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2.
J Med Virol ; 93(12): 6765-6777, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544330

ABSTRACT

Avidity is defined as the binding strength of immunoglobulin G (IgG) toward its target epitope. Avidity is directly related to affinity, as both processes are determined by the best fit of IgG to epitopes. We confirm and extend data on incomplete avidity maturation of IgG toward severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein (NP), spike protein-1 (S1), and its receptor-binding domain (RBD) in coronavirus disease 2019 (COVID-19) patients. In SARS-CoV-2-infected individuals, an initial rise in avidity maturation was ending abruptly, leading to IgG of persistently low or intermediate avidity. Incomplete avidity maturation might facilitate secondary SARS-CoV-2 infections and thus prevent the establishment of herd immunity. Incomplete avidity maturation after infection with SARS-CoV-2 (with only 11.8% of cases showing finally IgG of high avidity, that is, an avidity index > 0.6) was contrasted by regular and rapid establishment of high avidity in SARS-CoV-2 naïve individuals after two vaccination steps with the BioNTech messenger RNA (mRNA) Vaccine (78% of cases with high avidity). One vaccination step was not sufficient for induction of complete avidity maturation in vaccinated SARS-CoV-2 naïve individuals, as it induced high avidity only in 2.9% of cases within 3 weeks. However, one vaccination step was sufficient to induce high avidity in individuals with previous SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Antibodies, Viral/immunology , Antibody Formation/immunology , COVID-19/virology , COVID-19 Vaccines/immunology , Epitopes/immunology , Humans , Immunity, Herd/immunology , Immunologic Tests/methods , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods , Vaccines, Synthetic/immunology
3.
J Med Virol ; 93(12): 6803-6807, 2021 12.
Article in English | MEDLINE | ID: covidwho-1544308

ABSTRACT

We evaluated the Panbio™ COVID-19 Ag Rapid Test Device as a point-of-care diagnostic tool for COVID-19 in 357 patients at a pediatric emergency department. Thirty-four patients tested positive by reverse transcription polymerase chain reaction, of which 24 were positive by the antigen assay. The sensitivity and specificity of the assay were 70.5% and 100%, respectively.


Subject(s)
Antigens, Viral/immunology , COVID-19/diagnosis , COVID-19/immunology , SARS-CoV-2/immunology , COVID-19 Nucleic Acid Testing/methods , COVID-19 Serological Testing/methods , Child , Child, Preschool , Emergency Service, Hospital , Female , Humans , Immunologic Tests/methods , Infant , Male , Nasopharynx/immunology , Nasopharynx/virology , Point-of-Care Testing , Prospective Studies , Sensitivity and Specificity
4.
J Med Virol ; 93(12): 6778-6781, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544295

ABSTRACT

A high-throughput, fully automated antigen detection test for SARS-CoV-2 is a viable alternative to reverse-transcription polymerase chain reaction (RT-qPCR) for mass screening during outbreaks. In this study, we compared RT-qPCR for viral load and the VITROS® SARS-CoV-2 Antigen Test with reference to the results of the LUMIPULSE® SARS-CoV-2 Ag Test. Of 128 nasopharyngeal swab specimens taken from patients suspected of being infected with SARS-CoV-2, 49 were positive and 79 were negative according to RT-qPCR. Consistent dose-dependent detection with VITROS® assay was successfully achieved when using nasopharyngeal swab specimens with Ct values of 32.0 or lesser, whereas the CLEIA-based LUMIPULSE® assay was able to detect lower viral loads compared with the VITROS® assay. Our results show that the performance of the VITROS® assay was satisfactory for the diagnosis of contagious COVID-19 patients in the clinical setting. Highlights The performance of the VITROS® SARS-CoV-2 Antigen Test was sufficient for the diagnosis of contagious COVID-19. This test showed high sensitivity and specificity in the detection of SARS-CoV-2 in samples with a Ct value of 32 or less.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19 Testing/methods , COVID-19/diagnosis , COVID-19/immunology , Immunoenzyme Techniques/methods , Immunologic Tests/methods , SARS-CoV-2/immunology , Antigens, Viral/genetics , Antigens, Viral/immunology , COVID-19/virology , Humans , Mass Screening/methods , Nasopharynx/immunology , Nasopharynx/virology , RNA, Viral/genetics , RNA, Viral/immunology , Real-Time Polymerase Chain Reaction/methods , SARS-CoV-2/genetics , Sensitivity and Specificity , Viral Load/genetics , Viral Load/immunology
5.
J Med Virol ; 93(12): 6813-6817, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1530183

ABSTRACT

Vaccination for SARS-CoV-2 is necessary to overcome coronavirus disease 2019 (COVID-19). However, the time-dependent vaccine-induced immune response is not well understood. This study aimed to investigate the dynamics of SARS-CoV-2 antispike immunoglobulin G (IgG) response. Medical staff participants who received two sequential doses of the BNT162b2 vaccination on days 0 and 21 were recruited prospectively from the Musashino Red Cross Hospital between March and May 2021. The quantitative antispike receptor-binding domain (RBD) IgG antibody responses were measured using the Abbott SARS-CoV-2 IgGII Quant assay (cut off ≥50 AU/ml). A total of 59 participants without past COVID-19 history were continuously tracked with serum samples. The median age was 41 (22-75) years, and 14 participants were male (23.7%). The median antispike RBD IgG and seropositivity rates were 0 (0-31.1) AU/ml, 0.3 (0-39.5) AU/ml, 529.1 (48.3-8711.4) AU/ml, 18,836.9 (742.2-57,260.4) AU/ml, and 0%, 0%, 98.3%, and 100% on days 0, 3, 14, and 28 after the first vaccination, respectively. The antispike RBD IgG levels were significantly increased after day 14 from vaccination (p < 0.001) The BNT162b2 vaccination led almost all participants to obtain serum antispike RBD IgG 14 days after the first dose.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Antibodies, Viral/immunology , Antibody Formation/immunology , COVID-19/virology , Female , Humans , Immunologic Tests/methods , Male , Middle Aged , Prospective Studies , Vaccination/methods , Young Adult
7.
Clin Infect Dis ; 73(9): e2952-e2959, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1501018

ABSTRACT

BACKGROUND: The detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA by reverse-transcription polymerase chain reaction (PCR) does not necessarily indicate shedding of infective virions. There are limited data on the correlation between the isolation of SARS-CoV-2, which likely indicates infectivity, and PCR. METHODS: A total of 195 patients with Coronavirus disease 2019 were tested (outpatients, n = 178; inpatients, n = 12; and critically unwell patients admitted to the intensive care unit [ICU] patients, n = 5). SARS-CoV-2 PCR-positive samples were cultured in Vero C1008 cells and inspected daily for cytopathic effect (CPE). SARS-CoV-2-induced CPE was confirmed by PCR of culture supernatant. Where no CPE was observed, PCR was performed on day 4 to confirm absence of virus replication. The cycle thresholds (Cts) of the day 4 PCR (Ctculture) and the PCR of the original clinical sample (Ctsample) were compared, and positive cultures were defined where Ctsample - Ctculture was ≥3. RESULTS: Of 234 samples collected, 228 (97%) were from the upper respiratory tract. SARS-CoV-2 was isolated from 56 (24%), including in 28 of 181 (15%), 19 of 42 (45%), and 9 of 11 samples (82%) collected from outpatients, inpatients, and ICU patients, respectively. All 56 samples had Ctsample ≤32; CPE was observed in 46 (20%). The mean duration from symptom onset to culture positivity was 4.5 days (range, 0-18). SARS-CoV-2 was significantly more likely to be isolated from samples collected from inpatients (P < .001) and ICU patients (P < .0001) compared with outpatients, and in samples with lower Ctsample. CONCLUSIONS: SARS-CoV-2 culture may be used as a surrogate marker for infectivity and inform de-isolation protocols.


Subject(s)
COVID-19 , Animals , Chlorocebus aethiops , Critical Care , Humans , Immunologic Tests , SARS-CoV-2 , Vero Cells
8.
Aging (Albany NY) ; 13(21): 23895-23912, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1498164

ABSTRACT

The coronavirus disease 2019 (COVID-19) is presently the most pressing public health concern worldwide. Cytokine storm is an important factor leading to death of patients with COVID-19. This study aims to characterize serum cytokines of patients with severe or critical COVID-19. Clinical records were obtained from 149 patients who were tested at the Sino-French New City Branch of Tongji Hospital from 30 January to 30 March 2020. Data regarding the clinical features of the patients was collected and analyzed. Among the 149, 45 (30.2%) of them had severe conditions and 104 (69.8%) of that presented critical symptoms. In the meantime, 80 (53.7%) of that 149 died during hospitalization. Of all, male patients accounted for 94 (69.1%). Compared with patients in severe COVID-19, those who in critical COVID-19 had significantly higher levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-8, and IL-10. Moreover, the passed-away patients had considerably higher levels of TNF-α, IL-6, IL-8, and IL-10 than those survived from it. Regression analysis revealed that serum TNF-α level was an independent risk factor for the death of patient with severe conditions. Among the proinflammatory cytokines (IL-1ß, TNF-α, IL-8, and IL-6) analyzed herein, TNF-α was seen as a risk factor for the death of patients with severe or critical COVID-19. This study suggests that anti-TNF-α treatment allows patients with severe or critical COVID-19 pneumonia to recover.


Subject(s)
COVID-19 , Critical Illness , Interleukins/blood , Pneumonia, Viral , Tumor Necrosis Factor-alpha/blood , COVID-19/diagnosis , COVID-19/immunology , COVID-19/mortality , COVID-19/therapy , China/epidemiology , Critical Illness/mortality , Critical Illness/therapy , Female , Hospital Mortality , Humans , Immunologic Tests/methods , Male , Middle Aged , Mortality , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/etiology , Predictive Value of Tests , Risk Factors , SARS-CoV-2 , Severity of Illness Index , Tomography, X-Ray Computed/methods , Tumor Necrosis Factor Inhibitors/therapeutic use
9.
J Clin Microbiol ; 59(11): e0156421, 2021 10 19.
Article in English | MEDLINE | ID: covidwho-1480239

ABSTRACT

The utility of rapid antigen testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is measured within the context for which it is applied; diagnostic accuracy must be considered in determining if rapid antigen testing is appropriate for the clinical situation. In this issue of the Journal of Clinical Microbiology, J. N. Kanji, D. T. Proctor, W. Stokes, B. M. Berenger, et al. (J Clin Microbiol 59:e01411-21, 2021, https://doi.org/10.1128/JCM.01411-21) evaluate two rapid antigen tests that demonstrate high false-positive rates in asymptomatic health care workers. The assays may not be useful in situations where there is a shortage of staff, such as health care settings, since isolation would occur unnecessarily for these employees.


Subject(s)
COVID-19 , SARS-CoV-2 , Health Personnel , Humans , Immunologic Tests , Vaccination
10.
J Med Virol ; 93(10): 6050-6053, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1432433

ABSTRACT

During the "first wave" of the coronavirus disease 2019 (COVID-19) pandemic in the United Kingdom (March-June 2020), the city of Leicester was particularly hard hit, resulting in reimposed lockdown measures. Although initial polymerase chain reaction testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was attempted within the community, testing was soon abandoned due to an inability to keep up with demand by local laboratories. It is therefore feasible that undiagnosed transmission of COVID-19 in the community by asymptomatic individuals was a real possibility. Therefore, retrospective SARS-CoV-2 immunoglobulin G (IgG) testing of archived sera from out-patients visiting University Hospitals of Leicester NHS Trust service was performed to investigate the transmission of SARS-CoV-2 in the community. A total of 1779 sera samples were tested from samples collected between 16th March and 3rd June 2020, of which 202 (11.35%) were SARS-CoV-2 IgG positive. Positivity was lowest in March (2.54%) at the beginning of the pandemic before peaking in April (17.16%) before a decline in May and June (11.16% and 12.68%, respectively). This retrospective screening offers some insight into the early patterns of SARS-CoV-2 transmission within a sampled community population during the first wave of the COVID-19 pandemic; supporting the argument for more community screening during high incidences of pandemics.


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , COVID-19/epidemiology , Immunoglobulin G/blood , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Immunologic Tests , Infant , Infant, Newborn , Male , Mass Screening/statistics & numerical data , Middle Aged , Pandemics , Retrospective Studies , United Kingdom/epidemiology , Young Adult
11.
J Med Virol ; 93(12): 6813-6817, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1400917

ABSTRACT

Vaccination for SARS-CoV-2 is necessary to overcome coronavirus disease 2019 (COVID-19). However, the time-dependent vaccine-induced immune response is not well understood. This study aimed to investigate the dynamics of SARS-CoV-2 antispike immunoglobulin G (IgG) response. Medical staff participants who received two sequential doses of the BNT162b2 vaccination on days 0 and 21 were recruited prospectively from the Musashino Red Cross Hospital between March and May 2021. The quantitative antispike receptor-binding domain (RBD) IgG antibody responses were measured using the Abbott SARS-CoV-2 IgGII Quant assay (cut off ≥50 AU/ml). A total of 59 participants without past COVID-19 history were continuously tracked with serum samples. The median age was 41 (22-75) years, and 14 participants were male (23.7%). The median antispike RBD IgG and seropositivity rates were 0 (0-31.1) AU/ml, 0.3 (0-39.5) AU/ml, 529.1 (48.3-8711.4) AU/ml, 18,836.9 (742.2-57,260.4) AU/ml, and 0%, 0%, 98.3%, and 100% on days 0, 3, 14, and 28 after the first vaccination, respectively. The antispike RBD IgG levels were significantly increased after day 14 from vaccination (p < 0.001) The BNT162b2 vaccination led almost all participants to obtain serum antispike RBD IgG 14 days after the first dose.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Antibodies, Viral/immunology , Antibody Formation/immunology , COVID-19/virology , Female , Humans , Immunologic Tests/methods , Male , Middle Aged , Prospective Studies , Vaccination/methods , Young Adult
12.
J Infect Dis ; 224(5): 793-797, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1393272

ABSTRACT

We investigated whether the antibody response to coronavirus disease 2019 (COVID-19) mRNA vaccination is similar in women and men. In a community cohort without prior COVID-19, first vaccine dose produced higher immunoglobulin G (IgG) levels and percent inhibition of spike-ACE2 receptor binding, a surrogate measure of virus neutralization, in women compared to men (7.0 µg/mL, 51.6% vs 3.3 µg/mL, 36.4%). After 2 doses, IgG levels remained significantly higher for women (30.4 µg/mL) compared to men (20.6 µg/mL), while percent inhibition was similar (98.4% vs 97.7%). Sex-specific antibody response to mRNA vaccination informs future efforts to understand vaccine protection and side effects.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Immunoglobulin G/immunology , Vaccines, Synthetic/immunology , Adult , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Formation/immunology , Female , Humans , Immunologic Tests/methods , Male , Middle Aged , Neutralization Tests/methods , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods
13.
Biol Pharm Bull ; 44(9): 1332-1336, 2021 Sep 01.
Article in English | MEDLINE | ID: covidwho-1388871

ABSTRACT

Antigen tests for infectious diseases are inexpensive and easy-to-use, but the limit of detection (LOD) is generally higher than that of PCR tests, which are considered the gold standard. In the present study, we combined a sandwich enzyme-linked immunosorbent assay (ELISA) with thionicotinamide-adenine dinucleotide (thio-NAD) cycling to improve the LOD of antigen tests for coronavirus disease 2019 (COVID-19). For recombinant nucleocapsid proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the LOD of our ELISA with thio-NAD cycling was 2.95 × 10-17 moles/assay. When UV-irradiated inactive SARS-CoV-2 was used, the minimum detectable virions corresponding to 2.6 × 104 RNA copies/assay were obtained using our ELISA with thio-NAD cycling. The assay volume for each test was 100 µL. The minimum detectable value was smaller than that of the latest antigen test using a fluorescent immunoassay for SARS-CoV-2, indicating the validity of our detection system for COVID-19 diagnosis.


Subject(s)
Antibodies, Viral , COVID-19 Testing/methods , COVID-19/diagnosis , Enzyme-Linked Immunosorbent Assay/methods , NAD/analogs & derivatives , Nucleocapsid Proteins/immunology , SARS-CoV-2 , Antigens, Viral , COVID-19/virology , Humans , Immunologic Tests , Limit of Detection , Nucleocapsid/analysis , Sensitivity and Specificity
15.
Braz. arch. biol. technol ; 64(spe): e21200147, 2021. tab, graf
Article in English | LILACS (Americas) | ID: covidwho-1378146

ABSTRACT

Abstract With the COVID-19 pandemic, many diagnostic tests (molecular or immunological) were rapidly standardised, given the urgency of the situation, many are still in the process of being validated. The main objective of this study was to review the aspects of the diagnostic kits approved in Brazil and their application in the different federative units to gather epidemiological information. In order to achieve these objectives, a survey was carried out on the data available at the regulatory agency (ANVISA) and in the literature. The main countries that have registered products in Brazil are China (51.4%), Brazil (16.6%), South Korea (9.2%), USA (8.8%) and Germany (3.6%). The methodologies of these products are based on the detection of nucleic-acid (15.8%), antigen (13%) and antibody (71.2%). In the immunological tests, it was verified that the sensitivity ranged from 55 to 100% and the specificity from 80 to 100%. The percentage of cases in the samples tested in Brazil is elevated in almost all federative units since eight states showed 40% of positive cases in tested samples, while 18 states displayed between 20 and 40%. In conclusion, this review showed that Brazil is dependent on external technology to respond to pandemics, epidemics and endemics disease and needs to improve its biotechnological scheme to solve further diseases outbreaks.


Subject(s)
Humans , SARS Virus/isolation & purification , COVID-19/diagnosis , Immunologic Tests/instrumentation , Brazil/epidemiology , Enzyme-Linked Immunosorbent Assay/instrumentation , Chromatography, Affinity/instrumentation , COVID-19 Testing/instrumentation , COVID-19 Nucleic Acid Testing/methods
16.
J Infect Chemother ; 27(11): 1669-1673, 2021 Nov.
Article in English | MEDLINE | ID: covidwho-1356307

ABSTRACT

INTRODUCTION: The automated quantitative antigen test (QAT), which detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is suitable for mass screening. However, its diagnostic capability differentiated by time from onset and potential contribution to infectivity assessment have not been fully investigated. METHODS: A retrospective, observational study using nasopharyngeal swab specimens from coronavirus disease (COVID-19) inpatients was conducted using LumipulseⓇ SARS-CoV-2 antigen test. Diagnostic accuracy was examined for the early (up to 10 days after onset) and late (over 10 days after onset) stages. Time-course QAT changes and reverse-transcription quantitative polymerase chain reaction tests results were displayed as locally estimated scatterplot smoothing curve, and receiver operating characteristic curve (ROC) analysis was used to determine the appropriate cutoff value for differentiating the early and late stages. RESULTS: We obtained 100 specimens from 68 COVID-19 patients, including 51 early-stage and 49 late-stage specimens. QAT sensitivity and specificity were 0.82 (0.72-0.90) and 0.95 (0.75-0.99) for all periods, 0.93 (0.82-0.98) and 1.00 (0.39-1.00) for the early stage, and 0.66 (0.48-0.82) and 0.93 (0.69-0.99) for the late stage, respectively. The ROC analysis indicated an ideal cutoff value of 6.93 pg/mL for distinguishing early-from late-stage specimens. The sensitivity, specificity, positive predictive value, and negative predictive value for predicting the late stage were 0.76 (0.61-0.87), 0.76 (0.63-0.87), 0.76 (0.61-0.87), and 0.76 (0.63-0.87). CONCLUSIONS: QAT has favorable diagnostic accuracy in the early COVID-19 stages. In addition, an appropriate cutoff point can potentially facilitate rapid identification of noncontagious patients.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Immunologic Tests , Nasopharynx , Retrospective Studies , Sensitivity and Specificity
17.
Sensors (Basel) ; 21(15)2021 Jul 30.
Article in English | MEDLINE | ID: covidwho-1346529

ABSTRACT

The Lateral Flow Immunoassay (LFIA) is by far one of the most successful analytical platforms to perform the on-site detection of target substances. LFIA can be considered as a sort of lab-in-a-hand and, together with other point-of-need tests, has represented a paradigm shift from sample-to-lab to lab-to-sample aiming to improve decision making and turnaround time. The features of LFIAs made them a very attractive tool in clinical diagnostic where they can improve patient care by enabling more prompt diagnosis and treatment decisions. The rapidity, simplicity, relative cost-effectiveness, and the possibility to be used by nonskilled personnel contributed to the wide acceptance of LFIAs. As a consequence, from the detection of molecules, organisms, and (bio)markers for clinical purposes, the LFIA application has been rapidly extended to other fields, including food and feed safety, veterinary medicine, environmental control, and many others. This review aims to provide readers with a 10-years overview of applications, outlining the trends for the main application fields and the relative compounded annual growth rates. Moreover, future perspectives and challenges are discussed.


Subject(s)
Hand , Immunologic Tests , Biomarkers , Humans , Immunoassay
18.
Diagn Microbiol Infect Dis ; 101(4): 115514, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1330749

ABSTRACT

Several rapid testing methodologies have been approved for testing of symptomatic individuals but have not been validated for asymptomatic screening. We evaluated performance of the Abbott PanbioTM COVID-19 rapid antigen assay in the asymptomatic setting. We conducted a prospective study in an urban assessment center and in the context of long-term care staff screening. A total of 3014 individuals submitted paired nasopharyngeal samples, which were tested in parallel with the rapid antigen and laboratory-based, RT-PCR assays SARS-CoV-2 detection. There was 54.5% concordance in positive results between the rapid antigen assay and RT-PCR. All positive rapid antigen assay results were confirmed by RT-PCR. The negative predictive value of the rapid antigen assay minimally improved on the negative pre-test probability of SARS-CoV-2 infection. The Abbott PanbioTM COVID-19 rapid antigen test allowed for faster identification of infected individuals but cannot be used to rule-out SARS-CoV-2 infection.


Subject(s)
Asymptomatic Infections , COVID-19 Serological Testing/methods , COVID-19 Testing/methods , COVID-19/virology , SARS-CoV-2/isolation & purification , COVID-19/diagnosis , Canada , Humans , Immunologic Tests , Nasopharynx/virology , Predictive Value of Tests , Prospective Studies , Sensitivity and Specificity
19.
Clin Infect Dis ; 73(Suppl 1): S45-S53, 2021 07 15.
Article in English | MEDLINE | ID: covidwho-1315688

ABSTRACT

BACKGROUND: High-frequency, rapid-turnaround severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing continues to be proposed as a way of efficiently identifying and mitigating transmission in congregate settings. However, 2 SARS-CoV-2 outbreaks occurred among intercollegiate university athletic programs during the fall 2020 semester, despite mandatory directly observed daily antigen testing. METHODS: During the fall 2020 semester, athletes and staff in both programs were tested daily using Quidel's Sofia SARS Antigen Fluorescent Immunoassay, with positive antigen results requiring confirmatory testing with real-time reverse-transcription polymerase chain reaction. We used genomic sequencing to investigate transmission dynamics in these 2 outbreaks. RESULTS: In the first outbreak, 32 confirmed cases occurred within a university athletics program after the index patient attended a meeting while infectious, despite a negative antigen test on the day of the meeting. Among isolates sequenced from that outbreak, 24 (92%) of 26 were closely related, suggesting sustained transmission following an initial introduction event. In the second outbreak, 12 confirmed cases occurred among athletes from 2 university programs that faced each other in an athletic competition, despite receipt of negative antigen test results on the day of the competition. Sequences from both teams were closely related and distinct from viruses circulating in the community for team 1, suggesting transmission during intercollegiate competition in the community for team 2. CONCLUSIONS: These findings suggest that antigen testing alone, even when mandated and directly observed, may not be sufficient as an intervention to prevent SARS-CoV-2 outbreaks in congregate settings, and they highlight the importance of vaccination to prevent SARS-CoV-2 outbreak in congregate settings.


Subject(s)
COVID-19 , Sports , Humans , Immunologic Tests , SARS-CoV-2 , Universities
20.
J Virol Methods ; 296: 114224, 2021 10.
Article in English | MEDLINE | ID: covidwho-1294028

ABSTRACT

INTRODUCTION: We evaluated the Roche Elecsys IL6 assay on the Cobas immunoassay analyser. METHOD: Serum IL6 of 144 controls were compared to 52 samples from patients with COVID-like respiratory symptoms (17 SARS-CoV-2 RT-PCR positive); 25 of these were from the intensive care unit (ICU). We compared the IL6 levels to C-reactive protein (CRP) and procalcitonin (PCT) levels in all cases. RESULTS: The IL6 assay had coefficient-of-variation (CV) of 2.3 % (34.1 pg/mL) and 2.5 % (222.5 pg/mL), a limit of quantitation <1.6 pg/mL, and was linear from 1.6 to 4948 pg/mL. There was a significant difference in IL6 values between patients with COVID-like respiratory symptoms versus controls (p < 0.001). ROC analysis showed that IL6 > 6.4 pg/mL identified symptomatic cases (AUC 0.94, sensitivity 88.2 %, specificity 97.2 %). There was a significant difference between the IL6 of symptomatic ICU/non-ICU cases (median IL6 228 vs 11 pg/mL, p < 0.0001); ROC analysis showed IL6 > 75 pg/mL (sensitivity 76.0 %, specificity 88.9 %) was superior to CRP and PCT in predicting ICU admission (AUC: IL6 0.83, CRP 0.71, PCT 0.82). CONCLUSION: The performance of Elecsys IL6 assay is in keeping with the manufacturer's claims. IL6 > 6.4 pg/mL differentiates healthy from suspected COVID-19 cases and appears to be raised earlier than the other inflammatory markers in some cases. IL6 > 75 pg/mL was a good predictor of ICU admission.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/immunology , Interleukin-6/immunology , SARS-CoV-2/immunology , Biomarkers/blood , C-Reactive Protein/immunology , Female , Humans , Immunoassay , Immunologic Tests , Intensive Care Units , Interleukin-6/blood , Male , Procalcitonin/blood , Procalcitonin/immunology , ROC Curve , SARS-CoV-2/isolation & purification , Sensitivity and Specificity
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