925 research outputs found

    Diagnostic accuracy of covid-19 rapid antigen tests with unsupervised self-sampling in people with symptoms in the omicron period: cross sectional study.

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    During phase 1, 45.0% (n=279) of participants in the Flowflex group, 29.1% (n=239) in the MPBio group, and 35.4% ((n=257) in the Clinitest group were confirmatory testers (previously tested positive by a self-test at own initiative). Overall sensitivities with nasal self-sampling were 79.0% (95% confidence interval 74.7% to 82.8%) for Flowflex, 69.9% (65.1% to 74.4%) for MPBio, and 70.2% (65.6% to 74.5%) for Clinitest. Sensitivities were substantially higher in confirmatory testers (93.6%, 83.6%, and 85.7%, respectively) than in those who tested for other reasons (52.4%, 51.5%, and 49.5%, respectively). Sensitivities decreased from 87.0% to 80.9% (P=0.16 by χ2 test), 80.0% to 73.0% (P=0.60), and 83.1% to 70.3% (P=0.03), respectively, when transitioning from omicron accounting for 29% of infections to >95% of infections. During phase 2, 53.0% (n=288) of participants in the MPBio group and 44.4% (n=290) in the Clinitest group were confirmatory testers. Overall sensitivities with combined oropharyngeal and nasal self-sampling were 83.0% (78.8% to 86.7%) for MPBio and 77.3% (72.9% to 81.2%) for Clinitest. When combined oropharyngeal and nasal self-sampling was compared with nasal self-sampling, sensitivities were found to be slightly higher in confirmatory testers (87.4% and 86.1%, respectively) and substantially higher in those testing for other reasons (69.3% and 59.9%, respectively)

    Elevated risk of infection with SARS-CoV-2 Beta, Gamma, and Delta variants compared with Alpha variant in vaccinated individuals

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    The extent to which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) break through infection- or vaccine-induced immunity is not well understood. We analyzed 28,578 sequenced SARS-CoV-2 samples from individuals with known immune status obtained through national community testing in the Netherlands from March to August 2021. We found evidence of an increased risk of infection by the Beta (B.1.351), Gamma (P.1), or Delta (B.1.617.2) variants compared with the Alpha (B.1.1.7) variant after vaccination. No clear differences were found between vaccines. However, the effect was larger in the first 14 to 59 days after complete vaccination compared with ≥60 days. In contrast to vaccine-induced immunity, there was no increased risk for reinfection with Beta, Gamma, or Delta variants relative to the Alpha variant in individuals with infection-induced immunity.</p

    Steeper memory decline after COVID-19 lockdown measures

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    BACKGROUND: During COVID-19 lockdown measures, memory clinic patients reported worries for faster cognitive decline, due to loss of structure and feelings of loneliness and depression. We aimed to investigate the impact of the COVID-19 lockdown on rate of cognitive decline in a mixed memory clinic population, compared to matched historical controls. METHODS: We included patients who visited Alzheimer Center Amsterdam 6 months to 1 week before the first Dutch COVID-19 lockdown, and had a second visit 1 year later, after this lockdown period (n = 113; 66 ± 7 years old; 30% female; n = 55 dementia, n = 31 mild cognitive impairment (MCI), n = 18 subjective cognitive decline (SCD), n = 9 postponed diagnosis). Historical controls (visit in 2016/2017 and second visit 1 year later (n = 640)) were matched 1:1 to lockdown patients by optimal Mahalanobis distance matching (both groups n = 113). Groups were well matched. Differences between lockdown patients and historical controls over time in Mini-Mental State Examination, Trail Making Test part A and B, Rey-Auditory Verbal Learning Test (RAVLT) immediate and delayed recall, and category fluency scores were analyzed using linear mixed effect models with random intercepts. We examined differences in rate of cognitive decline between whole groups, and after stratification in SCD, MCI, and dementia separately. RESULTS: Lockdown patients had a faster rate of memory decline compared to controls on both RAVLT immediate [B(SE) =  - 2.62 (1.07), p = 0.015] and delayed recall [B(SE) =  - 1.07 (0.34), p = 0.002]. Stratification by syndrome diagnosis showed that this effect was largely attributable to non-demented participants, as we observed faster memory decline during lockdown in SCD and MCI (RAVLT immediate [SCD: B(SE) =  - 6.85 (2.97), p = 0.027; MCI: B(SE) =  - 6.14 (1.78), p = 0.001] and delayed recall [SCD: B(SE) =  - 2.45 (1.11), p = 0.035; MCI: B(SE) =  - 1.50 (0.51), p = 0.005]), but not in dementia. CONCLUSION: Memory clinic patients, specifically in pre-dementia stages, showed faster memory decline during COVID-19 lockdown, providing evidence that lockdown regulations had a deleterious effect on brain health. In individuals that may have been able to deal with accumulating, subclinical neuropathology under normal and structured circumstances, the additional stress of lockdown regulations may have acted as a "second hit," resulting in less beneficial disease trajectory

    Diagnostic accuracy of covid-19 rapid antigen tests with unsupervised self-sampling in people with symptoms in the omicron period: cross sectional study.

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    During phase 1, 45.0% (n=279) of participants in the Flowflex group, 29.1% (n=239) in the MPBio group, and 35.4% ((n=257) in the Clinitest group were confirmatory testers (previously tested positive by a self-test at own initiative). Overall sensitivities with nasal self-sampling were 79.0% (95% confidence interval 74.7% to 82.8%) for Flowflex, 69.9% (65.1% to 74.4%) for MPBio, and 70.2% (65.6% to 74.5%) for Clinitest. Sensitivities were substantially higher in confirmatory testers (93.6%, 83.6%, and 85.7%, respectively) than in those who tested for other reasons (52.4%, 51.5%, and 49.5%, respectively). Sensitivities decreased from 87.0% to 80.9% (P=0.16 by χ2 test), 80.0% to 73.0% (P=0.60), and 83.1% to 70.3% (P=0.03), respectively, when transitioning from omicron accounting for 29% of infections to >95% of infections. During phase 2, 53.0% (n=288) of participants in the MPBio group and 44.4% (n=290) in the Clinitest group were confirmatory testers. Overall sensitivities with combined oropharyngeal and nasal self-sampling were 83.0% (78.8% to 86.7%) for MPBio and 77.3% (72.9% to 81.2%) for Clinitest. When combined oropharyngeal and nasal self-sampling was compared with nasal self-sampling, sensitivities were found to be slightly higher in confirmatory testers (87.4% and 86.1%, respectively) and substantially higher in those testing for other reasons (69.3% and 59.9%, respectively)

    Diagnostic accuracy of SARS-CoV-2 rapid antigen self-tests in asymptomatic individuals in the Omicron period: cross sectional study.

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    OBJECTIVES: To assess the performances of three commonly used antigen rapid diagnostic tests used as self-tests in asymptomatic individuals in the Omicron period. METHODS: We performed a cross-sectional diagnostic test accuracy study in the Omicron period in three public health service COVID-19 test sites in the Netherlands, including 3600 asymptomatic individuals aged [Formula: see text] 16 years presenting for SARS-CoV-2 testing for any reason except confirmatory testing after a positive self-test. Participants were sampled for RT-PCR (reference test) and received one self-test (either Acon Flowflex [Flowflex], MP Biomedicals (MPBio), or Siemens-Healthineers CLINITEST [CLINITEST]) to perform unsupervised at home. Diagnostic accuracies of each self-test were calculated. RESULTS: Overall sensitivities were 27.5% (95% CI, 21.3–34.3%) for Flowflex, 20.9% (13.9–29.4%) for MPBio, and 25.6% (19.1–33.1%) for CLINITEST. After applying a viral load cut-off (≥5.2 log10 SARS-CoV-2 E-gene copies/mL), sensitivities increased to 48.3% (37.6–59.2%), 37.8% (22.5–55.2%), and 40.0% (29.5–51.2%), respectively. Specificities were >99% for all tests in most analyses. DISCUSSION: The sensitivities of three commonly used SARS-CoV-2 antigen rapid diagnostic tests when used as self-tests in asymptomatic individuals in the Omicron period were very low. Antigen rapid diagnostic test self-testing in asymptomatic individuals may only detect a minority of infections at that point in time. Repeated self-testing in case of a negative self-test is advocated to improve the diagnostic yield, and individuals should be advised to re-test when symptoms develop

    The International Virus Bioinformatics Meeting 2022

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    The International Virus Bioinformatics Meeting 2022 took place online, on 23-25 March 2022, and has attracted about 380 participants from all over the world. The goal of the meeting was to provide a meaningful and interactive scientific environment to promote discussion and collaboration and to inspire and suggest new research directions and questions. The participants created a highly interactive scientific environment even without physical face-to-face interactions. This meeting is a focal point to gain an insight into the state-of-the-art of the virus bioinformatics research landscape and to interact with researchers in the forefront as well as aspiring young scientists. The meeting featured eight invited and 18 contributed talks in eight sessions on three days, as well as 52 posters, which were presented during three virtual poster sessions. The main topics were: SARS-CoV-2, viral emergence and surveillance, virus-host interactions, viral sequence analysis, virus identification and annotation, phages, and viral diversity. This report summarizes the main research findings and highlights presented at the meeting

    Detection of SARS-CoV-2 in Air and on Surfaces in Rooms of Infected Nursing Home Residents

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    There is an ongoing debate on airborne transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) as a risk factor for infection. In this study, the level of SARS-CoV-2 in air and on surfaces of SARS-CoV-2 infected nursing home residents was assessed to gain insight in potential transmission routes. During outbreaks, air samples were collected using three different active and one passive air sampling technique in rooms of infected patients. Oropharyngeal swabs (OPS) of the residents and dry surface swabs were collected. Additionally, longitudinal passive air samples were collected during a period of 4 months in common areas of the wards. Presence of SARS-CoV-2 RNA was determined using RT-qPCR, targeting the RdRp- and E-genes. OPS, samples of two active air samplers and surface swabs with Ct-value 4 mu m 60% (6/10); 1-4 mu m 50% (5/10)

    The miniJPAS survey: A search for extreme emission-line galaxies

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    This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Context. Galaxies with extreme emission lines (EELGs) may play a key role in the evolution of the Universe, as well as in our understanding of the star formation process itself. For this reason an accurate determination of their spatial density and fundamental properties in different epochs of the Universe will constitute a unique perspective towards a comprehensive picture of the interplay between star formation and mass assembly in galaxies. In addition to this, EELGs are also interesting in order to explain the reionization of the Universe, since their interstellar medium (ISM) could be leaking ionizing photons, and thus they could be low z, analogous of extreme galaxies at high z. Aims. This paper presents a method to obtain a census of EELGs over a large area of the sky by detecting galaxies with rest-frame equivalent widths ≥300 Å in the emission lines [O II]λλ3727,3729Å, [O III]λ5007Å, and Hα. For this, we aim to use the J-PAS survey, which will image an area of ≈8000 deg2 with 56 narrow band filters in the optical. As a pilot study, we present a methodology designed to select EELGs on the miniJPAS images, which use the same filter dataset as J-PAS, and thus will be exportable to this larger survey. Methods. We make use of the miniJPAS survey data, conceived as a proof of concept of J-PAS, and covering an area of ≈1 deg2. Objects were detected in the rSDSS images and selected by imposing a condition on the flux in a given narrow-band J-PAS filter with respect to the contiguous ones, which is analogous to requiring an observed equivalent width larger than 300 Å in a certain emission line within the filter bandwidth. The selected sources were then classified as galaxies or quasi-stellar objects (QSOs) after a comparison of their miniJPAS fluxes with those of a spectral database of objects known to present strong emission lines. This comparison also provided a redshift for each source, which turned out to be consistent with the spectroscopic redshifts when available (|Δz/(1 + zspec)| ≤ 0.01). Results. The selected candidates were found to show a compact appearance in the optical images, some of them even being classified as point-like sources according to their stellarity index. After discarding sources classified as QSOs, a total of 17 sources turned out to exhibit EW0 ≥ 300 Å in at least one emission line, thus constituting our final list of EELGs. Our counts are fairly consistent with those of other samples of EELGs in the literature, although there are some differences, which were expected due to biases resulting from different selection criteria. © J. Iglesias-Páramo et al. 2022.This work has been partially funded by projects PID2019-107408GB-C44 from the Spanish PNAYA, co-funded with FEDER, and grand P18-FR-2664, funded by Junta de Andalucía. We acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709). RGD and LADG acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award to the Instituto de Astrofísica de Andalucía (SEV-2017-0709), and PID2019-109067-GB100. IM acknowledges financial support from the State Agency for Research of the Spanish MCIU through the PID2019-106027GB-C41. JCM acknowledges partial support from the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) through the grant PGC2018-097585-B-C22. SDP is grateful to the Fonds de Recherche du Québec – Nature et Technologies. LSJ acknowledges the support of CNPq (304819/2017-4) and FAPESP (2019/10923-5). JAFO acknowledges the financial support from the Spanish Ministry of Science and Innovation and the European Union – NextGenerationEU through the Recovery and Resilience Facility project ICTS-MRR-2021-03- CEFCA. Funding for the J-PAS Project has been provided by the Governments of España and Aragón though the Fondo de Inversión de Teruel, European FEDER funding and the MINECO and by the Brazilian agencies FINEP, FAPESP, FAPERJ and by the National Observatory of Brazil. Based on observations made with the JST/T250 telescope and PathFinder camera for the miniJPAS project at the Observatorio Astrofísico de Javalambre (OAJ), in Teruel, owned, managed, and operated by the Centro de Estudios de Física del Cosmos de Aragón (CEFCA). We acknowledge the OAJ Data Processing and Archiving Unit (UPAD) for reducing and calibrating the OAJ data used in this work. Funding for OAJ, UPAD, and CEFCA has been provided by the Governments of Spain and Aragón through the Fondo de Inversiones de Teruel; the Aragón Government through the Research Groups E96, E103, and E16_17R; the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) with grant PGC2018-097585-B-C21; the Spanish Ministry of Economy and Competitiveness (MINECO/FEDER, UE) under AYA2015-66211-C2-1-P, AYA2015-66211-C2-2, AYA2012-30789, and ICTS-2009-14; and European FEDER funding (FCDD10-4E-867, FCDD13-4E-2685). This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Funding for SDSS-IV has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-IV web site is https://www.sdss.org/. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 898633.Peer reviewe
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