...

Keyword(s):

Predictive Value ◽

High Sensitivity ◽

High Volume ◽

Educational Opportunities ◽

Antigen Test ◽

Sample Collection ◽

Rt Pcr ◽

Polymerase Chain ◽

Testing Site ◽

Antigen Tests

SARS-CoV-2 continues to develop new, increasingly infectious variants, such as delta and omicron. Here, we evaluate the efficacy of the Abbott BinaxNOW Rapid Antigen Test against the gold standard of Reverse Transcription Polymerase Chain Reaction (RT-PCR) in 1054 pediatric participants presenting to a state-owned high-volume Coronavirus Disease 2019 (COVID-19) testing site. During the testing period, the delta variant was predominant. Prior to sample collection, symptomatic and exposure status was collected for all participants based on Centers for Disease Control (CDC) criteria. RT-PCR results demonstrated an overall prevalence rate of 5.2%. For all participants, the sensitivity of the rapid antigen tests was 92.7% (95% CI 82.4% - 98.0%) and specificity was 98.0% (95% CI 97.0%-98.8%). For symptomatic participants, the sensitivity was 92.3% (95% CI 74.9% - 99.1%), specificity was 96.6% (95% CI 93.6%- 98.4%), positive predictive value (PPV) was 72.7% (95% CI 54.5% - 86.7%) and negative predictive value (NPV) was 99.2% (95% CI 98.2% - 100%). Among asymptomatic participants, the sensitivity was 92.6% (95% CI 75.7% - 99.1%), specificity was 98.6% (95% CI 97.5% - 99.3%) the PPV was 71.4% (95% CI 53.7% - 85.4%) and the NPV was 99.7% (95% CI 99.0% - 100%). Our reported sensitivity and NPV are higher than other pediatric studies, but specificity and PPV are lower. Importance Children are especially impacted by the disease and its ability to disrupt educational opportunities. Although vaccinations have been approved for children 5 years and older, many children remain unvaccinated. Widespread testing may improve the ability for children to remain in in-person activities, minimizing absences from school and extracurriculars. Highly accurate rapid antigen tests may be vital to containing future COVID-19 waves while mitigating detrimental effects.

Download Full-text

SARS-CoV-2 transmission in intercollegiate athletics not fully mitigated with daily antigen testing

10.1101/2021.03.03.21252838 ◽

2021 ◽

Author(s):

Gage K. Moreno ◽

Katarina M. Braun ◽

Ian W. Pray ◽

Hannah E. Segaloff ◽

Ailam Lim ◽

...

Keyword(s):

Intercollegiate Athletics ◽

High Frequency ◽

Index Patient ◽

Mitigation Strategies ◽

Athletic Programs ◽

Test Results ◽

Antigen Test ◽

Rt Pcr ◽

Polymerase Chain ◽

Antigen Testing

AbstractBackgroundHigh frequency, rapid turnaround SARS-CoV-2 testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, two SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester despite mandatory directly observed daily antigen testing.MethodsDuring the fall 2020 semester, athletes and staff in both programs were tested daily using Quidel’s Sofia SARS Antigen Fluorescent Immunoassay (FIA), with positive antigen results requiring confirmatory testing with real-time reverse transcription polymerase chain reaction (RT-PCR). We used genomic sequencing to investigate transmission dynamics in these two outbreaks.ResultsIn Outbreak 1, 32 confirmed cases occurred within a university athletics program after the index patient attended a meeting while infectious despite a negative antigen test on the day of the meeting. Among isolates sequenced from Outbreak 1, 24 (92%) of 26 were closely related, suggesting sustained transmission following an initial introduction event. In Outbreak 2, 12 confirmed cases occurred among athletes from two university programs that faced each other in an athletic competition despite receiving negative antigen test results on the day of the competition. Sequences from both teams were closely related and unique from strains circulating in the community, suggesting transmission during intercollegiate competition.ConclusionsThese findings suggest that antigen testing alone, even when mandated and directly observed, may not be sufficient as an intervention to prevent SARS-CoV-2 outbreaks in congregate settings, and highlights the importance of supplementing serial antigen testing with appropriate mitigation strategies to prevent SARS-CoV-2 outbreak in congregate settings.SummaryHigh frequency, rapid turnaround SARS-CoV-2 testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, here we describe two SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester.

Download Full-text

Detection of SARS-CoV-2 infection by rapid antigen test in comparison with RT-PCR in a public setting

10.1101/2021.01.22.21250042 ◽

2021 ◽

Cited By ~ 1

Author(s):

Kathrine Kronberg Jakobsen ◽

Jakob Schmidt Jensen ◽

Tobias Todsen ◽

Freddy Lippert ◽

Cyril Jean-Marie Martel ◽

...

Keyword(s):

False Negative ◽

Pcr Analysis ◽

Nasopharyngeal Swab ◽

Test Results ◽

Antigen Test ◽

Rt Pcr ◽

Predictive Values ◽

Public Setting ◽

Antigen Tests ◽

Sensitivity Specificity

AbstractBackgroundRapid and accurate detection of SARS-CoV-2 infection is essential in limiting the spread of infection during the ongoing COVID-19 pandemic. The aim of this study was to determine the accuracy of the STANDARD Q COVID-19 Ag test (SD BIOSENSOR) by comparison with RT-PCR in a public setting.MethodIndividuals aged 18 years or older who had booked an appointment for a RT-PCR test on December 26-31, 2020 at a public test center in Copenhagen, Denmark, were invited to participate. An oropharyngeal swab was collected for RT-PCR analysis, immediately followed by a nasopharyngeal swab examined by the STANDARD Q COVID-19 Ag test (SD BIOSENSOR). Sensitivity, specificity, positive and negative predictive values of the antigen test were calculated with test results from RT-PCR as reference.ResultsOverall, 4697 individuals were included (female n=2456, 53.3%; mean age: 44.7 years, SD: 16.9 years); 196 individuals were tested twice or more. Among 4811 paired conclusive test results from the RT-PCR and antigen tests, 221 (4.6%) RT-PCR tests were positive. The overall sensitivity and specificity of the antigen test were 69.7% and 99.5%, the positive and negative predictive values were 87.0% and 98.5%. Ct values were significantly higher among individuals with false negative antigen tests compared to true positives.ConclusionThe sensitivity, specificity, and predictive values found indicate that the STANDARD Q COVID-19 Ag is a good supplement to RT-PCR testing.

Download Full-text

Is it enough for COVID-19 screening test? Limitation of swab test and general characteristics of mild symptom patients

Science Progress ◽

10.1177/00368504211026152 ◽

2021 ◽

Vol 104 (2) ◽

pp. 003685042110261

Author(s):

Sungwoo Choi ◽

Hyo Jeong Choi ◽

Ho Jung Kim

Keyword(s):

Screening Test ◽

Community Treatment ◽

Upper Respiratory Tract ◽

Test Results ◽

Rt Pcr ◽

Pcr Assay ◽

Positive Rate ◽

Upper Respiratory ◽

Polymerase Chain ◽

Discharge Criteria

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test ( p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high ( p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) ( p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered ( p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.

Download Full-text

COVID-19 and pregnancy – where are we now? A review

Journal of Perinatal Medicine ◽

10.1515/jpm-2020-0132 ◽

2020 ◽

Vol 48 (5) ◽

pp. 428-434 ◽

Cited By ~ 7

Author(s):

Aleksandra Rajewska ◽

Wioletta Mikołajek-Bedner ◽

Joanna Lebdowicz-Knul ◽

Małgorzata Sokołowska ◽

Sebastian Kwiatkowski ◽

...

Keyword(s):

Case Fatality ◽

Fetal Distress ◽

Delivery Mode ◽

Test Results ◽

Rt Pcr ◽

Third Trimester ◽

The Third ◽

Laboratory Test Results ◽

Protective Antibodies ◽

Polymerase Chain

AbstractThe new acute respiratory disease severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is highly contagious. It has caused many deaths, despite a relatively low general case fatality rate (CFR). The most common early manifestations of infection are fever, cough, fatigue and myalgia. The diagnosis is based on the exposure history, clinical manifestation, laboratory test results, chest computed tomography (CT) findings and a positive reverse transcription-polymerase chain reaction (RT-PCR) result for coronavirus disease 2019 (COVID-19). The effect of SARS-CoV-2 on pregnancy is not already clear. There is no evidence that pregnant women are more susceptible than the general population. In the third trimester, COVID-19 can cause premature rupture of membranes, premature labour and fetal distress. There are no data on complications of SARS-CoV-2 infection before the third trimester. COVID-19 infection is an indication for delivery if necessary to improve maternal oxygenation. Decision on delivery mode should be individualised. Vertical transmission of coronavirus from the pregnant woman to the fetus has not been proven. As the virus is absent in breast milk, the experts encourage breastfeeding for neonatal acquisition of protective antibodies.

Download Full-text

Death and COVID-19 Anxiety in Home-Quarantined Individuals Aged 65 and Over During the Pandemic

OMEGA - Journal of Death and Dying ◽

10.1177/00302228211059894 ◽

2021 ◽

pp. 003022282110598

Author(s):

Hümeyra Aslaner ◽

Betül Özen ◽

Zeliha K. Erten ◽

Mebrure Beyza Gökçek

Keyword(s):

Polymerase Chain Reaction ◽

Death Anxiety ◽

Short Form ◽

Anxiety Score ◽

Test Results ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain ◽

Test Result ◽

Pcr Test

Urgent measures were taken for those at the age of 65 and over who were at the risk group all over the world due to the COVID-19 pandemic. It is known that many individuals at the age of 65 and over have experienced anxiety due to the uncertainties. This study aimed to determine the anxiety and death anxiety in individuals aged 65 and over who were isolation at home due to being diagnosed with COVID-19 or being in contact during the pandemic process. The study is descriptive and cross-sectional. It was performed with 656 home-quarantined individuals aged between 65–80 years with positive or negative real-time polymerase chain reaction (RT-PCR) test result. A form including questions about the death anxiety and the Coronavirus Anxiety Scale Short Form prepared by the researchers were administered to the individuals by phone call. Of the participants, 49.5% were male. Median COVID-19 anxiety score was 4 (0–18). Anxiety scores of the male and female participants were similar. Participants with negative polymerase chain reaction (PCR) results and those with death anxiety had higher COVID anxiety scores. Death anxiety has increased by 1.661 times in male gender, 1.983 times in RT-PCR positivity and 0.146 times in the presence of symptoms. Individuals with positive COVID-19 test results or those aged 65 and over who had death anxiety and negative COVID-19 test result but who were in home-isolation due to being a contact had higher anxiety score. For this reason, those with death anxiety can be supported in line with their religious beliefs to reduce anxiety. Those with negative PCR test results in quarantine can be adequately informed about the COVID-19.

Download Full-text

A Real-World Comparison of SARS-CoV-2 Rapid Antigen vs. Polymerase Chain Reaction Testing in Florida

Journal of Clinical Microbiology ◽

10.1128/jcm.01107-21 ◽

2021 ◽

Author(s):

Lao-Tzu Allan-Blitz ◽

Jeffrey D. Klausner

Keyword(s):

Polymerase Chain Reaction ◽

Real World ◽

Threshold Value ◽

Test Results ◽

Chain Reaction ◽

Cycle Threshold ◽

Large Populations ◽

Symptom Status ◽

Polymerase Chain ◽

Antigen Tests

Background The reported sensitivity of rapid, antigen-based diagnostics for SARS-CoV-2 infection varies. Few studies have evaluated rapid antigen tests in real-world settings or among large populations. Methods Beginning October 2020, Florida offered individuals presenting for SARS-CoV-2 testing polymerase chain reaction (PCR) testing if they tested positive by the Abbott BinaxNOW TM COVID-19 Ag Card, were symptomatic, or required or requested PCR testing. We compared test results among individuals who received both types of tests at four publicly-accessible testing sites across Florida. We calculated the positive percent agreement (PPA) between the two test types by symptom status. Subsequently, we evaluated the PPA among individuals regardless of symptoms with lower cycle threshold values (<30). Results Overall, 18,457 individuals were tested via both methods, of which 3,153 (17.1%) were positive by PCR. The PPA for the Abbott BinaxNOW TM COVID-19 Ag Card using the PCR comparator was 49.2% (95% CI 47.4%-50.9%). That performance was moderately improved among symptomatic individuals (51.9%; 95% CI 49.7%-54.0%). When restricted to positive PCR tests with a cycle threshold value <30, regardless of symptom status, the PPA was 75.3% (95% CI 72.8%-77.6%). Conclusion The PPA of the Abbott BinaxNOW TM COVID-19 Ag Card with PCR was lower than among previous reports. Our findings may reflect the performance of the BinaxNOW TM antigen test in real-world settings.

Download Full-text

Antigen Testing for COVID-19 Asymptomatic Screening: Why it Should be Preferred Over PCR Insights From Navy Region Japan’s Experience With a Comprehensive Antigen Testing Strategy

Military Medicine ◽

10.1093/milmed/usab331 ◽

2021 ◽

Author(s):

Ross A Mullinax

Keyword(s):

Public Health ◽

Infectious Virus ◽

Infectious Period ◽

Test Results ◽

Testing Strategy ◽

Viral Loads ◽

Viral Culture ◽

Polymerase Chain ◽

Antigen Testing

ABSTRACT Polymerase chain reaction (PCR) is commonly used in asymptomatic screening testing, but is suboptimal for this purpose as it will identify many old persistent positives that are no longer infectious. This can result in placement of individuals that are not infectious to others into isolation. This results in substantial adverse impact to military manning and operations, without any benefit to public health. Antigen testing does not have this same drawback. Antigen testing, while less sensitive than PCR, will identify the vast majority of infectious positives, especially those with higher viral loads that are more likely to transmit to others. Importantly, use of antigen testing will also greatly increase the certainty of benefit from isolation, reducing the risk of isolating those individuals who are beyond their infectious period and pose no threat to public health. The literature on this topic is reviewed, with particular focus on studies that perform viral culture in addition to PCR and antigen testing. This allows for determination of sensitivity for infectious virus. Also, Navy Region Japan’s experience with a comprehensive antigen testing strategy is described. The challenges presented by persistent positive PCR test results are examined, as well as the real-world benefits from implementing widespread use of antigen testing.

Download Full-text

Retrospective observational RT-PCR analyses on 688 babies born to 843 SARS-CoV-2 positive mothers, placental analyses and diagnostic analyses limitations suggest vertical transmission is possible.

Facts, Views and Vision in ObGyn ◽

10.52054/fvvo.13.1.001 ◽

2021 ◽

Vol 13 (1) ◽

pp. 53-66 ◽

Cited By ~ 1

Author(s):

G. Bahadur ◽

M. Bhat ◽

S. Acharya ◽

D. Janga ◽

B. Campbell ◽

...

Keyword(s):

Vertical Transmission ◽

Research Question ◽

Diagnostic Testing ◽

Placental Pathology ◽

Rt Pcr ◽

Chain Reaction ◽

Serial Testing ◽

Medical Termination ◽

Polymerase Chain ◽

Positive Results

Research question: Is there vertical transmission (from mother to baby antenatally or intrapartum) after SARS-CoV-2 (COVID-19) infected pregnancy? Study design: A systematic search related to SARS-CoV-2 (COVID-19), pregnancy, neonatal complications, viral and vertical transmission. The duration was from December 2019 to May 2020. Results: A total of 84 studies with 862 COVID positive women were included. Two studies had ongoing pregnancies while 82 studies included 705 babies, 1 miscarriage and 1 medical termination of pregnancy (MTOP). Most publications (50/84, 59.5%), reported small numbers (<5) of positive babies. From 75 studies, 18 babies were COVID-19 positive. The first reverse transcription polymerase chain reaction (RT-PCR) diagnostic test was done in 449 babies and 2 losses, 2nd RT-PCR was done in 82 babies, IgM tests were done in 28 babies, and IgG tests were done in 28 babies. On the first RT-PCR, 47 studies reported time of testing while 28 studies did not. Positive results in the first RT-PCR were seen in 14 babies. Earliest tested at birth and the average time of the result was 22 hours. Three babies with negative first RT-PCR became positive on the second RT-PCR at day 6, day 7 and at 24 hours which continued to be positive at 1 week. Four studies with a total of 4 placental swabs were positive demonstrating SARS-CoV-2 localised in the placenta. In 2 studies, 10 tests for amniotic fluid were positive for SARS-CoV-2. These 2 babies were found to be positive on RT-PCR on serial testing. Conclusion: Diagnostic testing combined with incubation period and placental pathology indicate a strong likelihood that intrapartum vertical transmission of SARS-CoV-2 (COVID-19) from mother to baby is possible.

Download Full-text