Nationwide quality assurance of high-throughput diagnostic molecular testing during the SARS-CoV-2 pandemic: role of the Belgian National Reference Centre.

Since the onset of the coronavirus disease (COVID-19) pandemic in Belgium, UZ/KU Leuven has played a crucial role as the National Reference Centre (NRC) for respiratory pathogens, to be the first Belgian laboratory to develop and implement laboratory developed diagnostic assays for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and later to assess the quality of commercial kits. To meet the growing demand for decentralised testing, both clinical laboratories and government-supported high-throughput platforms were gradually deployed across Belgium. Consequently, the role of the NRC transitioned from a specialised testing laboratory to strengthening capacity and coordinating quality assurance.

Detection of mpox virus in ambient air in a sexual health clinic.

Although transmitted mainly through direct (sexual) contact, mpox virus (MPXV) can be detected in ambient air. We explored the use of air sampling for diagnosis or (genomic) surveillance of mpox in a sexual health clinic. For six out of six patients who were infected with MPXV, all four of our ambient air PCR tests were positive.

Immunovirological and environmental screening reveals actionable risk factors for fatal COVID-19 during post-vaccination nursing home outbreaks.

Coronavirus 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.

Indoor air surveillance and factors associated with respiratory pathogen detection in community settings in Belgium.

Currently, the real-life impact of indoor climate, human behaviour, ventilation and air filtration on respiratory pathogen detection and concentration are poorly understood. This hinders the interpretability of bioaerosol quantification in indoor air to surveil respiratory pathogens and transmission risk. We tested 341 indoor air samples from 21 community settings in Belgium for 29 respiratory pathogens using qPCR.

Severity of COVID-19 among Hospitalized Patients: Omicron Remains a Severe Threat for Immunocompromised Hosts.

The 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.

Risk factors for disease severity and increased medical resource utilization in respiratory syncytial virus (+) hospitalized children: A descriptive study conducted in four Belgian hospitals.

Background: We aimed to provide regional data on clinical symptoms, medical resource utilization (MRU), and risk factors for increased MRU in hospitalized respiratory syncytial virus (RSV)-infected Belgian pediatric population.

Methods: This prospective, multicenter study enrolled RSV (+) hospitalized children (aged ≤5y) during the 2013-2015 RSV seasons. RSV was diagnosed within 24h of hospitalization.

Proposal for Human Respiratory Syncytial Virus Nomenclature below the Species Level.

Human respiratory syncytial virus (HRSV) is the leading viral cause of serious pediatric respiratory disease, and lifelong reinfections are common. Its 2 major subgroups, A and B, exhibit some antigenic variability, enabling HRSV to circulate annually. Globally, research has increased the number of HRSV genomic sequences available.

Recommendations for the introduction of metagenomic high-throughput sequencing in clinical virology, part I: Wet lab procedure.

Metagenomic high-throughput sequencing (mHTS) is a hypothesis-free, universal pathogen detection technique for determination of the DNA/RNA sequences in a variety of sample types and infectious syndromes. mHTS is still in its early stages of translating into clinical application. To support the development, implementation and standardization of mHTS procedures for virus diagnostics, the European Society for Clinical Virology (ESCV) Network on Next-Generation Sequencing (ENNGS) has been established.

Towards a unified classification for human respiratory syncytial virus genotypes.

Since the first human respiratory syncytial virus (HRSV) genotype classification in 1998, inconsistent conclusions have been drawn regarding the criteria that define HRSV genotypes and their nomenclature, challenging data comparisons between research groups. In this study, we aim to unify the field of HRSV genotype classification by reviewing the different methods that have been used in the past to define HRSV genotypes and by proposing a new classification procedure, based on well-established phylogenetic methods. All available complete HRSV genomes (>12,000 bp) were downloaded from GenBank and divided into the two subgroups: HRSV-A and HRSV-B.

Comparison of the Idylla™ Respiratory (IFV-RSV) panel with the GeneXpert Xpert® Flu/RSV assay: a retrospective study with nasopharyngeal and midturbinate samples.

The objective of this study was to compare the performance of the Idylla™ Respiratory (IFV-RSV) panel to the GeneXpert Xpert® Flu/RSV assay and establish the performance of a midturbinate swab compared to nasopharyngeal sampling. Considering GeneXpert® assay as imperfect reference standard, a positive percentage agreement between both assays of 98-100% for influenza A and 96-99% for influenza B could be calculated when 354 nasopharyngeal and 325 midturbinate swabs were retrospectively analyzed. Comparing midturbinate samples to nasopharyngeal specimens of 321 subjects, positive percentage agreement varied from 42% to 94% depending on both target virus and assay used.

Prevalence and seasonality of six respiratory viruses during five consecutive epidemic seasons in Belgium.

Background: 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.

In vivo evaluation of antiviral compounds on respiratory syncytial virus using a juvenile vervet monkey (Chlorocebus pygerythrus) infection model.

Several animal models with varying susceptibilities to respiratory syncytial virus (RSV) infection have been developed to study the specific aspects of RSV disease. Many of these models are used for testing antiviral compounds or in vaccine efficacy studies during preclinical evaluation. In this chapter, we describe the study design of an efficacy study of an RSV inhibitor, performed in a juvenile vervet monkey model for RSV.

Circulation of HRSV in Belgium: from multiple genotype circulation to prolonged circulation of predominant genotypes.

Molecular surveillance of HRSV in Belgium for 15 consecutive seasons (1996-2011) revealed a shift from a regular 3-yearly cyclic pattern, into a yearly alternating periodicity where HRSV-B is replaced by HRSV-A. Phylogenetic analysis for HRSV-A demonstrated the stable circulation of GA2 and GA5, with GA2 being dominant over GA5 during 5 consecutive seasons (2006-2011). We also identified 2 new genotype specific amino acid mutations of the GA2 genotype (A122 and Q156) and 7 new GA5 genotype specific amino acid mutations (F102, I108, T111, I125, D161, S191 and L217).

Susceptibility of the PER.C6 cell line for infection with clinical human respiratory syncytial virus isolates.

Human respiratory syncytial virus (HRSV) is one of the most important agents causing upper respiratory infection in infants. The susceptibility of the PER.C6 cell line for infection with clinical HRSV strains was investigated.

Exhaled breath condensate sampling is not a new method for detection of respiratory viruses.

Background: Exhaled breath condensate (EBC) sampling has been considered an inventive and novel method for the isolation of respiratory viruses.

Methods: In our study, 102 volunteers experiencing upper airway infection were recruited over the winter and early spring of 2008/2009 and the first half of the winter of 2009/2010. Ninety-nine EBCs were successfully obtained and screened for 14 commonly circulating respiratory viruses.

Antiviral activity of chloroquine against human coronavirus OC43 infection in newborn mice.

Until recently, human coronaviruses (HCoVs), such as HCoV strain OC43 (HCoV-OC43), were mainly known to cause 15 to 30% of mild upper respiratory tract infections. In recent years, the identification of new HCoVs, including severe acute respiratory syndrome coronavirus, revealed that HCoVs can be highly pathogenic and can cause more severe upper and lower respiratory tract infections, including bronchiolitis and pneumonia. To date, no specific antiviral drugs to prevent or treat HCoV infections are available.

Replication reduction neutralization test, a quantitative RT-PCR-based technique for the detection of neutralizing hantavirus antibodies.

Hantaviruses, which are mainly rodent-borne viruses, cause hemorrhagic fever with renal syndrome in the Old World, and hantavirus pulmonary syndrome in the New World. A neutralization test based on quantitative RT-PCR, the replication reduction neutralization test (RRNT), was developed for efficient detection of hantavirus-neutralizing antibodies. The effectiveness of the RRNT was evaluated by examining several hantaviruses and hantavirus-specific convalescent human serum samples.

A pancoronavirus RT-PCR assay for detection of all known coronaviruses.

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.

Truncated recombinant puumala virus nucleocapsid proteins protect mice against challenge in vivo.

In Europe, Puumala virus and Dobrava virus are the major hantaviruses that cause hemorrhagic fever with renal syndrome in humans. As hantaviruses can cause diseases with high morbidity and mortality rates, and as to date there is no specific treatment, efforts are concentrated on the development of vaccines. In this study we characterized the immunogenicity of recombinant nucleocapsid proteins of Puumala virus (PUUV) linked to a carrier protein corresponding to the outer membrane protein A from Klebsiella pneumoniae (rP40).

Plant lectins are potent inhibitors of coronaviruses by interfering with two targets in the viral replication cycle.

We describe the antiviral activity of plant lectins with specificity for different glycan structures against the severe acute respiratory syndrome coronavirus (SARS-CoV) and the feline infectious peritonitis virus (FIPV) in vitro. The SARS-CoV emerged in 2002 as an important cause of severe lower respiratory tract infection in humans, and FIPV infection causes a chronic and often fatal peritonitis in cats. A unique collection of 33 plant lectins with different specificities were evaluated.

Evaluation of the efficacy of disinfectants against Puumala hantavirus by real-time RT-PCR.

Puumala virus, a hantavirus belonging to the Bunyaviridae family, causes a human disease known as nephropathia epidemica, a mild form of hemorrhagic fever with renal syndrome. The implementation of effective decontamination procedures is critical in hantavirus research to minimize the risk of personnel exposure. This study investigated the efficacy of Clidox((R)), Dettol((R)), ethanol, Halamid-d((R)), peracetic acid, sodium hypochloride and Virkon((R))S for inactivating Puumala virus.

Evolutionary history of the closely related group 2 coronaviruses: porcine hemagglutinating encephalomyelitis virus, bovine coronavirus, and human coronavirus OC43.

The close genetic and antigenic relatedness among the group 2 coronaviruses human coronavirus OC43 (HCoV-OC43), bovine coronavirus (BCoV), and porcine hemagglutinating encephalomyelitis virus (PHEV) suggests that these three viruses with different host specificities diverged fairly recently. In this study, we determined the complete genomic sequence of PHEV (strain PHEV-VW572), revealing the presence of a truncated group 2-specific ns2 gene in PHEV in comparison to other group 2 coronaviruses. Using a relaxed molecular clock approach, we reconstructed the evolutionary relationships between PHEV, BCoV, and HCoV-OC43 in real-time units, which indicated relatively recent common ancestors for these species-specific coronaviruses.