scholarly journals COVID-19 Antibody Testing of Patients Admitted to the ICU by a Novel, Point-of-Care Assay, and the Relationship to Survival

2021 ◽  
Author(s):  
Stacey Casswell ◽  
Ann-Katrin Eriksson ◽  
Lena Moberg ◽  
Miklos Lipcsey ◽  
Michael Hultström ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Point Of Care ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Electrochemical Technology ◽  
Antibody Elisa ◽  
Assay Time ◽  
Highly Correlated ◽  
Point Of Care Assay

Abstract Diagnosing persons infected by COVID-19 is key to the control of the pandemic. It has, however, become increasingly important to identify those who have had the infection by measurement of circulating antibodies against Sars-COV-2 of the IgM and IgG type. In this report we show the development of a rapid and sensitive point-of-care assay for the measurement of IgG antibodies against the two spike proteins, S1 and S2, of the Sars-COV-2 virus.MethodThe AgPlus electrochemical technology was applied and the S1 and S2 proteins were biotinylated and immobilized onto streptavidin coated magnetic particles as the capture component of the assay. The IgG antibodies bound to the particles were detected by anti-human IgG and the signal expressed as nC (nano Coulomb). Assay time was <10 min.ResultsPlasma (n=211) from 117 SARS-Cov-2 PCR positive patients and from 78 persons with samples taken before the COVID-19 pandemic were analysed. The sensitivity and specificity of the assay were 91.9% and 100%, respectively. The assay was highly correlated to a predicate and FDA-approved IgG antibody ELISA (r=0.81). The IgG response was significantly lower in patients who died during their ICU stay.ConclusionsA poor IgG response after a COVID-19 infection is a serious risk factor as to death. A sensitive, rapid and accurate IgG antibody POC assay should be useful in the daily management and evaluation of COVID-19 infected patients.

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 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 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.

scholarly journals Prevalence of SARS-CoV-2 Antibodies Among Healthcare Workers at a Tertiary Academic Hospital in New York City

2020 ◽  
Author(s):  
Mayce Mansour ◽  
Emily Levin ◽  
Kimberly Muellers ◽  
Kimberly Stone ◽  
Rao Mendu ◽  
...  
Keyword(s):  
New York ◽  
Healthcare Workers ◽  
Igg Antibodies ◽  
Academic Hospital ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Frontline Staff ◽  
High Exposure ◽  
Cdc Guidelines ◽  
Viral Illness

Background: SARS-CoV-2 antibody testing is important for understanding immunity prevalence, and may have implications for healthcare workers (HCW) during the SARS-CoV-2 pandemic. Methods: We conducted immunologic testing of healthcare workers to determine the prevalence of SARS-CoV-2 IgG in this population. HCW were advised to wait at least two weeks from time of symptom onset or suspected exposure before undergoing testing. All participants were self-reported asymptomatic for at least three days at the time of testing. Results: Two hundred eighty-five samples were collected from March 24, 2020 to April 4, 2020. The average age of participants was 38 years (range 18-84), and 54% were male. Thirty-three percept tested IgG positive, 3% tested weakly positive, and 64% tested negative. Neither age nor sex was associated with antibody development. Conclusion: Thirty-six percent of HCW had IgG antibodies to SARS-CoV-2, reflecting the high exposure of inpatient and ambulatory frontline staff to this viral illness, most of whom had minimal symptoms and were working in the weeks preceding testing. While we continue to recommend standard protective precautions per CDC guidelines for all HCW, HCW with SARS-CoV-2 IgG may become our safest frontline providers as we learn if our IgG antibodies confer immunity. Knowing IgG antibody status may ease concerns regarding personal risk as this pandemic continues.

scholarly journals Joint Detection of Serum IgM/IgG Antibody Is an Important Key to Clinical Diagnosis of SARS-CoV-2 Infection

2020 ◽  
Vol 2020 ◽  
pp. 1-5 ◽  
Author(s):  
Fang Hu ◽  
Xiaoling Shang ◽  
Meizhou Chen ◽  
Changliang Zhang
Keyword(s):  
Screening Tool ◽  
Control Group ◽  
Joint Detection ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Serum Samples ◽  
Igg Antibody ◽  
Important Diagnostic Tool ◽  
Acid Test ◽  
Combined Detection

Background. This study was aimed to investigate the application of SARS-CoV-2 IgM and IgG antibodies in diagnosis of COVID-19 infection. Method. This study enrolled a total of 178 patients at Huangshi Central Hospital from January to February 2020. Among them, 68 patients were SARS-CoV-2 infected, confirmed with nucleic acid test (NAT) and CT imaging. Nine patients were in the suspected group (NAT negative) with fever and other respiratory symptoms. 101 patients were in the control group with other diseases and negative to SARS-CoV-2 infection. After serum samples were collected, SARS-CoV-2 IgG and IgM antibodies were tested by chemiluminescence immunoassay (CLIA) for all patients. Results. The specificity of serum IgM and IgG antibodies to SARS-CoV-2 was 99.01% (100/101) and 96.04% (97/101), respectively, and the sensitivity was 88.24% (60/68) and 97.06% (66/68), respectively. The combined detection rate of SARS-CoV-2 IgM and IgG antibodies was 98.53% (67/68). Conclusion. Combined detection of serum SARS-CoV-2 IgM and IgG antibodies had better sensitivity compared with single IgM or IgG antibody testing, which can be used as an important diagnostic tool for SARS-CoV-2 infection and a screening tool of potential SARS-CoV-2 carriers in clinics, hospitals, and accredited scientific laboratories.

scholarly journals Self-collection of capillary blood using Tasso-SST devices for Anti-SARS-CoV-2 IgG antibody testing

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0255841
Author(s):  
Tess Hendelman ◽  
Anu Chaudhary ◽  
Angela C. LeClair ◽  
Kimberly van Leuven ◽  
Jacqueline Chee ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Venous Blood ◽  
Epidemiologic Studies ◽  
Capillary Blood ◽  
Blood Collection ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Blood Samples ◽  
Deming Regression

Background Efforts to minimize COVID-19 exposure during the current SARS-CoV-2 pandemic have led to limitations in access to medical care and testing. The Tasso-SST kit includes all of the components necessary for remote, capillary blood self-collection. In this study, we sought to investigate the accuracy and reliability of the Tasso-SST device as a self-collection device for measurement of SARS-CoV-2 IgG antibodies. Methods Capillary blood was obtained via unsupervised and supervised application of the Tasso-SST device, and venous blood was collected by standard venipuncture. Unsupervised self-collected blood samples underwent either extreme summer or winter-simulated shipping conditions prior to testing. Sera obtained by all three methods were tested concurrently using the EuroImmun anti-SARS-CoV-2 S1 IgG assay in a CLIA-certified clinical laboratory. Results Successful Tasso-SST capillary blood collection by unsupervised and supervised administration was completed by 93.4% and 94.5% of participants, respectively. Sera from 56 participants, 55 with documented (PCR+) COVID-19, and 33 healthy controls were then tested for anti-SARS-CoV-2 IgG antibodies. Compared to venous blood results, Tasso-SST-collected (unstressed) and the summer- and winter-stressed blood samples demonstrated Deming regression slopes of 1.00 (95% CI: 0.99–1.02), 1.00 (95% CI: 0.98–1.01), and 0.99 (95% CI: 0.97–1.01), respectively, with an overall accuracy of 98.9%. Conclusions Capillary blood self-collection using the Tasso-SST device had a high success rate. Moreover, excellent concordance was found for anti-SARS-CoV-2 IgG results between Tasso-SST capillary and standard venous blood-derived sera. The Tasso-SST device should enable widespread collection of capillary blood for testing without medical supervision, facilitating epidemiologic studies.

scholarly journals Immunoglobulin (Ig)A seropositivity against SARS-CoV-2 in healthcare workers in Israel, 4 April to 13 July 2020: an observational study

2021 ◽  
Vol 26 (48) ◽  
Author(s):  
Yaniv Lustig ◽  
Carmit Cohen ◽  
Asaf Biber ◽  
Hanaa Jaber ◽  
Yael Becker Ilany ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Significant Risk ◽  
Igg Antibodies ◽  
Exposure Risk ◽  
Serum Samples ◽  
Igg Antibody ◽  
High Exposure ◽  
Iga Antibodies ◽  
Iga Response ◽  
Antibody Elisa

Introduction The COVID-19 pandemic has put healthcare workers (HCW) at significant risk. Presence of antibodies can confirm prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Aim This study investigates the prevalence of IgA and IgG antibodies against SARS-CoV-2 in HCW. Methods Performance of IgA and IgG antibody ELISA assays were initially evaluated in positive and negative SARS-CoV-2 serum samples. IgA and IgG antibodies against SARS-CoV-2 were measured in 428 asymptomatic HCW. We assessed the risk of two groups: HCW with high exposure risk outside work (HROW) residing in areas where COVID-19 was endemic (n = 162) and HCW with high exposure risk at work (HRAW) in a COVID-19 intensive care unit (ICU) (n = 97). Results Sensitivities of 80% and 81.2% and specificities of 97.2% and 98% were observed for IgA and IgG antibodies, respectively. Of the 428 HCW, three were positive for IgG and 27 for IgA. Only 3/27 (11%) IgA-positive HCW had IgG antibodies compared with 50/62 (81%) in a group of previous SARS-CoV-2-PCR-positive individuals. Consecutive samples from IgA-positive HCW demonstrated IgA persistence 18–83 days in 12/20 samples and IgG seroconversion in 1/20 samples. IgA antibodies were present in 8.6% of HROW and 2% of HRAW. Conclusions SARS-CoV-2 exposure may lead to asymptomatic transient IgA response without IgG seroconversion. The significance of these findings needs further study. Out of work exposure is a possible risk of SARS-CoV-2 infection in HCW and infection in HCW can be controlled if adequate protective equipment is implemented.

scholarly journals Dengue Detection: Advances in Diagnostic Tools from Conventional Technology to Point of Care

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 206
Author(s):  
Md Alamgir Kabir ◽  
Hussein Zilouchian ◽  
Muhammad Awais Younas ◽  
Waseem Asghar
Keyword(s):  
Low Income ◽  
Point Of Care ◽  
Structural Evolution ◽  
Diagnostic Tools ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Adequate Treatment ◽  
Conventional Technology ◽  
Vector Borne ◽  
Detection Strategies

The dengue virus (DENV) is a vector-borne flavivirus that infects around 390 million individuals each year with 2.5 billion being in danger. Having access to testing is paramount in preventing future infections and receiving adequate treatment. Currently, there are numerous conventional methods for DENV testing, such as NS1 based antigen testing, IgM/IgG antibody testing, and Polymerase Chain Reaction (PCR). In addition, novel methods are emerging that can cut both cost and time. Such methods can be effective in rural and low-income areas throughout the world. In this paper, we discuss the structural evolution of the virus followed by a comprehensive review of current dengue detection strategies and methods that are being developed or commercialized. We also discuss the state of art biosensing technologies, evaluated their performance and outline strategies to address challenges posed by the disease. Further, we outline future guidelines for the improved usage of diagnostic tools during recurrence or future outbreaks of DENV.

scholarly journals A Microflow Cytometry-Based Agglutination Immunoassay for Point-of-Care Quantitative Detection of SARS-CoV-2 IgM and IgG

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 433
Author(s):  
Jianxi Qu ◽  
Mathieu Chenier ◽  
Yushan Zhang ◽  
Chang-qing Xu
Keyword(s):  
Linear Relationship ◽  
Transit Time ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Quantitative Detection ◽  
Antibody Concentration ◽  
Igg Antibodies ◽  
Assay Time

A rapid, sensitive and simple microflow cytometry-based agglutination immunoassay (MCIA) was developed for point-of-care (POC) quantitative detection of SARS-CoV-2 IgM and IgG antibodies. The antibody concentration was determined by using the transit time of beads aggregates. A linear relationship was established between the average transit time and the concentration of SARS-CoV-2 IgM and IgG, respectively. The limit of detection (LOD) of SARS-CoV-2 IgM and IgG by the MCIA measurement are 0.06 mg/L and 0.10 mg/L, respectively. The 10 µL sample consumption, 30 min assay time and the compact setup make this technique suitable for POC quantitative detection of SARS-CoV-2 antibodies.

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