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

2021 ◽  
Author(s):  
Mehal Churiwal ◽  
Kelly D. Lin ◽  
Salman Khan ◽  
Srijana Chhetri ◽  
Meredith S. Muller ◽  
...  
Keyword(s):  
Cohort Study ◽  
Confidence Interval ◽  
Point Of Care ◽  
Natural Infection ◽  
Field Performance ◽  
Antibody Test ◽  
Asymptomatic Infection ◽  
Point Of Care Test ◽  
Antibody Tests ◽  
Rapid Antibody

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.

scholarly journals Accuracy of Rapid Point-of-Care Antibody Test in patients with suspected or confirmed COVID-19

2020 ◽  
Author(s):  
Rama Vancheeswaran ◽  
Merlin L Willcox ◽  
Beth Stuart ◽  
Matthew Knight ◽  
Hala Kandil ◽  
...  
Keyword(s):  
Point Of Care ◽  
Antibody Test ◽  
Reference Laboratory ◽  
List Type ◽  
Reference Standard ◽  
Point Of Care Test ◽  
History Of ◽  
Antibody Tests ◽  
Composite Reference Standard ◽  
Rapid Antibody

AbstractObjectivesTo assess the real-world diagnostic accuracy of the Livzon point-of-care rapid test for antibodies to SARS-COV-2DesignProspective cohort studySettingDistrict general hospital in EnglandParticipants173 Patients and 224 hospital staff with a history of COVID-19 symptoms, and who underwent PCR and/or reference antibody testing for COVID-19.InterventionsThe Livzon point-of-care (POC) lateral flow immunoassay rapid antibody test (IgM and IgG) was conducted at least 7 days after onset of symptoms and compared to the composite reference standard of PCR for SARS-COV-2 plus reference laboratory testing for antibodies to SARS-COV-2. The SARS-CoV-2 RT-PCR was tested using the available molecular technology during the study time (PHE laboratories, GeneXpert® system Xpert, Xpress SARS-CoV-2 and Source bioscience laboratory). All molecular platforms/assays were PHE/NHSE approved. The reference antibody test was the Elecsys Anti-SARS-CoV-2 assay (Roche diagnostics GmBH).Main outcome measuresSensitivity and specificity of the rapid antibody testResultsThe reference antibody test was positive in 190/268 (70.9%) of participants with a history of symptoms suggestive of COVID-19; in the majority (n=312) the POC test was taken 35 days or more after onset of symptoms. The POC antibody test had an overall sensitivity of 90.1% (292/328, 95% CI 86.3 – 93.1) and specificity of 100% (68/68, 95% CI 94.7 - 100) for confirming prior SARS-CoV-2 infection when compared to the composite reference standard. Sensitivity was 97.8% (89/92, 95% CI 92.3% to 99.7%) in participants who had been admitted to hospital and 84.4% (124/147, 95% CI 77.5% to 89.8%) in those with milder illness who had never been seen in hospital.ConclusionsThe Livzon point-of-care antibody test had comparable sensitivity and specificity to the reference laboratory antibody test, so could be used in clinical settings to support decision-making about patients presenting with more than 10 days of symptoms of COVID-19.What is already known on this topic-Presence of IgG and IgM antibodies to SARS-COV-2 indicates that the person was infected at least 7 days previously and is usually no longer infectious.-Rapid point-of-care tests for antibodies to SARS-COV-2 are widely available, cheap and easy to use-Preliminary evaluations suggested that rapid antibody tests may have insufficient accuracy to be useful for testing individual patients.What this study adds-The rapid point-of-care test for antibodies to SARS-COV-2 was 90.1% sensitive and 100% specific compared to reference standards for prior infection with COVID-19.-This is comparable to reference antibody tests-The point-of-care test evaluated in this study could be used to support clinical decision-making in real time, for patients presenting with symptoms of possible COVID-19 with at least 10 days of symptoms.

scholarly journals Clinical validation of a point-of-care antibody test for COVID-19

2020 ◽  
Author(s):  
Monila Patel ◽  
Yogesh Lakhotia ◽  
Sneha Shah ◽  
Nilay Suthar ◽  
Cherry Shah ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Sensitivity And Specificity ◽  
Significant Role ◽  
Point Of Care ◽  
Antibody Test ◽  
Lateral Flow ◽  
Clinical Validation ◽  
Rt Pcr ◽  
Antibody Tests ◽  
Spike Proteins

AbstractThe objective of this study was to evaluate the performance of a lateral flow antibody test for COVID-19, approved for use in India. Although many point-of-care antibody tests are available globally, they have been subjected to limited clinical validation. This has led to suboptimal outcomes in the field, where antibody tests play a significant role in tracking the immunity of individuals and communities. In this study an antibody test, ImmunoQuick that recognizes antibodies to the Nucleocapsid and Spike proteins of SARS CoV-2 was tested in 100 symptomatic patients with a positive or negative diagnosis of COVID-19, based on RT-PCR results. The overall sensitivity of the test was found to be 86.1% (95% CI: 76.4% to 92.8%) and specificity 100% (95% confidence interval: 73.5% to 100%). The sensitivity reached a peak of 95.7% with samples taken 17 days after the onset of symptoms. Overall, the sensitivity and specificity of the test are sufficient for assessing seroprevalence.

scholarly journals Feasibility and Field Performance of a Simultaneous Syphilis and HIV Point-of-Care Test Based Screening Strategy in at Risk Populations in Edmonton, Canada

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Joshua Bergman ◽  
Jennifer Gratrix ◽  
Sabrina Plitt ◽  
Jayne Fenton ◽  
Chris Archibald ◽  
...  
Keyword(s):  
At Risk ◽  
Predictive Value ◽  
Point Of Care ◽  
Field Performance ◽  
Antibody Test ◽  
Screening Strategy ◽  
Test Characteristics ◽  
Point Of Care Test ◽  
Sti Testing ◽  
At Risk Populations

Few studies have evaluated the feasibility of delivering syphilis point-of-care (POC) testing in outreach (nonclinical) settings in resource rich countries. The objectives of the study were to evaluate the feasibility and diagnostic performance of performing both HIV and syphilis POC testing in outreach settings and to document new cases identified in the study population. 1,265 outreach testing visits were offered syphilis and HIV POC testing and 81.5% (n=1,031) consented to testing. In our population, the SD Bioline 3.0 Syphilis Test had a sensitivity of 85.3% [CI (68.9–95.0)], specificity of 100.0% [CI (99.6–100.0)], positive predictive value (PPV) of 100.0% [CI (88.1–100.0)], and negative predictive value (NPV) of 99.5% [CI (98.9–99.8)]. Test characteristics for the INSTI HIV-1/HIV-2 Antibody Test had a 100.0% sensitivity [CI (39.8–100.00], 99.8 specificity [CI (99.3–100)], 66.7% PPV [CI (22.3–95.7)], and 100.0% NPV [CI (99.6–100.0)]. Four new cases of syphilis and four new HIV cases were diagnosed. In summary, at risk population seeking STI testing found POC tests to be acceptable, the POC tests performed well in outreach settings, and new cases of syphilis and HIV were identified and linked to treatment and care.

Development of a rapid antibody test for point-of-care diagnosis of animal African trypanosomosis

2017 ◽  
Vol 233 ◽  
pp. 32-38 ◽  
Author(s):  
Alain Boulangé ◽  
Davita Pillay ◽  
Cyrille Chevtzoff ◽  
Nicolas Biteau ◽  
Vanessa Comé de Graça ◽  
...  
Keyword(s):  
Point Of Care ◽  
Antibody Test ◽  
Rapid Antibody

scholarly journals Antibody seroprevalence and rate of asymptomatic infections with SARS-CoV-2 in Austrian hospital personnel

2021 ◽  
Author(s):  
Iris Leister ◽  
Elisabeth Ponocny-Seliger ◽  
Herwig Kollaritsch ◽  
Peter Dungel ◽  
Barbara Holzer ◽  
...  
Keyword(s):  
Antibody Test ◽  
World Health ◽  
Antibody Concentration ◽  
Study Cohort ◽  
Living Situation ◽  
Rehabilitation Facilities ◽  
Specific Igg ◽  
Antibody Tests ◽  
Time Point ◽  
Rapid Antibody

AbstractContextOn March 11, the World Health Organization (WHO) announced the current corona virus disease 2019 (COVID-19) outbreak as a pandemic. The first laboratory-confirmed case of COVID-19 in Austria was announced on February 27, 2020. Since then, the incidence of infection followed an exponential increase until a complete lockdown in March 2020. Thereafter easing of restrictions was gradually introduced and until mid-August daily infections remained mostly below 5 per 100.000 population.ObjectivesThe aims of this study are to determine i) how many employees in Austrian trauma hospitals and rehabilitation facilities have virus specific IgG and IgM, and/or neutralizing antibodies against SARS-CoV-2, ii) how many are active virus carriers (symptomatic and asymptomatic) during the study, iii) the antibody decline in seropositive subjects over a period of around six months, and iv) the utility of rapid antibody tests for outpatient screening.Study DesignOpen uncontrolled observational cross-sectional study.Setting/ParticipantsA total of 3301 employees in 11 Austrian trauma hospitals and rehabilitation facilities of the Austrian Social Insurance for Occupational Risks (AUVA) participated in the study.Study Interventions and MeasuresRapid antibody tests for SARS-CoV-2 specific IgG and IgM antibodies, and RT-PCR tests based on oropharyngeal swab samples, as well as laboratory-based antibody tests using ELISA/PRNT were performed. The tests were conducted twice, with an interval of 42.4±7.7 (Min=30, Max=64) days. Additionally, participants filled out a questionnaire including questions related to personal health, traveling activities, living situation, as well as inquiries of symptoms and comorbidities. Antibody positive tested participants were re-tested with ELISA/PRNT tests at a third time point on average 188.0±12.8 days after their initial test.ResultsIn our study cohort, only 27 out of 3301 participants (0.81%) had a positive antibody test at any time point during the study confirmed via neutralization test. Among participants who had positive test results in either of the antibody tests, 50.4% did not report any symptoms consistent with common manifestations of COVID-19 during the study period or within the preceding six weeks. In the group who tested positive during or prior to study inclusion the most common symptoms of an acute viral illness were rhinitis (21.9%), and loss of taste and olfactory sense (21.9%).The rapid antibody test was generally more sensitive based on serum (sensitivity=86.6%) as compared to whole blood (sensitivity=65.4). Concerning both ELISA tests overall the Roche test detected 24 (sensitivity=88.9%) and the Diasorin test 22 positive participants (sensitivity=81.5%).In participants with a positive PRNT, a significant decrease in PRNT concentration from 31.8±22.9 (Md=32.0) at T1 to 26.1±17.6 (Md=21.3) at T2 to 21.4±13.4 (Md=16.0) at T3 (χ2=23.848, df=2, p<0.001) was observed (χ2=23.848, df=2, p<0.001) – with an average time of 42.4±7.7 days between T1 and T2 and 146.9±13.8 days between T2 and T3.ConclusionsDuring the study period (May 11th – December 21th) only 0.81% were tested positive for antibodies in our study cohort. The antibody concentration decreases significantly over time with 14.8% (4 out of 27) losing detectable antibodies.

scholarly journals Frequencies and patterns of microbiology test requests from primary care in Oxfordshire, UK, 2008–2018: a retrospective cohort study of electronic health records to inform point-of-care testing

BMJ Open ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. e048527
Author(s):  
JM Ordóñez-Mena ◽  
Thomas R Fanshawe ◽  
Dona Foster ◽  
Monique Andersson ◽  
Sarah Oakley ◽  
...  
Keyword(s):  
Primary Care ◽  
Cohort Study ◽  
Retrospective Cohort Study ◽  
Retrospective Cohort ◽  
Urine Culture ◽  
Point Of Care ◽  
Temporal Trends ◽  
Secondary Outcome ◽  
Point Of Care Test ◽  
Primary Care Practices

ObjectivesTo inform point-of-care test (POCT) development, we quantified the primary care demand for laboratory microbiology tests by describing their frequencies overall, frequencies of positives, most common organisms identified, temporal trends in testing and patterns of cotesting on the same and subsequent dates.DesignRetrospective cohort study.SettingPrimary care practices in Oxfordshire.Participants393 905 patients (65% female; 49% aged 18–49).Primary and secondary outcome measuresThe frequencies of all microbiology tests requested between 2008 and 2018 were quantified. Patterns of cotesting were investigated with heat maps. All analyses were done overall, by sex and age categories.Results1 596 752 microbiology tests were requested. Urine culture±microscopy was the most common of all tests (n=673 612, 42%), was mainly requested without other tests and was the most common test requested in follow-up within 7 and 14 days. Of all urine cultures, 180 047 (27%) were positive and 172 651 (26%) showed mixed growth, and Escherichia coli was the most prevalent organism (132 277, 73% of positive urine cultures). Antenatal urine cultures and blood tests in pregnancy (hepatitis B, HIV and syphilis) formed a common test combination, consistent with their use in antenatal screening.ConclusionsThe greatest burden of microbiology testing in primary care is attributable to urine culture ± microscopy; genital and routine antenatal urine and blood testing are also significant contributors. Further research should focus on the feasibility and impact of POCTs for these specimen types.

scholarly journals Sensitivity of SARS-CoV-2 antibody tests with late convalescent sera

2021 ◽  
Author(s):  
Judith Kannenberg ◽  
Carolin Schnurra ◽  
Nina Reiners ◽  
Reinhard Henschler ◽  
Raymund Buhmann ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Antibody Test ◽  
Igg Antibody ◽  
Time Points ◽  
Igm Antibodies ◽  
Antibody Assays ◽  
Previous Infection ◽  
Antibody Levels ◽  
Antibody Tests ◽  
Over Time

SARS-CoV-2-specific IgM antibodies wane during the first three months after infection and IgG antibody levels decline. This may limit the ability of antibody tests to identify previous SARS CoV-2 infection at later time points. To examine if the sensitivity of antibody tests falls off, we compared the sensitivity of two nucleoprotein-based antibody tests, the Roche Elecsis II Anti-SARS-CoV-2 and the Abbott SARS-CoV-2 IgG assay and three glycoprotein-based tests, the Abbott SARS-CoV-2 IgG II Quant, Siemens Atellica IM COV2T and Euroimmun SARS-CoV-2 assay with 56 sera obtained 6-8 months after SARS-CoV-2 infection. The sensitivity of the Roche, Abbott SARS-CoV-2 IgG II Quant and Siemens antibody assays was 94.6 % (95% confidence interval (CI) 85.1-98.9 %), 98.2 % (95% CI: 90.4-99.9 %) and 100 % (95% CI: 93.6-100 %). The sensitivity of the N-based Abbott SARS-CoV-2 IgG and the glycoprotein-based Euroimmun ELISA was 48.2 % (95% CI: 34.7-62.0 %) and 83.9 % (95% CI: 71.7-92.4 %). The nucleoprotein-based Roche and the glycoprotein-based Abbott RBD and Siemens tests were more sensitive than the N-based Abbott and the Euroimmun antibody tests (p=0.0001 to p=0.039). The N-based Abbott antibody test was less sensitive 6-8 months than 4-10 weeks after SARS-CoV-2 infection (p = 0.0002). The findings show that most SARS CoV-2 antibody assays correctly identified previous infection 6-8 months after infection. The sensitivity of pan-Ig antibody tests was not reduced at 6-8 months when IgM antibodies have usually disappeared. However, one of the nucleoprotein-based antibody tests significantly lost sensitivity over time.

scholarly journals PREVALENCE AND INCIDENCE OF ANTIBODIES AGAINST SARS-COV-2 AMONG PRIMARY HEALTHCARE PROVIDERS IN BELGIUM DURING ONE YEAR OF THE COVID-19 EPIDEMIC: PROSPECTIVE COHORT STUDY PROTOCOL

2021 ◽  
Author(s):  
Niels Adriaenssens ◽  
Beatrice Scholtes ◽  
Robin Bruyndonckx ◽  
Jan Y Verbakel ◽  
An De Sutter ◽  
...  
Keyword(s):  
Health Care ◽  
Cohort Study ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Point Of Care ◽  
Population Exposure ◽  
Care Providers ◽  
Essential Information ◽  
Point Of Care Test ◽  
Seroprevalence Data

Introduction National severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence data provides essential information about population exposure to the virus and helps predict the future course of the epidemic. Early cohort studies have suggested declines in levels of antibodies in individuals, associated with, for example, illness severity, age and co-morbidities. This protocol focuses on the seroprevalence among primary health care providers (PHCPs) in Belgium. They manage the vast majority of COVID-19 patients in addition to other patients and therefore play an essential role in the efficient organisation of health care. Currently, evidence is lacking on 1. how many PHCPs get infected with SARS-CoV-2 in Belgium, 2. the rate at which this happens, 3. their clinical spectrum, 4. their risk factors, 5. the effectiveness of the measures to prevent infection and 6. the accuracy of the serology-based point-of-care test in a primary care setting. Methods and analysis This study will be set up as a prospective cohort study. General practitioners (GPs) and other PHCPs (working in a GP practice) will be recruited via professional networks and professional media outlets to register online to participate. Registered GPs and other PHCPs will be asked at each testing point (n=9) to perform a capillary blood sample antibody point-of-care test (OrientGene) and complete an online questionnaire. The primary outcomes are the prevalence and incidence of antibodies against SARS-CoV-2 in PHCPs during a 12-month follow-up period. Secondary outcomes include the longevity of antibodies against SARS-CoV-2. Ethics and dissemination: Ethical approval has been granted by the Ethics Committee of the University Hospital Antwerp/University of Antwerp (Belgian registration number: 3002020000237). Alongside journal publications, dissemination activities include the publication of monthly reports to be shared with the participants and the general population through the publicly available website of the Belgian health authorities (Sciensano).

scholarly journals Direct and Indirect Proof of SARS-CoV-2 Infections in Indigenous Wiwa Communities in North-Eastern Colombia—A Cross-Sectional Assessment Providing Preliminary Surveillance Data

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1120
Author(s):  
Gustavo Concha ◽  
Hagen Frickmann ◽  
Anke Oey ◽  
Monika Strengert ◽  
Lothar Kreienbrock ◽  
...  
Keyword(s):  
Point Of Care ◽  
Indigenous Communities ◽  
Serum Samples ◽  
Cross Sectional ◽  
Vaccination Programs ◽  
Point Of Care Test ◽  
North Eastern ◽  
Nasal Swabs ◽  
Study Participants ◽  
Rapid Antibody

To provide initial data on local SARS-CoV-2 epidemiology and spread in indigenous communities in north-eastern Colombia, respiratory swabs and serum samples from volunteers of indigenous communities were examined in March and April 2021. Samples from non-indigenous Colombians from the same villages were included as well. While previous exposure to SARS-CoV-2 was assessed by analysing serum samples for IgG and IgM with a rapid antibody point-of-care-test (POCT), screening for active infections was carried out with an antigen POCT test and real-time PCR from nasal swabs. In 380 indigenous and 72 non-indigenous volunteers, 61 (13.5%) active infections and an additional 113 (25%) previous infections were identified using diagnostic serology and molecular assays. Previous infections were more frequent in non-indigenous volunteers, and relevant associations of clinical features with active or previous SARS-CoV-2 infections were not observed. Symptoms reported were mild to moderate. SARS-CoV-2 was frequent in the assessed Colombian indigenous communities, as 38.5% of the study participants showed signs of exposure to SARS-CoV-2, which confirms the need to include these indigenous communities in screening and vaccination programs.

scholarly journals Antibody Seroprevalence and Rate of Asymptomatic Infections With SARS-CoV-2 in Austrian Hospital Personnel

2021 ◽  
Author(s):  
Iris Leister ◽  
Elisabeth Ponocny-Seliger ◽  
Herwig Kollaritsch ◽  
Peter Dungel ◽  
Barbara Holzer ◽  
...  
Keyword(s):  
Antibody Test ◽  
World Health ◽  
Antibody Concentration ◽  
Study Cohort ◽  
Living Situation ◽  
Rehabilitation Facilities ◽  
Specific Igg ◽  
Antibody Tests ◽  
Time Point ◽  
Rapid Antibody

Abstract Context: On March 11, the World Health Organization (WHO) announced the current corona virus disease 2019 (COVID-19) outbreak as a pandemic. The first laboratory-confirmed case of COVID-19 in Austria was announced on February 27, 2020. Since then, the incidence of infection followed an exponential increase until a complete lockdown in March 2020. Thereafter easing of restrictions was gradually introduced and until mid-August daily infections remained mostly below 5 per 100.000 population. Objectives: The aims of this study are to determine i) how many employees in Austrian trauma hospitals and rehabilitation facilities have virus specific IgG and IgM, and/or neutralizing antibodies against SARS-CoV-2, ii) how many are active virus carriers (symptomatic and asymptomatic) during the study, iii) the antibody decline in seropositive subjects over a period of around six months, and iv) the utility of rapid antibody tests for outpatient screening.Study Design: Open uncontrolled observational cross-sectional study.Setting/Participants: A total of 3301 employees in 11 Austrian trauma hospitals and rehabilitation facilities of the Austrian Social Insurance for Occupational Risks (AUVA) participated in the study.Study Interventions and Measures: Rapid antibody tests for SARS-CoV-2 specific IgG and IgM antibodies, and RT-PCR tests based on oropharyngeal swab samples, as well as laboratory-based antibody tests using ELISA/PRNT were performed. The tests were conducted twice, with an interval of 42.4±7.7 (Min=30, Max=64) days. Additionally, participants filled out a questionnaire including questions related to personal health, traveling activities, living situation, as well as inquiries of symptoms and comorbidities. Antibody positive tested participants were re-tested with ELISA/PRNT tests at a third time point on average 188.0±12.8 days after their initial test.Results: In our study cohort, only 27 out of 3301 participants (0.81%) had a positive antibody test at any time point during the study confirmed via neutralization test. Among participants who had positive test results in either of the antibody tests, 50.4% did not report any symptoms consistent with common manifestations of COVID-19 during the study period or within the preceding six weeks. In the group who tested positive during or prior to study inclusion the most common symptoms of an acute viral illness were rhinitis (21.9%), and loss of taste and olfactory sense (21.9%).The rapid antibody test was generally more sensitive based on serum (sensitivity=86.6%) as compared to whole blood (sensitivity=65.4). Concerning both ELISA tests overall the Roche test detected 24 (sensitivity=88.9%) and the Diasorin test 22 positive participants (sensitivity=81.5%).In participants with a positive PRNT, a significant decrease in PRNT concentration from 31.8±22.9 (Md=32.0) at T1 to 26.1±17.6 (Md=21.3) at T2 to 21.4±13.4 (Md=16.0) at T3 (c2=23.848, df=2, p<0.001) was observed (c2=23.848, df=2, p<0.001) – with an average time of 42.4±7.7 days between T1 and T2 and 146.9±13.8 days between T2 and T3. Conclusions: During the study period (May 11th – December 21th) only 0.81% were tested positive for antibodies in our study cohort. The antibody concentration decreases significantly over time with 14.8% (4 out of 27) losing detectable antibodies.

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