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1.
Int J Environ Res Public Health ; 19(22)2022 Nov 18.
Article in English | MEDLINE | ID: covidwho-2116003

ABSTRACT

BACKGROUND: Uncertainties remain regarding the nature and durability of the humoral immune response to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). AIM: This study investigated immunoglobulin G response and neutralizing activity to evaluate the mean antibody concentrations and response duration induced by each vaccination regimen in a French adult population. METHODS: A study including blood sampling and questionnaires was carried out from November 2020 to July 2021 with three separate follow-up phases. Spike proteins and neutralizing antibodies were quantified using ELISA and a virus-neutralization test. RESULTS: Overall, 295 participants were included. Seroprevalences were 11.5% (n = 34), 10.5% (n = 31), and 68.1% (n = 201) in phases 1, 2, and 3, respectively. Importantly, 5.8% (n = 17) of participants lost their natural antibodies. Antibody response of participants with only a prior infection was 88.2 BAU/mL, significantly lower than those vaccinated, which was 1909.3 BAU/mL (p = 0.04). Moreover, the antibody response of vaccinated participants with a prior infection was higher (3593.8 BAU/mL) than those vaccinated without prior infection (3402.9 BAU/mL) (p = 0.78). Vaccinated participants with or without prior infection had a higher seroneutralization rate (91.0%) than those unvaccinated with prior infection (65.0%). CONCLUSION: These results demonstrated that single infection does not confer effective protection against SARS-CoV-2.


Subject(s)
COVID-19 , Spike Glycoprotein, Coronavirus , Adult , Humans , Follow-Up Studies , SARS-CoV-2 , COVID-19/epidemiology , Antibodies, Viral
2.
Archives Des Maladies Professionnelles et De L'Environnement ; 83(4):370-370, 2022.
Article in French | EuropePMC | ID: covidwho-2012159

ABSTRACT

Introduction Dans le cadre de la pandémie mondiale au SARS-CoV-2, les personnels de santé (PS) sont professionnellement exposés à ce virus. Dans ce contexte, cette étude présente les données de surveillance de 5704 travailleurs d’un centre hospitalier, exposés au SARS-CoV-2. Matériel et méthode Les PS symptomatiques, les cas contacts et ceux présentant une forte anxiété ont été testés du 17/03/20 au 20/04/2020. Le diagnostic de COVID-19 a été réalisé par RT-PCR après prélèvement nasopharyngé. Résultats Au cours de cette période, 30,4 % (1735/5704) des PS ont bénéficié de 3057 écouvillons nasaux. Parmi ceux-ci, 8,0 % (138/1735) étaient infectés par le SRAS-CoV-2. Parmi les PS positifs au SARS-CoV-2, 21,7 % étaient asymptomatiques. Chez les PS symptomatiques, 8,1 % (77/952) des tests RT-PCR effectués étaient positifs ;chez les PS, cas contact, sans symptôme, 2,3 % (23/1010) des tests étaient positifs (p < 0,001) ;chez les PS, anxieux, asymptomatiques, 0,3 % (2/687) des tests étaient positifs. Les premiers étaient plus à risque d’être positifs que ces derniers (p < 0,001). Dans les unités COVID et les unités non-COVID, le nombre de personnes infectées par le SARS-CoV-2 était respectivement de 5,8 % (13/223) et 8,2 % (125/1512) (p = 0,2). Les catégories professionnelles les plus souvent infectées par le SARS-CoV2 étaient les infirmières (30,0 % ;40/138), les internes/médecins (21,0 % ;29/138) et les aides-soignants (10,9 % ;15/138). Parmi les médecins, la majorité étaient des internes (70,0 % ;20/29). Les travailleurs de plus de 50 ans étaient moins susceptibles d’être positifs au SARS-CoV-2 (3,8 % ;14/373) que les autres travailleurs plus jeunes (9,1 % ;124/1362) (p < 0,001). Aucun cas grave de COVID-19 n’a été signalé dans notre population au cours de cette période. Conclusion Parmi les PS positifs détectés, 21,7 % (25/115) étaient asymptomatiques. Ces données soulignent l’importance du dépistage systématique des cas contacts même asymptomatiques et de l’utilisation d’équipements de protection individuelle pour éviter la transmission. Le pourcentage des cas positifs diminuait à mesure que l’âge augmentait, en particulier après l’âge de 45 ans. Les personnels de plus de 45 ans, étant plus expérimentées et se sentant plus à risque, ont pu être mieux protégées ou affectées à des services moins à risque ou confinés à domicile. Les PS travaillant dans des unités COVID-19 n’étaient pas plus souvent infectés que ceux travaillant dans des unités non-COVID-19, probablement parce qu’ils étaient plus conscients des dangers et des risques associés au SARS-CoV-2, qu’ils disposaient de plus d’équipements de protection individuelle, qu’ils les portaient de manière plus stricte et qu’ils étaient mieux informés et formés.

3.
J Geriatr Oncol ; 13(6): 850-855, 2022 07.
Article in English | MEDLINE | ID: covidwho-1851497

ABSTRACT

PURPOSE: The COVID-19 vaccination campaign began in December 2020, in France, and primarily targeted the oldest people. Our study aimed to determine the level of acceptance of vaccination in a population of older patients with cancer. METHODS: From January 2021, we offered vaccination with the BNT162b2 COVID-19 vaccine to all patients 70 years and older referred to our geriatric oncology center in Marseille University Hospital (AP-HM) for geriatric assessment before initiation of an oncological treatment. Objectives were to evaluate acceptance rate of COVID-19 vaccination and to assess vaccine safety, reactogenicity, and efficacy two months after the first dose. RESULTS: Between January 18, 2021 and May 7, 2021, 150 older patients with cancer were offered vaccination after a geriatric assessment. The majority were men (61.3%), with a mean age of 81 years. The two most frequent primary tumors were digestive (29.4%) and thoracic (18%). The vaccine acceptance rate was 82.6% and the complete vaccination rate (2 doses) reached 75.3%. Among the vaccinated patients, 15.9% reported mild side effects after the first dose and 23.4% after the second dose, mostly arm pain and fatigue. COVID-19 cases were observed in 5.1% of vaccinated patients compared with 16.7% in unvaccinated patients. Of the 22 vaccinated patients who agreed to have their serum tested, 15 had antibodies against the spike protein at day 21 after the first dose. CONCLUSION: Our study showed a high acceptance rate of COVID-19 vaccination, with good tolerance in this frail population. These results highlight the benefits of organizing vaccination campaigns at the very beginning of oncological management in older patients. CLINICAL TRIAL REGISTRATION: This study was registered May 23, 2019 in ClinicalTrials.gov (NCT03960593).


Subject(s)
COVID-19 , Neoplasms , Vaccines , Aged , Aged, 80 and over , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Female , Humans , Male , Neoplasms/therapy , Vaccination
4.
Viruses ; 14(5)2022 05 03.
Article in English | MEDLINE | ID: covidwho-1820419

ABSTRACT

We aimed to investigate the immunoglobulin G response and neutralizing activity against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) among primary health care workers (PHCW) in France and assess the association between the neutralizing activity and several factors, including the coronavirus disease 2019 (COVID-19) vaccination scheme. A cross-sectional survey was conducted between 10 May 2021 and 31 August 2021. Participants underwent capillary blood sampling and completed a questionnaire. Sera were tested for the presence of antibodies against the nucleocapsid (N) protein and the S-1 portion of the spike (S) protein and neutralizing antibodies. In total, 1612 PHCW were included. The overall seroprevalences were: 23.6% (95% confidence interval (CI) 21.6-25.7%) for antibodies against the N protein, 94.7% (93.6-95.7%) for antibodies against the S protein, and 81.3% (79.4-83.2%) for neutralizing antibodies. Multivariate regression analyses showed that detection of neutralizing antibodies was significantly more likely in PHCW with previous SARS-CoV-2 infection than in those with no such history among the unvaccinated (odds ratio (OR) 16.57, 95% CI 5.96-59.36) and those vaccinated with one vaccine dose (OR 41.66, 95% CI 16.05-120.78). Among PHCW vaccinated with two vaccine doses, the detection of neutralizing antibodies was not significantly associated with previous SARS-CoV-2 infection (OR 1.31, 95% CI 0.86-2.07), but was more likely in those that received their second vaccine dose within the three months before study entry than in those vaccinated more than three months earlier (OR 5.28, 95% CI 3.51-8.23). This study highlights that previous SARS-CoV-2 infection and the time since vaccination should be considered when planning booster doses and the design of COVID-19 vaccine strategies.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Neutralizing , Antibodies, Viral , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines , Cross-Sectional Studies , Humans , Immunoglobulin G , Primary Health Care , SARS-CoV-2 , Seroepidemiologic Studies , Vaccination , Viral Envelope Proteins
5.
Viruses ; 12(6)2020 06 25.
Article in English | MEDLINE | ID: covidwho-1726024

ABSTRACT

The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) worldwide has highlighted the importance of reliable and rapid diagnostic testing to prevent and control virus circulation. Dozens of monoplex in-house RT-qPCR assays are already available; however, the development of dual-target assays is suited to avoid false-negative results caused by polymorphisms or point mutations, that can compromise the accuracy of diagnostic and screening tests. In this study, two mono-target assays recommended by WHO (E-Sarbeco (enveloppe gene, Charite University, Berlin, Germany) and RdRp-IP4 (RdRp, Institut Pasteur, Paris, France)) were selected and combined in a unique robust test; the resulting duo SARS-CoV-2 RT-qPCR assay was compared to the two parental monoplex tests. The duo SARS-CoV-2 assay performed equally, or better, in terms of sensitivity, specificity, linearity and signal intensity. We demonstrated that combining two single systems into a dual-target assay (with or without an MS2-based internal control) did not impair performances, providing a potent tool adapted for routine molecular diagnosis in clinical microbiology laboratories.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/diagnosis , Pneumonia, Viral/diagnosis , RNA-Dependent RNA Polymerase/genetics , Real-Time Polymerase Chain Reaction/methods , Viral Envelope Proteins/genetics , Viral Nonstructural Proteins/genetics , Betacoronavirus/genetics , COVID-19 , Coronavirus Envelope Proteins , Coronavirus Infections/virology , Coronavirus RNA-Dependent RNA Polymerase , Humans , Pandemics , Pneumonia, Viral/virology , RNA, Viral/analysis , SARS-CoV-2 , Sensitivity and Specificity , World Health Organization
6.
Viruses ; 12(6)2020 06 10.
Article in English | MEDLINE | ID: covidwho-1726022

ABSTRACT

There is currently debate about human coronavirus (HCoV) seasonality and pathogenicity, as epidemiological data are scarce. Here, we provide epidemiological and clinical features of HCoV patients with acute respiratory infection (ARI) examined in primary care general practice. We also describe HCoV seasonality over six influenza surveillance seasons (week 40 to 15 of each season) from the period 2014/2015 to 2019/2020 in Corsica (France). A sample of patients of all ages presenting for consultation for influenza-like illness (ILI) or ARI was included by physicians of the French Sentinelles Network during this period. Nasopharyngeal samples were tested for the presence of 21 respiratory pathogens by real-time RT-PCR. Among the 1389 ILI/ARI patients, 105 were positive for at least one HCoV (7.5%). On an annual basis, HCoVs circulated from week 48 (November) to weeks 14-15 (May) and peaked in week 6 (February). Overall, among the HCoV-positive patients detected in this study, HCoV-OC43 was the most commonly detected virus, followed by HCoV-NL63, HCoV-HKU1, and HCoV-229E. The HCoV detection rates varied significantly with age (p = 0.00005), with the age group 0-14 years accounting for 28.6% (n = 30) of HCoV-positive patients. Fever and malaise were less frequent in HCoV patients than in influenza patients, while sore throat, dyspnoea, rhinorrhoea, and conjunctivitis were more associated with HCoV positivity. In conclusion, this study demonstrates that HCoV subtypes appear in ARI/ILI patients seen in general practice, with characteristic outbreak patterns primarily in winter. This study also identified symptoms associated with HCoVs in patients with ARI/ILI. Further studies with representative samples should be conducted to provide additional insights into the epidemiology and clinical features of HCoVs.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus 229E, Human/isolation & purification , Coronavirus Infections/epidemiology , Coronavirus NL63, Human/isolation & purification , Coronavirus OC43, Human/isolation & purification , Respiratory Tract Infections/epidemiology , Adolescent , Adult , Aged , Child , Child, Preschool , Coronavirus Infections/diagnosis , Disease Outbreaks , Female , Humans , Infant , Infant, Newborn , Influenza, Human/epidemiology , Male , Middle Aged , Nasopharynx/virology , Primary Health Care , Real-Time Polymerase Chain Reaction , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/virology , SARS-CoV-2 , Seasons , Young Adult
7.
Viruses ; 12(6)2020 06 08.
Article in English | MEDLINE | ID: covidwho-1726020

ABSTRACT

Clinical samples collected in coronavirus disease 19 (COVID-19), patients are commonly manipulated in biosafety level 2 laboratories for molecular diagnostic purposes. Here, we tested French norm NF-EN-14476+A2 derived from European standard EN-14885 to assess the risk of manipulating infectious viruses prior to RNA extraction. SARS-CoV-2 cell-culture supernatant and nasopharyngeal samples (virus-spiked samples and clinical samples collected in COVID-19 patients) were used to measure the reduction of infectivity after 10 minute contact with lysis buffer containing various detergents and chaotropic agents. A total of thirteen protocols were evaluated. Two commercially available formulations showed the ability to reduce infectivity by at least 6 log 10, whereas others proved less effective.


Subject(s)
Betacoronavirus/drug effects , Coronavirus Infections/virology , Pneumonia, Viral/virology , Virus Inactivation/drug effects , Animals , Betacoronavirus/genetics , Betacoronavirus/isolation & purification , Betacoronavirus/physiology , COVID-19 , Cell Culture Techniques/methods , Chlorocebus aethiops , Containment of Biohazards/methods , Containment of Biohazards/standards , Humans , Nasopharynx/virology , Pandemics , RNA, Viral/isolation & purification , SARS-CoV-2 , Specimen Handling/methods , Vero Cells , Viral Load/methods
8.
Int J Environ Res Public Health ; 19(4)2022 02 10.
Article in English | MEDLINE | ID: covidwho-1690259

ABSTRACT

This study aimed to estimate the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection within the staff and student populations of the University of Corsica (France) during the second wave of the epidemic. METHODS: A cross-sectional survey was conducted from 23 November 2020 to 31 January 2021. The participants underwent blood sampling using a fingerstick procedure and completed an anonymized questionnaire. Sera were tested for the presence of anti-SARS-CoV-2 IgG (ELISA-S) and, if positive, with an in-house virus neutralization test (VNT). RESULTS: A total of 418 persons were included in the study. The overall seroprevalence was 12.8% (95% confidence interval (CI), 9.8-16.6%). A total of 15 (31%) of the 49 individuals who had a positive ELISA-S also had a positive VNT. Seropositivity was associated with living at the city campus during the week and on weekends (OR = 3.74 [1.40-12.00]), using public transportation/carpooling (OR = 2.00 [1.01-4.02]), and being in contact with a person who tested positive for SARS-CoV-2 (OR = 2.32 [1.20-4.40]). The main symptoms associated with seropositivity were "having had an acute respiratory infection" (OR = 3.05 [1.43-6.43]) and "experiencing loss of smell" (OR = 16.4 [5.87-50.7]). CONCLUSION: These results could be useful for SARS-CoV-2 prevention and control on university campuses.


Subject(s)
COVID-19 , SARS-CoV-2 , Antibodies, Viral , COVID-19/epidemiology , Cross-Sectional Studies , Humans , Seroepidemiologic Studies
9.
Anal Chem ; 94(2): 975-984, 2022 01 18.
Article in English | MEDLINE | ID: covidwho-1592056

ABSTRACT

Serological tests are essential for the control and management of COVID-19 pandemic (diagnostics and surveillance, and epidemiological and immunity studies). We introduce a direct serological biosensor assay employing proprietary technology based on plasmonics, which offers rapid (<15 min) identification and quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in clinical samples, without signal amplification. The portable plasmonic device employs a custom-designed multiantigen (RBD peptide and N protein) sensor biochip and reaches detection limits in the low ng mL-1 range employing polyclonal antibodies. It has also been implemented employing the WHO-approved anti-SARS-CoV-2 immunoglobulin standard. A clinical validation with COVID-19 positive and negative samples (n = 120) demonstrates its excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor as an accurate and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the disease management and for the evaluation of immunological status during vaccination or treatment.


Subject(s)
Biosensing Techniques , COVID-19 , Antibodies, Viral , Humans , Pandemics , SARS-CoV-2 , Sensitivity and Specificity
10.
iScience ; 24(11): 103329, 2021 Nov 19.
Article in English | MEDLINE | ID: covidwho-1474646

ABSTRACT

Since the beginning of the COVID-19 pandemics, variants have emerged. Some of them display increased transmissibility and/or resistance to immune response. Most of the mutations involved in the functional adaptation are found in the receptor-binding motif (RBM), close to the interface with the receptor ACE2. We thus developed a fast molecular assay to detect mutations in the RBM coding sequence. After amplification, the amplicon is heat-denatured and hybridized with an amplicon of reference. The presence of a mutation can be detected using a mismatch-specific endonuclease and the cleavage pattern is analyzed by capillary electrophoresis. The method was validated on RNA of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants produced in vitro before being implemented for clinical samples. The assay showed 97.8% sensitivity and 97.8% specificity. The procedure can be set up for high-throughput identification of the presence of mutations and serve as a first-line screening to select the samples for full genome sequencing.

11.
Int Arch Occup Environ Health ; 95(2): 419-424, 2022 03.
Article in English | MEDLINE | ID: covidwho-1469694

ABSTRACT

INTRODUCTION: SARS-CoV-2, which causes COVID-19, is a virus that has caused a global pandemic. Health workers (HWs) are major players in the fight against this infection and are occupationally exposed to the virus in the course of their work. In this context, this study presents surveillance data on 1714 workers in a hospital center in the south of France for the period from March 17 to April 20, 2020. MATERIALS AND METHODS: Symptomatic HWs, contact cases and those with high anxiety were tested. Diagnosis of COVID-19 was performed by RT-PCR after nasopharyngeal sampling. RESULTS: During this period, 30.4% of hospital staff received 3028 nasal swabs. Of these, 8.0% were infected with SARS-CoV-2. Among the SARS-CoV-2 positive HWs, 24.3% were asymptomatic. Among COVID unit and non COVID unit, the positive HWs for SARS-CoV-2 were, respectively, 5.8% and 8.2% (p = 0.2). HWs over 50 years of age were less likely to be positive for SARS-CoV-2 (3.8%) than other younger HWs (9.1%) (p < 0.001). No serious cases of COVID-19 were reported in our population during this period. DISCUSSION: Our study suggests that HWs who tested positive for COVID-19 are often asymptomatic. Therefore, PPE is pivotal to prevent HWs to patients and HWs to HWs transmission during workshifts. Contact tracing and screening is essential to limit the spread of the virus within the hospital. On the other hand, HWs working in COVID-19 units are not more often infected probably because they have a higher risk awareness than other HWs.


Subject(s)
COVID-19 , SARS-CoV-2 , Health Personnel , Hospitals, University , Humans , Pandemics , Personnel, Hospital
12.
Front Public Health ; 9: 715192, 2021.
Article in English | MEDLINE | ID: covidwho-1354899

ABSTRACT

We aimed to use serological surveillance based on serial cross-sectional sampling of residual sera obtained from clinical laboratories to compare the differences in age and sex profiles of infected persons in the first and second waves of SARS-CoV-2 in Corsica, France. Residual sera were obtained, including samples from individuals of all ages collected for routine screening or clinical management by clinical laboratories. All the sera collected were tested for the presence of anti-SARS-CoV-2 IgG using a kit for semi-quantitative detection of IgG antibodies against the S1 domain of the viral spike protein (ELISA-S). Samples that were borderline and positive in ELISA-S were tested with an in-house virus neutralization test. During the second-wave period, we collected between 6 November, 2020 and 12 February, 2021, 4,505 sera from patients aged 0-101 years (60.4% women). The overall weighted seroprevalence of residual sera collected during the second-wave period [8.04% (7.87-9.61)] was significantly higher than the overall weighted seroprevalence estimated at the end of the first wave between 16 April and 15 June, 2020 [5.46% (4.37-7.00)] (p-value = 0.00025). Ninety-eight (30.1%) of the 326 samples tested in the VNT assay had a positive neutralization antibody titer. Estimated seroprevalence increased significantly for men [odds ratio (OR) OR = 1.80 (1.30-2.54); p-value = 0.00026] and for people under 30 years of age [OR = 2.17 (1.46-3.28); p-value = 0.000032]. This increase was observed in young adults aged 20-29 years among whom antibody frequencies were around four-fold higher than those observed at the end of the first wave. In conclusion, our seroprevalence estimates, including the proportion of the participants who had produced neutralizing antibodies, indicate that in February, 2021 the population of Corsica was still far from being protected against SARS-Cov-2 by "herd immunity."


Subject(s)
COVID-19 , Epidemics , Adolescent , Antibodies, Viral , Cross-Sectional Studies , Female , Humans , Male , SARS-CoV-2 , Seroepidemiologic Studies , Young Adult
13.
Pathogens ; 10(7)2021 Jul 20.
Article in English | MEDLINE | ID: covidwho-1323318

ABSTRACT

BACKGROUND: The protocol study will focus on the seroprevalence of IgG antibodies to SARS-CoV-2 achieved by vaccination and/or natural protection as well as the history, symptoms, and risk factors for SARS-CoV-2 in four primary health-care workers (PHCWs) and their household contacts in metropolitan France. METHODS: Here, we propose a protocol for a nationwide survey to determine the seroprevalence of IgG antibodies to SARS-CoV-2 achieved by vaccination and/or natural protection in four PHCW populations (general practitioners, pediatricians, pharmacists and assistants, and dentists and assistants) and their household contacts. Participants will be included from June to July 2021 (Phase 1) among PHCW populations located throughout metropolitan France. They will be asked to provide a range of demographic and behavioral information since the first SARS-CoV-2 wave and a self-sampled dried blood spot. Phase 1 will involve also a questionnaire and serological study of PHCWs' household contacts. Seroprevalence will be estimated using two ELISAs designed to detect specific IgG antibodies to SARS-CoV-2 in humoral fluid, and these results will be confirmed using a virus neutralization test. This study will be repeated from November to December 2021 (Phase 2) to evaluate the evolution of immune status achieved by vaccination and/or natural protection of PHCWs and to describe the history of exposure to SARS-CoV-2.

15.
Biopreserv Biobank ; 18(6): 561-569, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-919312

ABSTRACT

When a new virus emerges and causes a significant epidemic, the emergency response relies on diagnostics, surveillance, testing, and proposal of treatments if they exist, and also in the longer term, redirection of research efforts toward understanding the newly discovered pathogen. To serve these goals, viral biobanks play a crucial role. The European Virus Archive (EVA) is a network of biobanks from research laboratories worldwide that has combined into a common set of practices and mutually beneficial objectives to give scientists the tools that they need to study viruses in general, and also to respond to a pandemic caused by emerging viruses. Taking the most recent outbreaks of the Zika virus and SARS-CoV-2 as examples, by looking at who orders what and when to the EVA, we illustrate how the global science community at large, public health, fundamental research and private companies, reorganize their activity toward diagnosing, understanding, and fighting the new pathogen.


Subject(s)
Biological Specimen Banks , COVID-19 , Pandemics , SARS-CoV-2/metabolism , Zika Virus Infection , Zika Virus/metabolism , COVID-19/epidemiology , COVID-19/metabolism , Europe/epidemiology , Humans , Zika Virus Infection/epidemiology , Zika Virus Infection/metabolism
16.
J Clin Med ; 9(11)2020 Nov 05.
Article in English | MEDLINE | ID: covidwho-908893

ABSTRACT

Our aim was to assess the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection after the lockdown in a sample of the Corsican population. Between 16 April and 15 June 2020, 2312 residual sera were collected from patients with a blood analysis conducted in one of the participating laboratories. Residual sera obtained from persons of all ages were tested for the presence of anti-SARS-CoV-2 Immunoglobulin G (IgG) using the EUROIMMUN enzyme immunoassay kit for semiquantitative detection of IgG antibodies against the S1 domain of viral spike protein (ELISA-S). Borderline and positive samples in ELISA-S were also tested with an in-house virus neutralization test (VNT). Prevalence values were adjusted for sex and age. A total of 1973 residual sera samples were included in the study. The overall seroprevalence based on ELISA-S was 5.27% (95% confidence interval (CI), 4.33-6.35) and 5.46% (4.51-6.57) after adjustment. Sex was not associated with IgG detection. However, significant differences were observed between age groups (p-value = 1 E-5). The highest values were observed among 10-19, 30-39, and 40-49 year-old age groups, ranging around 8-10%. The prevalence of neutralizing antibody titers ≥40 was 3% (2.28-3.84). In conclusion, the present study showed a low seroprevalence for COVID-19 in Corsica, a finding that is in accordance with values reported for other French regions in which the impact of the pandemic was low.

17.
Viruses ; 12(7)2020 07 07.
Article in English | MEDLINE | ID: covidwho-639283

ABSTRACT

Standard precautions to minimize the risk of SARS-CoV-2 transmission implies that infected cell cultures and clinical specimens may undergo some sort of inactivation to reduce or abolish infectivity. We evaluated three heat inactivation protocols (56 °C-30 min, 60 °C-60 min and 92 °C-15 min) on SARS-CoV-2 using (i) infected cell culture supernatant, (ii) virus-spiked human sera (iii) and nasopharyngeal samples according to the recommendations of the European norm NF EN 14476-A2. Regardless of the protocol and the type of samples, a 4 Log10 TCID50 reduction was observed. However, samples containing viral loads > 6 Log10 TCID50 were still infectious after 56 °C-30 min and 60 °C-60 min, although infectivity was < 10 TCID50. The protocols 56 °C-30 min and 60 °C-60 min had little influence on the RNA copies detection, whereas 92 °C-15 min drastically reduced the limit of detection, which suggests that this protocol should be avoided for inactivation ahead of molecular diagnostics. Lastly, 56 °C-30 min treatment of serum specimens had a negligible influence on the results of IgG detection using a commercial ELISA test, whereas a drastic decrease in neutralizing titers was observed.


Subject(s)
Betacoronavirus , Containment of Biohazards/methods , Coronavirus Infections/virology , Pneumonia, Viral/virology , Serologic Tests/methods , Virus Inactivation , Antibodies, Neutralizing/immunology , Betacoronavirus/immunology , COVID-19 , Containment of Biohazards/standards , Coronavirus Infections/diagnosis , Coronavirus Infections/prevention & control , Enzyme-Linked Immunosorbent Assay , Hot Temperature , Humans , Neutralization Tests , Pandemics/prevention & control , Pneumonia, Viral/diagnosis , Pneumonia, Viral/prevention & control , SARS-CoV-2 , Serologic Tests/standards
18.
Emerg Infect Dis ; 26(9)2020 09.
Article in English | MEDLINE | ID: covidwho-614160

ABSTRACT

We spotted severe acute respiratory syndrome coronavirus 2 on polystyrene plastic, aluminum, and glass for 96 hours with and without bovine serum albumin (3 g/L). We observed a steady infectivity (<1 log10 drop) on plastic, a 3.5 log10 decrease on glass, and a 6 log10 drop on aluminum. The presence of proteins noticeably prolonged infectivity.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/transmission , Disease Transmission, Infectious , Fomites/virology , Pneumonia, Viral/transmission , Aluminum/analysis , COVID-19 , Coronavirus Infections/virology , Glass/analysis , Humans , Pandemics , Plastics/analysis , Pneumonia, Viral/virology , SARS-CoV-2 , Time Factors
19.
Euro Surveill ; 25(6)2020 02.
Article in English | MEDLINE | ID: covidwho-664

ABSTRACT

Timely detection of novel coronavirus (2019-nCoV) infection cases is crucial to interrupt the spread of this virus. We assessed the required expertise and capacity for molecular detection of 2019-nCoV in specialised laboratories in 30 European Union/European Economic Area (EU/EEA) countries. Thirty-eight laboratories in 24 EU/EEA countries had diagnostic tests available by 29 January 2020. A coverage of all EU/EEA countries was expected by mid-February. Availability of primers/probes, positive controls and personnel were main implementation barriers.


Subject(s)
Betacoronavirus , Clinical Laboratory Techniques/standards , Coronavirus Infections/diagnosis , Coronavirus/genetics , Coronavirus/isolation & purification , Laboratories/standards , Pneumonia, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , COVID-19 , Clinical Laboratory Techniques/methods , Coronavirus/classification , Coronavirus Infections/genetics , Coronavirus Infections/virology , Disease Outbreaks , European Union , Humans , RNA, Viral/genetics , Reference Standards , SARS-CoV-2 , Sensitivity and Specificity , Sentinel Surveillance , Sequence Analysis
20.
Non-conventional | WHO COVID | ID: covidwho-457508

ABSTRACT

Real-time molecular techniques have become the reference methods for the direct diagnosis of pathogens. The reduction of steps is a key factor in order to decrease the risk of human errors resulting in invalid series and delayed results. We describe here a process involving the preparation of oligonucleotide primers and a hydrolysis probe in a single tube at predefined optimized concentrations that are stabilized via lyophilization (Lyoph-P&P). Lyoph-P&P was compared to the classic protocol using extemporaneously prepared liquid reagents, assaying (i) sensitivity, (ii) long-term stability at 4 °C, and (iii) long-term stability at 37 °C, mimicking transportation without a cold chain. Two previously published molecular assays were selected for this study. They target two emerging viruses that are listed on the blueprint of the WHO to be considered for preparedness and response actions: chikungunya virus (CHIKV) and Rift Valley fever phlebovirus (RVFV). The results of our study demonstrate that (i) Lyoph-P&P is stable for at least four days at 37 °C, supporting shipping without the need of a cold chain, (ii) Lyoph-P&P rehydrated solution is stable at 4 °C for at least two weeks, (iii) the sensitivity observed with Lyoph-P&P is at least equal to, and often better than, that observed with liquid formulation, and (iv) the validation of results observed with low-copy specimens is rendered easier by higher fluorescence levels. In conclusion, Lyoph-P&P holds several advantages over extemporaneously prepared liquid formulations and merits consideration as a novel real-time molecular assay for implementation into a laboratory with routine diagnostic activity. Since the meeting, this concept has been applied to the COVID-19 situation: two diagnostic assays (E gene and RdRp) have been developed and can be ordered on the European Virus Archive catalog (https://www.european-virus-archive.com/detection-kit/lyophilized-primers-and-probe-rt-pcr-2019-ncov-e-gene;https://www.european-virus-archive.com/detection-kit/lyophilized-primers-and-probe-rt-pcr-sars-cov-2-rdrp-gene).

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