Epidemiology of human adenoviruses: a 20-year retrospective observational study in hospitalized patients in Bern, Switzerland.

Background: Human adenovirus (HAdV) is an important pathogen seen in clinical practice. Long-term studies may help better understand epidemiological trends and changes in circulating genotypes over time. Purpose: Using a large biobank of samples from hospitalized, adenovirus-positive patients over a 20-year period, we aimed to analyze long-term epidemiological trends and genotypic relatedness among circulating HAdV strains. Methods: Based on samples from hospitalized patients confirmed to be HAdV positive in Bern, Switzerland, from 1998 to 2017, and on their associated demographic and clinical data, we identified epidemiological trends and risk factors associated with HAdV infection. HAdV genotyping was performed by PCR amplification and sequencing of the hypervariable hexon gene. The obtained sequences were phylogenetically compared with sequences from international HAdV strains. Results: HAdV was identified in 1302 samples tested. Cases of HAdV infection were reported throughout the years with no clear seasonality. Upper respiratory tract samples, conjunctivitis swabs, and stool had the highest positivity rate (56.2%, 18.7%, and 14.2% of the cases, respectively). HAdV infection was highest among children ≤4 years old. Increased number of HAdV cases were observed in years 2009 (n = 110) and 2010 (n =112). HAdV8 was the predominant genotype among patients older than 20 years, and was mostly associated with ophthalmic infection. Predominant genotypes among children ≤4 years old were HAdV1, HAdV2, and HAdV3, which were mostly associated with respiratory tract infections. Recurring peaks of increased HAdV cases were evidenced every 4 years among children ≤4 years old. Conclusion: Our study gives novel insights on long-term epidemiological trends and phylogenetic relatedness among circulating HAdV strains in Switzerland, country in which little data on HAdV prevalence and diversity was so far available

IGRA-positive patients and interferon-gamma/interleukin-2 signatures: Can the Fluorospot assay provide further information?

A goal of testing for latent tuberculosis (TB) infection is to identify individuals who are at increased risk for the development of active TB. No laboratory tool is currently available to distinguish between individuals in the process of progressing from latent TB infection towards active disease and those who are not. Determination of the interferon-gamma and interleukin-2 T cell signature might provide an additional and rapid tool to evaluate treatment necessity and clinical management of a patient. Here, we present three cases of interferon-gamma release assay-positive patients with differing interferon-gamma and interleukin-2 signatures when analyzed by the Fluorospot assay

Genome Sequences of Rare Human Enterovirus Genotypes Recovered from Clinical Respiratory Samples in Bern, Switzerland.

We report on genomic sequences of human enteroviruses (EVs) that were identified in respiratory samples in Bern, Switzerland, in 2018 and 2019. Besides providing sequences for coxsackievirus A2, echovirus 11, and echovirus 30, we determined the sequences of rare EV-D68 and EV-C105 genotypes circulating in Switzerland

Neuro-axonal injury in COVID-19: the role of systemic inflammation and SARS-CoV-2 specific immune response

Background: In coronavirus disease-2019 (COVID-19) patients, there is increasing evidence of neuronal injury by the means of elevated serum neurofilament light chain (sNfL) levels. However, the role of systemic inflammation and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific immune response with regard to neuronal injury has not yet been investigated. Methods: In a prospective cohort study, we recruited patients with mild–moderate (n = 39) and severe (n = 14) COVID-19 and measured sNfL levels, cytokine concentrations, SARS-CoV-2-specific antibodies including neutralizing antibody titers, and cell-mediated immune responses at enrollment and at 28(±7) days. We explored the association of neuro-axonal injury as by the means of sNfL measurements with disease severity, cytokine levels, and virus-specific immune responses. Results: sNfL levels, as an indicator for neuronal injury, were higher at enrollment and increased during follow-up in severely ill patients, whereas during mild–moderate COVID-19, sNfL levels remained unchanged. Severe COVID-19 was associated with increased concentrations of cytokines assessed [interleukin (IL)-6, IL-8, interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α)], higher anti-spike IgG and anti-nucleocapsid IgG concentrations, and increased neutralizing antibody titers compared with mild–moderate disease. Patients with more severe disease had higher counts of defined SARS-CoV-2-specific T cells. Increases in sNfL concentrations from baseline to day 28(±7) positively correlated with anti-spike protein IgG antibody levels and with titers of neutralizing antibodies. Conclusion: Severe COVID-19 is associated with increased serum concentration of cytokines and subsequent neuronal injury as reflected by increased levels of sNfL. Patients with more severe disease developed higher neutralizing antibody titers and higher counts of SARS-CoV-2-specific T cells during the course of COVID-19 disease. Mounting a pronounced virus-specific humoral and cell-mediated immune response upon SARS-CoV-2 infection did not protect from neuro-axonal damage as by the means of sNfL levels

Cerebrospinal fluid findings in an adult with human metapneumovirus–associated encephalitis

__To the Editor:__ Acute encephalitis/encephalopathy associated with human metapneumovirus (HMPV) has been documented in children. Recently, Fok et al. described an encephalitis case in an adult but were unable to test cerebrospinal fluid (CSF) for HMPV. Following authors’ recommendations, we performed diagnostic testing on the CSF of an adult with HMPV-associated encephalitis. A previously healthy 61-year-old man came to our institution with headache and seizures 5 days after onset of an influenza-like illness. A lumbar puncture on admission revealed pleocytosis (36 cells/μL) and a mononuclear predominance of 98%. Results of magnetic resonance imaging and computed tomography of the head and chest radiography on admission were inconclusive. The patient was treated in the intensive care unit for possible viral and bacterial meningoencephalitis. Although results of routine CSF-workup for infectious causes were unremarkable, total CSF protein level was elevated at 1.39 g/L (reference range 0.2–0.4 g/L). A nasopharyngeal swab specimen was positive for HMPV (cycle threshold 28.6) using duplex reverse transcription PCR (r-gene; Biomérieux, Marcy l’Etoile, France). However, HMPV reverse transcription PCR results were negative in the concurrent CSF sample. Immunofluorescence assays demonstrated HMPV IgG (serum titer 1:8,192; CSF titers 1:64 and 1:32). Indices calculated using the formula (IgGCSF HMPV/IgGSerum HMPV)/(IgGCSF total/IgGSerum total) were lower than the cut-off value of 4, indicating absence of intrathecal IgG against HMPV (Table). As in the study by Fok et al., our case supports consideration of HMPV as a causative agent of acute encephalitis after respiratory tract infection in adults. We could not demonstrate direct or indirect evidence of HMPV CSF invasion as the cause for HMPV-associated encephalitis in an adult, in contrast to a case in a child in which detection of HMPV in CSF suggested a causative role in acute encephalitis. Our data may point toward the role of nonspecific inflammatory response as the main pathogenic factor in HMPV-related encephalitis in adults

Generation of a Recombinant Gag Virus-Like-Particle Panel for the Evaluation of p24 Antigen Detection by Diagnostic HIV Tests.

BACKGROUND: Detection of HIV-1 p24 antigen permits early identification of primary HIV infection and timely intervention to limit further spread of the infection. Principally, HIV screening should equally detect all viral variants, but reagents for a standardised test evaluation are limited. Therefore, we aimed to create an inexhaustible panel of diverse HIV-1 p24 antigens. METHODS: We generated a panel of 43 recombinantly expressed virus-like particles (VLPs), containing the structural Gag proteins of HIV-1 subtypes A-H and circulating recombinant forms (CRF) CRF01_AE, CRF02_AG, CRF12_BF, CRF20_BG and group O. Eleven 4th generation antigen/antibody tests and five antigen-only tests were evaluated for their ability to detect VLPs diluted in human plasma to p24 concentrations equivalent to 50, 10 and 2 IU/ml of the WHO p24 standard. Three tests were also evaluated for their ability to detect p24 after heat-denaturation for immune-complex disruption, a pre-requisite for ultrasensitive p24 detection. RESULTS: Our VLP panel exhibited an average intra-clade p24 diversity of 6.7%. Among the 4th generation tests, the Abbott Architect and Siemens Enzygnost Integral 4 had the highest sensitivity of 97.7% and 93%, respectively. Alere Determine Combo and BioRad Access were least sensitive with 10.1% and 40.3%, respectively. Antigen-only tests were slightly more sensitive than combination tests. Almost all tests detected the WHO HIV-1 p24 standard at a concentration of 2 IU/ml, but their ability to detect this input for different subtypes varied greatly. Heat-treatment lowered overall detectability of HIV-1 p24 in two of the three tests, but only few VLPs had a more than 3-fold loss in p24 detection. CONCLUSIONS: The HIV-1 Gag subtype panel has a broad diversity and proved useful for a standardised evaluation of the detection limit and breadth of subtype detection of p24 antigen-detecting tests. Several tests exhibited problems, particularly with non-B subtypes

Hepatitis delta infection among persons living with HIV in Europe

Background and aims: A high prevalence of hepatitis delta virus (HDV) infection, the most severe form of viral hepatitis, has been reported among persons living with HIV (PLWH) in Europe. We analysed data from a large HIV cohort collaboration to characterize HDV epidemiological trends across Europe, as well as its impact on clinical outcomes. Methods: All PLWH with a positive hepatitis B surface antigen (HBsAg) in the Swiss HIV Cohort Study and EuroSIDA between 1988 and 2019 were tested for anti-HDV antibodies and, if positive, for HDV RNA. Demographic and clinical characteristics at initiation of antiretroviral therapy were compared between HDV-positive and HDV-negative individuals using descriptive statistics. The associations between HDV infection and overall mortality, liver-related mortality as well as hepatocellular carcinoma (HCC) were assessed using cumulative incidence plots and cause-specific multivariable Cox regression. Results: Of 2793 HBsAg-positive participants, 1556 (56%) had stored serum available and were included. The prevalence of HDV coinfection was 15.2% (237/1556, 95% confidence interval [CI]: 13.5%-17.1%) and 66% (132/200) of HDV-positive individuals had active HDV replication. Among persons who inject drugs (PWID), the prevalence of HDV coinfection was 50.5% (182/360, 95% CI: 45.3%-55.7%), with similar estimates across Europe, compared to 4.7% (52/1109, 95% CI: 3.5%-5.9%) among other participants. During a median follow-up of 10.8 years (interquartile range 5.6-17.8), 82 (34.6%) HDV-positive and 265 (20.1%) HDV-negative individuals died. 41.5% (34/82) of deaths were liver-related in HDV-positive individuals compared to 17.7% (47/265) in HDV-negative individuals. HDV infection was associated with overall mortality (adjusted hazard ratio 1.6; 95% CI 1.2-2.1), liver-related death (2.9, 1.6-5.0) and HCC (6.3, 2.5-16.0). Conclusion: We found a very high prevalence of hepatitis delta among PWID across Europe. Among PLWH who do not inject drugs, the prevalence was similar to that reported from populations without HIV. HDV coinfection was associated with liver-related mortality and HCC incidence

Host switching pathogens, infectious outbreaks and zoonosis: A Marie Skłodowska-Curie innovative training network (HONOURs)

The increase of the human population is accompanied by growing numbers of livestock to feed this population, as well as by an increase of human invasion into natural habitats of wild animals. As a result, both animals and humans are becoming progressively vulnerable to infections with known (zoonotic) pathogens, but are also increasingly exposed to novel viruses. Global trade as well as climate changes can contribute to pathogen transmission, e.g. through import of infected vectors or expansion of habitats for arthropod vectors such as mosquitoes and midges. Infectious disease outbreaks, especially those by novel viruses, are generally unexpected, and therefore we should be prepared with tools and abilities for immediate action, including the identification of the causative agent, the evaluation of its pathogenic potential for animals and humans, and the fast development of diagnostic assays to allow contact tracing and quarantine measures. HONOURs is a Marie Skłodowska-Curie Actions Innovative Training Network (MSCA-ITN), teaching 15 talented young researchers to become “preparedness-experts”. HONOURs, initiated in April 2017, involves 11 laboratories from 6 different European countries, all at the forefront of novel virus investigations and characterizations. The network includes surveillance experts in both the veterinary and the human health sector, who have developed and utilize highly sensitive virus discovery techniques, e.g. next generation sequencing based genomics and universal primers based PCR, to allow identification and characterization of novel viruses. Production of pure viral proteins, providing high-resolution structures, aids in the design of novel, fast and easy-to-use diagnostics. Organotypic in vitro cell cultures systems (e.g. pseudostratified human airway epithelia) provide tools for virus replication, if needed via a reverse genetics platform, and the production of virus stocks permits inoculation in animal models to examine disease, evaluate candidate vaccines, and fulfilment of the Koch's postulates. Scientists of the various institutes will provide training in the HONOURs network through specialized courses and workshops, combined with challenging research projects. The final aim of the network is to deliver 15 expert scientists, ready to act in case of the emergence of an epidemic

SARS-CoV-2 N501Y Introductions and Transmissions in Switzerland from Beginning of October 2020 to February 2021-Implementation of Swiss-Wide Diagnostic Screening and Whole Genome Sequencing.

The rapid spread of the SARS-CoV-2 lineages B.1.1.7 (N501Y.V1) throughout the UK, B.1.351 (N501Y.V2) in South Africa, and P.1 (B.1.1.28.1; N501Y.V3) in Brazil has led to the definition of variants of concern (VoCs) and recommendations for lineage specific surveillance. In Switzerland, during the last weeks of December 2020, we established a nationwide screening protocol across multiple laboratories, focusing first on epidemiological and microbiological definitions. In January 2021, we validated and implemented an N501Y-specific PCR to rapidly screen for VoCs, which are then confirmed using amplicon sequencing or whole genome sequencing (WGS). A total of 13,387 VoCs have been identified since the detection of the first Swiss case in October 2020, with 4194 being B.1.1.7, 172 B.1.351, and 7 P.1. The remaining 9014 cases of VoCs have been described without further lineage specification. Overall, all diagnostic centers reported a rapid increase of the percentage of detected VOCs, with a range of 6 to 46% between 25 to 31 of January 2021 increasing towards 41 to 82% between 22 to 28 of February. A total of 739 N501Y positive genomes were analysed and show a broad range of introduction events to Switzerland. In this paper, we describe the nationwide coordination and implementation process across laboratories, public health institutions, and researchers, the first results of our N501Y-specific variant screening, and the phylogenetic analysis of all available WGS data in Switzerland, that together identified the early introduction events and subsequent community spreading of the VoCs