Publications by authors named "Harry Vennema"

Objectives: SARS-CoV-2 viral load could be an important parameter for transmission potential. Here, we use RT-qPCR cycle threshold (Ct) values as a proxy for viral load. We assess the effect of COVID-19 vaccination and prior infection status on Ct value, while accounting for the virus variant.

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The integration of next-generation sequencing into clinical diagnostics and surveillance initiatives is impeded by the lack of data analysis pipelines that align with privacy legislation and laboratory certification protocols. To address these challenges, we developed Jovian, an open-source, virus-focused, metagenomic analysis workflow for Illumina data. Jovian generates scaffolds enriched with pertinent annotations, including taxonomic classification, combined with metrics needed for quality assessment (coverage depth, average GC content, localization of open reading frames, minority single nucleotide polymorphisms), and incorporates host and disease metadata.

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Article Synopsis
  • Enteric hepatitis A virus (HAV) often goes unnoticed in children but can severely affect adults; the study aimed to improve surveillance during an outbreak at a primary school.
  • Researchers used passive samplers in sewage to detect HAV RNA from November 2022 to March 2023, finding that 25% of samples tested positive and matched the strain from the symptomatic cases.
  • The study concludes that sewage monitoring with passive samplers is an effective tool for quickly detecting HAV, identifying unnoticed infections, and enhancing public health responses during outbreaks.
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We report an increase in GII.17 norovirus outbreaks and sporadic infections of acute gastroenteritis in Austria, Germany, France, Ireland, the Netherlands, England and the United States during the 2023/24 season. A decrease in GII.

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Norovirus is the primary cause of viral gastroenteritis (GE). To investigate norovirus epidemiology, there is a need for whole-genome sequencing and reference sets consisting of complete genomes. To investigate the potential of shotgun metagenomic sequencing on the Illumina platform for whole-genome sequencing, 71 reverse transcriptase quantitative PCR (RT-qPCR) norovirus positive-feces (threshold cycle [], <30) samples from norovirus surveillance within The Netherlands were subjected to metagenomic sequencing.

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In early May 2022, a global outbreak of mpox started among persons without travel history to regions known to be enzootic for monkeypox virus (MPXV). On 8 August 2022, the Netherlands reported its 1,000th mpox case, representing a cumulative incidence of 55 per million population, one of the highest cumulative incidences worldwide. We describe characteristics of the first 1,000 mpox cases in the Netherlands, reported between 20 May and 8 August 2022, within the context of the public health response.

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BackgroundIn summer 2022, SARS-CoV-2 Omicron BA.5 became dominant in Europe. In vitro studies have shown a large reduction of antibody neutralisation for this variant.

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Background: In fall 2020 when schools in the Netherlands operated under a limited set of COVID-19 measures, we conducted outbreaks studies in four secondary schools to gain insight in the level of school transmission and the role of SARS-CoV-2 transmission via air and surfaces.

Methods: Outbreak studies were performed between 11 November and 15 December 2020 when the wild-type variant of SARS-CoV-2 was dominant. Clusters of SARS-CoV-2 infections within schools were identified through a prospective school surveillance study.

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Background: Variants of concern (VOCs) of SARS-CoV-2 have caused resurging waves of infections worldwide. In the Netherlands, the Alpha, Beta, Gamma, and Delta VOCs circulated widely between September 2020 and August 2021. We sought to elucidate how various control measures, including targeted flight restrictions, had impacted the introduction and spread of these VOCs in the Netherlands.

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Large-scale vaccination campaigns have prevented countless hospitalizations and deaths due to COVID-19. However, the emergence of SARS-CoV-2 variants that escape from immunity challenges the effectiveness of current vaccines. Given this continuing evolution, an important question is when and how to update SARS-CoV-2 vaccines to antigenically match circulating variants, similarly to seasonal influenza viruses where antigenic drift necessitates periodic vaccine updates.

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Hepatitis E is caused by hepatitis E virus (HEV), one of the causes of acute viral hepatitis. Domestic pigs are considered as the main reservoir of HEV-3. The recently reported high prevalence of HEV in liver- and meat products on the Dutch market warranted a cross-sectional prevalence study on HEV infection among 5-6 months old pigs slaughtered in the Netherlands (n = 250).

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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.

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Variants of concern (VOCs) of SARS-CoV-2 have caused resurging waves of infections worldwide. In the Netherlands, Alpha, Beta, Gamma and Delta variants circulated widely between September 2020 and August 2021. To understand how various control measures had impacted the spread of these VOCs, we analyzed 39,844 SARS-CoV-2 genomes collected under the Dutch national surveillance program.

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Infections with the Omicron SARS-CoV-2 variant are rapidly increasing worldwide. Among 174,349 SARS-CoV-2-infected individuals (≥ 12 years), we observed an increased risk of S gene target failure, predictive of the Omicron variant, in vaccinated (odds ratio (OR): 3.6; 95% confidence interval (CI): 3.

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Late in 2020, two genetically-distinct clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with mutations of biological concern were reported, one in the United Kingdom and one in South Africa. Using a combination of data from routine surveillance, genomic sequencing and international travel we track the international dispersal of lineages B.1.

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We describe the lessons learned during a SARS-CoV-2 variant-of-concern Alpha outbreak investigation at a normal care unit in a university hospital in Amsterdam in December 2020. The outbreak consisted of nine nurses and two roomed-in patient family members. (attack rate 18%).

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We report a new norovirus GII.4 variant, GII.4 Hong Kong, with low-level circulation in 4 Eurasia countries since mid-2017.

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In late December 2019, a cluster of cases of pneumonia of unknown etiology were reported linked to a market in Wuhan, China. The causative agent was identified as the species Severe acute respiratory syndrome-related coronavirus and was named SARS-CoV-2 (ref. ).

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The family includes viruses with single-stranded, positive-sense RNA genomes of 7.4-8.3 kb.

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Noroviruses are genetically diverse RNA viruses associated with acute gastroenteritis in mammalian hosts. Phylogenetically, they can be segregated into different genogroups as well as P (polymerase)-groups and further into genotypes and P-types based on amino acid diversity of the complete VP1 gene and nucleotide diversity of the RNA-dependent RNA polymerase (RdRp) region of ORF1, respectively. In recent years, several new noroviruses have been reported that warrant an update of the existing classification scheme.

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Article Synopsis
  • Sequence-based typing of hepatitis A virus (HAV) is crucial for detecting and investigating outbreaks, as demonstrated during a significant EU-wide outbreak linked to frozen berries in 2013, though challenges arose due to partial genomic comparability among countries.
  • In 2014, the European Centre for Disease Prevention and Control (ECDC) surveyed EU/EEA countries to assess their HAV surveillance practices and proposed harmonized procedures to enhance cross-border outbreak response, focusing on sequencing methods.
  • Follow-up surveys in 2016 showed an increase in countries participating in centralized collection and sequencing of HAV samples, but disparities in the specific genomic regions sequenced still exist, indicating that further collaboration is needed for effective surveillance.
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Purpose: Human parechoviruses (HPeVs), particularly type 3, can cause severe neurological disease and neonatal sepsis in infants. HPeV3 lacks the receptor-binding motif arginine-glycine aspartic acid (RGD), and is proposed to use a different receptor associated with severe disease. In contrast, HPeV1, which contains the RGD motif, is associated with mild disease.

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Hepatitis E virus (HEV) is a common cause of acute hepatitis worldwide. In Europe, HEV is a zoonosis transmitted via contaminated pork meat or other pork food products. Genotype 3 is the most prevalent HEV type in the animal reservoir, as well as in humans.

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