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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-338375

ABSTRACT

The recent surge of hepatitis of unknown origin in children is hypothesized to be caused by adenovirus 41 and/or SARS-CoV-2 infections. A relatively high proportion of patients testing positive for these viruses concomitantly with the development of acute hepatitis supports this hypothesis. To formally incriminate these viral infections as causative agents of hepatitis, both a plausible physiopathological pathway and supporting epidemiological dynamics in the community need demonstration. In this study, we measured the level of circulation of adenovirus 40/41 and SARS-CoV-2 in the general population of the city of Leuven in Belgium using wastewater monitoring between December 2020 and May 2022 and indoor air sampling in day care centers between November 2021 and May 2022. We also retrospectively analyzed medical records of 12.672 children attending a tertiary hospital draining the same region between January 2019 and April 2022. Our results demonstrate a recent but modest increase in hepatitis of unknown origin concomitant with a surge of circulating adenovirus 41 and SARS-CoV-2 in the general population, including in children under 5.

2.
Viruses ; 14(6)2022 05 31.
Article in English | MEDLINE | ID: covidwho-1869829

ABSTRACT

We report two clusters of SARS-CoV-2 B.1.617.2 (Delta variant) infections in a group of 41 Indian nursing students who travelled from New Delhi, India, to Belgium via Paris, France. All students tested negative before departure and had a second negative antigen test upon arrival in Paris. Upon arrival in Belgium, the students were quarantined in eight different houses. Four houses remained COVID-free during the 24 days of follow-up, while all 27 residents of the other four houses developed an infection during quarantine, including the four residents who were fully vaccinated and the two residents who were partially vaccinated. Genome sequencing revealed two distinct clusters affecting one and three houses, respectively. In this group of students, vaccination status did not seem to prevent infection nor decrease the viral load. No severe symptoms were reported. Extensive contact tracing and 3 months of nationwide genomic surveillance confirmed that these outbreaks were successfully contained and did not contribute to secondary community transmission in Belgium. These clusters highlight the importance of repeated testing and quarantine measures among travelers coming from countries experiencing a surge of infections, as all infections were detected 6 days or more after arrival.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Quarantine , SARS-CoV-2/genetics , Students
3.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336911

ABSTRACT

ABSTRACT To investigate whether wastewater surveillance can be used as an early warning system to detect a rise in SARS-CoV-2 positive cases, and to follow the circulation of specific variants of concern (VOC) in particular geographical areas, wastewater samples were collected from local neighborhood sewers and from a large regional wastewater treatment plant (WWTP) in the area of Leuven, Belgium. In two residential sampling sites, a rise in viral SARS-CoV-2 copies in wastewater preceded the peaks in positive cases. In the WWTP, peaks in the wastewater viral load were seen simultaneous with the waves op positive cases caused by the original Wuhan SARS-CoV-2 strain, the Alpha variant and the Delta variant. For the Omicron BA.1 variant associated wave, the viral load in wastewater increased to a lesser degree, and much later than the increase in positive cases, which could be attributed to a lower level of fecal excretion, as measured in hospitalized patients. Circulation of SARS-CoV-2 VOCs (Alpha, Delta and Omicron) could be detected based on the presence of specific key mutations. The shift in variants was noticeable in the wastewater, with key mutations of two different variants being present simultaneously during the transition period. We found that wastewater based surveillance is a sensitive tool to monitor SARS-CoV-2 circulation levels and VOCs in larger regions. This can prove to be highly valuable in times of reducing testing capacity. Differences in excretion levels of various SARS-CoV-2 variants should however be taken into account when using wastewater surveillance to monitor SARS-CoV-2 circulation levels in the population.

4.
Arch Public Health ; 80(1): 98, 2022 Mar 29.
Article in English | MEDLINE | ID: covidwho-1770578

ABSTRACT

BACKGROUND: Testing for SARS-CoV-2, together with vaccination, is one of the most vital strategies in curbing the current COVID-19 pandemic. The pandemic has led to an unprecedented need for diagnostic testing and the rapid emergence of an abundance of commercial assays on the market. Due to the nature of the pandemic and in the interest of health protection, many of these assays received provisional authorisation for emergency use without thorough validation. To limit false negative and false positive results, it is key to define common criteria that SARS-CoV-2 assays need to fulfil. VALCOR or "VALidation of SARS-CORona Virus-2 assays" is a protocol designed to set up a framework for test validation of SARS-CoV-2 virus assays. OBJECTIVES: VALCOR is a study protocol for the validation of assays used for confirmation of the presence of SARS-CoV-2 in patients with COVID-19 disease or the screening of carriers of SARS-CoV-2 virus by the identification of viral RNA in oropharyngeal and/or nasopharyngeal specimens or other specimens from the human respiratory tract. METHODS: The VALCOR panel of samples will contain clinical human specimens and standardised artificial specimens. The collection of clinical specimens will include nasopharyngeal or oropharyngeal specimens or other specimens from the respiratory tract obtained from COVID-19 patients and healthy carriers of SARS-CoV-2 as well as specimens from subjects not carrying SARS-CoV-2. Artificial specimens include calibrated amounts of viral RNA of SARS-CoV-2 sequences provided by established competent agencies that produce reference materials for the assessment of the limit of detection of each assay. The panel of samples are sent from a central reference laboratory (having access to biobanks of clinical specimens tested already for SARS-CoV-2 with a reference comparator assay) to participating laboratories for testing with a SARS-CoV-2 index assay that requires evaluation. DISCUSSION: VALCOR provides a harmonised and standard framework to benchmark the testing performance of SARS-CoV-2 assays that are rapidly evolving. As the pandemic incited an urgent need for testing capacity, there is a gap in the comprehensive validation of SARS-CoV-2 assays. This study will generate comprehensive validation data for assays used for the diagnosis of SARS-CoV-2 and may serve as a basis for other validation protocols.

5.
Diagn Microbiol Infect Dis ; 103(1): 115659, 2022 May.
Article in English | MEDLINE | ID: covidwho-1676696

ABSTRACT

We retrospectively compared the long-term evolution of IgG anti-spike (S) and anti-nucleocapsid (N) levels (Abbott immunoassays) in 116 non-severe and 115 severe SARS-CoV-2 infected patients from 2 university hospitals up to 365 days post positive RT-PCR. IgG anti-S and anti-N antibody levels decayed exponentially up to 365 days after a peak 0 to 59 days after positive RT-PCR. Peak antibody level/cut-off ratio 0 to 59 days after positive RT-PCR was more than 70 for anti-S compared to less than 6 for anti-N (P < 0.01). Anti-S and anti-N were significantly higher in severe compared to non-severe patients up to 180 to 239 days and 300 to 365 days, respectively (P < 0.05). Despite similar half-lives, the estimated time to 50% seronegativity was more than 2 years for anti-S compared to less than 1 year for anti-N in non-severe and severe COVID-19 patients, due to the significantly higher peak antibody level/cut-off ratio for anti-S compared to anti-N.


Subject(s)
COVID-19 , Antibodies, Viral , Humans , Immunoglobulin G , Retrospective Studies , SARS-CoV-2 , Sensitivity and Specificity
6.
Life (Basel) ; 12(2)2022 Jan 21.
Article in English | MEDLINE | ID: covidwho-1650548

ABSTRACT

We present our approach to rapidly establishing a standardized, multi-site, nation-wide COVID-19 screening program in Belgium. Under auspices of a federal government Task Force responsible for upscaling the country's testing capacity, we were able to set up a national testing initiative with readily available resources, putting in place a robust, validated, high-throughput, and decentralized qPCR molecular testing platform with embedded proficiency testing. We demonstrate how during an acute scarcity of equipment, kits, reagents, personnel, protective equipment, and sterile plastic supplies, we introduced an approach to rapidly build a reliable, validated, high-volume, high-confidence workflow based on heterogeneous instrumentation and diverse assays, assay components, and protocols. The workflow was set up with continuous quality control monitoring, tied together through a clinical-grade information management platform for automated data analysis, real-time result reporting across different participating sites, qc monitoring, and making result data available to the requesting physician and the patient. In this overview, we address challenges in optimizing high-throughput cross-laboratory workflows with minimal manual intervention through software, instrument and assay validation and standardization, and a process for harmonized result reporting and nation-level infection statistics monitoring across the disparate testing methodologies and workflows, necessitated by a rapid scale-up as a response to the pandemic.

8.
J Clin Microbiol ; 59(7): e0037421, 2021 06 18.
Article in English | MEDLINE | ID: covidwho-1486479

ABSTRACT

We evaluated the quantitative DiaSorin Liaison severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test in symptomatic and asymptomatic individuals consulting their general practitioners (GPs) during a period of stable intense virus circulation (213/100,000 habitants per day). Leftover reverse transcription-PCR (RT-PCR) positive (n = 204) and negative (n = 210) nasopharyngeal samples were randomly selected among fresh routine samples collected from patients consulting their GPs. Samples were tested on Liaison XL according to the manufacturer's instructions. Equivocal results were considered negative. The overall sensitivity and specificity of the Liaison antigen test compared to RT-PCR were 65.7% (95% confidence interval [CI], 58.9% to 71.9%) and 100% (CI, 97.8% to 100%). Sensitivity in samples with viral loads of ≥105, ≥104, and ≥103 copies/ml were 100% (CI, 96.3% to 100.0%), 96.5% (CI, 91.8% to 98.7%), and 87.4% (CI, 81.3% to 91.5%), respectively. All samples with ≤103 copies/ml were antigen negative. The ratio of antigen concentration to viral load in samples with ≥103 copies/ml was comparable in symptomatic and asymptomatic individuals (P = 0.58). The proportion of RT-PCR-positive participants with a high viral load (≥105 copies/ml) was not significantly higher in symptomatic than in asymptomatic participants (63.9% [CI, 54.9% to 72.0%] versus 51.9% [CI, 41.1% to 62.6%]; P = 0.11), but the proportion of participants with a low viral load (<103 copies/ml) was significantly higher in asymptomatic than in symptomatic RT-PCR-positive participants (35.4% [CI, 25.8% to 46.4%] versus 14.3% [CI, 9.0% to 21.8%]; P < 0.01). Sensitivity and specificity in samples with a viral load of ≥104 copies/ml were 96.5% and 100%. The correlation of antigen concentration with viral load was comparable in symptomatic and asymptomatic individuals.


Subject(s)
COVID-19 , Humans , Outpatients , Real-Time Polymerase Chain Reaction , Reverse Transcription , SARS-CoV-2 , Sensitivity and Specificity , Viral Load
10.
J Clin Microbiol ; 59(7): e0037421, 2021 06 18.
Article in English | MEDLINE | ID: covidwho-1276886

ABSTRACT

We evaluated the quantitative DiaSorin Liaison severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test in symptomatic and asymptomatic individuals consulting their general practitioners (GPs) during a period of stable intense virus circulation (213/100,000 habitants per day). Leftover reverse transcription-PCR (RT-PCR) positive (n = 204) and negative (n = 210) nasopharyngeal samples were randomly selected among fresh routine samples collected from patients consulting their GPs. Samples were tested on Liaison XL according to the manufacturer's instructions. Equivocal results were considered negative. The overall sensitivity and specificity of the Liaison antigen test compared to RT-PCR were 65.7% (95% confidence interval [CI], 58.9% to 71.9%) and 100% (CI, 97.8% to 100%). Sensitivity in samples with viral loads of ≥105, ≥104, and ≥103 copies/ml were 100% (CI, 96.3% to 100.0%), 96.5% (CI, 91.8% to 98.7%), and 87.4% (CI, 81.3% to 91.5%), respectively. All samples with ≤103 copies/ml were antigen negative. The ratio of antigen concentration to viral load in samples with ≥103 copies/ml was comparable in symptomatic and asymptomatic individuals (P = 0.58). The proportion of RT-PCR-positive participants with a high viral load (≥105 copies/ml) was not significantly higher in symptomatic than in asymptomatic participants (63.9% [CI, 54.9% to 72.0%] versus 51.9% [CI, 41.1% to 62.6%]; P = 0.11), but the proportion of participants with a low viral load (<103 copies/ml) was significantly higher in asymptomatic than in symptomatic RT-PCR-positive participants (35.4% [CI, 25.8% to 46.4%] versus 14.3% [CI, 9.0% to 21.8%]; P < 0.01). Sensitivity and specificity in samples with a viral load of ≥104 copies/ml were 96.5% and 100%. The correlation of antigen concentration with viral load was comparable in symptomatic and asymptomatic individuals.


Subject(s)
COVID-19 , Humans , Outpatients , Real-Time Polymerase Chain Reaction , Reverse Transcription , SARS-CoV-2 , Sensitivity and Specificity , Viral Load
12.
J Clin Microbiol ; 59(7): e0037421, 2021 06 18.
Article in English | MEDLINE | ID: covidwho-1183283

ABSTRACT

We evaluated the quantitative DiaSorin Liaison severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen test in symptomatic and asymptomatic individuals consulting their general practitioners (GPs) during a period of stable intense virus circulation (213/100,000 habitants per day). Leftover reverse transcription-PCR (RT-PCR) positive (n = 204) and negative (n = 210) nasopharyngeal samples were randomly selected among fresh routine samples collected from patients consulting their GPs. Samples were tested on Liaison XL according to the manufacturer's instructions. Equivocal results were considered negative. The overall sensitivity and specificity of the Liaison antigen test compared to RT-PCR were 65.7% (95% confidence interval [CI], 58.9% to 71.9%) and 100% (CI, 97.8% to 100%). Sensitivity in samples with viral loads of ≥105, ≥104, and ≥103 copies/ml were 100% (CI, 96.3% to 100.0%), 96.5% (CI, 91.8% to 98.7%), and 87.4% (CI, 81.3% to 91.5%), respectively. All samples with ≤103 copies/ml were antigen negative. The ratio of antigen concentration to viral load in samples with ≥103 copies/ml was comparable in symptomatic and asymptomatic individuals (P = 0.58). The proportion of RT-PCR-positive participants with a high viral load (≥105 copies/ml) was not significantly higher in symptomatic than in asymptomatic participants (63.9% [CI, 54.9% to 72.0%] versus 51.9% [CI, 41.1% to 62.6%]; P = 0.11), but the proportion of participants with a low viral load (<103 copies/ml) was significantly higher in asymptomatic than in symptomatic RT-PCR-positive participants (35.4% [CI, 25.8% to 46.4%] versus 14.3% [CI, 9.0% to 21.8%]; P < 0.01). Sensitivity and specificity in samples with a viral load of ≥104 copies/ml were 96.5% and 100%. The correlation of antigen concentration with viral load was comparable in symptomatic and asymptomatic individuals.


Subject(s)
COVID-19 , Humans , Outpatients , Real-Time Polymerase Chain Reaction , Reverse Transcription , SARS-CoV-2 , Sensitivity and Specificity , Viral Load
13.
Radiol Cardiothorac Imaging ; 2(2): e200196, 2020 Apr.
Article in English | MEDLINE | ID: covidwho-1155986

ABSTRACT

PURPOSE: To demonstrate the accuracy and reproducibility of low-dose submillisievert chest CT for the diagnosis of coronavirus disease 2019 (COVID-19) infection in patients in the emergency department. MATERIALS AND METHODS: This was a Health Insurance Portability and Accountability Act-compliant, institutional review board-approved retrospective study. From March 14 to 24, 2020, 192 patients in the emergency department with symptoms suggestive of COVID-19 infection were studied by using low-dose chest CT and real-time reverse transcription polymerase chain reaction (RT-PCR). Image analysis included the likelihood of COVID-19 infection and the semiquantitative extent of lung involvement. CT images were analyzed by two radiologists blinded to the RT-PCR results. Reproducibility was assessed using the McNemar test and intraclass correlation coefficient. Time between CT acquisition and report was measured. RESULTS: When compared with RT-PCR, low-dose submillisievert chest CT demonstrated excellent sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosis of COVID-19 (86.7%, 93.6%, 91.1%, 90.3%, and 90.2%, respectively), in particular in patients with clinical symptoms for more than 48 hours (95.6%, 93.2%, 91.5%, 96.5%, and 94.4%, respectively). In patients with a positive CT result, the likelihood of disease increased from 43.2% (pretest probability) to 91.1% or 91.4% (posttest probability), while in patients with a negative CT result, the likelihood of disease decreased to 9.6% or 3.7% for all patients or those with clinical symptoms for >48 hours. The prevalence of alternative diagnoses based on chest CT in patients without COVID-19 infection was 17.6%. The mean effective radiation dose was 0.56 mSv ± 0.25 (standard deviation). Median time between CT acquisition and report was 25 minutes (interquartile range: 13-49 minutes). Intra- and interreader reproducibility of CT was excellent (all intraclass correlation coefficients ≥ 0.95) without significant bias in the Bland-Altman analysis. CONCLUSION: Low-dose submillisievert chest CT allows for rapid, accurate, and reproducible assessment of COVID-19 infection in patients in the emergency department, in particular in patients with symptoms lasting longer than 48 hours. Chest CT has the additional advantage of offering alternative diagnoses in a significant subset of patients.© RSNA, 2020.

14.
J Clin Virol ; 136: 104765, 2021 03.
Article in English | MEDLINE | ID: covidwho-1087042

ABSTRACT

BACKGROUND: Most SARS-CoV-2 infected patients develop IgG antibodies within 2-3 weeks after symptom onset. Antibody levels have been shown to gradually decrease in the first months after infection, but few data are available at six months or later. METHODS: A retrospective multi-center study was performed using 652 samples of 236 PCR-confirmed SARS-CoV-2 infected patients from 2 Belgian University hospitals. Patients were included if at least two samples were available (range 2-7 samples); including at least one sample collected 30 days or later after first positive PCR (range 0-240 days). Of those 236 patients, 19.1 % were classified as mild/asymptomatic (mild) and 80.9 % as moderate to critical (severe). IgG anti-nucleocapsid antibodies (anti-N) were measured using the Abbott Architect immunoassay. RESULTS: 22.2 % of mild and 2.6 % of severe COVID-19 cases never seroconverted (p < 0.001). Of the mild patients who seroconverted 0-59 days after PCR; 18.8 %, 40.0 % and 61.1 % were seronegative in the windows 60-119 days, 120-179 days and 180-240 days after PCR, respectively. In severe patients, these numbers were 1.9 %, 10.8 % and 29.4 % respectively (p < 0.05 each). Antibody levels were significantly higher in severe patients compared to mild patients in each 60 day window (p < 0.001 each). CONCLUSIONS: SARS-CoV-2 anti-N IgG antibody levels steadily decreased after 2 months up to 8 months post PCR. Of severe COVID-19 patients, 70.6 % remained positive up to eight months after infection. Antibody levels were significantly lower in mild SARS-CoV-2 infected patients and 61.1 % became seronegative within 6 months after the first positive PCR.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , Immunoglobulin G/blood , Nucleocapsid/immunology , SARS-CoV-2/immunology , Seroconversion , Humans , Longitudinal Studies , Retrospective Studies , Time Factors
15.
Prenat Diagn ; 40(13): 1755-1758, 2020 12.
Article in English | MEDLINE | ID: covidwho-1070796

ABSTRACT

Even though the global COVID-19 pandemic may affect how medical care is delivered in general, most countries try to maintain steady access for women to routine pregnancy care, including fetal anomaly screening. This means that, also during this pandemic, fetal anomalies will be detected, and that discussions regarding invasive genetic testing and possibly fetal therapy will need to take place. For patients, concerns about Severe Acute Respiratory Syndrome-Corona Virus 2 will add to the anxiety caused by the diagnosis of a serious fetal anomaly. Yet, also for fetal medicine teams the situation gets more complex as they must weigh up the risks and benefits to the fetus as well as the mother, while managing a changing evidence base and logistic challenges in their healthcare system.


Subject(s)
COVID-19 , Fetal Therapies , Pandemics , Disasters , Female , Humans , Infectious Disease Transmission, Vertical , Pregnancy , Pregnancy Complications, Infectious
16.
mBio ; 12(1)2021 01 19.
Article in English | MEDLINE | ID: covidwho-1066819

ABSTRACT

Bats host many viruses pathogenic to humans, and increasing evidence suggests that rotavirus A (RVA) also belongs to this list. Rotaviruses cause diarrheal disease in many mammals and birds, and their segmented genomes allow them to reassort and increase their genetic diversity. Eighteen out of 2,142 bat fecal samples (0.8%) collected from Europe, Central America, and Africa were PCR-positive for RVA, and 11 of those were fully characterized using viral metagenomics. Upon contrasting their genomes with publicly available data, at least 7 distinct bat RVA genotype constellations (GCs) were identified, which included evidence of reassortments and 6 novel genotypes. Some of these constellations are spread across the world, whereas others appear to be geographically restricted. Our analyses also suggest that several unusual human and equine RVA strains might be of bat RVA origin, based on their phylogenetic clustering, despite various levels of nucleotide sequence identities between them. Although SA11 is one of the most widely used reference strains for RVA research and forms the backbone of a reverse genetics system, its origin remained enigmatic. Remarkably, the majority of the genotypes of SA11-like strains were shared with Gabonese bat RVAs, suggesting a potential common origin. Overall, our findings suggest an underexplored genetic diversity of RVAs in bats, which is likely only the tip of the iceberg. Increasing contact between humans and bat wildlife will further increase the zoonosis risk, which warrants closer attention to these viruses.IMPORTANCE The increased research on bat coronaviruses after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) allowed the very rapid identification of SARS-CoV-2. This is an excellent example of the importance of knowing viruses harbored by wildlife in general, and bats in particular, for global preparedness against emerging viral pathogens. The current effort to characterize bat rotavirus strains from 3 continents sheds light on the vast genetic diversity of rotaviruses and also hints at a bat origin for several atypical rotaviruses in humans and animals, implying that zoonoses of bat rotaviruses might occur more frequently than currently realized.


Subject(s)
Chiroptera/virology , Rotavirus Infections/transmission , Rotavirus Infections/virology , Rotavirus/genetics , Zoonoses/transmission , Zoonoses/virology , Animals , COVID-19/transmission , COVID-19/virology , Diarrhea/virology , Genetic Variation , Genome, Viral , Genotype , Horses , Humans , Metagenomics , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Phylogeny , SARS-CoV-2/isolation & purification
18.
Nat Commun ; 11(1): 5838, 2020 11 17.
Article in English | MEDLINE | ID: covidwho-933686

ABSTRACT

Emergence of SARS-CoV-2 causing COVID-19 has resulted in hundreds of thousands of deaths. In search for key targets of effective therapeutics, robust animal models mimicking COVID-19 in humans are urgently needed. Here, we show that Syrian hamsters, in contrast to mice, are highly permissive to SARS-CoV-2 and develop bronchopneumonia and strong inflammatory responses in the lungs with neutrophil infiltration and edema, further confirmed as consolidations visualized by micro-CT alike in clinical practice. Moreover, we identify an exuberant innate immune response as key player in pathogenesis, in which STAT2 signaling plays a dual role, driving severe lung injury on the one hand, yet restricting systemic virus dissemination on the other. Our results reveal the importance of STAT2-dependent interferon responses in the pathogenesis and virus control during SARS-CoV-2 infection and may help rationalizing new strategies for the treatment of COVID-19 patients.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/pathology , Coronavirus Infections/virology , Disease Models, Animal , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , STAT2 Transcription Factor/metabolism , Signal Transduction , Animals , Betacoronavirus/pathogenicity , COVID-19 , Coronavirus Infections/immunology , Coronavirus Infections/metabolism , Cricetinae , Immunity, Innate , Interferon Type I/genetics , Interferon Type I/metabolism , Lung/pathology , Lung/virology , Mice , Pandemics , Pneumonia, Viral/immunology , Pneumonia, Viral/metabolism , SARS-CoV-2 , STAT2 Transcription Factor/genetics , Virus Replication
19.
Clin Microbiol Infect ; 26(11): 1557.e1-1557.e7, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-919700

ABSTRACT

OBJECTIVES: The aim was to determine the antibody response against SARS-CoV-2 spike protein and nucleoprotein using four automated immunoassays and three ELISAs for the detection of total Ig antibodies (Roche) or IgG (Abbott, Diasorin, Snibe, Euroimmun, Mikrogen) in COVID-19 patients. METHODS: Sensitivity and dynamic trend to seropositivity were evaluated in 233 samples from 114 patients with moderate, severe or critical COVID-19 confirmed with PCR on nasopharyngeal swab. Specificity was evaluated in 113 samples collected before January 2020, including 24 samples from patients with non-SARS coronavirus infection. RESULTS: Sensitivity for all assays was 100% (95% confidence interval 83.7-100) 3 weeks after onset of symptoms. Specificity varied between 94.7% (88.7-97.8) and 100% (96.1-100). Calculated at the cut-offs that corresponded to a specificity of 95% and 97.5%, Roche had the highest sensitivity (85.0% (79.8-89.0) and 81.1% (76.6-85.7), p < 0.05 except vs. Abbott). Seroconversion occurred on average 2 days earlier for Roche total Ig anti-N and the three IgG anti-N assays (Abbott, Mikrogen, Euroimmun) than for the two IgG anti-S assays (Diasorin, Euroimmun) (≥50% seroconversion day 9-10 vs. day 11-12 and p < 0.05 for percent seropositive patients day 9-10 to 17-18). There was no significant difference in the IgG antibody time to seroconversion between critical and non-critical patients. DISCUSSION: Seroconversion occurred within 3 weeks after onset of symptoms with all assays and on average 2 days earlier for assays detecting IgG or total Ig anti-N than for IgG anti-S. The specificity of assays detecting anti-N was comparable to anti-S and excellent in a challenging control population.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/immunology , Coronavirus Infections/diagnosis , Nucleocapsid Proteins/immunology , Pneumonia, Viral/diagnosis , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Aged, 80 and over , Betacoronavirus/isolation & purification , COVID-19 , COVID-19 Testing , Clinical Laboratory Techniques , Coronavirus Nucleocapsid Proteins , Enzyme-Linked Immunosorbent Assay , Female , Humans , Immunoassay , Immunoglobulin G/blood , Male , Middle Aged , Pandemics , Phosphoproteins , Retrospective Studies , SARS-CoV-2 , Sensitivity and Specificity , Seroconversion , Young Adult
20.
Acta Clin Belg ; 77(2): 295-300, 2022 Apr.
Article in English | MEDLINE | ID: covidwho-872891

ABSTRACT

OBJECTIVES: To examine the added value of anti-SARS-CoV-2 antibody testing in a nursing home during an acute COVID-19 outbreak. RT-PCR is the gold standard, but can be false-negative. METHODS: 119 residents and 93 staff members were tested with RT-PCR test and/or a rapid IgM/IgG test. Of these participants, 176 had both tests, 24 only RT-PCR, and 12 only IgM/IgG in the period April 14 to 16 April 2020. RESULTS: 40 (34%) residents and 11 (13%) staff were PCR-positive. Using a rapid IgM/IgG test, 17 (17%) residents and 18 (20%) staff were positive for IgM and/or IgG (IgM/IgG). Thirty-two PCR-positive residents had an IgM/IgG test: 9 (28%), 11 (34%), and 13 (41%) were positive for IgM, IgG, and IgM/IgG. Ten PCR-positive staff had an IgM/IgG test: 3 (30%), 6 (60%), and 6 (60%) were positive for IgM, IgG, and IgM/IgG. Additional IgM/IgG tests were performed in 9 residents 11 to 14 days after the positive RT-PCR test. Of those, 7 (78%) tested positive for IgM/IgG. When retested 3 weeks later, the 2 remaining residents also tested positive. Of the 134 PCR-negative participants who had an IgM/IgG test, 15 were positive for IgM/IgG (8% of the 200 participants tested with RT-PCR). CONCLUSIONS: During an acute outbreak in a nursing home, 26% of residents and staff were PCR-positive. An additional 8% was diagnosed using IgM/IgG antibody testing. The use of RT-PCR alone as the sole diagnostic method for surveillance during an acute outbreak is insufficient to grab the full extent of the outbreak.


Subject(s)
COVID-19 , COVID-19/diagnosis , COVID-19/epidemiology , Disease Outbreaks , Humans , Immunoglobulin M , Nursing Homes , SARS-CoV-2 , Sensitivity and Specificity
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