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1.
Klin Lab Diagn ; 65(11): 688-692, 2020 Dec 04.
Article in English | MEDLINE | ID: covidwho-1780383

ABSTRACT

The study presents the results of the creation and evaluation of the diagnostic characteristics of the rapid immunochromatographic test for the qualitative detection and differentiation of IgM/IgG antibodies to SARS-CoV-2 in human serum, plasma, and whole blood "ИХА-COVID-19-IgM / IgG". Have been tested some samples without antibodies to SARS-CoV-2 and a samples with two and one type of specific antibodies. The coincidence of the results of immunochromatographic analysis with the results of the immunochemiluminescent method was 87.2%. Test kit can be use as the rapid diagnostic test in the context of the COVID-19 pandemic and to assess the immune status of convalescents.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Serological Testing , COVID-19/diagnosis , Immunoassay , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Humans
2.
Virol J ; 19(1): 24, 2022 02 03.
Article in English | MEDLINE | ID: covidwho-1770554

ABSTRACT

INTRODUCTION: In this work, six SARS-CoV-2-specific antibody assays were evaluated, namely, two pan-immunoglobulin (pan-Ig) assays [Roche Elecsys Anti-SARS-CoV-2 (named "Elecsys" in this study) and the PerkinElmer SuperFlex™ Anti-SARS-CoV-2 Ab Assay (SuperFlex_Ab)], two IgM assays [SuperFlex™ Anti-SARS-CoV-2 IgM Assay (SuperFlex_IgM) and YHLO iFlash-SARS-CoV-2 IgM (iFlash_IgM)], and two IgG assays [SuperFlex™ Anti-SARS-CoV-2 IgG Assay (SuperFlex_IgG) and iFlash-SARS-CoV-2 IgG (iFlash_IgG)]. Combination assays of SuperFlex™ (SuperFlex_any) and iFlash (iFlash_any) were also evaluated. METHODS: A total of 438 residual serum samples from 54 COVID-19 patients in the COVID-19 group and 100 samples from individuals without evidence of SARS-CoV-2 infection in the negative control group were evaluated. RESULTS: In the early stage of COVID-19 infection, within 14 days of symptom onset, the seropositive rate was lower than that of the late stage 15 days after onset (65.4% vs 99.6%). In the total period, the pan-Ig and IgG assays had higher sensitivity (90.8-95.3%) than the IgM assays (36.5-40.7%). SuperFlex_Ab and SuperFlex_any had higher sensitivity than Elecsys and SuperFlex_IgG (p < 0.05). The specificity of all the assays was 100%, except for SuperFlex_IgM (99.0%). The concordance rate between each assay was higher (96.4-100%) in the late stage than in the early stage (77.4-98.1%). CONCLUSION: For the purpose of COVID-19 diagnosis, antibody testing should be performed 15 days after onset. For the purpose of epidemiological surveillance, highly sensitive assays should be used as much as possible, such as SuperFlex_Ab, iFlash_IgG and their combination. IgM assays were not suitable for these purposes.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Serological Testing/methods , COVID-19 , COVID-19/diagnosis , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , SARS-CoV-2/immunology , Sensitivity and Specificity
3.
Front Immunol ; 13: 751705, 2022.
Article in English | MEDLINE | ID: covidwho-1686480

ABSTRACT

COVID-19 affects children to a lesser extent than adults but they can still get infected and transmit SARS-CoV-2 to their contacts. Field deployable non-invasive sensitive diagnostic techniques are needed to evaluate the infectivity dynamics of SARS-CoV-2 in pediatric populations and guide public health interventions, particularly if this population is not fully vaccinated. We evaluated the utility of high-throughput Luminex assays to quantify saliva IgM, IgA and IgG antibodies against five SARS-CoV-2 spike (S) and nucleocapsid (N) antigens in a contacts and infectivity longitudinal study in 122 individuals (52 children and 70 adults). We compared saliva versus serum/plasma samples in infected children and adults diagnosed by weekly RT-PCR over 35 days (n=62), and those who consistently tested negative over the same follow up period (n=60), in the Summer of 2020 in Barcelona, Spain. Saliva antibody levels in SARS-CoV-2 RT-PCR positive individuals were significantly higher than in negative individuals and correlated with those measured in sera/plasmas. Asymptomatic infected individuals had higher levels of anti-S IgG than symptomatic individuals, suggesting a protective anti-disease role for antibodies. Higher anti-S IgG and IgM levels in serum/plasma and saliva, respectively, in infected children compared to infected adults could also be related to stronger clinical immunity in them. Among infected children, males had higher levels of saliva IgG to N and RBD than females. Despite overall correlation, individual clustering analysis suggested that responses that may not be detected in blood could be patent in saliva, and vice versa. In conclusion, measurement of SARS-CoV-2-specific saliva antibodies should be considered as a complementary non-invasive assay to serum/plasma to determine COVID-19 prevalence and transmission in pediatric populations before and after vaccination campaigns.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoassay/methods , Saliva , Adult , Child , Female , Humans , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , SARS-CoV-2 , Spain
4.
Viral Immunol ; 34(10): 708-713, 2021 12.
Article in English | MEDLINE | ID: covidwho-1595620

ABSTRACT

The coronavirus infectious disease 2019 (COVID-19), which is initiated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has imposed critical challenges to global health. Understanding the kinetic of SARS-CoV-2-specific IgM and IgG responses in different subsets of COVID-19 patients is crucial to get insight into the humoral immune response elicited against the virus. We investigated IgM and IgG responses against SARS-CoV-2 nucleocapsid (N) and receptor-binding domain (RBD) of spike protein in two groups of recovered and deceased COVID-19 patients. The levels of IgM and IgG specific to N and RBD proteins were detected by ELISA. N- and RBD-specific IgM was higher in deceased patients in comparison with recovered patients, while there was no significant difference in N- and RBD-specific IgG between the two groups. A significant correlation was observed between IgG and IgM titers against RBD and N, in both groups of patients. These results argue against impaired antibody response in deceased COVID-19 patients.


Subject(s)
Antibodies, Viral/analysis , Antibodies, Viral/immunology , Antibody Formation , Antigens, Viral/immunology , COVID-19/immunology , COVID-19/mortality , SARS-CoV-2/immunology , Female , Humans , Immunoglobulin G/analysis , Immunoglobulin G/immunology , Immunoglobulin M/analysis , Immunoglobulin M/immunology , Iran/epidemiology , Male , Middle Aged , Nucleocapsid/chemistry , Nucleocapsid/immunology , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology
5.
Eur Rev Med Pharmacol Sci ; 25(19): 5942-5946, 2021 10.
Article in English | MEDLINE | ID: covidwho-1478936

ABSTRACT

OBJECTIVE: The pandemic disease by SARS-CoV-2 infection does not have an effective treatment. To prevent the disease, scientists developed vaccines that the clinicians use as an emergency licensed vaccine. The objective of this study was to determine the side effects in personnel vaccinated at the Military Central Hospital of Mexico with the BNT162b2 vaccine. PATIENTS AND METHODS: This study included the subjects who had received both doses of the BNT162b2 vaccine between December 2020 and February 2021. We asked about the side effects after the first and the second vaccine doses. One group had no history of COVID-19, and the second had a history of COVID-19. ANTI-SARS-CoV-2 antibodies were measured by the immunodetection technique in the second group only. RESULTS: We included 946 participants, 62% were women, and 80% were without comorbidities; 680 were included in the first group, and only 266 were in the second group. After the first dose, 77% of the first group and 86% of the second group presented some side effects. After the second dose, 84% of the first group and 89% of the second group showed some side effects. The main side effect was mild pain. All participants (126) were IgG positive, and only 26.9% were IgM positive at 17.5 days (12.8 days, 20.3 days) after the second dose. CONCLUSIONS: There is a positive correlation between side effects after the first dose in patients with a history of previous SARS-CoV-2 infection compared to those who did not. Nevertheless, this correlation is not present after the second dose. The low percentage of IgM could be related to the time interval between vaccination and sample measure.


Subject(s)
COVID-19 Vaccines/adverse effects , Hospitals, Military/statistics & numerical data , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/complications , COVID-19/diagnosis , COVID-19 Vaccines/administration & dosage , Drug-Related Side Effects and Adverse Reactions , Female , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , Mexico , Middle Aged , Military Personnel , Young Adult
7.
Sci Rep ; 11(1): 3081, 2021 02 04.
Article in English | MEDLINE | ID: covidwho-1387463

ABSTRACT

Clinic-based estimates of SARS-CoV-2 may considerably underestimate the total number of infections. Access to testing in the US has been heterogeneous and symptoms vary widely in infected persons. Public health surveillance efforts and metrics are therefore hampered by underreporting. We set out to provide a minimally biased estimate of SARS-CoV-2 seroprevalence among adults for a large and diverse county (Orange County, CA, population 3.2 million). We implemented a surveillance study that minimizes response bias by recruiting adults to answer a survey without knowledge of later being offered SARS-CoV-2 test. Several methodologies were used to retrieve a population-representative sample. Participants (n = 2979) visited one of 11 drive-thru test sites from July 10th to August 16th, 2020 (or received an in-home visit) to provide a finger pin-prick sample. We applied a robust SARS-CoV-2 Antigen Microarray technology, which has superior measurement validity relative to FDA-approved tests. Participants include a broad age, gender, racial/ethnic, and income representation. Adjusted seroprevalence of SARS-CoV-2 infection was 11.5% (95% CI: 10.5-12.4%). Formal bias analyses produced similar results. Prevalence was elevated among Hispanics (vs. other non-Hispanic: prevalence ratio [PR] = 1.47, 95% CI 1.22-1.78) and household income < $50,000 (vs. > $100,000: PR = 1.42, 95% CI: 1.14 to 1.79). Results from a diverse population using a highly specific and sensitive microarray indicate a SARS-CoV-2 seroprevalence of ~ 12 percent. This population-based seroprevalence is seven-fold greater than that using official County statistics. In this region, SARS-CoV-2 also disproportionately affects Hispanic and low-income adults.


Subject(s)
Antibodies, Viral/analysis , COVID-19 , /statistics & numerical data , Adolescent , Adult , Bias , COVID-19/diagnosis , COVID-19/epidemiology , California/epidemiology , Female , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , Middle Aged , Prevalence , Public Health Surveillance , Seroepidemiologic Studies , Young Adult
8.
Pediatrics ; 148(5)2021 11.
Article in English | MEDLINE | ID: covidwho-1365458

ABSTRACT

BACKGROUND AND OBJECTIVES: Passive and active immunity transfer through human milk (HM) constitutes a key element in the infant's developing immunity. Certain infectious diseases and vaccines have been described to induce changes in the immune components of HM. METHODS: We conducted a prospective cohort single-institution study from February 2 to April 4, 2021. Women who reported to be breastfeeding at the time of their coronavirus disease 2019 (COVID-19) vaccination were invited to participate. Blood and milk samples were collected on day 14 after their second dose of the vaccine. Immunoglobulin G (IgG) antibodies against nucleocapsid protein as well as IgG, immunoglobulin M and immunoglobulin A (IgA) antibodies against the spike 1 protein receptor-binding domain against severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2 RBD-S1) were analyzed in both serum and HM samples. RESULTS: Most of the participants (ie, 94%) received the BNT162b2 messenger RNA COVID-19 vaccine. The mean serum concentration of anti-SARS-CoV-2 RBD-S-IgG antibodies in vaccinated individuals was 3379.6 ± 1639.5 binding antibody units per mL. All vaccinated study participants had anti-SARS-CoV-2 RBD-S1-IgG, and 89% of them had anti-SARS-CoV-2 RBD-S-IgA in their milk. The antibody concentrations in the milk of mothers who were breastfeeding 24 months were significantly higher than in mothers with breastfeeding periods <24 months (P < .001). CONCLUSIONS: We found a clear association between COVID-19 vaccination and specific immunoglobulin concentrations in HM. This effect was more pronounced when lactation periods exceeded 23 months. The influence of the lactation period on immunoglobulins was specific and independent of other variables.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Vaccines , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Milk, Human/chemistry , Milk, Human/immunology , SARS-CoV-2/immunology , Adult , Female , Humans , Infant , Infant, Newborn , Male , Prospective Studies , Vaccination
9.
Hum Antibodies ; 29(3): 217-223, 2021.
Article in English | MEDLINE | ID: covidwho-1278369

ABSTRACT

BACKGROUND: As the extent of the pandemic and its seroprevalence pattern has been less clarified in pediatrics to date, we aimed to conduct this study to investigate the clinical and laboratory characteristics of COVID-19 in Iranian children, with a focus on evaluating the antibody prevalence and its relation with the laboratory tests. METHODS: All children with highly suspected COVID-19 were included. Anti-nucleoprotein SARS-CoV-2 were measured using SARS-CoV-2 immunoglobulin M (IgM) and SARS-CoV-2 IgG ELISA kits. Hypothesis testing was carried out through SPSS to unravel any association between the measurement tools and important clinical and laboratory characteristics. RESULTS: In this study, 254 patients were evaluated and 117 cases (46%) were male. The nucleic acid detection results for patient 55 were negative, but the IgM and IgG results were positive. Totally, 190 patients were tested for IgM in which only 14 (7.3%) had positive tests. Positive IgG was detected in 51 (20%) out of 254 patients; among them, 30 patients had negative SARS-CoV-2 RT-PCR (59%). Lower level of platelets in IgG positive group in comparison with the IgG negative group was observed (P value: 0.015). Moreover, higher alanine aminotransferase (ALT) was observed in the in IgG positive group (P value: 0.02). In patients with positive IgM, relative hypocalcemia (median of 8.25; IQR: 8.02-8.62) was found which appeared to be significant (P value: 0.02). CONCLUSION: This is the first largest study describing the SARS-CoV-2 seropositivity among children in Iran and provides important insight about the COVID-19 infection in children.


Subject(s)
Antibodies, Viral/analysis , Antibodies, Viral/immunology , COVID-19/diagnosis , COVID-19/immunology , Hospitals , Pediatrics , Referral and Consultation , SARS-CoV-2/immunology , Adolescent , COVID-19/epidemiology , Child , Child, Preschool , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoglobulin G/analysis , Immunoglobulin G/immunology , Immunoglobulin M/analysis , Immunoglobulin M/immunology , Infant , Infant, Newborn , Iran/epidemiology , Male , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Seroepidemiologic Studies
10.
Ann Lab Med ; 41(6): 577-587, 2021 Nov 01.
Article in English | MEDLINE | ID: covidwho-1264321

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody assays have high clinical utility in managing the pandemic. We compared antibody responses and seroconversion of coronavirus disease 2019 (COVID-19) patients using different immunoassays. METHODS: We evaluated 12 commercial immunoassays, including three automated chemiluminescent immunoassays (Abbott, Roche, and Siemens), three enzyme immunoassays (Bio-Rad, Euroimmun, and Vircell), five lateral flow immunoassays (Boditech Med, SD biosensor, PCL, Sugentech, and Rapigen), and one surrogate neutralizing antibody assay (GenScript) in sequential samples from 49 COVID-19 patients and 10 seroconversion panels. RESULTS: The positive percent agreement (PPA) of assays for a COVID-19 diagnosis ranged from 84.0% to 98.5% for all samples (>14 days after symptom onset), with IgM or IgA assays showing higher PPAs. Seroconversion responses varied across the assay type and disease severity. Assays targeting the spike or receptor-binding domain protein showed a tendency for early seroconversion detection and higher index values in patients with severe disease. Index values from SARS-CoV-2 binding antibody assays (three automated assays, one LFIA, and three EIAs) showed moderate to strong correlations with the neutralizing antibody percentage (r=0.517-0.874), and stronger correlations in patients with severe disease and in assays targeting spike protein. Agreement among the 12 assays was good (74.3%-96.4%) for detecting IgG or total antibodies. CONCLUSIONS: Positivity rates and seroconversion of SARS-CoV-2 antibodies vary depending on the assay kits, disease severity, and antigen target. This study contributes to a better understanding of antibody response in symptomatic COVID-19 patients using currently available assays.


Subject(s)
Antibodies, Viral/analysis , COVID-19 Testing/methods , COVID-19/diagnosis , SARS-CoV-2/immunology , COVID-19/pathology , COVID-19/virology , Humans , Immunoassay , Immunoglobulin A/analysis , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Reagent Kits, Diagnostic , SARS-CoV-2/isolation & purification , Sensitivity and Specificity , Severity of Illness Index
11.
PLoS One ; 16(6): e0252628, 2021.
Article in English | MEDLINE | ID: covidwho-1256044

ABSTRACT

Serological assessment of SARS-CoV-2 specific responses are an essential tool for determining the prevalence of past SARS-CoV-2 infections in the population especially when testing occurs after symptoms have developed and limited contact tracing is in place. The goal of our study was to test a new 10-plex electro-chemiluminescence-based assay to measure IgM and IgG responses to the spike proteins from multiple human coronaviruses including SARS-CoV-2, assess the epitope specificity of the SARS-CoV-2 antibody response against full-length spike protein, receptor-binding domain and N-terminal domain of the spike protein, and the nucleocapsid protein. We carried out the assay on samples collected from three sample groups: subjects diagnosed with COVID-19 from the U.S. Army hospital at Camp Humphreys in Pyeongtaek, South Korea; healthcare administrators from the same hospital but with no reported diagnosis of COVID-19; and pre-pandemic samples. We found that the new CoV-specific multiplex assay was highly sensitive allowing plasma samples to be diluted 1:30,000 with a robust signal. The reactivity of IgG responses to SARS-CoV-2 nucleocapsid protein and IgM responses to SARS-CoV-2 spike protein could distinguish COVID-19 samples from non-COVID-19 and pre-pandemic samples. The data from the three sample groups also revealed a unique pattern of cross-reactivity between SARS-CoV-2 and SARS-CoV-1, MERS-CoV, and seasonal coronaviruses HKU1 and OC43. Our findings show that the CoV-2 IgM response is highly specific while the CoV-2 IgG response is more cross-reactive across a range of human CoVs and also showed that IgM and IgG responses show distinct patterns of epitope specificity. In summary, this multiplex assay was able to distinguish samples by COVID-19 status and characterize distinct trends in terms of cross-reactivity and fine-specificity in antibody responses, underscoring its potential value in diagnostic or serosurveillance efforts.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Antibodies, Viral/analysis , Antibody Formation , Cross Reactions , Female , Humans , Immunoglobulin G/analysis , Immunoglobulin G/immunology , Immunoglobulin M/analysis , Immunoglobulin M/immunology , Luminescence , Male , Middle Aged , Middle East Respiratory Syndrome Coronavirus/immunology , Military Personnel , Nucleocapsid Proteins/immunology , SARS Virus/immunology , SARS-CoV-2/pathogenicity , Sensitivity and Specificity , Spike Glycoprotein, Coronavirus/immunology , United States
12.
Respir Res ; 22(1): 119, 2021 Apr 23.
Article in English | MEDLINE | ID: covidwho-1202183

ABSTRACT

BACKGROUND: In the absence of PCR detection of SARS-CoV-2 RNA, accurate diagnosis of COVID-19 is challenging. Low-dose computed tomography (CT) detects pulmonary infiltrates with high sensitivity, but findings may be non-specific. This study assesses the diagnostic value of SARS-CoV-2 serology for patients with distinct CT features but negative PCR. METHODS: IgM/IgG chemiluminescent immunoassay was performed for 107 patients with confirmed (group A: PCR + ; CT ±) and 46 patients with suspected (group B: repetitive PCR-; CT +) COVID-19, admitted to a German university hospital during the pandemic's first wave. A standardized, in-house CT classification of radiological signs of a viral pneumonia was used to assess the probability of COVID-19. RESULTS: Seroconversion rates (SR) determined on day 5, 10, 15, 20 and 25 after symptom onset (SO) were 8%, 25%, 65%, 76% and 91% for group A, and 0%, 10%, 19%, 37% and 46% for group B, respectively; (p < 0.01). Compared to hospitalized patients with a non-complicated course (non-ICU patients), seroconversion tended to occur at lower frequency and delayed in patients on intensive care units. SR of patients with CT findings classified as high certainty for COVID-19 were 8%, 22%, 68%, 79% and 93% in group A, compared with 0%, 15%, 28%, 50% and 50% in group B (p < 0.01). SARS-CoV-2 serology established a definite diagnosis in 12/46 group B patients. In 88% (8/9) of patients with negative serology > 14 days after symptom onset (group B), clinico-radiological consensus reassessment revealed probable diagnoses other than COVID-19. Sensitivity of SARS-CoV-2 serology was superior to PCR > 17d after symptom onset. CONCLUSIONS: Approximately one-third of patients with distinct COVID-19 CT findings are tested negative for SARS-CoV-2 RNA by PCR rendering correct diagnosis difficult. Implementation of SARS-CoV-2 serology testing alongside current CT/PCR-based diagnostic algorithms improves discrimination between COVID-19-related and non-related pulmonary infiltrates in PCR negative patients. However, sensitivity of SARS-CoV-2 serology strongly depends on the time of testing and becomes superior to PCR after the 2nd week following symptom onset.


Subject(s)
COVID-19/blood , COVID-19/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Algorithms , Critical Care/statistics & numerical data , Female , Hospitalization/statistics & numerical data , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , Middle Aged , Pandemics , Polymerase Chain Reaction , Retrospective Studies , Seroconversion , Serologic Tests , Tomography, X-Ray Computed , Young Adult
13.
Nephron ; 145(4): 363-370, 2021.
Article in English | MEDLINE | ID: covidwho-1201313

ABSTRACT

BACKGROUND/AIMS: The coronavirus disease 2019 (CO-VID-19) pandemic is the major current health emergency worldwide, adding a significant burden also to the community of nephrologists for the management of their patients. Here, we analyzed the impact of COVID-19 infection in renal patients to assess the time to viral clearance, together with the production and persistence of IgG and IgM antibody response, in consideration of the altered immune capacity of this fragile population. METHODS: Viral clearance and antibody kinetics were investigated in 49 renal patients recovered from COVID-19 infection: 7 of them with chronic decompensated renal failure, 31 under dialysis treatment, and 11 kidney transplant recipients. RESULTS: The time span between the diagnosis of infection and recovery based on laboratory testing (2 negative nasopharyngeal swabs in consecutive days) was 31.7 ± 13.3 days. Three new positive cases were detected from 8 to 13 days following recovery. At the first serological determination after swab negativization, all the patients developed IgG and IgM antibodies. The semiquantitative analysis showed a progressive increase in IgG and a slow reduction in IgM. DISCUSSION/CONCLUSION: In subjects with decompensated chronic kidney disease, under dialysis and in transplant recipients, viral clearance is lengthened compared to the general population. However, in spite of their common status of immunodepression, all of them were able to produce specific antibodies. These data might provide useful insights for monitoring and planning health-care activities in the weak category of patients with compromised renal function recovered from COVID-19.


Subject(s)
COVID-19/immunology , COVID-19/virology , Kidney Transplantation , Renal Dialysis , Adult , Aged , Aged, 80 and over , Antibodies, Viral/analysis , COVID-19/epidemiology , Female , Glomerular Filtration Rate , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Kidney Failure, Chronic/complications , Kidney Failure, Chronic/immunology , Kidney Failure, Chronic/therapy , Kinetics , Male , Middle Aged , Nasopharynx/immunology , Nasopharynx/virology , Retrospective Studies , Transplant Recipients , Treatment Outcome
14.
Int J Occup Med Environ Health ; 34(2): 203-209, 2021 May 27.
Article in English | MEDLINE | ID: covidwho-1140809

ABSTRACT

OBJECTIVES: Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome virus 2 (SARS-CoV-2) had spread worldwide since December 2019 and became a pandemic in March 2020. The diagnosis of an active infection is based on the real-time reverse transcriptase-polymerase chain reaction (RT-PCR) from the nasopharyngeal swab specimen. The aim of the current analysis was to assess the usefulness of the rapid serological tests for diagnosing SARS-CoV-2 infections. MATERIAL AND METHODS: The rapid serological tests detecting IgG/IgM antibodies for SARS-CoV-2 were voluntarily performed in asymptomatic employees of 2 companies. The examination was conducted at the date and time selected online by the study participants. The testing team consisted of 2 nurses collecting the samples and 1 doctor who interpreted the results. Each positive rapid test result was verified by an RT-PCR examination from a nasopharyngeal swab. The testing kits named Vazyme: 2019-nCoV IgG/IgM Detection Kit (Colloidal Gold-Based) were provided by the employer along with the manual and certificates. RESULTS: The overall interest in testing among employees was below the employer's expectations and reached 30% and 20% in each of the 2 companies, respectively. A total of 516 participants were included in the analysis. Ten positive results of the rapid tests were documented, including 7 for IgM and 3 for IgG antibodies. No positive result was confirmed by the detection of the genetic material of the SARS-CoV-2 by the RT-PCR examination. CONCLUSIONS: Herein, the authors demonstrated the uselessness of rapid serological tests performed in asymptomatic volunteers for diagnosing SARS-CoV-2 infections. Int J Occup Med Environ Health. 2021;34(2):203-9.


Subject(s)
Antibodies, Viral/analysis , COVID-19/epidemiology , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Pandemics , SARS-CoV-2/immunology , Adult , COVID-19/immunology , COVID-19/virology , Female , Humans , Immunoglobulin M/immunology , Male , Middle Aged
15.
Sci Rep ; 11(1): 5198, 2021 03 04.
Article in English | MEDLINE | ID: covidwho-1117665

ABSTRACT

The quantitative range and reproducibility of current serological tests for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are not optimized. Herein, we developed a diagnostic test that detects SARS-CoV-2 IgG and IgM with high quantitativeness and reproducibility and low interference. The system was based on the high-sensitivity chemiluminescence enzyme immunoassay (HISCL) platform and detects IgG and IgM specific to SARS-CoV-2 spike and nucleocapsid proteins. Quantification accuracy and reproducibility were evaluated using serially diluted samples from 60 SARS-CoV-2-infected patients. Assay performance was evaluated using serum samples from the SARS-CoV-2-infected patients and 500 SARS-CoV-2-negative serum samples collected before the emergence of SARS-CoV-2. The system showed high quantification accuracy (range, 102), high reproducibility (within 5%), and no cross-reaction between SARS1- and MERS-S proteins. Detection accuracy was 98.3% and 93.3% for IgG and IgM against spike proteins and 100% and 71.7% for IgG and IgM against nucleocapsid proteins, respectively. Mean antibody levels were > 10 times that in negative samples upon admission and > 100 times that at convalescent periods. Clinical severity upon admission was not correlated with IgG or IgM levels. This highly quantitative, reproducible assay system with high clinical performance may help analyze temporal serological/immunological profiles of SARS-CoV-2 infection and SARS-CoV-2 vaccine effectiveness.


Subject(s)
COVID-19 Testing/methods , Immunoglobulin G/analysis , Immunoglobulin M/analysis , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Humans , Immunoenzyme Techniques , Luminescent Measurements , Male , Middle Aged , ROC Curve , Young Adult
16.
Biosens Bioelectron ; 181: 113134, 2021 Jun 01.
Article in English | MEDLINE | ID: covidwho-1116329

ABSTRACT

The coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread into a global pandemic. Early and accurate diagnosis and quarantine remain the most effective mitigation strategy. Although reverse transcriptase polymerase chain reaction (RT-qPCR) is the gold standard for COVID-19 diagnosis, recent studies suggest that nucleic acids were undetectable in a significant number of cases with clinical features of COVID-19. Serologic assays that detect human antibodies to SARS-CoV-2 serve as a complementary method to diagnose these cases, as well as to identify asymptomatic cases and qualified convalescent serum donors. However, commercially available enzyme-linked immunosorbent assays (ELISA) are laborious and non-quantitative, while point-of-care assays suffer from low detection accuracy. To provide a serologic assay with high performance and portability for potential point-of-care applications, we developed DNA-assisted nanopore sensing for quantification of SARS-CoV-2 related antibodies in human serum. Different DNA structures were used as detection reporters for multiplex quantification of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against the nucleocapsid protein of SARS-CoV-2 in serum specimens from patients with conformed or suspected infection. Comparing to a clinically used point-of-care assay and an ELISA assay, our technology can reliably quantify SARS-CoV-2 antibodies with higher accuracy, large dynamic range, and potential for assay automation.


Subject(s)
Antibodies, Viral/analysis , Biosensing Techniques , COVID-19 Testing/methods , COVID-19/diagnosis , Nanopores , DNA , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , SARS-CoV-2 , Sensitivity and Specificity
17.
Curr Med Sci ; 41(1): 46-50, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1081788

ABSTRACT

Positive nucleic acid (NA) results have been found in recovered and discharged COVID-19 patients, but the proportion is unclear. This study was designed to analyze the recurrent positive rate of NA results after consecutively negative results, and the relationship between the specific antibody production and positive NA rate. According to Strengthening the Reporting of Observational Studies in Epidemiology guidelines, data of inpatients in Sino-French New City Branch of Tongji Hospital between Jan. 28 and Mar. 6, 2020 were collected. A total of 564 COVID-19 patients over 14 years old who received the examinations of NA and antibodies against SARS-CoV-2 were included. Days of viral shedding and specific antibodies were recorded and assessed. Among NA tests in respiratory samples (throat swabs, nasopharyngeal swabs, sputum and flushing fluid in alveoli), the patients with all-negative NA results accounted for 17.20%, those with single-positive results for 46.63%, and those with multiple-positive results for 36.17% respectively. Besides, the recurrent positive NA results after consecutively negative results appeared in 66 patients (11.70%). For multiple-positive patients, median viral shedding duration was 20 days (range: 1 to 57 days). Of the 205 patients who received 2 or more antibody tests, 141 (68.78%) had decreased IgG and IgM concentrations. IgM decreased to normal range in 24 patients, with a median of 44 days from symptom onset. Viral shedding duration was not significantly correlated with gender, age, disease severity, changes in pulmonary imaging, and antibody concentration. It is concluded that antibody level and antibody change had no significant correlation with the positive rate of NA tests and the conversion rate after continuous negative NA tests. In order to reduce the recurrent positive proportion after discharge, 3 or more consecutive negative NA test results with test interval more than 24 h every time are suggested for the discharge or release from quarantine.


Subject(s)
Antibodies, Viral/analysis , COVID-19/diagnosis , SARS-CoV-2/physiology , Adult , Aged , Aged, 80 and over , COVID-19/immunology , Female , Guidelines as Topic , Humans , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Male , Middle Aged , Respiratory System/virology , Retrospective Studies , SARS-CoV-2/immunology , Virus Shedding
19.
Int J Environ Res Public Health ; 18(3)2021 01 21.
Article in English | MEDLINE | ID: covidwho-1067745

ABSTRACT

BACKGROUND: Knowledge about the COVID-19 outbreak is still sparse, especially in a cross-national setting. COVID-19 is caused by a SARS-CoV-2 infection. The aim of the study is to contribute to the surveillance of the pandemic by bringing new knowledge about SARS-CoV-2 seropositivity among healthcare workers. It seeks to evaluate whether certain job functions are associated with a higher risk of being infected and to clarify if such association is mediated by the number of individuals that employees meet during a workday. In addition, we investigate regional and national differences in seroprevalence. METHODS: This research involved a bi-national prospective observational cohort study including 3272 adults employed at Falck in Sweden and Denmark. Participants were tested for SARS-CoV-2 antibodies every second week for a period of 8 weeks from 22 June 2020 until 10 August 2020. Descriptive statistics as well as multivariable logistic regression analyses were applied. RESULTS: Of the 3272 Falck employees participating in this study, 159 (4.9%) tested positive for SARS-CoV-2 antibodies. The seroprevalence was lower among Danish Falck employees than among those from Sweden (2.8% in Denmark and 8.3% in Sweden). We also found that the number of customer or patient contacts during a workday was the most prominent predictor for seropositivity and that ambulance staff was the most vulnerable staff group. CONCLUSION: Our study presents geographical variations in seroprevalence within the Falck organization and shows evidence that social interaction is one of the biggest risk factors for becoming infected with SARS-CoV-2.


Subject(s)
Antibodies, Viral/analysis , COVID-19/immunology , Health Personnel/statistics & numerical data , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Adult , COVID-19/diagnosis , COVID-19 Serological Testing , Denmark/epidemiology , Humans , Prevalence , Prospective Studies , SARS-CoV-2/immunology , Seroepidemiologic Studies , Sweden/epidemiology
20.
Int J Environ Res Public Health ; 18(3)2021 01 21.
Article in English | MEDLINE | ID: covidwho-1045436

ABSTRACT

BACKGROUND: Knowledge about the COVID-19 outbreak is still sparse, especially in a cross-national setting. COVID-19 is caused by a SARS-CoV-2 infection. The aim of the study is to contribute to the surveillance of the pandemic by bringing new knowledge about SARS-CoV-2 seropositivity among healthcare workers. It seeks to evaluate whether certain job functions are associated with a higher risk of being infected and to clarify if such association is mediated by the number of individuals that employees meet during a workday. In addition, we investigate regional and national differences in seroprevalence. METHODS: This research involved a bi-national prospective observational cohort study including 3272 adults employed at Falck in Sweden and Denmark. Participants were tested for SARS-CoV-2 antibodies every second week for a period of 8 weeks from 22 June 2020 until 10 August 2020. Descriptive statistics as well as multivariable logistic regression analyses were applied. RESULTS: Of the 3272 Falck employees participating in this study, 159 (4.9%) tested positive for SARS-CoV-2 antibodies. The seroprevalence was lower among Danish Falck employees than among those from Sweden (2.8% in Denmark and 8.3% in Sweden). We also found that the number of customer or patient contacts during a workday was the most prominent predictor for seropositivity and that ambulance staff was the most vulnerable staff group. CONCLUSION: Our study presents geographical variations in seroprevalence within the Falck organization and shows evidence that social interaction is one of the biggest risk factors for becoming infected with SARS-CoV-2.


Subject(s)
Antibodies, Viral/analysis , COVID-19/immunology , Health Personnel/statistics & numerical data , Immunoglobulin G/analysis , Immunoglobulin M/analysis , Adult , COVID-19/diagnosis , COVID-19 Serological Testing , Denmark/epidemiology , Humans , Prevalence , Prospective Studies , SARS-CoV-2/immunology , Seroepidemiologic Studies , Sweden/epidemiology
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