Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 397
Filter
Add filters

Document Type
Year range
2.
PLoS One ; 17(1): e0261853, 2022.
Article in English | MEDLINE | ID: covidwho-1622346

ABSTRACT

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is used worldwide to test and trace the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). "Extraction-less" or "direct" real time-reverse transcription polymerase chain reaction (RT-PCR) is a transparent and accessible qualitative method for SARS-CoV-2 detection from nasopharyngeal or oral pharyngeal samples with the potential to generate actionable data more quickly, at a lower cost, and with fewer experimental resources than full RT-qPCR. This study engaged 10 global testing sites, including laboratories currently experiencing testing limitations due to reagent or equipment shortages, in an international interlaboratory ring trial. Participating laboratories were provided a common protocol, common reagents, aliquots of identical pooled clinical samples, and purified nucleic acids and used their existing in-house equipment. We observed 100% concordance across laboratories in the correct identification of all positive and negative samples, with highly similar cycle threshold values. The test also performed well when applied to locally collected patient nasopharyngeal samples, provided the viral transport media did not contain charcoal or guanidine, both of which appeared to potently inhibit the RT-PCR reaction. Our results suggest that direct RT-PCR assay methods can be clearly translated across sites utilizing readily available equipment and expertise and are thus a feasible option for more efficient COVID-19 coronavirus disease testing as demanded by the continuing pandemic.


Subject(s)
COVID-19 Testing/methods , COVID-19/diagnosis , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction/methods , Reverse Transcription/genetics , SARS-CoV-2/genetics , COVID-19/virology , Feasibility Studies , Humans , Nasopharynx/virology , Pandemics/prevention & control , Sensitivity and Specificity , Serologic Tests/methods , Specimen Handling/methods
3.
JAMA Netw Open ; 5(1): e2142796, 2022 01 04.
Article in English | MEDLINE | ID: covidwho-1615909

ABSTRACT

Importance: The SARS-CoV-2 viral trajectory has not been well characterized in incident infections. These data are needed to inform natural history, prevention practices, and therapeutic development. Objective: To characterize early SARS-CoV-2 viral RNA load (hereafter referred to as viral load) in individuals with incident infections in association with COVID-19 symptom onset and severity. Design, Setting, and Participants: This prospective cohort study was a secondary data analysis of a remotely conducted study that enrolled 829 asymptomatic community-based participants recently exposed (<96 hours) to persons with SARS-CoV-2 from 41 US states from March 31 to August 21, 2020. Two cohorts were studied: (1) participants who were SARS-CoV-2 negative at baseline and tested positive during study follow-up, and (2) participants who had 2 or more positive swabs during follow-up, regardless of the initial (baseline) swab result. Participants collected daily midturbinate swab samples for SARS-CoV-2 RNA detection and maintained symptom diaries for 14 days. Exposure: Laboratory-confirmed SARS-CoV-2 infection. Main Outcomes and Measures: The observed SARS-CoV-2 viral load among incident infections was summarized, and piecewise linear mixed-effects models were used to estimate the characteristics of viral trajectories in association with COVID-19 symptom onset and severity. Results: A total of 97 participants (55 women [57%]; median age, 37 years [IQR, 27-52 years]) developed incident infections during follow-up. Forty-two participants (43%) had viral shedding for 1 day (median peak viral load cycle threshold [Ct] value, 38.5 [95% CI, 38.3-39.0]), 18 (19%) for 2 to 6 days (median Ct value, 36.7 [95% CI, 30.2-38.1]), and 31 (32%) for 7 days or more (median Ct value, 18.3 [95% CI, 17.4-22.0]). The cycle threshold value has an inverse association with viral load. Six participants (6%) had 1 to 6 days of viral shedding with censored duration. The peak mean (SD) viral load was observed on day 3 of shedding (Ct value, 33.8 [95% CI, 31.9-35.6]). Based on the statistical models fitted to 129 participants (60 men [47%]; median age, 38 years [IQR, 25-54 years]) with 2 or more SARS-CoV-2-positive swab samples, persons reporting moderate or severe symptoms tended to have a higher peak mean viral load than those who were asymptomatic (Ct value, 23.3 [95% CI, 22.6-24.0] vs 30.7 [95% CI, 29.8-31.4]). Mild symptoms generally started within 1 day of peak viral load, and moderate or severe symptoms 2 days after peak viral load. All 535 sequenced samples detected the G614 variant (Wuhan strain). Conclusions and Relevance: This cohort study suggests that having incident SARS-CoV-2 G614 infection was associated with a rapid viral load peak followed by slower decay. COVID-19 symptom onset generally coincided with peak viral load, which correlated positively with symptom severity. This longitudinal evaluation of the SARS-CoV-2 G614 with frequent molecular testing serves as a reference for comparing emergent viral lineages to inform clinical trial designs and public health strategies to contain the spread of the virus.


Subject(s)
COVID-19/virology , RNA, Viral , SARS-CoV-2 , Severity of Illness Index , Viral Load , Virus Shedding , Adult , COVID-19/complications , Female , Humans , Incidence , Longitudinal Studies , Male , Middle Aged , Molecular Diagnostic Techniques/methods , Polymerase Chain Reaction/methods , Prospective Studies , Serologic Tests
4.
BMC Infect Dis ; 22(1): 21, 2022 Jan 04.
Article in English | MEDLINE | ID: covidwho-1606369

ABSTRACT

BACKGROUND: In symptomatic patients, the diagnostic approach of COVID-19 should be holistic. We aimed to evaluate the concordance between RT-PCR and serological tests (IgM/IgG), and identify the factors that best predict mortality (clinical stages or viral load). METHODS: The study included 242 patients referred to the University hospital of Kinshasa for suspected COVID-19, dyspnea or ARDS between June 1st, 2020 and August 02, 2020. Both antibody-SARS-CoV2 IgM/IgG and RT-PCR method were performed on the day of admission to hospital. The clinical stages were established according to the COVID-19 WHO classification. The viral load was expressed by the CtN2 (cycle threshold value of the nucleoproteins) and the CtE (envelope) genes of SARS- CoV-2 detected using GeneXpert. Kappa test and Cox regression were used as appropriate. RESULTS: The GeneXpert was positive in 74 patients (30.6%). Seventy two patients (29.8%) had positive IgM and 34 patients (14.0%) had positive IgG. The combination of RT-PCR and serological tests made it possible to treat 104 patients as having COVID-19, which represented an increase in cases of around 41% compared to the result based on GeneXpert alone. The comparison between the two tests has shown that 57 patients (23.5%) had discordant results. The Kappa coefficient was 0.451 (p < 0.001). We recorded 23 deaths (22.1%) among the COVID-19 patients vs 8 deaths (5.8%) among other patients. The severe-critical clinical stage increased the risk of mortality vs. mild-moderate stage (aHR: 26.8, p < 0.001). The values of CtE and CtN2 did not influence mortality significantly. CONCLUSION: In symptomatic patients, serological tests are a support which makes it possible to refer patients to the dedicated COVID-19 units and treat a greater number of COVID-19 patients. WHO Clinical classification seems to predict mortality better than SARS-Cov2 viral load.


Subject(s)
COVID-19 , RNA, Viral , Antibodies, Viral , Democratic Republic of the Congo/epidemiology , Humans , Immunoglobulin M , SARS-CoV-2 , Serologic Tests
5.
PLoS One ; 16(11): e0259097, 2021.
Article in English | MEDLINE | ID: covidwho-1575776

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a high risk of transmission in close-contact indoor settings, which may include households. Prior studies have found a wide range of household secondary attack rates and may contain biases due to simplifying assumptions about transmission variability and test accuracy. METHODS: We compiled serological SARS-CoV-2 antibody test data and prior SARS-CoV-2 test reporting from members of 9,224 Utah households. We paired these data with a probabilistic model of household importation and transmission. We calculated a maximum likelihood estimate of the importation probability, mean and variability of household transmission probability, and sensitivity and specificity of test data. Given our household transmission estimates, we estimated the threshold of non-household transmission required for epidemic growth in the population. RESULTS: We estimated that individuals in our study households had a 0.41% (95% CI 0.32%- 0.51%) chance of acquiring SARS-CoV-2 infection outside their household. Our household secondary attack rate estimate was 36% (27%- 48%), substantially higher than the crude estimate of 16% unadjusted for imperfect serological test specificity and other factors. We found evidence for high variability in individual transmissibility, with higher probability of no transmissions or many transmissions compared to standard models. With household transmission at our estimates, the average number of non-household transmissions per case must be kept below 0.41 (0.33-0.52) to avoid continued growth of the pandemic in Utah. CONCLUSIONS: Our findings suggest that crude estimates of household secondary attack rate based on serology data without accounting for false positive tests may underestimate the true average transmissibility, even when test specificity is high. Our finding of potential high variability (overdispersion) in transmissibility of infected individuals is consistent with characterizing SARS-CoV-2 transmission being largely driven by superspreading from a minority of infected individuals. Mitigation efforts targeting large households and other locations where many people congregate indoors might curb continued spread of the virus.


Subject(s)
COVID-19/epidemiology , COVID-19/transmission , Family Characteristics , Humans , Incidence , Likelihood Functions , Pandemics/statistics & numerical data , SARS-CoV-2/pathogenicity , Sensitivity and Specificity , Serologic Tests/methods , Utah/epidemiology
6.
Clin Transl Med ; 11(12): e668, 2021 12.
Article in English | MEDLINE | ID: covidwho-1568016

ABSTRACT

The level of postvaccine protection depends on two factors: antibodies and T-cell responses. While the first one is relatively easily measured, the measuring of the second one is a difficult problem. The recent studies indicate that the first one may be a good proxy for the protection, at least for SARS-CoV-2. The massive data currently gathered by both researcher and citizen scientists may be pivotal in confirming this observation, and the collective body of evidence is growing daily. This leads to an acceptance of IgG antibody levels as an accessible biomarker of individual's protection. With enormous and immediate need for assessing patient condition at the point of care, quantitative antibody analysis remains the most effective and efficient way to assess the protection against the disease. Let us not discount importance of reference points in the turmoil of current pandemics.


Subject(s)
Antibodies, Viral/chemistry , Antibodies/chemistry , Biomarkers/metabolism , COVID-19/blood , COVID-19/immunology , Antibody Specificity , Humans , Immune System , Immunity , Immunoglobulin G/metabolism , Intensive Care Units , Pandemics , Point-of-Care Systems , SARS-CoV-2 , Serologic Tests/methods , Serologic Tests/standards , Vaccines
7.
Biosens Bioelectron ; 199: 113866, 2022 Mar 01.
Article in English | MEDLINE | ID: covidwho-1560591

ABSTRACT

The outbreak of COVID-19 pandemics highlighted the need of sensitive, selective, and easy-to-handle biosensing devices. In the contemporary scenario, point-of-care devices for mass testing and infection mapping within a population have proven themselves as of primordial importance. Here, we introduce a graphene-based Electrical-Electrochemical Vertical Device (EEVD) point-of-care biosensor, strategically engineered for serologic COVID-19 diagnosis. EEVD uses serologic IgG quantifications on SARS-CoV-2 Receptor Binding Domain (RBD) bioconjugate immobilized onto device surface. EEVD combines graphene basal plane with high charge carrier mobility, high conductivity, low intrinsic resistance, and interfacial sensitivity to capacitance alterations. EEVD application was carried out in real human serum samples. Since EEVD is a miniaturized device, it requires just 40 µL of sample for a point-of-care COVID-19 infections detection. When compared to serologic assays such ELISA and other immunochromatographic methods, EEVD presents some advantages such as time of analyses (15 min), sample preparation, and a LOD of 1.0 pg mL-1. We glimpse that EEVD meets the principles of robustness and accuracy, desirable analytic parameters for assays destined to pandemics control strategies.


Subject(s)
Biosensing Techniques , COVID-19 , Graphite , Antibodies, Viral , COVID-19 Testing , Humans , Point-of-Care Systems , SARS-CoV-2 , Sensitivity and Specificity , Serologic Tests
8.
Pan Afr Med J ; 38: 55, 2021.
Article in French | MEDLINE | ID: covidwho-1547713

ABSTRACT

The first outbreak of epidemic respiratory disease due to unknown etiology was reported in the Chinese city of Wuhan December 2019. The World Health Organization (WHO) firstly used the term "new coronavirus 2019" on December 29, 2019. This pandemic, which is currently called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a disease caused by SARS-CoV-2. It was subsequently called coronavirus disease 2019 (COVID-19) by the WHO. The purpose of this study was to determine the prevalence of antibodies against SARS-CoV-2 in all employees of the Nouakchott National Hospital Center (CHN). The study was conducted during the week 20/05/2020 to 27/05/2020. It involved 853 employees of all ranks (doctors, pharmacists, nurses, secretaries, security personnel, administrators...) of whom 504 were male and 331 were female, with a sex ratio of 1,52 with an average age of 39 years, ranging from 20 to 60 years. The screening for IgG and IgM antibodies to SARS-CoV-2 was performed using Biotime (Xiamen Biotime Biotechnology Co., Ltd.) immunochromatographic technique. Out of 835 employees included in our study, 14 were positive (1.67%) of whom 12 had IgM and IgG anti-SARS-CoV-2 antibodies and 2 had isolated IgM. Nasopharyngeal swab polymerase chain reaction (PCR) was performed in these 14 patients and was positive in six. While PCR is the gold standard for the diagnosis of SARS-CoV-2, serological tests for SARS-CoV-2 antibodies, in particular rapid tests (RDTs) are a diagnostic complement to COVID-19. They have the advantage of being easy to realize, of being safe both in the laboratories and outside the laboratories. RDTs enabled us to detect asymptomatic SARS-CoV-2 carriers within CHN employees. This allowed for patients management and isolation to protect patients and their environments.


Subject(s)
COVID-19 Testing , COVID-19/diagnosis , Health Personnel , SARS-CoV-2/isolation & purification , Adult , Antibodies, Viral/blood , COVID-19/epidemiology , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Male , Mauritania/epidemiology , Middle Aged , Serologic Tests/methods , Young Adult
9.
J Med Virol ; 93(12): 6794-6797, 2021 12.
Article in English | MEDLINE | ID: covidwho-1544304

ABSTRACT

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected all inhabited continents, and India is currently experiencing a devastating second wave of coronavirus disease-2019 (COVID-19). Here, we examined the duration of clearance of SARS-CoV-2 in respiratory samples from 207 infected cases by real-time reverse-transcription polymerase chain reaction (RT-PCR). A substantial proportion of COVID-19 positive cases with cycle threshold (Ct) values more than or equal to 31 (45.7%) were subsequently tested negative for SARS-CoV-2 RNA within 7 days of initial detection of the viral load. A total of 60% of all the patients with COVID-19, irrespective of their Ct values, cleared SARS-CoV-2 RNA within 14 days of the initial detection. Longitudinal assessment of RT-PCR test results in individuals requiring 15-30 days to clear SARS-CoV-2 RNA showed a significant reduction of the viral load in samples with high or intermediate viral loads (Ct values ≤ 25 and between 26 and 30, respectively) but the follow-up group with low viral RNA (Ct values ≥ 31) exhibited a stable viral load. Together, these results suggest that COVID-19 positive cases with Ct values more than or equal to 31 require reduced duration to clear SARS-CoV-2, and thus, a shorter isolation period for this group might be considered to facilitate adequate space in the COVID Care Centres and reduce the burden on healthcare infrastructure.


Subject(s)
COVID-19/virology , SARS-CoV-2/genetics , Viral Load/genetics , Adult , Aged , COVID-19 Testing/methods , Diagnostic Tests, Routine/methods , Female , Humans , India , Longitudinal Studies , Male , Middle Aged , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Sensitivity and Specificity , Serologic Tests/methods , Young Adult
10.
Ann Intern Med ; 174(2): 287-288, 2021 02.
Article in English | MEDLINE | ID: covidwho-1526981
11.
Transbound Emerg Dis ; 68(6): 3103-3106, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1526430

ABSTRACT

SARS-CoV-2 RT-PCR cycle threshold values from 18,803 cases (2 March-4 October) in Madrid define three stages: (i) initial ten weeks with sustained reduction in viral load (Ct: 23.4-32.3), (ii) stability with low viral loads (Ct: 31.9-35.5) in the next nine weeks and (iii) sudden increase with progressive higher viral loads until reaching stability at high levels in the next twelve weeks, coinciding with an increased percentage of positive cases and reduced median age. These data indicate differential virological/epidemiological patterns between the first and second COVID-19 waves in Madrid.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , COVID-19/veterinary , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Serologic Tests/veterinary , Viral Load/veterinary
12.
BMC Cardiovasc Disord ; 21(1): 528, 2021 11 08.
Article in English | MEDLINE | ID: covidwho-1505900

ABSTRACT

BACKGROUND: The value of mechanical circulatory support (MCS) in cardiogenic shock, especially the combination of the ECMELLA approach (Impella combined with ECMO), remains controversial. CASE PRESENTATION: A previously healthy 33-year-old female patient was submitted to a local emergency department with a flu-like infection and febrile temperatures up to 39 °C. The patient was tested positive for type-A influenza, however negative for SARS-CoV-2. Despite escalated invasive ventilation, refractory hypercapnia (paCO2: 22 kPa) with severe respiratory acidosis (pH: 6.9) and a rising norepinephrine rate occurred within a few hours. Due to a Horovitz-Index < 100, out-of-centre veno-venous extracorporeal membrane oxygenation (vv-ECMO)-implantation was performed. A CT-scan done because of anisocoria revealed an extended dissection of the right vertebral artery. While the initial left ventricular function was normal, echocardiography revealed severe global hypokinesia. After angiographic exclusion of coronary artery stenoses, we geared up LV unloading by additional implantation of an Impella CP and expanded the vv-ECMO to a veno-venous-arterial ECMO (vva-ECMO). Clinically relevant bleeding from the punctured femoral arteries resulted in massive transfusion and was treated by vascular surgery later on. Under continued MCS, LVEF increased to approximately 40% 2 days after the initiation of ECMELLA. After weaning, the Impella CP was explanted at day 5 and the vva-ECMO was removed on day 9, respectively. The patient was discharged in an unaffected neurological condition to rehabilitation 25 days after the initial admission. CONCLUSIONS: This exceptional case exemplifies the importance of aggressive MCS in severe cardiogenic shock, which may be especially promising in younger patients with non-ischaemic cardiomyopathy and potentially reversible causes of cardiogenic shock. This case impressively demonstrates that especially young patients may achieve complete neurological restoration, even though the initial prognosis may appear unfavourable.


Subject(s)
Extracorporeal Membrane Oxygenation/methods , Heart-Assist Devices , Influenza A virus/isolation & purification , Influenza, Human , Respiration, Artificial/methods , Respiratory Insufficiency , Ventricular Dysfunction, Left , Adult , COVID-19/diagnosis , Clinical Deterioration , Critical Care/methods , Echocardiography/methods , Female , Heart Failure/physiopathology , Heart Failure/therapy , Humans , Influenza, Human/complications , Influenza, Human/diagnosis , Influenza, Human/physiopathology , Respiratory Insufficiency/etiology , Respiratory Insufficiency/physiopathology , Respiratory Insufficiency/therapy , SARS-CoV-2 , Serologic Tests/methods , Severity of Illness Index , Shock, Cardiogenic/etiology , Shock, Cardiogenic/physiopathology , Shock, Cardiogenic/therapy , Treatment Outcome , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/therapy
13.
Acta Biomed ; 92(5): e2021311, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1504640

ABSTRACT

BACKGROUND: SARS-CoV-2 infection has become a global public health concern globally. Even though Healthcare Workers (HCWs) are supposedly at increased risk for SARS-CoV-2 infection, to date no pooled evidence has been collected. MATERIALS AND METHODS: We searched online electronic databases (PubMed, Embase, medRxiv.org for pre-prints) for all available contribution (up to May 20, 2019). Two Authors independently screened articles and extracted the data. The pooled prevalence of SARS-CoV-2 was analyzed using the random-effects model. The possible sources of heterogeneity were analyzed through subgroup analysis, and meta-regression. RESULTS: The overall pooled prevalence of SARS-CoV-2 was 3.5% (95%CI 1.8-6.6) for studies based on molecular assays, 5.5% (95%CI 2.1-14.1) for studies based on serological assays, and 6.5% (95%CI 2.5-15.6) for point-of-care capillary blood tests. Among subgroups, serological tests identified higher risk for SARS-CoV-2 seropositivity in physicians than in nurses (OR 1.436, 95%CI 1.026 to 2.008). Regression analysis indicated the possible presence of publication bias only for molecular tests (t -3.3526, p-value 0.002648). CONCLUSIONS: The overall pooled prevalence of SARS-CoV-2 was lower than previously expected, but available studies were affected by significant heterogeneity, and the molecular studies by significant publication bias. Therefore, further high-quality research in the field is warranted.


Subject(s)
COVID-19 , SARS-CoV-2 , Delivery of Health Care , Health Personnel , Humans , Serologic Tests
14.
Euro Surveill ; 26(44)2021 11.
Article in English | MEDLINE | ID: covidwho-1504591

ABSTRACT

IntroductionThe detection of SARS-CoV-2 with rapid diagnostic tests (RDT) has become an important tool to identify infected people and break infection chains. These RDT are usually based on antigen detection in a lateral flow approach.AimWe aimed to establish a comprehensive specimen panel for the decentralised technical evaluation of SARS-CoV-2 antigen rapid diagnostic tests.MethodsWhile for PCR diagnostics the validation of a PCR assay is well established, there is no common validation strategy for antigen tests, including RDT. In this proof-of-principle study we present the establishment of a panel of 50 pooled clinical specimens that cover a SARS-CoV-2 concentration range from 1.1 × 109 to 420 genome copies per mL of specimen. The panel was used to evaluate 31 RDT in up to six laboratories.ResultsOur results show that there is considerable variation in the detection limits and the clinical sensitivity of different RDT. We show that the best RDT can be applied to reliably identify infectious individuals who present with SARS-CoV-2 loads down to 106 genome copies per mL of specimen. For the identification of infected individuals with SARS-CoV-2 loads corresponding to less than 106 genome copies per mL, only three RDT showed a clinical sensitivity of more than 60%.ConclusionsSensitive RDT can be applied to identify infectious individuals with high viral loads but not to identify all infected individuals.


Subject(s)
COVID-19 , SARS-CoV-2 , Antigens, Viral , Diagnostic Tests, Routine , Humans , Sensitivity and Specificity , Serologic Tests
15.
Acta Biomed ; 92(5): e2021208, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1504536

ABSTRACT

Respiratory involvement is the most common clinical manifestation of COVID-19, but neurological symptoms and complications are increasingly being recognized. Seizures and status epilepticus (SE) have been described as possible consequences of hypoxia and metabolic derangements during SARS-CoV-2 infection, direct viral invasion of the central nervous system, or as para or post-infectious complications. Single episodes of SE have been described, occurring during the acute phase of COVID-19 or once the patients have been recovered. Herein, we present the case of a patient with a positive serology test for SARS-CoV-2 (IgG+, IgM-) and recurrent SE occurring within 36 days. Diagnostic work-up ruled out other known causes of SE. A post-COVID-19 infectious inflammatory/immune response is hypothesized as the possible trigger of SE.


Subject(s)
COVID-19 , Status Epilepticus , COVID-19 Testing , Humans , SARS-CoV-2 , Serologic Tests , Status Epilepticus/diagnosis , Status Epilepticus/etiology
16.
J Clin Microbiol ; 59(9): e0055921, 2021 08 18.
Article in English | MEDLINE | ID: covidwho-1501527

ABSTRACT

External quality assessment (EQA) is a key instrument for achieving harmonization, and thus a high quality, of diagnostic procedures. As reliable test results are crucial for accurate assessment of SARS-CoV-2 infection prevalence, vaccine response, and immunity, and thus for successful management of the ongoing COVID-19 pandemic, the Reference Institute for Bioanalytics (RfB) was the first EQA provider to offer an open scheme for anti-SARS-CoV-2 antibody detection. The main objectives of this EQA were (i) to gain insights into the current diagnostic landscape and the performance of serological tests in Europe and (ii) to provide recommendations for diagnostic improvements. Within the EQA, a blinded panel of precharacterized human serum samples with variable anti-SARS-CoV-2 antibody titers was provided for detection of anti-SARS-CoV-2 IgG, IgA, and IgM antibodies. Across the three distribution rounds in 2020, 284 laboratories from 22 countries reported a total of 3,744 results for anti-SARS-CoV-2 antibody detection using more than 24 different assays for IgG. Overall, 97/3,004 results were false for anti-SARS-CoV-2 IgG, 88/248 for IgA, and 34/124 for IgM. Regarding diagnostic sensitivity and specificity, substantial differences were found between the different assays used, as well as between certified and noncertified tests. For cutoff samples, a drop in the diagnostic sensitivity to 46.3% and high interlaboratory variability were observed. In general, this EQA highlights the current variability of anti-SARS-CoV-2 antibody detection, technical limitations with respect to cutoff samples, and the lack of harmonization of testing procedures. Recommendations are provided to help laboratories and manufacturers further improve the quality of anti-SARS-CoV-2 serological diagnostics.


Subject(s)
COVID-19 , Pandemics , Antibodies, Viral , Humans , Immunoglobulin M , SARS-CoV-2 , Sensitivity and Specificity , Serologic Tests
17.
IEEE Rev Biomed Eng ; 14: 30-47, 2021.
Article in English | MEDLINE | ID: covidwho-1501335

ABSTRACT

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). To counter COVID-19 spreading, an infrastructure to provide rapid and thorough molecular diagnostics and serology testing is the cornerstone of outbreak and pandemic management. We hereby review the clinical insights with regard to using molecular tests and immunoassays in the context of COVID-19 management life cycle: the preventive phase, the preparedness phase, the response phase and the recovery phase. The spatial and temporal distribution of viral RNA, antigens and antibodies during human infection is summarized to provide a biological foundation for accurate detection of the disease. We shared the lessons learned and the obstacles encountered during real world high-volume screening programs. Clinical needs are discussed to identify existing technology gaps in these tests. Leverage technologies, such as engineered polymerases, isothermal amplification, and direct amplification from complex matrices may improve the productivity of current infrastructure, while emerging technologies like CRISPR diagnostics, visual end point detection, and PCR free methods for nucleic acid sensing may lead to at-home tests. The lessons learned, and innovations spurred from the COVID-19 pandemic could upgrade our global public health infrastructure to better combat potential outbreaks in the future.


Subject(s)
COVID-19/diagnosis , COVID-19/immunology , Immunoassay/methods , Pathology, Molecular/methods , Animals , Humans , Life Cycle Stages , Pandemics/prevention & control , SARS-CoV-2/immunology , Serologic Tests/methods
18.
Ann Med ; 53(1): 1956-1959, 2021 12.
Article in English | MEDLINE | ID: covidwho-1500884

ABSTRACT

PURPOSE: To determine the seroprevalence of SARS-CoV-2 antibodies in eye healthcare workers (EHCW) in the largest ophthalmology centre in Guatemala and factors associated with antibody positivity. METHODS: We conducted a cross sectional sero-survey in all the staff at the largest ophthalmology centre in Guatemala. Serum samples were collected and tested for total antibodies against SARS-CoV-2 employing Roche Elecsys Anti-SARS-CoV-2 Immunoassay. Results were reported as reactive or non-reactive. According to patient exposure the staff were divided into low risk (technicians, domestic and administrative staff) and high risk (nurses, ophthalmologists, anaesthesiologists, and optometrists). Among those with positive antibodies, they were given a survey that included demographic characteristics, COVID-19 exposure, and related symptomatology. Logistic regression was used to determine the factors associated with antibody positivity. RESULTS: On November 25th a total of 94 healthcare workers were sero-surveyed, mean age was 34.15 years (±8.41), most (57.44%) were females. Seroprevalence was 18%, the majority (77%) were in the low-risk group; while 64% at high-risk, tested negative. Those at low exposure, were five times more likely to have antibodies than those at high exposure (OR:5.69; 95% CI 1.69-19.13). Age and gender were not associated to seropositivity. CONCLUSIONS: We found a similar seroprevalence of SARS-CoV-2 antibodies in EHCW to what has been reported in other healthcare groups. Seropositivity was higher among HCW with fewer patient exposure, hence the probability of community transmission.Key messagesEven though eye healthcare workers are believed to be at higher risk of infection, the prevalence of antibodies against SARS-CoV-2 in this group is comparable to what has been reported previously in other healthcare groups.


Subject(s)
Antibodies, Viral/blood , COVID-19/epidemiology , Health Personnel/statistics & numerical data , Ophthalmologists/statistics & numerical data , SARS-CoV-2/isolation & purification , Adult , Aged , Aged, 80 and over , Biomarkers/blood , COVID-19/diagnosis , COVID-19/transmission , COVID-19/virology , COVID-19 Testing , Cross-Sectional Studies , Female , Guatemala/epidemiology , Humans , Male , Middle Aged , Ophthalmologists/psychology , Ophthalmology , SARS-CoV-2/genetics , Seroepidemiologic Studies , Serologic Tests
19.
Elife ; 92020 06 08.
Article in English | MEDLINE | ID: covidwho-1497819

ABSTRACT

SARS-CoV-2 presents an unprecedented international challenge, but it will not be the last such threat. Here, we argue that the world needs to be much better prepared to rapidly detect, define and defeat future pandemics. We propose that a Global Immunological Observatory and associated developments in systems immunology, therapeutics and vaccine design should be at the heart of this enterprise.


Subject(s)
Communicable Disease Control/organization & administration , Communicable Diseases, Emerging/prevention & control , Coronavirus Infections/epidemiology , Disaster Planning/organization & administration , Global Health , International Cooperation , Pandemics/prevention & control , Pneumonia, Viral/epidemiology , Population Surveillance , Animals , Anti-Infective Agents , COVID-19 , Climate Change , Cohort Studies , Communicable Disease Control/methods , Communicable Diseases, Emerging/diagnosis , Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/immunology , Drug Development , Forecasting , Global Health/trends , Humans , Interdisciplinary Communication , Mass Screening/organization & administration , Models, Animal , Population Surveillance/methods , Serologic Tests , Vaccines , Weather , Zoonoses
SELECTION OF CITATIONS
SEARCH DETAIL
...