Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 111
Filter
Add filters

Year range
1.
Biochem Med (Zagreb) ; 31(1): 010708, 2021 Feb 15.
Article in English | MEDLINE | ID: covidwho-1084994

ABSTRACT

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serological tests have been suggested as an additional diagnostic tool in highly suspected cases with a negative molecular test and determination of seroprevalence in population. We compared the diagnostic performance of eight commercial serological assays for IgA, IgM, and IgG antibodies to the SARS-CoV-2 virus. Materials and methods: The comparison study was performed on a total of 76 serum samples: 30 SARS-CoV-2 polymerase chain reaction (PCR)-negative and 46 SARS-CoV-2 PCR-positive patients with asymptomatic to severe disease and symptoms duration from 3-30 days. The study included: three rapid lateral flow immunochromatographic assays (LFIC), two enzyme-linked immunosorbent assays (ELISA), and three chemiluminescence immunoassays (CLIA). Results: Agreement between IgM assays were minimal to moderate (kappa 0.26 to 0.63) and for IgG moderate to excellent (kappa 0.72 to 0.92). Sensitivities improved with > 10 days of symptoms and were: 30% to 89% for IgM; 89% to 100% for IgG; 96% for IgA; 100% for IgA/IgM combination; 96% for total antibodies. Overall specificities were: 90% to 100% for IgM; 85% to 100% for IgG; 90% for IgA; 70% for IgA/IgM combination; 100% for total antibodies. Diagnostic accuracy for IgG ELISA and CIA assays were excellent (AUC ≥ 0.90), without significant difference. IgA showed significantly better diagnostic accuracy than IgM (P < 0.001). Conclusion: There is high variability between IgM assays independently of the assay format, while IgG assays showed moderate to perfect agreement. The appropriate time for testing is crucial for the proper immunity investigation.


Subject(s)
/methods , /diagnosis , /virology , Humans , Sensitivity and Specificity , Serologic Tests/methods
3.
Public Health ; 190: 132-134, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-1033173

ABSTRACT

OBJECTIVES: The impact of the COVID-19 pandemic in Scotland has been amongst the most severe in Europe. Serological surveillance is critical to determine the overall extent of infection across populations and to inform the public health response. This study aimed to estimate the proportion of people who have antibodies to SARS-CoV-2 ('seroprevalence') in the general population of Scotland and to see if this changes over time. STUDY DESIGN/METHODS: Between International Organization for Standardization (ISO) week 17 (i.e. week commencing 20th April) and ISO week 25 (week commencing 15 June), 4751 residual blood samples were obtained from regional biochemistry laboratories in six participating regional health authority areas covering approximately 75% of the Scottish population. Samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies using the LIAISON®SARS-CoV-2 S1/S2 IgG assay (DiaSorin, Italy). Seroprevalence rates were adjusted for the sensitivity and specificity of the assay using Bayesian methods. RESULTS: The combined adjusted seroprevalence across the study period was 4.3% (95% confidence interval: 4.2%-4.5%). The proportion varied each week between 1.9% and 6.8% with no difference in antibody positivity by age, sex or geographical area. CONCLUSIONS: At the end of the first wave of the COVID-19 pandemic, only a small fraction of the Scottish population had antibodies to SARS-CoV-2. Control of COVID-19 requires the ability to detect asymptomatic and mild infections that would otherwise remain undetected through existing surveillance systems. This is important to determine the true number of infections within the general population which, in turn, can help to understand transmission, inform control measures and provide a denominator for the estimation of severity measures such as the proportion of infected people who have been hospitalised and/or have died.


Subject(s)
Antibodies, Viral/blood , Coronavirus Infections/virology , Immunoglobulin G/blood , Pandemics , Population Surveillance/methods , /immunology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Middle Aged , Prevalence , Public Health Surveillance , Scotland/epidemiology , Seroepidemiologic Studies , Serologic Tests/methods
5.
Viruses ; 13(1)2020 12 29.
Article in English | MEDLINE | ID: covidwho-1004760

ABSTRACT

Diagnostic tests have been considered as the main alternative for the control of coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as a correct diagnosis allows for decision making when facing the disease, particularly as there is a lack of effective therapeutic protocols and vaccines. Thus, in this review, we summarized the main diagnostic approaches currently available for the diagnosis of SARS-CoV-2 infection in humans based on studies available in article databases. The tests can be organized into two main categories: nucleic acid-based tests, recommended for the initial detection of the virus, and serological tests, recommended for assessing the disease progression. The studies have shown that the performance of diagnostic methods depends on different factors, such as the type of samples and the characteristics of each assay. It was identified that the positivity of the tests is mainly related to the onset of symptoms. We also observed that point-of-care diagnoses are considered as one of the main trends in this area, due to the low-cost and simplicity of the assay; however, the analytical performance must be critically analyzed. Thus, the COVID-19 pandemic has highlighted the critical role of diagnostic technologies in the control of infectious diseases.


Subject(s)
/diagnosis , Clinical Laboratory Techniques/methods , Molecular Diagnostic Techniques/methods , Serologic Tests/methods , Enzyme-Linked Immunosorbent Assay , Humans , Pandemics , Polymerase Chain Reaction/methods
6.
Int Immunopharmacol ; 92: 107330, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-988111

ABSTRACT

In addition to molecular testing, there is evolving interest for anti-SARS-CoV-2 antibodies serologic assays. Majority of them focus on IgM/IgG despite IgA important role in mucosal immunity. A simultaneous anti-SARS-CoV-2 IgA/IgG/IgM immunoassay, performed on an automated instrument by ELISA kit coated with native inactivated SARS-CoV-2, was detected on two control groups (negative swab healthcare workers; pre-pandemic healthy or with other viral infections individuals) and on two COVID-19 patient groups (early and late infection). Specificities were 100% in all groups, indicating no cross-reactivity with other infectious or pre-pandemic sera. Sensitivities were 94% in early infection group and 97% in total positive patient group, reaching 100% in late infection group. To our knowledge, this is the first technique based on native SARS-CoV-2. It is able to identify more positive samples than kits using recombinant antigens, therefore virus native epitopes as well as simultaneous anti-SARS-CoV-2 IgA/IgM/IgG detection could help to contain COVID-19 spreading.


Subject(s)
Antibodies, Viral/blood , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Antibodies, Viral/immunology , Antibody Specificity , /virology , Humans , Immunoassay/methods , Sensitivity and Specificity , Serologic Tests/methods
7.
Ann Clin Lab Sci ; 50(6): 852-854, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-984501

ABSTRACT

Due to the COVID-19 pandemic, the Food and Drug Administration issued an Emergency Use Authorization to permit developers of certain serological tests to market their product prior to a comprehensive review. Nonetheless, the reliability of these assays is of great importance in order to be useful as a tool in estimating the relative proportions of different populations that have been exposed to SARS-CoV-2. We provide a sampling of 145 individuals from an ambulatory setting simultaneously tested with a qualitative point of care rapid finger prick Lateral Wave® IgM and IgG assay and a sample for the Mayo Clinic enzyme linked immunosorbent assay (ELISA) IgM/IgG antibody assay. Significant discrepancies did exist between the purported antibody responses as demonstrated by each assay.


Subject(s)
Antibodies, Viral/blood , Enzyme-Linked Immunosorbent Assay/methods , Immunoglobulin G/blood , Immunoglobulin M/blood , Point-of-Care Systems/standards , /isolation & purification , Biological Assay , /virology , Humans , Serologic Tests/methods
8.
J Med Internet Res ; 22(10): e19152, 2020 10 30.
Article in English | MEDLINE | ID: covidwho-982931

ABSTRACT

BACKGROUND: Real-time polymerase chain reaction (RT-PCR) testing for the identification of viral nucleic acid is the current standard for the diagnosis of SARS-CoV-2 infection, but technical issues limit its utilization for large-scale screening. Serological immunoglobulin M (IgM)/IgG testing has been proposed as a useful tool for detecting SARS-CoV-2 exposure. OBJECTIVE: The objective of our study was to compare the results of the rapid serological VivaDiag test for SARS-CoV-2-related IgM/IgG detection with those of the standard RT-PCR laboratory test for identifying SARS-CoV-2 nucleic acid. METHODS: We simultaneously performed both serological and molecular tests with a consecutive series of 191 symptomatic patients. The results provided by a new rapid serological colorimetric test for analyzing IgM/IgG expression were compared with those of RT-PCR testing for SARS-CoV-2 detection. RESULTS: Of the 191 subjects, 70 (36.6%) tested positive for SARS-CoV-2 based on RT-PCR results, while 34 (17.3%) tested positive based on serological IgM/IgG expression. Additionally, 13 (6.8%) subjects tested positive based on serological test results, but also tested negative based on RT-PCR results. The rapid serological test had a sensitivity of 30% and a specificity of 89% compared to the standard RT-PCR assay. Interestingly, the performance of both assays improved 8 days after symptom appearance. After 10 days had passed since symptom appearance, the predictive value of the rapid serological test was higher than that of the standard molecular assay (proportion of positive results: 40% vs 20%). Multivariate analysis showed that age >58 years (P<.01) and period of >15 days after symptom onset (P<.02) were significant and independent factors associated with serological test positivity. CONCLUSIONS: The rapid serological test analyzed in this study seems limited in terms of usefulness when diagnosing SARS-CoV-2 infection. However, it may be useful for providing relevant information on people's immunoreaction to COVID-19 exposure.


Subject(s)
Betacoronavirus/immunology , Betacoronavirus/isolation & purification , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/virology , Real-Time Polymerase Chain Reaction/methods , Serologic Tests/methods , Betacoronavirus/genetics , Coronavirus Infections/immunology , Female , Humans , Immunoglobulin G/analysis , Immunoglobulin G/immunology , Immunoglobulin M/analysis , Immunoglobulin M/immunology , Male , Middle Aged , Pandemics , Pneumonia, Viral/immunology , Sensitivity and Specificity
9.
Cochrane Database Syst Rev ; 6: CD013652, 2020 06 25.
Article in English | MEDLINE | ID: covidwho-981322

ABSTRACT

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus and resulting COVID-19 pandemic present important diagnostic challenges. Several diagnostic strategies are available to identify current infection, rule out infection, identify people in need of care escalation, or to test for past infection and immune response. Serology tests to detect the presence of antibodies to SARS-CoV-2 aim to identify previous SARS-CoV-2 infection, and may help to confirm the presence of current infection. OBJECTIVES: To assess the diagnostic accuracy of antibody tests to determine if a person presenting in the community or in primary or secondary care has SARS-CoV-2 infection, or has previously had SARS-CoV-2 infection, and the accuracy of antibody tests for use in seroprevalence surveys. SEARCH METHODS: We undertook electronic searches in the Cochrane COVID-19 Study Register and the COVID-19 Living Evidence Database from the University of Bern, which is updated daily with published articles from PubMed and Embase and with preprints from medRxiv and bioRxiv. In addition, we checked repositories of COVID-19 publications. We did not apply any language restrictions. We conducted searches for this review iteration up to 27 April 2020. SELECTION CRITERIA: We included test accuracy studies of any design that evaluated antibody tests (including enzyme-linked immunosorbent assays, chemiluminescence immunoassays, and lateral flow assays) in people suspected of current or previous SARS-CoV-2 infection, or where tests were used to screen for infection. We also included studies of people either known to have, or not to have SARS-CoV-2 infection. We included all reference standards to define the presence or absence of SARS-CoV-2 (including reverse transcription polymerase chain reaction tests (RT-PCR) and clinical diagnostic criteria). DATA COLLECTION AND ANALYSIS: We assessed possible bias and applicability of the studies using the QUADAS-2 tool. We extracted 2x2 contingency table data and present sensitivity and specificity for each antibody (or combination of antibodies) using paired forest plots. We pooled data using random-effects logistic regression where appropriate, stratifying by time since post-symptom onset. We tabulated available data by test manufacturer. We have presented uncertainty in estimates of sensitivity and specificity using 95% confidence intervals (CIs). MAIN RESULTS: We included 57 publications reporting on a total of 54 study cohorts with 15,976 samples, of which 8526 were from cases of SARS-CoV-2 infection. Studies were conducted in Asia (n = 38), Europe (n = 15), and the USA and China (n = 1). We identified data from 25 commercial tests and numerous in-house assays, a small fraction of the 279 antibody assays listed by the Foundation for Innovative Diagnostics. More than half (n = 28) of the studies included were only available as preprints. We had concerns about risk of bias and applicability. Common issues were use of multi-group designs (n = 29), inclusion of only COVID-19 cases (n = 19), lack of blinding of the index test (n = 49) and reference standard (n = 29), differential verification (n = 22), and the lack of clarity about participant numbers, characteristics and study exclusions (n = 47). Most studies (n = 44) only included people hospitalised due to suspected or confirmed COVID-19 infection. There were no studies exclusively in asymptomatic participants. Two-thirds of the studies (n = 33) defined COVID-19 cases based on RT-PCR results alone, ignoring the potential for false-negative RT-PCR results. We observed evidence of selective publication of study findings through omission of the identity of tests (n = 5). We observed substantial heterogeneity in sensitivities of IgA, IgM and IgG antibodies, or combinations thereof, for results aggregated across different time periods post-symptom onset (range 0% to 100% for all target antibodies). We thus based the main results of the review on the 38 studies that stratified results by time since symptom onset. The numbers of individuals contributing data within each study each week are small and are usually not based on tracking the same groups of patients over time. Pooled results for IgG, IgM, IgA, total antibodies and IgG/IgM all showed low sensitivity during the first week since onset of symptoms (all less than 30.1%), rising in the second week and reaching their highest values in the third week. The combination of IgG/IgM had a sensitivity of 30.1% (95% CI 21.4 to 40.7) for 1 to 7 days, 72.2% (95% CI 63.5 to 79.5) for 8 to 14 days, 91.4% (95% CI 87.0 to 94.4) for 15 to 21 days. Estimates of accuracy beyond three weeks are based on smaller sample sizes and fewer studies. For 21 to 35 days, pooled sensitivities for IgG/IgM were 96.0% (95% CI 90.6 to 98.3). There are insufficient studies to estimate sensitivity of tests beyond 35 days post-symptom onset. Summary specificities (provided in 35 studies) exceeded 98% for all target antibodies with confidence intervals no more than 2 percentage points wide. False-positive results were more common where COVID-19 had been suspected and ruled out, but numbers were small and the difference was within the range expected by chance. Assuming a prevalence of 50%, a value considered possible in healthcare workers who have suffered respiratory symptoms, we would anticipate that 43 (28 to 65) would be missed and 7 (3 to 14) would be falsely positive in 1000 people undergoing IgG/IgM testing at days 15 to 21 post-symptom onset. At a prevalence of 20%, a likely value in surveys in high-risk settings, 17 (11 to 26) would be missed per 1000 people tested and 10 (5 to 22) would be falsely positive. At a lower prevalence of 5%, a likely value in national surveys, 4 (3 to 7) would be missed per 1000 tested, and 12 (6 to 27) would be falsely positive. Analyses showed small differences in sensitivity between assay type, but methodological concerns and sparse data prevent comparisons between test brands. AUTHORS' CONCLUSIONS: The sensitivity of antibody tests is too low in the first week since symptom onset to have a primary role for the diagnosis of COVID-19, but they may still have a role complementing other testing in individuals presenting later, when RT-PCR tests are negative, or are not done. Antibody tests are likely to have a useful role for detecting previous SARS-CoV-2 infection if used 15 or more days after the onset of symptoms. However, the duration of antibody rises is currently unknown, and we found very little data beyond 35 days post-symptom onset. We are therefore uncertain about the utility of these tests for seroprevalence surveys for public health management purposes. Concerns about high risk of bias and applicability make it likely that the accuracy of tests when used in clinical care will be lower than reported in the included studies. Sensitivity has mainly been evaluated in hospitalised patients, so it is unclear whether the tests are able to detect lower antibody levels likely seen with milder and asymptomatic COVID-19 disease. The design, execution and reporting of studies of the accuracy of COVID-19 tests requires considerable improvement. Studies must report data on sensitivity disaggregated by time since onset of symptoms. COVID-19-positive cases who are RT-PCR-negative should be included as well as those confirmed RT-PCR, in accordance with the World Health Organization (WHO) and China National Health Commission of the People's Republic of China (CDC) case definitions. We were only able to obtain data from a small proportion of available tests, and action is needed to ensure that all results of test evaluations are available in the public domain to prevent selective reporting. This is a fast-moving field and we plan ongoing updates of this living systematic review.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Antibody Specificity , Coronavirus Infections/epidemiology , False Negative Reactions , False Positive Reactions , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Pandemics , Pneumonia, Viral/epidemiology , Reference Standards , Reverse Transcriptase Polymerase Chain Reaction/standards , Reverse Transcriptase Polymerase Chain Reaction/statistics & numerical data , Selection Bias , Sensitivity and Specificity , Serologic Tests/methods , Serologic Tests/standards
11.
Biomed Res Int ; 2020: 9878453, 2020.
Article in English | MEDLINE | ID: covidwho-934159

ABSTRACT

Knowledge of the sensitivities of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody tests beyond 35 days after the clinical onset of COVID-19 is insufficient. We aimed to describe positivity rate of SARS-CoV-2 assays employing three different measurement principles over a prolonged period. Two hundred sixty-eight samples from 180 symptomatic patients with COVID-19 and a reverse transcription polymerase chain reaction (RT-PCR) test followed by serological investigation of SARS-CoV-2 antibodies were included. We conducted three chemiluminescence (including electrochemiluminescence assay (ECLIA)), four enzyme-linked immunosorbent assay (ELISA), and one lateral flow immunoassay (LFIA) test formats. Positivity rates, as well as positive (PPVs) and negative predictive values (NPVs), were calculated for each week after the first clinical presentation for COVID-19. Furthermore, combinations of tests were assessed within an orthogonal testing approach employing two independent assays and predictive values were calculated. Heat maps were constructed to graphically illustrate operational test characteristics. During a follow-up period of more than 9 weeks, chemiluminescence assays and one ELISA IgG test showed stable positivity rates after the third week. With the exception of ECLIA, the PPVs of the other chemiluminescence assays were ≥95% for COVID-19 only after the second week. ELISA and LFIA had somewhat lower PPVs. IgM exhibited insufficient predictive characteristics. An orthogonal testing approach provided PPVs ≥ 95% for patients with a moderate pretest probability (e.g., symptomatic patients), even for tests with a low single test performance. After the second week, NPVs of all but IgM assays were ≥95% for patients with low to moderate pretest probability. The confirmation of negative results using an orthogonal algorithm with another assay provided lower NPVs than the single assays. When interpreting results from SARS-CoV-2 tests, the pretest probability, time of blood draw, and assay characteristics must be carefully considered. An orthogonal testing approach increases the accuracy of positive, but not negative, predictions.


Subject(s)
Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Antibodies, Viral/blood , Clinical Laboratory Techniques/methods , Coronavirus Infections/blood , Coronavirus Infections/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Female , Humans , Immunoassay/methods , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/diagnosis , Reverse Transcriptase Polymerase Chain Reaction/methods , Sensitivity and Specificity , Serologic Tests/methods
12.
Clin Lab ; 66(11)2020 Nov 01.
Article in English | MEDLINE | ID: covidwho-922944

ABSTRACT

BACKGROUND: In December 2019, a novel coronavirus (SARS-CoV-2) causing symptomatic illness (COVID-19) occurred in Wuhan, China. Travel-associated cases were reported in many other countries leading to epidemic transmission. The number of cases has increased rapidly but laboratory diagnosis is limited. METHODS: We collected samples from two groups of patients diagnosed with COVID-19 for experiments. In one group, 63 serum samples were analyzed IgG and IgM antibodies by enzyme-linked immunosorbent assay (ELISA) and 35 healthy serum samples were served as controls. In the other group, 91 plasma samples were analyzed by colloidal gold-immunochromatographic assay (GICA) for IgG and IgM antibodies and 35 healthy plasma samples were served as controls. Throat swab samples for nucleic acids retest were collected from 81/91 of these participant. RESULTS: The sensitivity of the combined ELISA IgM and IgG detection was 55/63 (87.3%). Sensitivity of the com-bined GICA IgM and IgG detection was 75/91 (82.4%). Both methods were negative for healthy controls and had a specificity of 100%. In 81 cases, the follow up throat swab samples were retested by RT-PCR, showing that 42 cases were positive. The sensitivity was 51.9% (42/81). The area under the receiver operating characteristic (ROC) curve for IgG (AUC(IgG)) was 0.934. The area under the ROC curve for IgM (AUC(IgM)) was 0.812. The area under the ROC curve for IgG + IgM (AUC(IgG+IgM)) was 0.983. CONCLUSIONS: The serological test of SARS-CoV-2 can be used as an important supplement to the existing RT-PCR test for the specific and rapid diagnosis of COVID-19. AUC(IgG) > AUC(IgM) indicates that IgG has better classification performance than IgM. AUC(IgG + IgM) > AUC(IgG) indicates that the combination of IgG and IgM has better classification performance than IgG alone.


Subject(s)
Betacoronavirus/isolation & purification , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Pneumonia, Viral/diagnosis , Serologic Tests/methods , Betacoronavirus/immunology , Case-Control Studies , Coronavirus Infections/blood , Coronavirus Infections/immunology , Humans , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/immunology , Sensitivity and Specificity
13.
Clin Infect Dis ; 71(15): 825-832, 2020 07 28.
Article in English | MEDLINE | ID: covidwho-908926

ABSTRACT

BACKGROUND: On 7 February 2020, French Health authorities were informed of a confirmed case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in an Englishman infected in Singapore who had recently stayed in a chalet in the French Alps. We conducted an investigation to identify secondary cases and interrupt transmission. METHODS: We defined as a confirmed case a person linked to the chalet with a positive reverse-transcription polymerase chain reaction sample for SARS-CoV-2. RESULTS: The index case stayed 4 days in the chalet with 10 English tourists and a family of 5 French residents; SARS-CoV-2 was detected in 5 individuals in France, 6 in England (including the index case), and 1 in Spain (overall attack rate in the chalet: 75%). One pediatric case, with picornavirus and influenza A coinfection, visited 3 different schools while symptomatic. One case was asymptomatic, with similar viral load as that of a symptomatic case. Seven days after the first cases were diagnosed, 1 tertiary case was detected in a symptomatic patient with from the chalet a positive endotracheal aspirate; all previous and concurrent nasopharyngeal specimens were negative. Additionally, 172 contacts were monitored; all contacts tested for SARS-CoV-2 (N = 73) were negative. CONCLUSIONS: The occurrence in this cluster of 1 asymptomatic case with similar viral load as a symptomatic patient suggests transmission potential of asymptomatic individuals. The fact that an infected child did not transmit the disease despite close interactions within schools suggests potential different transmission dynamics in children. Finally, the dissociation between upper and lower respiratory tract results underscores the need for close monitoring of the clinical evolution of suspected cases of coronavirus disease 2019.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/virology , Pneumonia, Viral/virology , Aged , Aged, 80 and over , Cluster Analysis , Female , France , Humans , Middle Aged , Pandemics , Retrospective Studies , Serologic Tests/methods
14.
Front Immunol ; 11: 570927, 2020.
Article in English | MEDLINE | ID: covidwho-895301

ABSTRACT

The emergence and rapid spread of SARS-CoV-2 in December 2019 has brought the world to a standstill. While less pathogenic than the 2002-2003 SARS-CoV, this novel betacoronavirus presents a global threat due to its high transmission rate, ability to invade multiple tissues, and ability to trigger immunological hyperactivation. The identification of the animal reservoir and intermediate host were important steps toward slowing the spread of disease, and its genetic similarity to SARS-CoV has helped to determine pathogenesis and direct treatment strategies. The exponential increase in cases has necessitated fast and reliable testing procedures. Although RT-PCR remains the gold standard, it is a time-consuming procedure, paving the way for newer techniques such as serologic tests and enzyme immunoassays. Various clinical trials using broad antiviral agents in addition to novel medications have produced controversial results; however, the advancement of immunotherapy, particularly monoclonal antibodies and immune modulators is showing great promise in clinical trials. Non-orthodox medications such as anti-malarials have been tested in multiple institutions but definitive conclusions are yet to be made. Adjuvant therapies have also proven to be effective in decreasing mortality in the disease course. While no formal guidelines have been established, the multitude of ongoing clinical trials as a result of unprecedented access to research data brings us closer to halting the SARS-CoV-2 pandemic.


Subject(s)
Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Clinical Laboratory Techniques/methods , Coronavirus Infections , Pandemics , Pneumonia, Viral , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/therapeutic use , Alanine/analogs & derivatives , Alanine/therapeutic use , Antibodies, Monoclonal/therapeutic use , Antibodies, Viral/therapeutic use , Betacoronavirus/genetics , Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Coronavirus Infections/pathology , Coronavirus Infections/therapy , Disease Reservoirs/virology , Drug Repositioning/methods , Humans , Immunoenzyme Techniques , Immunotherapy , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/diagnosis , Pneumonia, Viral/pathology , Pneumonia, Viral/therapy , Receptors, Virus/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Serologic Tests/methods , Spike Glycoprotein, Coronavirus/metabolism
15.
PLoS One ; 15(10): e0240395, 2020.
Article in English | MEDLINE | ID: covidwho-890178

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an emerging threat worldwide. This study aims to assess the serologic profiles and time kinetics of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients with COVID-19 using two immunoassays. METHODS: A total of 97 samples serially collected from 17 patients with COVID-19 and 137 negative control samples were analyzed for IgM and IgG against SARS-CoV-2 using the AFIAS COVID-19 Ab (Boditech Med Inc., Chuncheon, Republic of Korea) and the EDI™ Novel Coronavirus COVID-19 ELISA Kit (Epitope Diagnostics, Inc., San Diego, CA). RESULTS: With both assays, IgM and IgG rapidly increased after 7 days post symptom onset (PSO). IgM antibody levels reached a peak at 15-35 d PSO and gradually decreased. IgG levels gradually increased and remained at similar levels after 22-35 d. The diagnostic sensitivities of IgM/IgG for ≤14d PSO were 21.4%/35.7~57.1% and increased to 41.2~52.9%/88.2~94.1% at >14 d PSO with specificities of 98.5%/94.2% for AFIAS COVID-19 Ab and 100.0%/96.4% for EDI™ Novel Coronavirus COVID-19 ELISA Kit. Among 137 negative controls, 12 samples (8.8%) showed positive or indeterminate results. CONCLUSIONS: The antibody kinetics against SARS-CoV-2 are similar to common findings of acute viral infectious diseases. Antibody testing is useful for ruling out SARS-CoV-2 infection after 14 d PSO, detecting past infection, and epidemiologic surveys.


Subject(s)
Antibodies, Viral/blood , Antibodies, Viral/immunology , Betacoronavirus/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Serologic Tests/methods , Adult , Aged , Aged, 80 and over , Coronavirus Infections/virology , Enzyme-Linked Immunosorbent Assay/methods , Female , Fluorescent Antibody Technique/methods , Follow-Up Studies , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Kinetics , Male , Middle Aged , Pandemics , Pneumonia, Viral/virology , Sensitivity and Specificity , Young Adult
16.
Am J Case Rep ; 21: e927812, 2020 Oct 03.
Article in English | MEDLINE | ID: covidwho-854653

ABSTRACT

BACKGROUND This is a case report of an immunocompromised patient with a history of non-Hodgkin lymphoma and persistent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection who was seronegative and successfully treated with convalescent plasma. CASE REPORT A 63-year-old woman with a past medical history of non-Hodgkin lymphoma in remission while on maintenance therapy with the anti-CD20 monoclonal antibody, obinutuzumab, tested positive for SARS-CoV-2 via nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) testing over 12 weeks and persistently tested seronegative for immunoglobulin G (IgG) antibodies using SARS-CoV-2 IgG chemiluminescent microparticle immunoassay technology. During this time, the patient experienced waxing and waning of symptoms, which included fever, myalgia, and non-productive cough, but never acquired severe respiratory distress. She was admitted to our hospital on illness day 88, and her symptoms resolved after the administration of convalescent plasma. CONCLUSIONS As the understanding of the pathogenesis of SARS-CoV-2 continues to evolve, we can currently only speculate about the occurrence of chronic infection vs. reinfection. The protective role of antibodies and their longevity against SARS-CoV-2 remain unclear. Since humoral immunity has an integral role in SARS-CoV-2 infection, various phase 3 vaccine trials are underway. In the context of this pandemic, the present case demonstrates the challenges in our understanding of testing and treating immunocompromised patients.


Subject(s)
Antibodies, Monoclonal, Humanized/administration & dosage , Coronavirus Infections/complications , Coronavirus Infections/diagnosis , Immunocompromised Host , Lymphoma, Non-Hodgkin/immunology , Pneumonia, Viral/complications , Pneumonia, Viral/diagnosis , Antineoplastic Agents, Immunological/administration & dosage , Clinical Laboratory Techniques/methods , Coronavirus Infections/therapy , Female , Follow-Up Studies , Humans , Immunization, Passive/methods , Lymphoma, Non-Hodgkin/complications , Lymphoma, Non-Hodgkin/drug therapy , Middle Aged , Pandemics , Real-Time Polymerase Chain Reaction/methods , Serologic Tests/methods , Severity of Illness Index , Treatment Outcome
17.
BMJ Open ; 10(10): e040036, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-841445

ABSTRACT

INTRODUCTION: As of 30 April 2020, the novel betacoronavirus SARS-CoV-2 had infected more than 3 172 000 individuals, killing over 224 000 people and spreading to more than 200 countries. Italy was the most affected country in Europe and the third most affected in the world in terms of the number of cases. Therefore, the aims of this study are: (1) to estimate the prevalence of asymptomatic SARS-CoV-2-positive individuals among the general population of Verona; (2) to assess the accuracy (sensitivity, specificity and predictive values) of an ELISA serological test for the screening of SARS-CoV-2. METHODS AND ANALYSIS: The study will be carried out on a random sample of subjects aged at least 10 years from the general population of Verona. Participants will undergo the measurement of vital parameters (oxygen saturation measured by oximeter, respiratory rate and body temperature detected by laser thermometer), the administration of a COVID-19-related symptoms questionnaire, the collection of a blood sample and a nasopharyngeal swab. Our evaluation will include the statistical technique of Latent Class Analysis, which will be the basis for the estimation of prevalence. ETHICS AND DISSEMINATION: The study protocol has been approved by the Ethics Committee of Verona and Rovigo provinces on 15 April 2020 (internal protocol number 2641CESC). The study results will be submitted for publication in international, peer-reviewed journals and the complete dataset will be deposited in a public repository. Most relevant data will be made available to policy-makers as well as disseminated to stakeholders and to the community.


Subject(s)
Asymptomatic Infections/epidemiology , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Mass Screening/methods , Pandemics , Pneumonia, Viral/diagnosis , Pneumonia, Viral/epidemiology , Serologic Tests/methods , Adult , Antibodies, Viral/blood , Betacoronavirus , Child , Clinical Protocols , Coronavirus Infections/blood , Coronavirus Infections/virology , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay/methods , Humans , Immunoglobulins/blood , Italy , Pneumonia, Viral/blood , Pneumonia, Viral/virology , Prevalence , Research Design , Sensitivity and Specificity , Severe Acute Respiratory Syndrome
19.
Clin Chem Lab Med ; 58(12): 2001-2008, 2020 10 07.
Article in English | MEDLINE | ID: covidwho-835982

ABSTRACT

Serological testing for the detection of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is emerging as an important component of the clinical management of patients with coronavirus disease 2019 (COVID-19) as well as the epidemiological assessment of SARS-CoV-2 exposure worldwide. In addition to molecular testing for the detection of SARS-CoV-2 infection, clinical laboratories have also needed to increase testing capacity to include serological evaluation of patients with suspected or known COVID-19. While regulatory approved serological immunoassays are now widely available from diagnostic manufacturers globally, there is significant debate regarding the clinical utility of these tests, as well as their clinical and analytical performance requirements prior to application. This document by the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) Taskforce on COVID-19 provides interim guidance on: (A) clinical indications and target populations, (B) assay selection, (C) assay evaluation, and (D) test interpretation and limitations for serological testing of antibodies against SARS-CoV-2 infection. These evidence-based recommendations will provide practical guidance to clinical laboratories in the selection, verification, and implementation of serological assays and are of the utmost importance as we expand our pandemic response from initial case tracing and containment to mitigation strategies to minimize resurgence and further morbidity and mortality.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , International Agencies , Practice Guidelines as Topic , Serologic Tests/methods , Antibodies, Viral/immunology , Humans
20.
PLoS One ; 15(10): e0240076, 2020.
Article in English | MEDLINE | ID: covidwho-835957

ABSTRACT

Public health emergency of SARS-CoV-2 has facilitated diagnostic testing as a related medical countermeasure against COVID-19 outbreak. Numerous serologic antibody tests have become available through an expedited federal emergency use only process. This paper highlights the analytical characteristic of an ELISA based assay by AnshLabs and three random access immunoassay (RAIA) by DiaSorin, Roche, and Abbott that have been approved for emergency use authorization (EUA), at a tertiary academic center in a low disease-prevalence area. The AnshLabs gave higher estimates of sero-prevalence, over the three RAIA methods. For positive results, AnshLabs had 93.3% and 100% agreement with DiaSorin or Abbott and Roche respectively. For negative results, AnshLabs had 74.3% and 78.3% agreement with DiaSorin and Roche or Abbott respectively. All discrepant samples that were positive by AnshLabs and negative by RAIA tested positive by all-in-one step SARS-CoV-2 Total (COV2T) assay performed on the automated Siemens Advia Centaur XPT analyzer. None of these methods, however, are useful in early diagnosis of SARS-CoV-2.


Subject(s)
Antibodies, Viral/immunology , Betacoronavirus/immunology , Clinical Laboratory Techniques/methods , Coronavirus Infections/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , Pneumonia, Viral/diagnosis , Serologic Tests/methods , Coronavirus Infections/virology , Diagnostic Tests, Routine , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Nucleocapsid Proteins/immunology , Pandemics , Pneumonia, Viral/virology , Reverse Transcriptase Polymerase Chain Reaction/methods , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus/immunology
SELECTION OF CITATIONS
SEARCH DETAIL