49 research outputs found
Prevalence and seasonality of six respiratory viruses during five consecutive epidemic seasons in Belgium
No full textBACKGROUND:
Acute Respiratory Infections (ARIs) are a major health problem, especially in young children and the elderly.
OBJECTIVES:
Insights into the seasonality of respiratory viruses can help us understand when the burden on society is highest and which age groups are most vulnerable.
STUDY DESIGN:
We monitored six respiratory viruses during five consecutive seasons (2011-2016) in Belgium. Patient specimens (n=22876), tested for one or more of the following respiratory viruses, were included in this analysis: Influenza viruses (IAV & IBV), Human respiratory syncytial virus (hRSV), Human metapneumovirus (hMPV), Adenovirus (ADV) and Human parainfluenza virus (hPIV). Data were analysed for four age categories: <6y, 6-17y, 18-64y and ≥65y.
RESULTS:
Children <6y had the highest infection rates (39% positive vs. 20% positive adults) and the highest frequency of co-infections. hRSV (28%) and IAV (32%) caused the most common respiratory viral infections and followed, like hMPV, a seasonal pattern with winter peaks. hRSV followed an annual pattern with two peaks: first in young children and ±7 weeks later in elderly. This phenomenon has not been described in literature so far. hPIV and ADV occurred throughout the year with higher rates in winter.
CONCLUSIONS:
Children <6y are most vulnerable for respiratory viral infections and have a higher risk for co-infections. hRSV and IAV are the most common respiratory infections with peaks during the winter season in Belgium.sponsorship: Kaat Ramaekers, Els Keyaerts, Annabel Rector, Kurt Beuselinck, Marc Van Ranst and Annie Borremans declare that there is no association that might pose a conflict of interest. Katrien Lagrou reports grants, personal fees and non-financial support from MSD, personal fees and non-financial support from Pfizer, personal fees and non-financial support from Gilead, outside the submitted work. (MSD, Pfizer)status: Publishe
Systematic Molecular Influenza A/B Screening Upon Hospital Admission in Belgium, January-April 2022: Positivity Ratios and Viral Loads According to Symptomatology, Age, and Vaccination Status
No full textThree hospitals implemented molecular point-of-care tests (POCTs) to screen patients for SARS-CoV-2 infection upon admission during the 2021/2022 influenza season, which in Belgium lasted from January to April 2022. The samples were simultaneously tested for influenza A/B. Influenza positivity at admission was examined in relation to patient characteristics and symptomatology. Influenza POCTs were performed on all patients requiring urgent hospitalization, regardless of the admission reason. A total of 9327 patients were included in the study, of which 411 (4.4%) tested positive for influenza A/B. Asymptomatic infection and mild illness accounted for respectively 11.2% (95% CI: 8.5%-14.6%), and 43.3% (95% CI: 38.6%-48.1%) of the cases. A total of 66% (95% CI: 60%-72%) of all patients in these symptom categories (asymptomatic and mild illness) showed a high viral load (cycle threshold [Ct] < 24). Only in 30 (7.3%, 95% CI: 5.2%-10.2%) of all cases and in two (4.4%, 95% CI: 1.2%-14.5%) of the asymptomatic cases, the symptomatology worsened during hospital stay. Coinfections with both influenza and SARS-CoV-2 occurred in 35 patients (8.5% of all influenza positive patients). There was no difference in symptomatology between patients with co-infections and those with an influenza mono-infection. Patients could not be reliably categorized into carriers with low versus high viral loads based on symptomatology, age, and vaccination status. More than half of the influenza-positive individuals were either asymptomatic or had mild symptoms upon admission, while often carrying high viral loads. Our results show that without screening of patients at hospital admission, a considerable number of patients with a high viral load may be incorrectly classified as being not infectious
Immunovirological and environmental screening reveals actionable risk factors for fatal COVID-19 during post-vaccination nursing home outbreaks.
No full textCoronavirus Disease 2019 (COVID-19) vaccination has resulted in excellent protection against fatal disease, including in older adults. However, risk factors for post-vaccination fatal COVID-19 are largely unknown. We comprehensively studied three large nursing home outbreaks (20-35% fatal cases among residents) by combining severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) aerosol monitoring, whole-genome phylogenetic analysis and immunovirological profiling of nasal mucosa by digital nCounter transcriptomics. Phylogenetic investigations indicated that each outbreak stemmed from a single introduction event, although with different variants (Delta, Gamma and Mu). SARS-CoV-2 was detected in aerosol samples up to 52 d after the initial infection. Combining demographic, immune and viral parameters, the best predictive models for mortality comprised IFNB1 or age, viral ORF7a and ACE2 receptor transcripts. Comparison with published pre-vaccine fatal COVID-19 transcriptomic and genomic signatures uncovered a unique IRF3 low/IRF7 high immune signature in post-vaccine fatal COVID-19 outbreaks. A multi-layered strategy, including environmental sampling, immunomonitoring and early antiviral therapy, should be considered to prevent post-vaccination COVID-19 mortality in nursing homes
Identification of six new polymorphisms in the human coronavirus 229E receptor gene (aminopeptidase N/CD13)
No full textAbstractObjective: Human aminopeptidase N (APN/CD13/ANPEP) has been identified as the receptor for human coronavirus (HCoV) 229E. In this study, we analyzed the region of the APN gene that encodes a stretch of amino acid residues, essential for its HCoV-229E receptor function (amino acids 260–353).Methods: Full-length APN exon 3, intron 3 and exon 4, was PCR-amplified and sequenced in DNA samples from 100 unrelated Caucasian Belgian healthy volunteers.Results: We identified seven polymorphisms, including four intron 3 and three exon 4 variations. Apart from the already known C956T exon 4 mutation, the six other polymorphisms have not yet been described. The most prevalent APN variations in this population (C956T leading to an alanine to valine substitution, G978T, G987A and intron3-C389T) always occurred together at an allele frequency of 8.5%. Haploid DNA sequencing demonstrated the presence of these four variations on the same allele. Three polymorphisms in intron 3, intron3-G395C, intron3-C86T, and intron3-C429T, were identified with an allele frequency of 3.5%, 1% and 0.5% respectively. Five haplotypes were identified in the population of 100 individuals.Conclusion: These results demonstrate that there is a relatively broad spectrum of variations in the APN domain critical for coronavirus binding.The nucleotide sequence reported here has been submitted to the GenBank database with the following accession number: AF527789
Severity of COVID-19 among Hospitalized Patients: Omicron Remains a Severe Threat for Immunocompromised Hosts
No full textThe Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in the general population in the context of a relatively high immunity gained through the early waves of coronavirus disease 19 (COVID-19), and vaccination campaigns. Despite this context, a significant number of patients were hospitalized, and identifying the risk factors associated with severe disease in the Omicron era is critical for targeting further preventive, and curative interventions. We retrospectively analyzed the individual medical records of 1501 SARS-CoV-2 positive hospitalized patients between 13 December 2021, and 13 February 2022, in Belgium, of which 187 (12.5%) were infected with Delta, and 1036 (69.0%) with Omicron. Unvaccinated adults showed an increased risk of moderate/severe/critical/fatal COVID-19 (crude OR 1.54; 95% CI 1.09–2.16) compared to vaccinated patients, whether infected with Omicron or Delta. In adults infected with Omicron and moderate/severe/critical/fatal COVID-19 (n = 323), immunocompromised patients showed an increased risk of in-hospital mortality related to COVID-19 (adjusted OR 2.42; 95% CI 1.39–4.22), compared to non-immunocompromised patients. The upcoming impact of the pandemic will be defined by evolving viral variants, and the immune system status of the population. The observations support that, in the context of an intrinsically less virulent variant, vaccination and underlying patient immunity remain the main drivers of severe disease
Viral load quantitation of SARS-coronavirus RNA using a one-step real-time RT-PCR
No full textSummaryIntroductionSevere acute respiratory syndrome (SARS) is an emerging infectious disease that first occurred in humans in the People's Republic of China in November 2002 and has subsequently spread worldwide. A novel virus belonging to the Coronaviridae family has been identified as the cause of this pulmonary disease. The severity of the disease combined with its rapid spread requires the development of fast and sensitive diagnostic assays.ResultsA real-time quantitative RT-PCR was designed in the nsp11 region of the replicase 1B domain of the SARS-coronavirus (SARS-CoV) genome. To evaluate this quantitative RT-PCR, cRNA standards were constructed by in vitro transcription of SARS-CoV Frankfurt 1 RNA using T7 RNA polymerase, followed by real-time RT-PCR. The assay allowed quantitation over a range of 102 to 108 RNA copies per reaction.ConclusionsExtrapolated to clinical samples, this novel assay has a detection range of 104 to 1010 copies of viral genome equivalents per millilitre. In comparison to the current de facto cRNA Artus Biotech standard, the in-house cRNA standard gives a 100-fold higher absolute quantity, suggesting a possible underestimation of the viral load when using the Artus Biotech standard
Circulation of genetically distinct contemporary human coronavirus OC43 strains
No full textAbstractIn this study, we report the complete genome sequence of two contemporary human coronavirus OC43 (HCoV-OC43) strains detected in 2003 and 2004, respectively. Comparative genetic analyses of the circulating strains and the prototype HCoV-OC43 strain (ATCC VR759) were performed. Remarkably, a lower than expected similarity is found between the complete genomes and more in particular between the spike genes of the BE03 and BE04 strains. This finding suggests the existence of two genetically distinct HCoV-OC43 strains, circulating in Belgium in 2003 and 2004. Spike gene sequencing of three additional 2003 and two additional 2004 HCoV-OC43 strains, and subsequent phylogenetic analysis confirm this assumption. Compared to the ATCC prototype HCoV-OC43 strain, an important amino acid substitution is present in the potential cleavage site sequence of the spike protein of all contemporary strains, restoring the N-RRXRR-C motif, associated with increased spike protein cleavability in bovine coronaviruses. We here describe specific characteristics associated with circulating HCoV-OC43 strains, and we provide substantial evidence for the genetic variability of HCoV-OC43
Inhibition of SARS-coronavirus infection in vitro by S-nitroso-N-acetylpenicillamine, a nitric oxide donor compound
No full textAbstractIntroduction: The recent outbreak of severe acute respiratory syndrome (SARS) warrants the search for effective antiviral agents to treat the disease. This study describes the assessment of the antiviral potential of nitric oxide (NO) against SARS coronavirus (SARS-CoV) strain Frankfurt-1 replicating in African Green Monkey (Vero E6) cells.Results: Two organic NO donor compounds, S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SNP), were tested in a broad range of concentrations. The non-nitrosylated form of SNAP, N-acetylpenicillamine (NAP), was included as a control compound in the assay. Antiviral activity was estimated by the inhibition of the SARS-CoV cytopathic effect in Vero E6 cells, determined by a tetrazolium-based colorimetric method. Cytotoxicity of the compounds was tested in parallel.Conclusion: The survival rate of SARS-CoV infected cells was greatly increased by the treatment with SNAP, and the concentration of this compound needed to inhibit the viral cytopathic effect to 50% was 222μM, with a selectivity index of 3. No anti-SARS-CoV effect could be detected for SNP and NAP
Ranst M. A pancoronavirus RTPCR assay for detection of all known coronaviruses. Methods Mol Biol 2008
No full textAbstract The recent discoveries of novel human coronaviruses, including the coronavirus causing SARS, and the previously unrecognized human coronaviruses HCoV-NL63 and HCoV-HKU1, indicate that the family Coronaviridae harbors more members than was previously assumed. All human coronaviruses characterized at present are associated with respiratory illnesses, ranging from mild common colds to more severe lower respiratory tract infections. Since the etiology of a relatively large percentage of respiratory tract diseases remains unidentified, it is possible that for a certain number of these illnesses, a yet unknown viral causative agent may be found. Screening for the presence of novel coronaviruses requires the use of a method that can detect all coronaviruses known at present. In this chapter, we describe a pancoronavirus degenerate primer-based method that allows the detection of all known and possibly unknown coronaviruses by RT-PCR amplification and sequencing of a 251-bp fragment of the coronavirus polymerase gene
