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Emerging Infectious Diseases May 2021We describe a series of severe neuroinvasive infections caused by Toscana virus, identified by real-time reverse transcription PCR testing, in 8 hospitalized patients in...
We describe a series of severe neuroinvasive infections caused by Toscana virus, identified by real-time reverse transcription PCR testing, in 8 hospitalized patients in Bucharest, Romania, during the summer seasons of 2017 and 2018. Of 8 patients, 5 died. Sequencing showed that the circulating virus belonged to lineage A.
Topics: Bunyaviridae Infections; Humans; Romania; Sandfly fever Naples virus
PubMed: 33900182
DOI: 10.3201/eid2705.204598 -
Viruses Aug 2019We screened ticks and human clinical specimens to detect and characterize tick phleboviruses and pathogenicity in vertebrates. Ticks were collected at locations in...
We screened ticks and human clinical specimens to detect and characterize tick phleboviruses and pathogenicity in vertebrates. Ticks were collected at locations in Istanbul (Northwest Anatolia, Thrace), Edirne, Kırklareli, and Tekirdağ (Thrace), Mersin (Mediterranean Anatolia), Adiyaman and Şanlıurfa (Southeastern Anatolia) provinces from 2013-2018 and were analyzed following morphological identification and pooling. Specimens from individuals with febrile disease or meningoencephalitic symptoms of an unknown etiology were also evaluated. The pools were screened via generic tick phlebovirus amplification assays and products were sequenced. Selected pools were used for cell culture and suckling mice inoculations and next generation sequencing (NGS). A total of 7492 ticks were screened in 609 pools where 4.2% were positive. A phylogenetic sequence clustering according to tick species was observed. No human samples were positive. NGS provided near-complete viral replicase coding sequences in three pools. A comprehensive analysis revealed three distinct, monophyletic virus genotypes, comprised of previously-described viruses from Anatolia and the Balkans, with unique fingerprints in conserved amino acid motifs in viral replicase. A novel tick phlebovirus group was discovered circulating in the Balkans and Turkey, with at least three genotypes or species. No evidence for replication in vertebrates or infections in clinical cases could be demonstrated.
Topics: Animals; Chlorocebus aethiops; Genotype; Humans; Mice; Phlebovirus; Phylogeny; RNA-Dependent RNA Polymerase; Ticks; Turkey; Vero Cells; Viral Proteins
PubMed: 31374842
DOI: 10.3390/v11080703 -
Viruses Jan 2021Phleboviruses transmitted by phlebotomine sandflies are endemic in the Mediterranean basin. (TOSV), (SFSV), and (SFNV) are responsible of summer fever, with...
Phleboviruses transmitted by phlebotomine sandflies are endemic in the Mediterranean basin. (TOSV), (SFSV), and (SFNV) are responsible of summer fever, with well-known pathogenic potential for humans ranging from asymptomatic to mild fever, in addition to neuro-invasive infections during summer. Although TOSV, in particular, is a significant and well-known human pathogen, SFVs remain neglected, with many gaps in the relevant knowledge. Sero-epidemiological studies and case reports recently showed a geographical wider distribution than previously considered, although the real incidence of phleboviruses infections in the Mediterranean area is still unknown. Here we retrospectively evaluated the circulation of phleboviruses during summer seasons between 2007 and 2019 in 649 patients showing neurological symptoms using both molecular and serological approaches. We found that 42/649 (6.5%) subjects experienced phlebovirus infection and only 10/42 cases were detected by molecular assays, whereas the other 32/42 were identified using serological approaches, including neutralization assays. During the 2013 summer, an outbreak in the Lombardy region is described because the prevalence of phlebovirus infection reached 37.2% (19/51 subjects). Interestingly, only 5/19 (26.5%) reported traveling in endemic areas. Of note, no cross-neutralization was observed between different strains tested, showing the possibility to be reinfected by newly discovered phlebovirus strains. In conclusion, phlebovirus infections are still inadequately considered by physicians and are generally underestimated. However, based on our results, sandfly fever viruses should be routinely included in diagnostic panels during summer period, including in Northern Italy.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antibodies, Neutralizing; Female; Humans; Immunoglobulin G; Immunoglobulin M; Italy; Male; Middle Aged; Phlebotomus Fever; Phlebovirus; RNA, Viral; Retrospective Studies; Seasons; Young Adult
PubMed: 33573092
DOI: 10.3390/v13020209 -
Emerging Infectious Diseases Oct 2020We isolated 17 viral strains capable of causing cytopathic effects in mammalian cells and death in neonatal mice from sand flies in China. Phylogenetic analysis showed...
We isolated 17 viral strains capable of causing cytopathic effects in mammalian cells and death in neonatal mice from sand flies in China. Phylogenetic analysis showed that these strains belonged to the genus Phlebovirus. These findings highlight the need to control this potentially emerging virus to help safeguard public health.
Topics: Animals; China; Mice; Phlebovirus; Phylogeny; Psychodidae
PubMed: 32946723
DOI: 10.3201/eid2610.191374 -
The Journal of Biological Chemistry Jan 2018Regulated mRNA decay plays a vital role in determining both the level and quality of cellular gene expression. Viral RNAs must successfully evade this host RNA decay...
Regulated mRNA decay plays a vital role in determining both the level and quality of cellular gene expression. Viral RNAs must successfully evade this host RNA decay machinery to establish a productive infection. One way for RNA viruses to accomplish this is to target the cellular exoribonuclease XRN1, because this enzyme is accessible in the cytoplasm and plays a major role in mRNA decay. Members of the Flaviviridae use RNA structures in their 5'- or 3'-untranslated regions to stall and repress XRN1, effectively stabilizing viral RNAs while also causing significant dysregulation of host cell mRNA stability. Here, we use a series of biochemical assays to demonstrate that the 3'-terminal portion of the nucleocapsid (N) mRNA of Rift Valley fever virus, a phlebovirus of the Bunyaviridae family, also can effectively stall and repress XRN1. The region responsible for impeding XRN1 includes a G-rich portion that likely forms a G-quadruplex structure. The 3'-terminal portions of ambisense-derived transcripts of multiple arenaviruses also stalled XRN1. Therefore, we conclude that RNAs from two additional families of mammalian RNA viruses stall and repress XRN1. This observation. emphasizes the importance and commonality of this viral strategy to interfere with the 5'-to-3'-exoribonuclease component of the cytoplasmic RNA decay machinery.
Topics: 3' Untranslated Regions; Exoribonucleases; HEK293 Cells; HeLa Cells; Host-Pathogen Interactions; Humans; Microtubule-Associated Proteins; Phlebovirus; RNA Stability; RNA, Messenger; RNA, Viral; Rift Valley fever virus; Sequence Analysis, RNA
PubMed: 29118186
DOI: 10.1074/jbc.M117.805796 -
The Journal of Infectious Diseases Mar 2014Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This...
BACKGROUND
Severe fever with thrombocytopenia syndrome (SFTS) is caused by SFTS virus (SFTSV), a novel bunyavirus reported to be endemic in central and northeastern China. This article describes the first identified patient with SFTS and a retrospective study on SFTS in Japan.
METHODS
Virologic and pathologic examinations were performed on the patient's samples. Laboratory diagnosis of SFTS was made by isolation/genome amplification and/or the detection of anti-SFTSV immunoglobulin G antibody in sera. Physicians were alerted to the initial diagnosis and asked whether they had previously treated patients with symptoms similar to those of SFTS.
RESULTS
A female patient who died in 2012 received a diagnosis of SFTS. Ten additional patients with SFTS were then retrospectively identified. All patients were aged ≥50 years and lived in western Japan. Six cases were fatal. The ratio of males to females was 8:3. SFTSV was isolated from 8 patients. Phylogenetic analyses indicated that all of the Japanese SFTSV isolates formed a genotype independent to those from China. Most patients showed symptoms due to hemorrhage, possibly because of disseminated intravascular coagulation and/or hemophagocytosis.
CONCLUSIONS
SFTS has been endemic to Japan, and SFTSV has been circulating naturally within the country.
Topics: Animals; Bunyaviridae Infections; Chlorocebus aethiops; Female; Humans; Japan; Male; Middle Aged; Phlebovirus; Phylogeny; Retrospective Studies; Vero Cells
PubMed: 24231186
DOI: 10.1093/infdis/jit603 -
Virologica Sinica Feb 2017Severe fever with thrombocytopenia syndrome virus (SFTSV) is a globe-shaped virus covered by a dense icosahedral array of glycoproteins Gn/Gc that mediate the attachment... (Review)
Review
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a globe-shaped virus covered by a dense icosahedral array of glycoproteins Gn/Gc that mediate the attachment of the virus to host cells and the fusion of viral and cellular membranes. Several membrane factors are involved in virus entry, including C-type lectins and nonmuscle myosin heavy chain IIA. The post-fusion crystal structure of the Gc protein suggests that it is a class II membrane fusion protein, similar to the E/E1 protein of flaviviruses and alphaviruses. The virus particles are internalized into host cell endosomes through the clathrin-dependent pathway, where the low pH activates the fusion of the virus with the cell membrane. With information from studies on other bunyaviruses, herein we will review our knowledge of the entry process of SFTSV.
Topics: Animals; Host-Pathogen Interactions; Humans; Phlebovirus; Virus Internalization
PubMed: 27995422
DOI: 10.1007/s12250-016-3858-6 -
Viruses Nov 2023Rift Valley fever phlebovirus (RVFV) is a zoonotic pathogen that causes Rift Valley fever (RVF) in livestock and humans. Currently, there is no licensed human vaccine or...
Rift Valley fever phlebovirus (RVFV) is a zoonotic pathogen that causes Rift Valley fever (RVF) in livestock and humans. Currently, there is no licensed human vaccine or antiviral drug to control RVF. Although multiple species of animals and humans are vulnerable to RVFV infection, host factors affecting susceptibility are not well understood. To identify the host factors or genes essential for RVFV replication, we conducted CRISPR-Cas9 knockout screening in human A549 cells. We then validated the putative genes using siRNA-mediated knock-downs and CRISPR-Cas9-mediated knock-out studies. The role of a candidate gene in the virus replication cycle was assessed by measuring intracellular viral RNA accumulation, and the virus titers were analyzed using plaque assay or TCID assay. We identified approximately 900 genes with potential involvement in RVFV infection and replication. Further evaluation of the effect of six genes on viral replication using siRNA-mediated knock-downs revealed that silencing two genes ( and ) significantly impaired RVFV replication. For further analysis, we focused on the gene since the role of the gene in RVFV replication was previously described in detail. knockout A549 cell lines were generated and used to dissect the effect of on a bunyavirus, RVFV, and an orthobunyavirus, La Crosse encephalitis virus (LACV). We observed significant effects of knockout cells on both intracellular RVFV RNA levels and viral titers. At the intracellular RNA level, affected RVFV replication at a later phase of its replication cycle (24 h) when compared with the LACV replication, which was affected in an earlier replication phase (12 h). In summary, we identified as an essential host factor for the replication of two different viruses, RVFV and LACV, both of which belong to the order. Future studies will investigate the mechanistic role through which facilitates phlebovirus replication.
Topics: Animals; Humans; Rift Valley Fever; Rift Valley fever virus; Phlebovirus; Virus Replication; RNA, Small Interfering; Adaptor Proteins, Signal Transducing
PubMed: 38005928
DOI: 10.3390/v15112251 -
Journal of Clinical Virology : the... Jan 2021Heartland virus (HRTV), a recently reclassified member of the genus Bandavirus, family Phenuiviridae, was first isolated in 2009 from a Missouri farmer exhibiting...
BACKGROUND
Heartland virus (HRTV), a recently reclassified member of the genus Bandavirus, family Phenuiviridae, was first isolated in 2009 from a Missouri farmer exhibiting leukopenia and thrombocytopenia with suspected ehrlichiosis. Since then, more HRTV cases have been diagnosed, and firstline laboratory diagnostic assays are needed to identify future infections Objectives. We sought to develop rapid and reliable IgM and IgG microsphere immunoassays (MIAs) to test sera of patients suspected of having HRTV infection, and to distinguish between recent and past infections.
STUDY DESIGN
Heartland virus antigen was captured by an anti-HRTV monoclonal antibody covalently bound to microspheres. Antibodies in human sera from confirmed HRTV-positive and negative cases were reacted with the microsphere complexes and detected using a BioPlex® 200 instrument. Assay cutoffs were determined by receiver operator characteristic analysis of the normalized test output values, equivocal zones for each assay were defined, and sensitivities, specificities, accuracies, and imprecision values were calculated.
RESULTS
Sensitivities, specificities and accuracies of the IgM and IgG MIAs were all >95 %. Both tests were precise within and between assay plates, and cross-reactivity with other arboviruses was not observed.
CONCLUSIONS
HRTV IgM and IgG MIAs are accurate and rapid first-line methods to serologically identify recent and past HRTV infections.
Topics: Antibodies, Viral; Antigens, Viral; Cross Reactions; Humans; Immunoassay; Immunoglobulin M; Microspheres; Phlebovirus
PubMed: 33248359
DOI: 10.1016/j.jcv.2020.104693 -
The American Journal of Tropical... Feb 2020The genus is a diverse group of globally occurring viruses, including tick-, mosquito-, and sand fly-borne pathogens. Phleboviruses have historically been classified by...
The genus is a diverse group of globally occurring viruses, including tick-, mosquito-, and sand fly-borne pathogens. Phleboviruses have historically been classified by serological methods. However, molecular methods alone have been used to identify emergent novel and related strains in recent years. This makes reconciling the classification of historically and newly characterized viruses challenging. To address this in part, we describe the characterization of the genomes of the Frijoles and Chilibre species complex phleboviruses, and three unclassified phleboviruses isolated in the Americas: Caimito, Itaporanga, and Rio Grande viruses that had previously only been described at the serological level. With the exception of , the phleboviruses sequenced in this study are phylogenetically related to the current species , , or the Chagres antigenic complex. Unexpectedly, molecular and phylogenetic analysis suggests Chilibre and Caimito viruses are taxonomically related to the family . These viruses have a genomic architecture similar to peribunyaviruses and form monophyletic groups within the genus . Our data highlight the importance of reconciling serological and molecular taxonomic classification. In addition, we suggest the taxonomy of Chilibre and Caimito viruses should be revised.
Topics: Americas; Animals; Genome, Viral; Humans; Phlebovirus; Phylogeny
PubMed: 31802735
DOI: 10.4269/ajtmh.19-0717