Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 78
Filter
Add filters

Document Type
Year range
1.
Saudi Med J ; 42(7): 742-749, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1513260

ABSTRACT

OBJECTIVES: To identify the prevalence of COVID-19 antibodies among operating room and critical care staff. METHODS: In this cross-sectional study, we recruited 319 Healthcare workers employed in the operation theater and intensive care unit of King Abdulaziz University Hospital (KAUH), a tertiary teaching hospital in Jeddah, Saudi Arabia between August 9, 2020 and November 2, 2020. All participants completed a 20-item questionnaire on demographic data and COVID-19 risk factors and provided blood samples. Antibody testing was performed using an in-house enzyme immunoassay and microneutralization test. RESULTS: Of the 319 participants, 39 had detectable COVID-19 antibodies. Five of them had never experienced any symptoms suggestive of COVID-19, and only 19 were previously diagnosed with COVID-19. The odds of developing COVID-19 or having corresponding antibodies increased if participants experienced COVID-19 symptoms (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.2-7.5) or reported contact with an infected family member (OR, 5.3; 95% CI, 2.5-11.2). Disease acquisition was not associated with employment in the ICU and involvement in the intubation of or close contact with COVID-19 patients. Of the 19 previously diagnosed participants, 6 did not possess any detectable COVID-19 antibodies. CONCLUSIONS: Healthcare workers may have undiagnosed COVID-19, and those previously infected may not have long-lasting immunity. Therefore, hospitals must continue to uphold strict infection control during the COVID-19 pandemic.


Subject(s)
COVID-19 Serological Testing/statistics & numerical data , COVID-19/diagnosis , Health Personnel , SARS-CoV-2/isolation & purification , Adult , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/epidemiology , Critical Care , Cross-Sectional Studies , Enzyme-Linked Immunosorbent Assay , Female , Hospitals, Teaching , Humans , Infectious Disease Transmission, Patient-to-Professional , Male , Middle Aged , Operating Rooms , Pandemics , Prevalence , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Saudi Arabia/epidemiology
2.
PLoS One ; 16(10): e0259070, 2021.
Article in English | MEDLINE | ID: covidwho-1484863

ABSTRACT

Public health surveillance systems likely underestimate the true prevalence and incidence of SARS-CoV-2 infection due to limited access to testing and the high proportion of subclinical infections in community-based settings. This ongoing prospective, observational study aimed to generate accurate estimates of the prevalence and incidence of, and risk factors for, SARS-CoV-2 infection among residents of a central North Carolina county. From this cohort, we collected survey data and nasal swabs every two weeks and venous blood specimens every month. Nasal swabs were tested for the presence of SARS-CoV-2 virus (evidence of active infection), and serum specimens for SARS-CoV-2-specific antibodies (evidence of prior infection). As of June 23, 2021, we have enrolled a total of 153 participants from a county with an estimated 76,285 total residents. The anticipated study duration is at least 24 months, pending the evolution of the pandemic. Study data are being shared on a monthly basis with North Carolina state health authorities and future analyses aim to compare study data to state-wide metrics over time. Overall, the use of a probability-based sampling design and a well-characterized cohort will enable collection of critical data that can be used in planning and policy decisions for North Carolina and may be informative for other states with similar demographic characteristics.


Subject(s)
COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , COVID-19/epidemiology , Population Surveillance , Adult , COVID-19/diagnosis , COVID-19 Nucleic Acid Testing/methods , COVID-19 Serological Testing/methods , Cohort Studies , Demography/statistics & numerical data , Female , Humans , Male , North Carolina , Practice Guidelines as Topic , Risk
4.
Nat Commun ; 12(1): 5621, 2021 09 23.
Article in English | MEDLINE | ID: covidwho-1437680

ABSTRACT

Although serological studies have shown that antibodies against SARS-CoV-2 play an important role in protection against (re)infection, the dynamics of mucosal antibodies during primary infection and their potential impact on viral load and the resolution of disease symptoms remain unclear. During the first pandemic wave, we assessed the longitudinal nasal antibody response in index cases with mild COVID-19 and their household contacts. Nasal and serum antibody responses were analysed for up to nine months. Higher nasal receptor binding domain and spike protein-specific antibody levels at study inclusion were associated with lower viral load. Older age was correlated with more frequent COVID-19 related symptoms. Receptor binding domain and spike protein-specific mucosal antibodies were associated with the resolution of systemic, but not respiratory symptoms. Finally, receptor binding domain and spike protein-specific mucosal antibodies remained elevated up to nine months after symptom onset.


Subject(s)
Antibodies, Neutralizing/analysis , Antibodies, Viral/analysis , COVID-19/diagnosis , Nasal Mucosa/metabolism , SARS-CoV-2/immunology , Adolescent , Adult , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/metabolism , Antibodies, Viral/immunology , Antibodies, Viral/metabolism , COVID-19/blood , COVID-19/immunology , COVID-19/virology , COVID-19 Serological Testing/statistics & numerical data , Child , Humans , Immunity, Mucosal , Longitudinal Studies , Male , Middle Aged , Nasal Mucosa/immunology , Nasal Mucosa/virology , Severity of Illness Index , Viral Load , Young Adult
5.
Microbiol Spectr ; 9(2): e0108221, 2021 10 31.
Article in English | MEDLINE | ID: covidwho-1434911

ABSTRACT

We describe the results of testing health care workers, from a tertiary care hospital in Japan that had experienced a coronavirus disease 2019 (COVID-19) outbreak during the first peak of the pandemic, for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody seroconversion. Using two chemiluminescent immunoassays and a confirmatory surrogate virus neutralization test, serological testing revealed that a surprising 42% of overlooked COVID-19 diagnoses (27/64 cases) occurred when case detection relied solely on SARS-CoV-2 nucleic acid amplification testing (NAAT). Our results suggest that the NAAT-positive population is only the tip of the iceberg and the portion left undetected might potentially have led to silent transmissions and triggered the spread. A questionnaire-based risk assessment was further indicative of exposures to specific aerosol-generating procedures (i.e., noninvasive ventilation and airway suctioning) having mediated transmission and served as the origins of the outbreak. Our observations are supportive of a multitiered testing approach, including the use of serological diagnostics, in order to accomplish exhaustive case detection along the whole COVID-19 spectrum. IMPORTANCE We describe the results of testing frontline health care workers, from a hospital in Japan that had experienced a COVID-19 outbreak, for SARS-CoV-2-specific antibodies. Antibody testing revealed that a surprising 42% of overlooked COVID-19 diagnoses occurred when case detection relied solely on PCR-based viral detection. COVID-19 clusters have been continuously striking the health care system around the globe. Our findings illustrate that such clusters are lined with hidden infections eluding detection with diagnostic PCR and that the cluster burden in total is more immense than actually recognized. The mainstays of diagnosing infectious diseases, including COVID-19, generally consist of two approaches, one aiming to detect molecular fragments of the invading pathogen and the other to measure immune responses of the host. Considering antibody testing as one trustworthy option to test our way through the pandemic can aid in the exhaustive case detection of COVID-19 patients with variable presentations.


Subject(s)
COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , COVID-19/epidemiology , Cross Infection/epidemiology , Health Personnel/statistics & numerical data , SARS-CoV-2/isolation & purification , Adult , Antibodies, Viral/blood , Cost of Illness , Female , Humans , Immunoglobulin G/blood , Japan/epidemiology , Male , Neutralization Tests , Occupational Exposure , Risk Assessment , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Seroconversion , Surveys and Questionnaires , Tertiary Care Centers
6.
Mol Syst Biol ; 17(9): e10243, 2021 09.
Article in English | MEDLINE | ID: covidwho-1395372

ABSTRACT

Systems serology provides a broad view of humoral immunity by profiling both the antigen-binding and Fc properties of antibodies. These studies contain structured biophysical profiling across disease-relevant antigen targets, alongside additional measurements made for single antigens or in an antigen-generic manner. Identifying patterns in these measurements helps guide vaccine and therapeutic antibody development, improve our understanding of diseases, and discover conserved regulatory mechanisms. Here, we report that coupled matrix-tensor factorization (CMTF) can reduce these data into consistent patterns by recognizing the intrinsic structure of these data. We use measurements from two previous studies of HIV- and SARS-CoV-2-infected subjects as examples. CMTF outperforms standard methods like principal components analysis in the extent of data reduction while maintaining equivalent prediction of immune functional responses and disease status. Under CMTF, model interpretation improves through effective data reduction, separation of the Fc and antigen-binding effects, and recognition of consistent patterns across individual measurements. Data reduction also helps make prediction models more replicable. Therefore, we propose that CMTF is an effective general strategy for data exploration in systems serology.


Subject(s)
AIDS Serodiagnosis , COVID-19 Serological Testing , COVID-19/immunology , Data Interpretation, Statistical , HIV Infections/immunology , AIDS Serodiagnosis/methods , AIDS Serodiagnosis/statistics & numerical data , Antibodies, Viral/blood , Antibodies, Viral/metabolism , COVID-19 Serological Testing/methods , COVID-19 Serological Testing/statistics & numerical data , Humans , Immunity, Humoral , Killer Cells, Natural/immunology , Logistic Models , Receptors, Fc/immunology , Receptors, IgG/immunology
7.
MMWR Morb Mortal Wkly Rep ; 70(33): 1120-1123, 2021 Aug 20.
Article in English | MEDLINE | ID: covidwho-1365866

ABSTRACT

Controlling the spread of SARS-CoV-2, the virus that causes COVID-19, in Alaska is challenging. Alaska includes many remote and isolated villages with small populations (ranging from 15 to >1,000 persons) that are accessible only by air from larger communities. Until rapid point-of-care testing became widely available, a primary challenge in the diagnosis of COVID-19 in rural Alaska was slow turnaround times for SARS-CoV-2 test results, attributable to the need to transport specimens to testing facilities. To provide more timely test results and isolation of cases, the Yukon Kuskokwim Health Corporation (YKHC) introduced Abbott BinaxNOW COVID-19 Ag rapid antigen test (BinaxNOW) on November 9, 2020, in the rural Yukon-Kuskokwim Delta region in southwestern Alaska. To evaluate the impact of implementing antigen testing, YKHC reviewed the results of 54,981 antigen and molecular tests for SARS-CoV-2 performed in the Yukon-Kuskokwim Delta during September 15, 2020-March 1, 2021. Introduction of rapid, point-of-care testing was followed by a more than threefold reduction in daily SARS-CoV-2 case rates during approximately 1 month before the introduction of COVID-19 vaccination. The median turnaround time for SARS-CoV-2 test results decreased by >30%, from 6.4 days during September 15-November 8, 2020, to 4.4 days during November 9, 2020-March 1, 2021 (p<0.001). Daily incidence decreased 65% after the introduction of BinaxNOW, from 342 cases per 100,000 population during the week of November 9 to 119 during the week of December 13 (p<0.001). These findings indicate that point-of-care rapid antigen testing can be a valuable tool in reducing turnaround times in rural communities where local access to laboratory-based nucleic acid amplification testing (NAAT) is not readily available and could thereby reduce transmission by facilitating rapid isolation of infected persons, contact tracing, and implementation of local mitigation strategies.


Subject(s)
COVID-19 Serological Testing/statistics & numerical data , COVID-19/diagnosis , Rural Population , SARS-CoV-2/isolation & purification , Alaska/epidemiology , Antigens, Viral , COVID-19/epidemiology , COVID-19 Serological Testing/methods , Humans , SARS-CoV-2/immunology , Time Factors
8.
Arch Pathol Lab Med ; 145(8): 929-936, 2021 08 01.
Article in English | MEDLINE | ID: covidwho-1359389

ABSTRACT

CONTEXT.­: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) testing is used for serosurveillance and will be important to evaluate vaccination status. Given the urgency to release coronavirus disease 2019 (COVID-19) serology tests, most manufacturers have developed qualitative tests. OBJECTIVE.­: To evaluate clinical performance of 6 different SARS-CoV-2 IgG assays and their quantitative results to better elucidate the clinical role of serology testing in COVID-19. DESIGN.­: Six SARS-CoV-2 IgG assays were tested using remnant specimens from 190 patients. Sensitivity and specificity were evaluated for each assay with the current manufacturer's cutoff and a lower cutoff. A numeric result analysis and discrepancy analysis were performed. RESULTS.­: Specificity was higher than 93% for all assays, and sensitivity was higher than 80% for all assays (≥7 days post-polymerase chain reaction testing). Inpatients with more severe disease had higher numeric values compared with health care workers with mild or moderate disease. Several discrepant serology results were those just below the manufacturers' cutoff. CONCLUSIONS.­: Severe acute respiratory syndrome coronavirus 2 IgG antibody testing can aid in the diagnosis of COVID-19, especially with negative polymerase chain reaction. Quantitative COVID-19 IgG results are important to better understand the immunologic response and disease course of this novel virus and to assess immunity as part of future vaccination programs.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/immunology , Immunoglobulin G/blood , SARS-CoV-2/immunology , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , Cohort Studies , Humans , New York City/epidemiology , Pandemics , Sensitivity and Specificity , Severity of Illness Index
9.
Math Med Biol ; 38(3): 396-416, 2021 08 15.
Article in English | MEDLINE | ID: covidwho-1356687

ABSTRACT

Formulating accurate and robust classification strategies is a key challenge of developing diagnostic and antibody tests. Methods that do not explicitly account for disease prevalence and uncertainty therein can lead to significant classification errors. We present a novel method that leverages optimal decision theory to address this problem. As a preliminary step, we develop an analysis that uses an assumed prevalence and conditional probability models of diagnostic measurement outcomes to define optimal (in the sense of minimizing rates of false positives and false negatives) classification domains. Critically, we demonstrate how this strategy can be generalized to a setting in which the prevalence is unknown by either (i) defining a third class of hold-out samples that require further testing or (ii) using an adaptive algorithm to estimate prevalence prior to defining classification domains. We also provide examples for a recently published SARS-CoV-2 serology test and discuss how measurement uncertainty (e.g. associated with instrumentation) can be incorporated into the analysis. We find that our new strategy decreases classification error by up to a decade relative to more traditional methods based on confidence intervals. Moreover, it establishes a theoretical foundation for generalizing techniques such as receiver operating characteristics by connecting them to the broader field of optimization.


Subject(s)
COVID-19 Serological Testing/statistics & numerical data , COVID-19/diagnosis , SARS-CoV-2 , Algorithms , Antibodies, Viral/blood , COVID-19/classification , COVID-19/epidemiology , COVID-19 Serological Testing/classification , Computational Biology , Data Analysis , Decision Theory , Humans , Immunoglobulin G/blood , Models, Statistical , Pandemics/statistics & numerical data , Prevalence , ROC Curve , Uncertainty
10.
J Immunol Methods ; 496: 113096, 2021 09.
Article in English | MEDLINE | ID: covidwho-1349521

ABSTRACT

Serology or antibody tests for COVID-19 are designed to detect antibodies (mainly Immunoglobulin M (IgM) and Immunoglobulin G (IgG) produced in response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) infection. In this study, 30 lateral flow immunoassays were tested using serum or plasma from patients with confirmed SARS CoV-2 infection. Negative serological controls were accessed from a well-characterised bank of sera which were stored prior to February 2020. Operational characteristics and ease of use of the assays are reported. 4/30 (13%) of kits (Zheihang Orient Gene COVID-19 IgG/IgM, Genrui Novel Coronavirus (2019-nCoV) IgG/IgM, Biosynex COVID-19 BSS IgG/IgM, Boson Biotech 2019-nCoV IgG/IgM) were recommended for SAHPRA approval based on kit sensitivity. Of these, only the Orientgene was recommended by SAHPRA in August 2020 for use within the approved national testing algorithm while the remaining three received limited authorization for evaluation. All kits evaluated work on the same basic principle of immunochromatography with minor differences noted in the shape and colour of cartridges, the amount of specimen volume required and the test duration. Performance of the lateral flow tests were similar to sensitivities and specificities reported in other studies. The cassettes of the majority of kits evaluated (90%) detected both IgG and IgM. Only 23% of kits evaluated contained all consumables required for point-of-care testing. The study highlights the need for thorough investigation of kits prior to implementation.


Subject(s)
Antibodies, Viral/isolation & purification , COVID-19 Serological Testing/instrumentation , COVID-19/diagnosis , Immunoassay/instrumentation , Reagent Kits, Diagnostic/statistics & numerical data , Antibodies, Viral/blood , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , COVID-19/virology , COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , Humans , Immunoassay/statistics & numerical data , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin G/isolation & purification , Immunoglobulin M/blood , Immunoglobulin M/immunology , Immunoglobulin M/isolation & purification , Point-of-Care Testing/statistics & numerical data , RNA, Viral/blood , RNA, Viral/isolation & purification , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Sensitivity and Specificity
11.
Am J Epidemiol ; 190(8): 1689-1695, 2021 08 01.
Article in English | MEDLINE | ID: covidwho-1337252

ABSTRACT

Our objective was to estimate the diagnostic accuracy of real-time polymerase chain reaction (RT-PCR) and lateral flow immunoassay (LFIA) tests for coronavirus disease 2019 (COVID-19), depending on the time after symptom onset. Based on the cross-classified results of RT-PCR and LFIA, we used Bayesian latent-class models, which do not require a gold standard for the evaluation of diagnostics. Data were extracted from studies that evaluated LFIA (immunoglobulin G (IgG) and/or immunoglobulin M (IgM)) assays using RT-PCR as the reference method. The sensitivity of RT-PCR was 0.68 (95% probability interval (PrI): 0.63, 0.73). IgG/M sensitivity was 0.32 (95% PrI :0.23; 0.41) for the first week and increased steadily. It was 0.75 (95% PrI: 0.67; 0.83) and 0.93 (95% PrI: 0.88; 0.97) for the second and third weeks after symptom onset, respectively. Both tests had a high to absolute specificity, with higher point median estimates for RT-PCR specificity and narrower probability intervals. The specificity of RT-PCR was 0.99 (95% PrI: 0.98; 1.00). and the specificity of IgG/IgM was 0.97 (95% PrI: 0.92, 1.00), 0.98 (95% PrI: 0.95, 1.00) and 0.98 (95% PrI: 0.94, 1.00) for the first, second, and third weeks after symptom onset. The diagnostic accuracy of LFIA varies with time after symptom onset. Bayesian latent-class models provide a valid and efficient alternative for evaluating the rapidly evolving diagnostics for COVID-19, under various clinical settings and different risk profiles.


Subject(s)
COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , COVID-19/diagnosis , Immunoassay/statistics & numerical data , Real-Time Polymerase Chain Reaction/statistics & numerical data , Antibodies, Viral/blood , Bayes Theorem , COVID-19/immunology , Humans , Latent Class Analysis , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Sensitivity and Specificity , Time Factors
12.
Nat Med ; 27(3): 447-453, 2021 03.
Article in English | MEDLINE | ID: covidwho-1319034

ABSTRACT

A surprising feature of the SARS-CoV-2 pandemic to date is the low burdens reported in sub-Saharan Africa (SSA) countries relative to other global regions. Potential explanations (for example, warmer environments1, younger populations2-4) have yet to be framed within a comprehensive analysis. We synthesized factors hypothesized to drive the pace and burden of this pandemic in SSA during the period from 25 February to 20 December 2020, encompassing demographic, comorbidity, climatic, healthcare capacity, intervention efforts and human mobility dimensions. Large diversity in the probable drivers indicates a need for caution in interpreting analyses that aggregate data across low- and middle-income settings. Our simulation shows that climatic variation between SSA population centers has little effect on early outbreak trajectories; however, heterogeneity in connectivity, although rarely considered, is likely an important contributor to variance in the pace of viral spread across SSA. Our synthesis points to the potential benefits of context-specific adaptation of surveillance systems during the ongoing pandemic. In particular, characterizing patterns of severity over age will be a priority in settings with high comorbidity burdens and poor access to care. Understanding the spatial extent of outbreaks warrants emphasis in settings where low connectivity could drive prolonged, asynchronous outbreaks resulting in extended stress to health systems.


Subject(s)
COVID-19/epidemiology , COVID-19/virology , SARS-CoV-2/genetics , Adult , Africa South of the Sahara/epidemiology , Aged , Aged, 80 and over , COVID-19/diagnosis , COVID-19/pathology , COVID-19 Serological Testing/statistics & numerical data , Comorbidity , Disease Outbreaks , Effect Modifier, Epidemiologic , Female , History, 21st Century , Humans , Infection Control , Male , Middle Aged , Mortality , Pandemics , Prognosis , Risk Factors , SARS-CoV-2/isolation & purification , Severity of Illness Index
13.
PLoS One ; 16(7): e0254581, 2021.
Article in English | MEDLINE | ID: covidwho-1311287

ABSTRACT

BACKGROUND: Research has revealed that asymptomatic and pre-symptomatic infections are important contributors to the transmission of SARS-CoV-2 in populations. In Egypt, the true prevalence of infections is veiled due to the low number of screening tests. The aim of this study was to determine the SARS-CoV-2 PCR positivity rate as well the seroprevalence of the SARS-CoV-2 antibodies before the ultimate development of a second wave of the epidemic in Cairo, Egypt. METHODS: Our study was carried out between May 5 and the end of October 2020. It included all patients requiring admission to Ain Shams University hospitals. An interview questionnaire was used to collect demographic and clinical data. Laboratory tests for all participants included RT-PCR and total antibody assay for SARS-CoV-2. RESULTS: A total of 4,313 subjects were enrolled in our study, with females representing 56% of the sample. Adults and middle-aged individuals represented around 60% of the study sample. The positivity rate of SARS-CoV-2 PCR was 3.84% (95% CI 3.29-4.48), and the SARS-CoV-2 antibody seroprevalence was 29.82% (95% CI: 28.16-31.51). Males showed a higher risk for getting the COVID-19 infection, while middle-age group had significantly higher antibody seroprevalence rates. CONCLUSION: SARS-CoV-2 infection imposes a high burden on the community as detected by high seroprevalence rates.


Subject(s)
COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , COVID-19/epidemiology , Adolescent , Adult , COVID-19/diagnosis , Egypt , Female , Hospitals, University/statistics & numerical data , Humans , Male , Mass Screening/statistics & numerical data , Middle Aged , Seroepidemiologic Studies
14.
BMC Med ; 19(1): 163, 2021 07 14.
Article in English | MEDLINE | ID: covidwho-1309910

ABSTRACT

BACKGROUND: Few studies had described the health consequences of patients with coronavirus disease 2019 (COVID-19) especially in those with severe infections after discharge from hospital. Moreover, no research had reported the health consequences in health care workers (HCWs) with COVID-19 after discharge. We aimed to investigate the health consequences in HCWs with severe COVID-19 after discharge from hospital in Hubei Province, China. METHODS: We conducted an ambidirectional cohort study in "Rehabilitation Care Project for Medical Staff Infected with COVID-19" in China. The participants were asked to complete three physical examinations (including the tests of functional fitness, antibodies to SARS-CoV-2 and immunological indicators) at 153.4 (143.3, 164.8), 244.3 (232.4, 259.1), and 329.4 (319.4, 339.3) days after discharge, respectively. Mann-Whitney U test, Kruskal-Wallis test, t test, one-way ANOVA, χ2, and Fisher's exact test were used to assess the variance between two or more groups where appropriate. RESULTS: Of 333 HCWs with severe COVID-19, the HCWs' median age was 36.0 (31.0, 43.0) years, 257 (77%) were female, and 191 (57%) were nurses. Our research found that 70.4% (114/162), 48.9% (67/137), and 29.6% (37/125) of the HCWs with severe COVID-19 were considered to have not recovered their functional fitness in the first, second, and third functional fitness tests, respectively. The HCWs showed improvement in muscle strength, flexibility, and agility/dynamic balance after discharge in follow-up visits. The seropositivity of IgM (17.0% vs. 6.6%) and median titres of IgM (3.0 vs. 1.4) and IgG (60.3 vs. 45.3) in the third physical examination was higher than that in the first physical examination. In the third physical examination, there still were 42.1% and 45.9% of the HCWs had elevated levels of IL-6 and TNF-α, and 11.9% and 6.3% of the HCWs had decreased relative numbers of CD3+ T cells and CD4+ T cells. CONCLUSION: The HCWs with severe COVID-19 showed improvement in functional fitness within 1 year after discharge, active intervention should be applied to help their recovery if necessary. It is of vital significance to continue monitoring the functional fitness, antibodies to SARS-CoV-2 and immunological indicators after 1 year of discharge from hospital in HCWs with severe COVID-19.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing , COVID-19 , Exercise Test , Health Personnel/statistics & numerical data , SARS-CoV-2/immunology , Adult , COVID-19/epidemiology , COVID-19/immunology , COVID-19/physiopathology , COVID-19/rehabilitation , COVID-19 Serological Testing/methods , COVID-19 Serological Testing/statistics & numerical data , China/epidemiology , Exercise Test/methods , Exercise Test/statistics & numerical data , Female , Follow-Up Studies , Functional Status , Humans , Interleukin-6/blood , Male , Patient Discharge/statistics & numerical data , Severity of Illness Index , Tumor Necrosis Factor-alpha/blood
15.
Repert. med. cir ; 30(suplemento): 16-20, 2021. graf.
Article in English, Spanish | LILACS (Americas) | ID: covidwho-1270344

ABSTRACT

Introducción: : El síndrome respiratorio agudo severo por coronavirus (SARS-CoV-2), el virus que origina la enfermedad 2019 (COVID-19) se ha diseminado con rapidez por todo el mundo desde que surgió en Wuhan, China, a finales de 2019. Objetivo: describir el comportamiento de positividad de muestras tomadas para SARS-CoV-2. Metodología: esta investigación se centró en las muestras de PCR y antígeno procesadas para COVID-19, con la información proveniente del Instituto Nacional de Salud en el periodo comprendido entre el 1 de enero a 31 de marzo 2021. Resultados: para la prueba de PCR en cada uno de los meses de enero a marzo 2021 en Colombia, se detalló que los días con mayor porcentaje de casos positivos fueron 12 de enero 56,3%, 7 de enero 44,9%, 6 de enero 45,1%, 5 de enero 43,7%, 2 de enero 38,1%, 24 de marzo 35,2%, y 26 de marzo con 31,3%. Para la prueba de antígeno en cada uno de los meses de enero a marzo 2021 en Colombia, se anota que los días con mayor porcentaje de casos positivos fueron 11 de enero 32,7%, 4 de enero 31,0%, 15 de enero 28,9%, 18 de enero 22,4%, 22 de marzo 21,1%, 28 de marzo 20,7%, y 17 de febrero 20,1%. Conclusión: hay que continuar la búsqueda activa de contagiados a través de la práctica de mayor número de pruebas de PCR, antígeno viral y molecular, la última con un alto nivel de precisión por parte de las EPS, y que a su vez aceleren el proceso de entrega de resultados.


Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19) has spread rapidly around the world since it emerged in Wuhan, China, in late 2019. Objective: to describe the positivity rates of samples tested for SARS-CoV-2. Methodology: the research focused on PCR and antigen tests processed for COVID-19, using the information released by the National Institute of Health between January 1 and March 31 2021. Results: the highest positivity rate for PCR testing for each month between January to March 2021 in Colombia was found on the following days: January 12: 56.3%, January 7: 44.9%, January 6: 45.1%, January 5: 43.7%, January 2: 38.1%, March 24: 35.2% and March 26: (31.3%. The days with the highest percentage of positive cases found by antigen testing for each month from January to March 2021 in Colombia, were January 11: 32.7%, January 4: 31.0%, January 15: 28.9%, January 18: 22.4%, March 22: 21.1%, March 28: 20.7% and February 17: 20.1%. Conclusion: an active search of infected people must be continued through the practice of a greater number of PCR and viral antigen and molecular tests. The latter has been reported by the EPS to show very high accuracy, which accelerates the result delivery process.


Subject(s)
Humans , Correlation of Data , COVID-19/diagnosis , Analysis of Variance , Colombia , COVID-19 Nucleic Acid Testing/statistics & numerical data , COVID-19 Serological Testing/statistics & numerical data , SARS-CoV-2/immunology , COVID-19/transmission
16.
Viruses ; 13(6)2021 06 14.
Article in English | MEDLINE | ID: covidwho-1270128

ABSTRACT

Humoral immunity has emerged as a vital immune component against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nevertheless, a subset of recovered Coronavirus Disease-2019 (COVID-19) paucisymptomatic/asymptomatic individuals do not generate an antibody response, constituting a paradox. We assumed that immunodiagnostic assays may operate under a competitive format within the context of antigenemia, potentially explaining this phenomenon. We present a case where persistent antigenemia/viremia was documented for at least 73 days post-symptom onset using 'in-house' methodology, and as it progressively declined, seroconversion took place late, around day 55, supporting our hypothesis. Thus, prolonged SARS-CoV-2 antigenemia/viremia could mask humoral responses, rendering, in certain cases, the phenomenon of 'non-responders' a misnomer.


Subject(s)
Antibodies, Viral/blood , Antigens, Viral/blood , Antigens, Viral/immunology , COVID-19 Serological Testing/standards , COVID-19/diagnosis , SARS-CoV-2/immunology , Antibodies, Viral/metabolism , Antigens, Viral/metabolism , Binding Sites, Antibody , COVID-19/blood , COVID-19/immunology , COVID-19/virology , COVID-19 Serological Testing/statistics & numerical data , Humans , Immunity, Humoral/immunology , Immunoglobulin G/blood , Male , Sensitivity and Specificity , Seroconversion , Young Adult
17.
Viruses ; 13(6)2021 06 12.
Article in English | MEDLINE | ID: covidwho-1270125

ABSTRACT

With the spread of new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), there is a need to assess the protection conferred by both previous infections and current vaccination. Here we tested the neutralizing activity of infected and/or vaccinated individuals against pseudoviruses expressing the spike of the original SARS-CoV-2 isolate Wuhan-Hu-1 (WH1), the D614G mutant and the B.1.1.7 variant. Our data show that parameters of natural infection (time from infection and nature of the infecting variant) determined cross-neutralization. Uninfected vaccinees showed a small reduction in neutralization against the B.1.1.7 variant compared to both the WH1 strain and the D614G mutant. Interestingly, upon vaccination, previously infected individuals developed more robust neutralizing responses against B.1.1.7, suggesting that vaccines can boost the neutralization breadth conferred by natural infection.


Subject(s)
Antibodies, Neutralizing/blood , COVID-19 Vaccines/immunology , COVID-19/immunology , Neutralization Tests/statistics & numerical data , SARS-CoV-2/immunology , Vaccination/statistics & numerical data , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/blood , COVID-19 Serological Testing/statistics & numerical data , COVID-19 Vaccines/administration & dosage , Cross Reactions/immunology , Female , Humans , Immunity, Humoral , Male , Middle Aged , Prospective Studies , SARS-CoV-2/genetics
18.
West J Emerg Med ; 22(3): 565-571, 2021 Apr 09.
Article in English | MEDLINE | ID: covidwho-1266884

ABSTRACT

INTRODUCTION: Limited data on the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among healthcare workers (HCW) are publicly available. In this study we sought to determine the seroprevalence of SARS-CoV-2 in a population of HCWs in a pediatric emergency department (ED). METHODS: We conducted this observational cohort study from April 14-May 13, 2020 in a pediatric ED in Orange County, CA. Asymptomatic HCW ≥18 years of age were included in the study. Blood samples were obtained by fingerstick at the start of each shift. The inter-sampling interval was ≤96 hours. The primary outcome was positive seroprevalence of SARS-CoV-2 as determined with an antibody fast detection kit (Colloidal Gold, Superbio, Timisoara, Romania) for the SARS-CoV-2 immunoglobulin M/immunoglobulin G (IgM/IgG) antibody. RESULTS: A total of 143 HCWs participated in the study. Overall SARS-CoV-2 seroprevalence was 10.5% (n = 15). Positive seroprevalence was classified as IgG only (4.9%), IgM+IgG (3.5%), or IgM only (2.1%). SARS-CoV-2 was detected by reverse transcription polymerase chain reaction RT-PCR in 0.7% of the overall study population (n = 1). Samples obtained on Day 1 indicated seropositivity in 4.2% of the study population (n = 6). Subsequent seroconversion occurred in 6.3% of participants (n = 9). The rate of seroconversion was linear with a rate of approximately one new case every two days, starting at Day 9 of the study. CONCLUSION: We observed a linear rate of seroconversion to SARS-CoV-2-positive status among asymptomatic HCWs who underwent daily symptom surveys and temperature screens in an environment with universal source control. Rapid antibody testing may be useful for screening for SARS-CoV-2 seropositivity in high-risk populations, such as HCWs in the ED.


Subject(s)
COVID-19 Serological Testing/statistics & numerical data , COVID-19/blood , Health Personnel/statistics & numerical data , Adult , COVID-19/epidemiology , Cohort Studies , Emergency Service, Hospital/statistics & numerical data , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Mass Screening/methods , Middle Aged , Risk Factors , SARS-CoV-2 , Seroepidemiologic Studies
19.
Ann Clin Biochem ; 58(5): 487-495, 2021 09.
Article in English | MEDLINE | ID: covidwho-1255783

ABSTRACT

BACKGROUND: A number of immunoassays have been developed to measure antibodies specific to SARS-CoV-2. More data is required on their comparability, particularly among those with milder infections and in the general practice population. The aim of this study was to compare four high-throughput automated anti-SARS-CoV-2 assays using samples collected from hospitalized patients and healthcare workers with confirmed SARS-CoV-2 infection. In addition, we collected general practice samples to compare antibody results and determine seroprevalence. METHODS: Samples were collected from 57 hospitalized patients and nine healthcare workers at 14 days and at 28 days following confirmed SARS-CoV-2 infection. Samples were also collected from 225 patients presenting to general practice. Four assays were used: Abbott Architect IgG, Beckman Coulter DxI 800 IgG, Roche Cobas e801 total antibody and Siemens Advia Centaur XPT total antibody. RESULTS: All four assays showed concordance at 14 days in 83.9% of hospitalized patients and in 66.7% of healthcare workers. All four assays showed concordance at 28 days in 88.4% of hospitalized patients and 77.8% of healthcare workers. The sensitivity to detect recent infection was higher for the IgG assays than the total assays. All four assays showed concordance of 95.1% in the general practice population. Seroprevalence ranged from 4.9 to 5.8% depending on the assay used. CONCLUSIONS: All four assays showed excellent comparability, but it may be possible to obtain a negative result for any of the anti-SARS-CoV-2 assays in patients with confirmed previous SARS-CoV-2 infection. An equivocal range would be useful for all anti-SARS-CoV-2 assays.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/diagnosis , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Viral/blood , COVID-19/epidemiology , COVID-19 Serological Testing/statistics & numerical data , Female , General Practice , Health Personnel , High-Throughput Screening Assays/methods , High-Throughput Screening Assays/statistics & numerical data , Hospitalization , Humans , Immunoassay/methods , Immunoassay/statistics & numerical data , Male , Middle Aged , Pandemics , Seroepidemiologic Studies , United Kingdom/epidemiology , Young Adult
20.
Ann Clin Biochem ; 58(5): 496-504, 2021 09.
Article in English | MEDLINE | ID: covidwho-1255782

ABSTRACT

STUDY OBJECTIVE: SARS-CoV-2, which causes coronavirus disease (COVID-19), continues to cause significant morbidity and mortality. The diagnosis of acute infection relies on reverse transcription-polymerase chain reaction (RT-PCR)-based viral detection. The objective of this study was to evaluate the optimal serological testing strategy for anti-SARS-CoV-2 antibodies which provides an important indicator of prior infection and potential short-term immunity. METHODS: The sensitivity and specificity of four different ELISA assays (Euroimmun IgG, Euroimmun NCP-IgG, Fortress and DIAsource) and one CLIA assay (Roche ELECSYS) were evaluated in 423 samples; 137 patients with confirmed RT-PCR COVID-19 infection (true positives), and 100 pre-pandemic samples collected prior to October 2019 (true negatives). A further 186 samples were collected from health-care staff and analysed by all five assays. RESULTS: The Fortress ELISA assay demonstrated the highest sensitivity and specificity followed by the Roche ECLIA assay. The highest overall sensitivity came from the assays that measured total antibody (IgM-IgG combined) and the three assays that performed the best (Fortress, Roche, Euroimmun IgG) all have different antigens as their target proteins which suggests that antigen target does not affect assay performance. In mildly symptomatic participants with either a negative RT-PCR or no RT-PCR performed, 16.76% had detectable antibodies suggesting previous infection. CONCLUSIONS: We recommend a combined testing strategy utilizing assays with different antigenic targets using the fully automated Roche ECLIA assay and confirming discordant samples with the Fortress Total Antibody ELISA assay. This study provides an important indicator of prior infection in symptomatic and asymptomatic individuals.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/diagnosis , COVID-19/immunology , Pandemics , SARS-CoV-2 , Antibodies, Viral/blood , COVID-19/epidemiology , COVID-19 Nucleic Acid Testing , COVID-19 Serological Testing/statistics & numerical data , Electrochemical Techniques/methods , Electrochemical Techniques/statistics & numerical data , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/statistics & numerical data , Female , Health Personnel , Humans , Immunoglobulin G/blood , Ireland/epidemiology , Luminescent Measurements/methods , Luminescent Measurements/statistics & numerical data , Male , Pregnancy , Sensitivity and Specificity
SELECTION OF CITATIONS
SEARCH DETAIL
...