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

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

Wellcome Open Research ◽

10.12688/wellcomeopenres.16662.1 ◽

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

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

Public Health Reports ◽

10.1177/00333549211018190 ◽

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.

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

Journal of Emergency Medicine Trauma and Acute Care ◽

10.5339/jemtac.2021.qhc.5 ◽

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.

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Determination of Sero-Prevalence of SARS-CoV-2 antibody among immunized individuals with Covid-19 vaccine in a tertiary center, Nepal

International Journal of Multidisciplinary Research and Growth Evaluation ◽

10.54660/anfo.2021.3.1.6 ◽

2022 ◽

pp. 62-65

Author(s):

Gopal Lama ◽

Lilee Shrestha ◽

Nabin Karmacharya ◽

Rekha Manandhar ◽

Runa Jha

Keyword(s):

Antibody Titer ◽

Serum Antibody ◽

Antibody Test ◽

Cross Sectional Study ◽

Antibody Testing ◽

Cross Sectional ◽

Robust Immune Response ◽

Tertiary Center

Background: Coronavirus Disease 2019 (covid-19) is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). People who are infected with SARS-CoV-2 or are vaccinated with covid-19 vaccines are supposed to develop immunoglobulins and these immune responses in human body will determine the efficacy of the vaccines as well as help to discover new therapeutic options. Methods: A cross-sectional study conducted between April to June, 2021, assessing serum antibody titer from participants who had taken the first dose of covishieldTM vaccine (naïve as well as prior covid-19 infected individuals). Antibody testing was carried out with Roche Elecsys Anti-SARS-CoV-2 S electrochemiluminescence immunoassay on Roche Cobas e 601 module. Twenty-eight of these participants had follow up repeat antibody test after second dose of vaccine. Results: A total of 122 participants with the first dose of CovishieldTM vaccine were all tested seropositive, antibody titer ranging from minimum of 2.95 U/mL to maximum 2500 U/mL. Average antibody titer was 308.9 U/mL for naive cohort and 1604 U/mL for prior covid-19 infection. In twenty-eight participants who had antibody titer measured after 1 month of second dose, average titer was 1459.7 U/mL for naïve cohort and 1803.4 U/mL for prior covid-19 infected individuals, which was statistically significant compared to antibody response after the first dose. Conclusions: Antibody responses against SARS-CoV-2 following immunization was 100%, with significant development after second dose in naïve population while robust immune response was present after first dose in prior SARS-CoV-2 infected individuals.

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

10.1101/2020.12.07.20245183 ◽

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.

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A survey of outpatient Internal Medicine clinician perceptions of diagnostic error

Diagnosis ◽

10.1515/dx-2019-0070 ◽

2020 ◽

Vol 7 (2) ◽

pp. 107-114

Author(s):

John C. Matulis ◽

Susan N. Kok ◽

Eugene C. Dankbar ◽

Andrew J. Majka

Keyword(s):

Internal Medicine ◽

Diagnostic Error ◽

System Level ◽

Secondary Outcome ◽

Care Practice ◽

Test Results ◽

Community Based ◽

Referral Practice ◽

Question Survey

AbstractBackgroundLittle is known about how practicing Internal Medicine (IM) clinicians perceive diagnostic error, and whether perceptions are in agreement with the published literature.MethodsA 16-question survey was administered across two IM practices: one a referral practice providing care for patients traveling for a second opinion and the other a traditional community-based primary care practice. Our aim was to identify individual- and system-level factors contributing to diagnostic error (primary outcome) and conditions at greatest risk of diagnostic error (secondary outcome).ResultsSixty-five of 125 clinicians surveyed (51%) responded. The most commonly perceived individual factors contributing to diagnostic error included atypical patient presentations (83%), failure to consider other diagnoses (63%) and inadequate follow-up of test results (53%). The most commonly cited system-level factors included cognitive burden created by the volume of data in the electronic health record (EHR) (68%), lack of time to think (64%) and systems that do not support collaboration (40%). Conditions felt to be at greatest risk of diagnostic error included cancer (46%), pulmonary embolism (43%) and infection (37%).ConclusionsInadequate clinician time and sub-optimal patient and test follow-up are perceived by IM clinicians to be persistent contributors to diagnostic error. Clinician perceptions of conditions at greatest risk of diagnostic error may differ from the published literature.

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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

Open Forum Infectious Diseases ◽

10.1093/ofid/ofaa515.1909 ◽

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

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The effect of antibody test result knowledge on transmission reducing behaviours

10.31234/osf.io/unm7r ◽

2021 ◽

Author(s):

Alison Morrow ◽

Sara Jenks ◽

Becky Batchelor

Keyword(s):

Health Beliefs ◽

Self Efficacy ◽

Health Belief ◽

Antibody Test ◽

Perceived Benefits ◽

Antibody Testing ◽

The Face ◽

Cues To Action ◽

Belief Model

This study explored the effect knowledge of antibody status has on compliance with transmission reducing behaviours (TRBs). Participants (n=82) comprised of NHS Lothian staff and individuals enrolled in the BioResource study with community diagnosed and treated SARS-CoV-2 infections. They completed a baseline health beliefs questionnaire, provided blood samples for antibody testing and received result 2-4 weeks later. Around 2-4 weeks later, participants completed follow-up health belief questionnaires. The questionnaire was designed based on the constructs of the Health Belief Model, the most prominent framework for understanding why individuals may or may not act in the face of a threat. Fifty-six participants completed the follow-up health belief questionnaires. Knowledge of antibody status did not affect compliance with TRBs. Increased perceived benefits, cues to action and self-efficacy, and decreased perceived barriers, to comply with TRBs was significantly associated with higher compliance. No significant correlation was found between measures of susceptibility or severity and compliance with TRBs. Interventions to increase perceived benefits, cues to action and self-efficacy, and decrease barriers, to engaging in TRBs should be explored.

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Celiac Disease: Are Endomysial Antibody Test Results Being Used Appropriately?

Clinical Chemistry ◽

10.1373/clinchem.2007.090308 ◽

2007 ◽

Vol 53 (10) ◽

pp. 1775-1781 ◽

Cited By ~ 3

Author(s):

Kelly E McGowan ◽

Martha E Lyon ◽

Steven D Loken ◽

J Decker Butzner

Keyword(s):

Celiac Disease ◽

Antibody Test ◽

Gluten Free Diet ◽

Intestinal Biopsy ◽

Gluten Free ◽

Test Results ◽

Male And Female ◽

Serum Iga ◽

Number Of Patients

Abstract Background: The aim of this study was to retrospectively examine how positive IgA-endomysial antibody (EMA) test results for celiac disease were being interpreted and acted on by physicians in the Calgary Health Region. Methods: We reviewed consecutive EMA test results, with or without a serum IgA, obtained during a 17-month period. Seropositive tests were cross-referenced to the surgical database to determine the number of patients who underwent intestinal biopsy and the results of the biopsy. We sent questionnaires to the ordering physicians of positive tests with no record of intestinal biopsy. Results: Among 11 716 EMA tests in 9533 patients, 349 results were positive in 313 patients (3%). Intestinal biopsies were performed in 218 (70%) of the seropositive patients; 194 of them were diagnostic of celiac disease. Celiac disease was also found in 10 EMA-negative patients. Of the 109 positive tests performed in 95 patients with no subsequent biopsy, 28 had appropriate indications to not perform a biopsy; the most common reason being that the test had been ordered to follow up on a previous biopsy-proven diagnosis of celiac disease (n = 21). For 33 other positive test results without a subsequent biopsy, management appeared to be inappropriate, most commonly (n = 21) because of a recommendation to follow a gluten-free diet despite lack of a tissue diagnosis of celiac disease. For the remaining 48 positive EMA results, administrative issues prevented evaluation (n = 19), the patients refused further evaluation (n = 11), or physician surveys were not returned (n = 18). Conclusions: Celiac disease affected 2% of patients, with a similar prevalence in male and female patients. Most positive EMA tests (77%) were appropriately managed by physicians. Beginning a gluten-free diet without biopsy or failing to follow up on a positive EMA test remain common errors of management.

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