scholarly journals Indicators of COVID-19 status in a cohort study of university staff and post-graduate research students, including results from home antibody testing

2020 ◽  
Author(s):  
Katrina A. S. Davis ◽  
Ewan Carr ◽  
Daniel Leightley ◽  
Valentina Vitiello ◽  
Gabriella Bergin-Cartwright ◽  
...  
Keyword(s):  
Cohort Studies ◽  
Antibody Test ◽  
Self Report ◽  
Test Results ◽  
Long Term Effects ◽  
Antibody Testing ◽  
Postgraduate Students ◽  
Research Students ◽  
Core Symptoms

AbstractBackgroundCohort studies of people with a history of COVID-19 infection and controls will be essential to understand the epidemiology of long-term effects. However, clinical diagnosis requires resources that are frequently restricted to the severely ill. Cohort studies may have to rely on surrogate indicators of COVID-19 illness. We describe the prevalence and overlap of five potential indicators: self-reported suspicion, self-reported core symptoms, symptom algorithm, self-reported routine test results, and home antibody testing.MethodsAn occupational cohort of staff and postgraduate students at a large London university who participated in surveys and antibody testing. Self-report items cover March to June 2020 and antibody test results from ‘lateral flow’ IgG/IgM antibody test cassettes sent to participants in June 2020.ResultsValid antibody test results were returned for 1882 participants. Of the COVID-19 indicators, the highest prevalence was core symptoms (770 participants positive, 41%), followed by participant suspicion of infection (n=509, 27%), a symptom algorithm (n=297, 16%), study antibody positive test (n=124, 6.6%) and self-report of a positive external test (n=39, 2.1%). Study antibody positive result was rare in people who had no suspicion they had experienced COVID-19 (n=4, 0.7%) or did not experience core symptoms (n=10, 1.6%). When study antibody test results were compared with earlier external antibody results in those who had reported them, the study antibody results agreed in 88% cases (kappa= 0.636), with a lower proportion testing positive on this occasion (proportion with antibodies detected 15% in study test vs 24% in external testing).DiscussionOur results demonstrate that there is some agreement between different COVID indicators, but that they a more complete story when used together. Antibody testing may provide greater certainty and be one of the only ways to detect asymptomatic cases, but is likely to under-ascertain due to weak antibody responses to mild infection, which wane over time. Cohort studies will need to review how they deal with different and sometimes conflicting indicators of COVID-19 illness in order to study the long-term outcomes of COVID-19 infection and related impacts.What is already known on this subject?Research into the effects of COVID-19 in the community is needed to respond to the pandemic. Objective testing has not been widely available and accuracy may not be high when carried out in retrospect. Many cohort studies are considering how best to measure COVID-19 infection status.What this study adds?Antibody testing is feasible, but it is possible that sensitivity may be poor. Each indicator included added different aspects to the ascertainment of COVID-19 exposure. Using combinations of self-reported and objectively measured variables, it may be possible to tailor COVID-19 indicators to the situation.

scholarly journals Applying the proportionality principle to COVID-19 antibody testing

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
H D Gunnarsdóttir ◽  
M S Sinha ◽  
S Gerke ◽  
T Minssen
Keyword(s):  
European Union ◽  
Antibody Test ◽  
International Travel ◽  
Differential Treatment ◽  
Individual Freedom ◽  
Test Results ◽  
The European Union ◽  
Antibody Testing ◽  
Proportionality Principle

Abstract As the COVID-19 pandemic continues to ravage the globe, many nations have started to relax stringent restrictions in an effort to restart the economy. While Member States of the European Union have approached reopening without the use of antibody testing for COVID-19, such testing may be central to a long-term, sustainable strategy for international travel, employment, and the allocation and monitoring of vaccines. As the use of antibody testing to dictate the enjoyment of individual freedom remains highly controversial, we describe its use in the context of three case studies (return to the workplace, travel and vaccination), applying the substantive legal balancing entailed in the proportionality principle. Differential treatment of individuals based on COVID-19 antibody test results can be justified through the proportionality principle, which offers a sound dividing line between a reasonable and legitimate response and an unjust and discriminatory response.

A Nationwide Survey of COVID-19 Testing in LGBTQ+ Populations in the United States

2021 ◽  
pp. 003335492110181
Author(s):  
Richard J. Martino ◽  
Kristen D. Krause ◽  
Marybec Griffin ◽  
Caleb LoSchiavo ◽  
Camilla Comer-Carruthers ◽  
...  
Keyword(s):  
United States ◽  
Gay Men ◽  
Antibody Test ◽  
Nationwide Survey ◽  
The United States ◽  
Sociodemographic Characteristics ◽  
Full Time ◽  
Test Results ◽  
Antibody Testing ◽  
And Gender

Objectives Lesbian, gay, bisexual, transgender, or queer and questioning (LGBTQ+) people and populations face myriad health disparities that are likely to be evident during the COVID-19 pandemic. The objectives of our study were to describe patterns of COVID-19 testing among LGBTQ+ people and to differentiate rates of COVID-19 testing and test results by sociodemographic characteristics. Methods Participants residing in the United States and US territories (N = 1090) aged ≥18 completed an internet-based survey from May through July 2020 that assessed COVID-19 testing and test results and sociodemographic characteristics, including sexual orientation and gender identity (SOGI). We analyzed data on receipt and results of polymerase chain reaction (PCR) and antibody testing for SARS-CoV-2 and symptoms of COVID-19 in relation to sociodemographic characteristics. Results Of the 1090 participants, 182 (16.7%) received a PCR test; of these, 16 (8.8%) had a positive test result. Of the 124 (11.4%) who received an antibody test, 45 (36.3%) had antibodies. Rates of PCR testing were higher among participants who were non–US-born (25.4%) versus US-born (16.3%) and employed full-time or part-time (18.5%) versus unemployed (10.8%). Antibody testing rates were higher among gay cisgender men (17.2%) versus other SOGI groups, non–US-born (25.4%) versus US-born participants, employed (12.6%) versus unemployed participants, and participants residing in the Northeast (20.0%) versus other regions. Among SOGI groups with sufficient cell sizes (n > 10), positive PCR results were highest among cisgender gay men (16.1%). Conclusions The differential patterns of testing and positivity, particularly among gay men in our sample, confirm the need to create COVID-19 public health messaging and programming that attend to the LGBTQ+ population.

Challenges to Overcome and Scaffolding to Build on

2019 ◽  
Vol 9 (3) ◽  
pp. 50-67
Author(s):  
Hao Yang ◽  
Zhiqiang Ma
Keyword(s):  
Teacher Perceptions ◽  
Flipped Classroom ◽  
Public University ◽  
Test Results ◽  
Learning Behavior ◽  
Long Term Effects ◽  
Exploratory Case Study ◽  
Flipped Classrooms

While current research on the flipped classroom generally focuses on test results and (or) student/teacher perceptions as a measurement of its pedagogical efficacy, students' adaptation to it and the essential conditions for its application are rarely explored. This exploratory case study aims to rectify this by examining how university students adapted to flipped classrooms implemented in a public university in East China. The findings suggest that while the flipped model is impeded by entrenched polarity between students in terms of their learning dispositions and academic competence, students do develop a prototype of theories of learning, a sense of better self through learning from their peers and an awareness of the importance of intrinsic motivation. A gradualist approach is thus proposed for implementing flipped classrooms, which requires longitudinal studies accordingly to understand its long-term effects on learning behavior hitherto left unexplored.

Effects of Post-Tightening on the Residual Bolt Force and the Sealing Performance of Flanged Connections With PTFE Gaskets (Long Term Effects at Room Temperature)

2011 ◽  
Author(s):  
Taiki Hagiri ◽  
Takashi Kobayashi ◽  
Kengou Nishiura ◽  
Kazuaki Uchiyama
Keyword(s):  
Room Temperature ◽  
Test Results ◽  
Long Term Effects ◽  
Viscoelastic Characteristic ◽  
Sealing Performance ◽  
Nominal Size ◽  
Gasket Material

It is known that bolt forces reduce significantly after tightening bolted flanged connections in which expanded PTFE gaskets are used. Bolts are often post-tightened in practice after a while to compensate for the reduction of bolt forces. The viscoelastic characteristic of expanded PTFE gaskets is the main cause for the phenomenon. However, the long term effects of the post-tightening on the residual bolt forces and the sealing performance of flanged connections have not been clarified yet. In this study, two sets of flanged connections (2 inch in nominal size), in which PTFE gaskets were used, were prepared and tightened. One of the flanges was post-tightened after a designated time. The reduction of bolt forces and the change in the sealing performance were measured for about two months. The results were compared with those of flanges without post-tightening. Based on the test results, the effectiveness of post-tightening was discussed from the viewpoint of the residual bolt force and the sealing performance. It has been clarified that the effectiveness of post-tightening depends on gasket material and that post-tightening is effective for expanded PTFE gaskets.

scholarly journals Life span of Covid-19 antibodies following infection in a sample worker population in Qatar

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Mohamad Hamad BA Al-Naemi ◽  
Walid Sayed Hassanen ◽  
Sherif Fawzi Mohamed El Nahrawi ◽  
Rama Abdulsalam Rashad
Keyword(s):  
Social History ◽  
Antibody Test ◽  
Test Results ◽  
Antibody Testing ◽  
Study Population ◽  
Human Immune Response ◽  
Human Immune ◽  
Spread Of Infection ◽  
Test Result ◽  
Rule Out

Background: COVID-19 antibodies’ longevity following infection is still unclear. Early data brought hope that acquired immunity was possible but subsequent studies suggested that immune protection might be short-lived. The results of recent studies provide greater insight into the human immune response to COVID-19. The Qatar Gas medical department’s strategy in preventing spread of infection among offshore and onshore workers consisted of maximizing the opportunities for COVID-19 polymerise chain reaction (PCR) and antibody testing. A large amount of data revealing the possible lifespan of COVID-19 antibodies in the study population was collected. Methods: Out of hundreds of employees who volunteered in this study about seroprevalance of COVID-19 antibodies, 52 whose results were reactive were tested for COVID-19 PCR before being selected. Employees with reactive or inconclusive PCR test results were excluded. Age, medical/surgical/social history, apart from past COVID-19 infection, were not selection criteria. We measured the period of time between the date of diagnosis and the antibody test result, segregating those still reactive from those who tested non-reactive at any point in time. The reactive group were retested for antibodies every 90 days as long as results continued to be reactive. Any cured employee was retested if they developed symptoms or was exposed to a confirmed positive case, to rule out the possibility of re-infection during this timeframe. Results: Only one employee was non-reactive after 110 days of COVID-19 PCR positive test result. 22 employees tested reactive although their PCR result had been negative. 30 employees tested reactive after a positive PCR with an average duration of 145 days, the shortest and longest being 24 and 223 respectively. Conclusion: We determined that antibodies’ longevity may extend to more than 6 months following COVID-19 infection and that there may be an early decay of antibodies in a limited proportion of the population, however further studies are recommended on larger populations. We noticed no cases of COVID-19 reinfection.

Space-exposed seed experiment developed for students

1992 ◽  
Vol 50 (1) ◽  
pp. 860-861
Author(s):  
Donna Leeper ◽  
Kelvin Bridgers ◽  
Ernest C. Hammond
Keyword(s):  
The United States ◽  
Test Results ◽  
Long Term Effects ◽  
The Earth ◽  
Long Duration ◽  
Foreign Countries ◽  
Abundant Supply ◽  
Germination And Growth ◽  
To Receive

The SEEDS project was flown in orbit aboard the Long Duration Exposure (LDEF) for nearly six years. During this time in space, the tomato seeds received an enormously abundant supply of cosmic radiation. Upon the return of the LDEF to earth, the SEEDS project was distributed throughout the United States and 30 foreign countries for analysis. The purpose of the experiment was to determine the long term effects of cosmic rays on living tissue. At Morgan, the analysis performed varied from germination and growth rates to electron microscopy and x ray analysis.In analyzing the seeds under the electron microscope, usual observations were performed on the nutritional and epidermic layers of the seed. These layers appeared to be more porous in the space-exposed seeds than in the Earth-based control seeds. This unusual characteristic may explain the increase in the space seeds’ growth pattern. (Several test results show that the space-exposed seeds germinate sooner than the Earth-based seeds. Also, the space exposed seeds are growing at a faster rate.) The porous nutritional region may allow the the seeds to receive necessary nutrients and liquids more readily. Thus, enabling the plant to grow at a much faster rate.

scholarly journals LB-12. SARS-CoV-2 RNA and Antibodies among People Experiencing Homelessness and Staying in Shelters or Outdoor Encampments in Denver, Colorado, May-July 2020

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S849-S850
Author(s):  
David McCormick ◽  
Tracy Scott ◽  
Jesse Chavez ◽  
Kay Wilcox ◽  
Grace E Marx ◽  
...  
Keyword(s):  
Native American ◽  
Venous Blood ◽  
Antibody Test ◽  
Sociodemographic Factors ◽  
Mitigation Strategies ◽  
Homeless Shelters ◽  
Test Results ◽  
Rt Pcr ◽  
Antibody Testing ◽  
Antibody Tests

Abstract Background The COVID-19 pandemic has disproportionately affected people experiencing homelessness (PEH) residing in shelters. Initial and regular testing of PEH in communities with moderate or substantial SARS-CoV-2 transmission may limit spread in shelters. We analyzed factors associated with positive SARS-CoV-2 RNA and antibody tests for PEH staying in shelters or encampments in Denver, Colorado. Methods In May 2020, Denver Public Health collaborated with local leaders to identify 4 homeless shelters and 3 outdoor encampments for voluntary, universal SARS-CoV-2 testing. At each testing event, a short questionnaire including sociodemographic factors and symptoms was administered to PEH who consented to testing. SARS-CoV-2 RNA testing by reverse transcription polymerase chain reaction (RT-PCR) was performed on nasopharyngeal swabs; antibody testing was performed on venous blood samples. PEH reporting a prior positive RT-PCR test were not retested but were eligible for antibody testing. Statistical calculations were performed with an α of 0.05; all tests were two-sided. Results From June 2–July 28, 2020, 931 PEH were approached. A total of 863 RT-PCR tests were performed at 14 testing events, and 334 antibody tests were performed at 5 testing events. Overall, 604 and 259 RT-PCR tests were conducted in 4 shelters and 3 encampments, respectively; 189 and 145 antibody tests were conducted in 3 shelters and 2 encampments, respectively. PEH tested in shelters were older, more often men, less often Native American, and less likely to report COVID-19 symptoms than those tested at encampments (Table 1). Overall, 9% of PEH tested in shelters tested positive for SARS-CoV-2 compared to 3% of PEH tested in encampments (p=0.002); 8% of men had positive RT-PCR results compared to 2% of women (p=0.03) (Table 2). PEH tested at shelters had a higher percentage of detectable SARS-CoV-2 antibodies than those tested in encampments (24% vs 8%, p=0.0002; Table 3). Neither RT-PCR nor antibody test results differed significantly by race or ethnicity. Table 1. Demographics of participants residing in encampments compared with shelters in Denver, Colorado, May-July 2020 (n=931) Table 2. Comparison of participants testing positive or negative for SARS-CoV-2 RT-PCR* by location and demographics, in Denver, Colorado, May-July 2020 Table 3. Comparison of participants testing positive or negative for antibodies against SARS-CoV-2 by location and demographics in Denver, Colorado, May-July 2020 Conclusion A greater percentage of PEH tested positive for both SARS-CoV-2 RNA and antibodies at shelters than encampments, suggesting that continued assessment of mitigation strategies in shelters should be a priority. Disclosures All Authors: No reported disclosures

scholarly journals Preventing Recurrence of Depression: Long-Term Effects of a Randomized Controlled Trial on Cognitive Control Training for Remitted Depressed Patients

2021 ◽  
pp. 216770262097977
Author(s):  
Kristof Hoorelbeke ◽  
Nathan Van den Bergh ◽  
Rudi De Raedt ◽  
Marieke Wichers ◽  
Ernst H. W. Koster
Keyword(s):  
Cognitive Control ◽  
Preventive Intervention ◽  
Controlled Trial ◽  
Self Report ◽  
Long Term Effects ◽  
Depressed Patients ◽  
Cognitive Transfer ◽  
Cognitive Control Training

Previous studies suggest that cognitive control training (CCT) shows potential as a preventive intervention for depression. In this study, the first to examine long-term preventive effects of CCT, we examined effects on (a) task-specific cognitive transfer at 1-year follow-up, (b) recurrence of depression, and (c) functioning over the course of a year. Each of 92 remitted depressed patients were randomly assigned to a CCT condition or an active control condition (ACT). Effects of training were monitored using weekly assessments of emotion regulation, cognitive complaints, depressive symptoms, and resilience (brief weekly questionnaire). At 1-year follow-up, participants completed a structured clinical interview, cognitive transfer task, and questionnaires. We observed task-specific cognitive transfer ( p < .001, d = 1.23) and lower recurrence rates in the CCT condition ( p = .04; odds ratio = 0.38). However, no long-term beneficial effects of training were observed on the weekly ratings of functioning, and groups did not differ in performance on the self-report questionnaires at 1-year follow-up.

scholarly journals The Avon Longitudinal Study of Parents and Children - A resource for COVID-19 research: Home-based antibody testing results, October 2020. An emphasis on self-screening at a population level

2021 ◽  
Vol 6 ◽  
pp. 34
Author(s):  
Kate Northstone ◽  
Daniel Smith ◽  
Claire Bowring ◽  
Amanda Hill ◽  
Richard Hobbs ◽  
...  
Keyword(s):  
Longitudinal Study ◽  
Antibody Test ◽  
Population Level ◽  
Sociodemographic Factors ◽  
Population Based ◽  
Self Report ◽  
Antibody Testing ◽  
Home Based ◽  
Parents And Children ◽  
Avon Longitudinal Study

The Avon Longitudinal Study of Parents and Children (ALSPAC) is a prospective population-based cohort study which recruited pregnant women in 1990-1992 and has followed these women, their partners (Generation 0; G0) and offspring (Generation 1; G1) ever since. The study reacted rapidly to the COVID-19 pandemic, deploying online questionnaires in March and May 2020. Home-based antibody tests and a further questionnaire were sent to 5220 participants during a two-week period of October 2020.  4.2% (n=201) of participants reported a positive antibody test (3.2% G0s [n=81]; 5.6% G1s [n=120]). 43 reported an invalid test, 7 did not complete and 3 did not report their result. Participants uploaded a photo of their test to enable validation: all positive tests, those where the participant could not interpret the result and a 5% random sample were manually checked against photos. We report 92% agreement (kappa=0.853). Positive tests were compared to additional COVID-19 status information: 58 (1.2%) participants reported a previous positive test, 73 (1.5%) reported that COVID-19 was suspected by a doctor, but not tested and 980 (20.4%) believed they had COVID-19 due to their own suspicions.  Of those reporting a positive result on our antibody test, 55 reported that they did not think they had had COVID-19. Results from antibody testing and questionnaire data will be complemented by health record linkage and results of other biological testing– uniting Pillar testing data with home testing and self-report. Data have been released as an update to the original datasets released in July 2020. It comprises: 1) a standard dataset containing all participant responses to all three questionnaires with key sociodemographic factors and 2) as individual participant-specific release files enabling bespoke research across all areas supported by the study. This data note describes the antibody testing, associated questionnaire and the data obtained from it.

scholarly journals Behavioural responses to SARS-CoV-2 antibody testing in England: REACT-2 study

2021 ◽  
Vol 6 ◽  
pp. 203
Author(s):  
Rozlyn Redd ◽  
Emily Cooper ◽  
Christina Atchison ◽  
Isabella Pereira ◽  
Polly Hollings ◽  
...  
Keyword(s):  
Research Programme ◽  
Antibody Test ◽  
Test Results ◽  
Antibody Testing ◽  
Community Based ◽  
Prevalence Studies ◽  
Behavioural Responses ◽  
Self Testing ◽  
Community Transmission

Background:  This study assesses the behavioural responses to SARS-CoV-2 antibody test results as part of the REal-time Assessment of Community Transmission-2 (REACT-2) research programme, a large community-based surveillance study of antibody prevalence in England. Methods: A follow-up survey was conducted six weeks after the SARS-CoV-2 antibody test. The follow-up survey included 4500 people with a positive result and 4039 with a negative result. Reported changes in behaviour were assessed using difference-in-differences models. A nested interview study was conducted with 40 people to explore how they thought through their behavioural decisions. Results: While respondents reduced their protective behaviours over the six weeks, we did not find evidence that positive test results changed participant behaviour trajectories in relation to the number of contacts the respondents had, for leaving the house to go to work, or for leaving the house to socialise in a personal place. The qualitative findings supported these results. Most people did not think that they had changed their behaviours because of their test results, however they did allude to some changes in their attitudes and perceptions around risk, susceptibility, and potential severity of symptoms. Conclusions: We found limited evidence that knowing your antibody status leads to behaviour change in the context of a research study. While this finding should not be generalised to widespread self-testing in other contexts, it is reassuring given the importance of large prevalence studies, and the practicalities of doing these at scale using self-testing with lateral flow immunoassay (LFIA).

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