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1.
BMJ Open ; 11(8), 2021.
Article in English | ProQuest Central | ID: covidwho-1842917

ABSTRACT

ObjectivesWe explore the importance of SARS-CoV-2 sentinel surveillance testing in primary care during a regional COVID-19 outbreak in Austria.DesignProspective cohort study.SettingA single sentinel practice serving 22 829 people in the ski-resort of Schladming-Dachstein.ParticipantsAll 73 patients presenting with mild-to-moderate flu-like symptoms between 24 February and 03 April, 2020.InterventionNasopharyngeal sampling to detect SARS-CoV-2 using real-time reverse transcriptase-quantitative PCR (RT-qPCR).Outcome measuresWe compared RT-qPCR at presentation with confirmed antibody status. We split the outbreak in two parts, by halving the period from the first to the last case, to characterise three cohorts of patients with confirmed infection: early acute (RT-qPCR reactive) in the first half;and late acute (reactive) and late convalescent (non-reactive) in the second half. For each cohort, we report the number of cases detected, the accuracy of RT-qPCR, the duration and variety of symptoms, and the number of viral clades present.ResultsTwenty-two patients were diagnosed with COVID-19 (eight early acute, seven late acute and seven late convalescent), 44 patients tested SARS-CoV-2 negative and 7 were excluded. The sensitivity of RT-qPCR was 100% among all acute cases, dropping to 68.1% when including convalescent. Test specificity was 100%. Mean duration of symptoms for each group were 2 days (range 1–4) among early acute, 4.4 days (1–7) among late acute and 8 days (2–12) among late convalescent. Confirmed infection was associated with loss of taste. Acute infection was associated with loss of taste, nausea/vomiting, breathlessness, sore throat and myalgia;but not anosmia, fever or cough. Transmission clusters of three viral clades (G, GR and L) were identified.ConclusionsRT-qPCR testing in primary care can rapidly and accurately detect SARS-CoV-2 among people with flu-like illness in a heterogeneous viral outbreak. Targeted testing in primary care can support national sentinel surveillance of COVID-19.

2.
Water Res ; 215: 118257, 2022 May 15.
Article in English | MEDLINE | ID: covidwho-1721084

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) gave rise to an international public health emergency in 3 months after its emergence in Wuhan, China. Typically for an RNA virus, random mutations occur constantly leading to new lineages, incidental with a higher transmissibility. The highly infective alpha lineage, firstly discovered in the UK, led to elevated mortality and morbidity rates as a consequence of Covid-19, worldwide. Wastewater surveillance proved to be a powerful tool for early detection and subsequent monitoring of the dynamics of SARS-CoV-2 and its variants in a defined catchment. Using a combination of sequencing and RT-qPCR approaches, we investigated the total SARS-CoV-2 concentration and the emergence of the alpha lineage in wastewater samples in Vienna, Austria linking it to clinical data. Based on a non-linear regression model and occurrence of signature mutations, we conclude that the alpha variant was present in Vienna sewage samples already in December 2020, even one month before the first clinical case was officially confirmed and reported by the health authorities. This provides evidence that a well-designed wastewater monitoring approach can provide a fast snapshot and may detect the circulating lineages in wastewater weeks before they are detectable in the clinical samples. Furthermore, declining 14 days prevalence data with simultaneously increasing SARS-CoV-2 total concentration in wastewater indicate a different shedding behavior for the alpha variant. Overall, our results support wastewater surveillance to be a suitable approach to spot early circulating SARS-CoV-2 lineages based on whole genome sequencing and signature mutations analysis.


Subject(s)
COVID-19 , Wastewater-Based Epidemiological Monitoring , COVID-19/epidemiology , Humans , SARS-CoV-2/genetics , Waste Water
3.
Elife ; 112022 01 13.
Article in English | MEDLINE | ID: covidwho-1622818

ABSTRACT

Despite tremendous progress in the understanding of COVID-19, mechanistic insight into immunological, disease-driving factors remains limited. We generated maVie16, a mouse-adapted SARS-CoV-2, by serial passaging of a human isolate. In silico modeling revealed how only three Spike mutations of maVie16 enhanced interaction with murine ACE2. maVie16 induced profound pathology in BALB/c and C57BL/6 mice, and the resulting mouse COVID-19 (mCOVID-19) replicated critical aspects of human disease, including early lymphopenia, pulmonary immune cell infiltration, pneumonia, and specific adaptive immunity. Inhibition of the proinflammatory cytokines IFNγ and TNF substantially reduced immunopathology. Importantly, genetic ACE2-deficiency completely prevented mCOVID-19 development. Finally, inhalation therapy with recombinant ACE2 fully protected mice from mCOVID-19, revealing a novel and efficient treatment. Thus, we here present maVie16 as a new tool to model COVID-19 for the discovery of new therapies and show that disease severity is determined by cytokine-driven immunopathology and critically dependent on ACE2 in vivo.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/virology , Interferon-gamma/pharmacology , SARS-CoV-2/pathogenicity , Adaptive Immunity/immunology , Animals , Disease Models, Animal , Interferon-gamma/metabolism , Mice, Inbred BALB C , Mice, Inbred C57BL , Peptidyl-Dipeptidase A/genetics , Spike Glycoprotein, Coronavirus/genetics
4.
Sci Immunol ; 6(57)2021 03 04.
Article in English | MEDLINE | ID: covidwho-1148101

ABSTRACT

CD8+ T cell immunity to SARS-CoV-2 has been implicated in COVID-19 severity and virus control. Here, we identified nonsynonymous mutations in MHC-I-restricted CD8+ T cell epitopes after deep sequencing of 747 SARS-CoV-2 virus isolates. Mutant peptides exhibited diminished or abrogated MHC-I binding in a cell-free in vitro assay. Reduced MHC-I binding of mutant peptides was associated with decreased proliferation, IFN-γ production and cytotoxic activity of CD8+ T cells isolated from HLA-matched COVID-19 patients. Single cell RNA sequencing of ex vivo expanded, tetramer-sorted CD8+ T cells from COVID-19 patients further revealed qualitative differences in the transcriptional response to mutant peptides. Our findings highlight the capacity of SARS-CoV-2 to subvert CD8+ T cell surveillance through point mutations in MHC-I-restricted viral epitopes.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19 , Epitopes, T-Lymphocyte , HLA-A Antigens/immunology , Immunity, Cellular , Mutation , SARS-CoV-2 , CD8-Positive T-Lymphocytes/pathology , COVID-19/genetics , COVID-19/immunology , COVID-19/pathology , Cell Proliferation , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , High-Throughput Nucleotide Sequencing , Humans , Interferon-gamma/immunology , Peptides/genetics , Peptides/immunology , SARS-CoV-2/genetics , SARS-CoV-2/immunology
5.
Sci Transl Med ; 12(573)2020 12 09.
Article in English | MEDLINE | ID: covidwho-940793

ABSTRACT

Superspreading events shaped the coronavirus disease 2019 (COVID-19) pandemic, and their rapid identification and containment are essential for disease control. Here, we provide a national-scale analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) superspreading during the first wave of infections in Austria, a country that played a major role in initial virus transmissions in Europe. Capitalizing on Austria's well-developed epidemiological surveillance system, we identified major SARS-CoV-2 clusters during the first wave of infections and performed deep whole-genome sequencing of more than 500 virus samples. Phylogenetic-epidemiological analysis enabled the reconstruction of superspreading events and charts a map of tourism-related viral spread originating from Austria in spring 2020. Moreover, we exploited epidemiologically well-defined clusters to quantify SARS-CoV-2 mutational dynamics, including the observation of low-frequency mutations that progressed to fixation within the infection chain. Time-resolved virus sequencing unveiled viral mutation dynamics within individuals with COVID-19, and epidemiologically validated infector-infectee pairs enabled us to determine an average transmission bottleneck size of 103 SARS-CoV-2 particles. In conclusion, this study illustrates the power of combining epidemiological analysis with deep viral genome sequencing to unravel the spread of SARS-CoV-2 and to gain fundamental insights into mutational dynamics and transmission properties.


Subject(s)
COVID-19/epidemiology , COVID-19/transmission , Mutation/genetics , SARS-CoV-2/genetics , Austria/epidemiology , Base Sequence , COVID-19/genetics , COVID-19/virology , Host-Pathogen Interactions/genetics , Humans , Mutation Rate , Phylogeny
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