scholarly journals SARS-CoV-2 Seroprevalence in Relation to Timing of Symptoms

2020 ◽  
Author(s):  
Joseph Ebinger ◽  
Gregory J. Botwin ◽  
Christine M. Albert ◽  
Mona Alotaibi ◽  
Moshe Arditi ◽  
...  
Keyword(s):  
Antibody Testing ◽  
Antibody Assay ◽  
Igg Antibody ◽  
Symptom Clustering

Of individuals with SARS-CoV-2 IgG antibody testing performed, those who contemporaneously experienced a cluster of Covid-19 relevant symptoms in the 1-2 months preceding the antibody assay were more likely to test positive whereas those who experienced the symptom clustering in the prior 3-6 months were more likely to test negative. These findings suggest that antibodies likely wane over a period of months, particularly in relation to the timing of symptoms.

scholarly journals Kinetics and performance of the Abbott Architect SARS-CoV-2 IgG antibody assay

2020 ◽  
Author(s):  
Fergus Hamilton ◽  
Peter Muir ◽  
Marie Attwood ◽  
Alan Noel ◽  
Barry Vipond ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Clinical Settings ◽  
Antibody Testing ◽  
Antibody Assay ◽  
Igg Antibody ◽  
Negative Results ◽  
Hospitalised Patients ◽  
And Performance ◽  
Negative Controls ◽  
Abbott Architect

ObjectivesTo assess the performance (sensitivity and specificity) of the Abbott Architect SARS-CoV-2 IgG antibody assay across three clinical settings.MethodsAntibody testing was performed on three clinical cohorts of COVID-19 disease: hospitalised patients with PCR confirmation, hospitalized patients with a clinical diagnosis but negative PCR, and symptomatic healthcare workers (HCW’s). Pre-pandemic respiratory infection sera were tested as negative controls. The sensitivity of the assay was calculated at different time points (<5 days, 5-9 days, 10-14 days, 15-19 days, >20 days, >42 days), and compared between cohorts.ResultsPerformance of the Abbot Architect SARS-CoV-2 assay varied significantly between cohorts. For PCR confirmed hospitalised patients (n = 114), early sensitivity was low: <5 days: 44.4% (95%CI: 18.9%-73.3%), 5-9 days: 32.6% (95%CI, 20.5%-47.5%), 10-14 days: 65.2% (95% CI 44.9%-81.2%), 15-20 days: 66.7% (95% CI: 39.1%-86.2%) but by day 20, sensitivity was 100% (95%CI, 86.2-100%).In contrast, 17 out of 114 symptomatic healthcare workers tested at >20 days had negative results, generating a sensitivity of 85.1% (95%CI, 77.4% - 90.5%). All pre-pandemic sera were negative, a specificity of 100%. Seroconversion rates were similar for PCR positive and PCR negative hospitalised cases.ConclusionsThe sensitivity of the Abbot Architect SARS-CoV-2 IgG assay increases over time, with sensitivity not peaking until 20 days post symptoms. Performance varied markedly by setting, with sensitivity significantly worse in symptomatic healthcare workers than in the hospitalised cohort. Clinicians, policymakers, and patients should be aware of the reduced sensitivity in this setting.

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

2020 ◽  
Author(s):  
RIn Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
Measurement System ◽  
False Positive ◽  
Laboratory Testing ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

scholarly journals Regional Difference in Seroprevalence of SARS-CoV-2 in Tokyo: Results from the community point-of-care antibody testing

2020 ◽  
Author(s):  
Morihito Takita ◽  
Tomoko Matsumura ◽  
Kana Yamamoto ◽  
Erika Yamashita ◽  
Kazutaka Hosoda ◽  
...  
Keyword(s):  
Regional Difference ◽  
Point Of Care ◽  
Herd Immunity ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Community Based ◽  
Entire Cohort ◽  
Control And Prevention ◽  
Specific Igg ◽  
Polymerase Chain

AbstractThe serosurvey is an alternative way to know the magnitude of the population infected by coronavirus disease 2019 (COVID-19) since the expansion of capacity of the polymerase chain reaction (PCR) to detect the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was delayed. We herein report seroprevalence of COVID-19 accessed in the two community clinics in Tokyo. The point-of-care immunodiagnostic test was implemented to detect the SARS-CoV-2 specific IgG antibody in the peripheral capillary blood. The overall positive percentage of SARS-CoV-2 IgG antibody is 3.83% (95% confidence interval: 2.76-5.16) for the entire cohort (n =1,071). The central Tokyo of 23 special wards exhibited a significantly higher prevalence compared to the other area of Tokyo (p =0.02, 4.68% [95%CI: 3.08-6.79] versus 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). The seroprevalence of the cohort surveyed in this study is low for herd immunity, which suggests the need for robust disease control and prevention. A community-based approach, rather than state or prefectural levels, is of importance to figure out profiles of the SARS-COV-2 outbreak.

scholarly journals Clinical evaluation of an immunochromatographic IgM/IgG antibody assay and chest computed tomography for the diagnosis of COVID-19

2020 ◽  
Vol 128 ◽  
pp. 104393 ◽  
Author(s):  
Kazuo Imai ◽  
Sakiko Tabata ◽  
Mayu Ikeda ◽  
Sakiko Noguchi ◽  
Yutaro Kitagawa ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Clinical Evaluation ◽  
Antibody Assay ◽  
Igg Antibody ◽  
Chest Computed Tomography

scholarly journals Seroprevalence study of SARS-CoV-2 infection in General Practice in Ireland

BJGP Open ◽  
2021 ◽  
pp. BJGPO.2021.0038
Author(s):  
Michael Edmund O'Callaghan ◽  
Elizabeth Ryan ◽  
Cathal Walsh ◽  
Peter Hayes ◽  
Monica Casey ◽  
...  
Keyword(s):  
General Practice ◽  
Average Length ◽  
Point Of Care ◽  
Antibody Test ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Seroprevalence Study ◽  
History Of ◽  
Pcr Test

Background: SARS-CoV-2 antibody testing in community settings may help us better understand the immune response to this virus and therefore help guide public health efforts. Aim: Conduct a seroprevalence study of IgG antibodies in Irish GP clinics. Design and Setting: Participants were 172 staff and 799 patients of 15 general practices in the Midwest region of Ireland. Methods: This seroprevalence study utilised 2 manufacturers’ point-of-care (POC) SARS-CoV-2 IgM-IgG combined antibody tests, offered to patients and staff in general practice from mid-June to mid-July 2020. Results: Immunoglobulin G (IgG) seroprevalence was 12.6% in patients attending general practice and 11.1% in staff working in general practice, with administrative staff having the lowest seroprevalence at 2.5% and nursing staff having the highest at 17.6%. Previous symptoms suggestive of SARS-CoV-2 and history of a polymerase chain reaction (PCR) test were associated with higher seroprevalence. IgG antibodies were detected in approximately 80% of participants who had a previous PCR-confirmed infection. Average length of time between participants’ positive PCR test and positive IgG antibody test was 83 days. Conclusion: Patients and healthcare staff in general practice in Ireland had relatively high rates of IgG to SARS-CoV-2 compared to the national average at the time (1.7%). Four-fifths of participants with a history of confirmed COVID-19 disease still had detectable antibodies an average of 12 weeks post-infection. While not proof of immunity, SARS-CoV-2 POC testing can be used to estimate IgG seroprevalence in general practice settings.

scholarly journals Validation of dried blood spot sample modifications to two commercially available COVID-19 IgG antibody immunoassays

Bioanalysis ◽  
2020 ◽  
Author(s):  
Theodore T Zava ◽  
David T Zava
Keyword(s):  
Venous Blood ◽  
Dried Blood Spot ◽  
Blood Collection ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Nucleocapsid Proteins ◽  
Antibody Assays ◽  
Finger Stick ◽  
Blood Spot

Aim: Coronavirus disease 2019 antibody testing often relies on venous blood collection, which is labor-intensive, inconvenient and expensive compared with finger-stick capillary dried blood spot (DBS) collection. The purpose of our work was to determine if two commercially available anti-severe acute respiratory syndrome coronavirus 2 enzyme-linked immunosorbent assays for IgG antibodies against spike S1 subunit and nucleocapsid proteins could be validated for use with DBS. Materials & methods: Kit supplied reagents were used to extract DBS, and in-house DBS calibrators were included on every run. Results: Positive/negative concordance between DBS and serum was 100/99.3% for the spike S1 subunit assay and 100/98% for the nucleocapsid assay. Conclusion: Validation of the DBS Coronavirus disease 2019 IgG antibody assays demonstrated that serum and DBS can produce equivalent results with minimal kit modifications.

Sign in / Sign up

Export Citation Format

Share Document