127 research outputs found

    Sandfly-Borne Viruses of Demonstrated/Relevant Medical Importance

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    Sandflies show distribution in a vast geographical area from Europe to Asia, Africa, Australia, and Central and South America where they can transmit a large number of viruses. Between these viruses, the most important are grouped into the Phlebovirus genus (family Phenuiviridae). Among them, several sandfly-borne phleboviruses cause self-limiting febrile disease (sandfly fever) or central and peripheral nervous system infections. Data concerning the geographic distribution of these phleboviruses has drastically increased during the last decade in both the new and the old worlds. The current situation depicts a high viral diversity with taxonomic groups containing human pathogenic and non-pathogenic viruses. This merits to provide insight to address the question of medical and veterinary public health impact of all these viruses, which are poorly studied. To do so, integrated and translational approaches must use ecological, epidemiological, serological and direct clinical evidence. Beside, other viruses transmitted by sandflies and belonging to Rhabdoviridae and Reoviridae families can also be of veterinary and public health importance. The chapter aims to provide a comprehensive view of the sandfly-borne viral pathogens of the public health impact on humans and other vertebrates in the old and new worlds

    European Network for Neglected Vectors and Vector-Borne Infections COST Action Guidelines: What Is This About and What Is This For?

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    European network for neglected vectors and vector-borne infections COST action guidelines: What Is this about and what iIs this For

    Emerging viral respiratory tract infections—environmental risk factors and transmission

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    This article is made available for unrestricted research re-use and secondary analysis in any form or by any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.The past decade has seen the emergence of several novel viruses that cause respiratory tract infections in human beings, including Middle East respiratory syndrome coronavirus (MERS-CoV) in Saudi Arabia, an H7N9 influenza A virus in eastern China, a swine-like influenza H3N2 variant virus in the USA, and a human adenovirus 14p1 also in the USA. MERS-CoV and H7N9 viruses are still a major worldwide public health concern. The pathogenesis and mode of transmission of MERS-CoV and H7N9 influenza A virus are poorly understood, making it more difficult to implement intervention and preventive measures. A united and coordinated global response is needed to tackle emerging viruses that can cause fatal respiratory tract infections and to fill major gaps in the understanding of the epidemiology and transmission dynamics of these viruses

    Toscana, West Nile, Usutu and tick-borne encephalitis viruses: external quality assessment for molecular detection of emerging neurotropic viruses in Europe, 2017

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    BackgroundNeurotropic arboviruses are increasingly recognised as causative agents of neurological disease in Europe but underdiagnosis is still suspected. Capability for accurate diagnosis is a prerequisite for adequate clinical and public health response.AimTo improve diagnostic capability in EVD-La

    Cowpox Virus Transmission from Pet Rats to Humans, France

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    In early 2009, four human cases of cowpox virus cutaneous infection in northern France, resulting from direct contact with infected pet rats (Rattus norvegicus), were studied. Pet rats, originating from the same pet store, were shown to be infected by a unique virus strain. Infection was then transmitted to humans who purchased or had contact with pet rats

    Point of Care Strategy for Rapid Diagnosis of Novel A/H1N1 Influenza Virus

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    Within months of the emergence of the novel A/H1N1 pandemic influenza virus (nA/H1N1v), systematic screening for the surveillance of the pandemic was abandoned in France and in some other countries. At the end of June 2009, we implemented, for the public hospitals of Marseille, a Point Of Care (POC) strategy for rapid diagnosis of the novel A/H1N1 influenza virus, in order to maintain local surveillance and to evaluate locally the kinetics of the pandemic.Two POC laboratories, located in strategic places, were organized to receive and test samples 24 h/24. POC strategy consisted of receiving and processing naso-pharyngeal specimens in preparation for the rapid influenza diagnostic test (RIDT) and real-time RT-PCR assay (rtRT-PCR). This strategy had the theoretical capacity of processing up to 36 samples per 24 h. When the flow of samples was too high, the rtRT-PCR test was abandoned in the POC laboratories and transferred to the core virology laboratory. Confirmatory diagnosis was performed in the core virology laboratory twice a day using two distinct rtRT-PCR techniques that detect either influenza A virus or nA/N1N1v. Over a period of three months, 1974 samples were received in the POC laboratories, of which 111 were positive for nA/H1N1v. Specificity and sensitivity of RIDT were 100%, and 57.7% respectively. Positive results obtained using RIDT were transmitted to clinical practitioners in less than 2 hours. POC processed rtRT-PCR results were available within 7 hours, and rtRT-PCR confirmation within 24 hours.The POC strategy is of benefit, in all cases (with or without rtRT-PCR assay), because it provides continuous reception/processing of samples and reduction of the time to provide consolidated results to the clinical practitioners. We believe that implementation of the POC strategy for the largest number of suspect cases may improve the quality of patient care and our knowledge of the epidemiology of the pandemic

    Coordinated Implementation of Chikungunya Virus Reverse Transcription–PCR

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    A preformulated chikungunya virus real-time reverse transcription–PCR, quality-confirmed oligonucleotides, and noninfectious virus controls were distributed by the European Network for the Diagnosis of Imported Viral Diseases. An international proficiency study with 31 participants demonstrated that ad hoc implementation of molecular diagnostics was feasible and successful

    ICTV Virus Taxonomy Profile : Arenaviridae

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    Members of the family Arenaviridae produce enveloped virions containing genomes consisting of two or three single-stranded RNA segments totalling about 10.5 kb. Arenaviruses can infect mammals, including humans and other primates, snakes, and fish. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Arenaviridae, which is available at www.ictv.global/report/arenaviridae.Non peer reviewe

    RNA and DNA Bacteriophages as Molecular Diagnosis Controls in Clinical Virology: A Comprehensive Study of More than 45,000 Routine PCR Tests

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    Real-time PCR techniques are now commonly used for the detection of viral genomes in various human specimens and require for validation both external and internal controls (ECs and ICs). In particular, ICs added to clinical samples are necessary to monitor the extraction, reverse transcription, and amplification steps in order to detect false-negative results resulting from PCR-inhibition or errors in the technical procedure. Here, we performed a large scale evaluation of the use of bacteriophages as ICs in routine molecular diagnosis. This allowed to propose simple standardized procedures (i) to design specific ECs for both DNA and RNA viruses and (ii) to use T4 (DNA) or MS2 (RNA) phages as ICs in routine diagnosis. Various technical formats for using phages as ICs were optimised and validated. Subsequently, T4 and MS2 ICs were evaluated in routine real-time PCR or RT-PCR virological diagnostic tests, using a series of 8,950 clinical samples (representing 36 distinct specimen types) sent to our laboratory for the detection of a variety of DNA and RNA viruses. The frequency of inefficient detection of ICs was analyzed according to the nature of the sample. Inhibitors of enzymatic reactions were detected at high frequency in specific sample types such as heparinized blood and bone marrow (>70%), broncho-alveolar liquid (41%) and stools (36%). The use of T4 and MS2 phages as ICs proved to be cost-effective, flexible and adaptable to various technical procedures of real-time PCR detection in virology. It represents a valuable strategy for enhancing the quality of routine molecular diagnosis in laboratories that use in-house designed diagnostic systems, which can conveniently be associated to the use of specific synthetic ECs. The high rate of inhibitors observed in a variety of specimen types should stimulate the elaboration of improved technical protocols for the extraction and amplification of nucleic acids

    A Retrospective Overview of Enterovirus Infection Diagnosis and Molecular Epidemiology in the Public Hospitals of Marseille, France (1985–2005)

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    Human enteroviruses (HEV) are frequent human pathogens and, associated in particular with large outbreaks of aseptic meningitis. Here, we have compiled a database of clinical HEV isolates from the Public Hospitals of Marseille, from 1985 to 2005. Amongst 654 isolates that could be characterized by complete sequencing of the VP1 gene, 98% belonged to species HEV-B; the most frequently isolated serotypes were Echovirus E30, E11, E7, E6 and E4. The high incidence of E30 and the recent emergence of E13 are consistent with reports worldwide and peak HEV isolation occurred mostly in the late spring and summer months. The proportion of echoviruses has decreased across the years, while that of coxsackieviruses has increased. Stool (the most frequent sample type) allowed detection of all identified serotypes. MRC5 (Human lung fibroblasts) cell line was the most conducive cell line for HEV isolation (84.9% of 10 most common serotype isolates, 96.3% in association with BGM (Buffalo green monkey kidney cells)). Previous seroneutralization-based serotype identification demonstrated 55.4% accuracy when compared with molecular VP1 analysis. Our analysis of a large number of clinical strains over 20 years reinforced the validity of VP1 serotyping and showed that comparative p-distance scores can be coupled with phylogenetic analysis to provide non-ambiguous serotype identification. Phylogenetic analysis in the VP1, 2C and 3D regions also provided evidence for recombination events amongst clinical isolates. In particular, it identified isolates with dissimilar VP1 but almost identical nonstructural regions
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