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Uirusu 2018Seven years have passed since the discovery of a novel infectious disease, severe fever with thrombocytopenia syndrome (SFTS) caused by a novel Phlebovirus, SFTS virus... (Review)
Review
Seven years have passed since the discovery of a novel infectious disease, severe fever with thrombocytopenia syndrome (SFTS) caused by a novel Phlebovirus, SFTS virus (SFTSV), in PR China. It was also confirmed that SFTS was endemic to Japan through an identification of a woman, who died of SFTSV infection in Yamaguchi prefecture in late 2012. Approximately 6 years have passed since the discovery of SFTS-endemicity in Japan. At present, SFTS is endemic to PR China, South Korea and western Japan. SFTSV is maintained between several species of ticks such as Haemaphysalis longicornis and wild and domestic animals in nature. Therefore, we cannot escape from the risk of being infected with SFTSV. Based on the similarity in the characteristics of the clinical symptoms including the high case fatality rate, mode of infection to humans, pathology and virology between SFTS and Crimean-Congo hemorrhagic fever (CCHF), SFTS should be classified as viral hemorrhagic fever. Although the time from the discovery of SFTS is still short, there have been many scientific reports on the epidemiological, clinical, and/or pathological, and virological studies on SFTS. Favipiravir was reported to show an efficacy in the prevention and treatment of SFTSV infections in an animal model. A clinical study to evaluate the efficacy of favipiravir in the treatment of SFTS patients has been initiated in Japan. Specific and effective treatment with antiviral drugs for and preventive measures of SFTS with vaccination shoued be developed through scientific, clinical, and basic research.
Topics: Animals; Antiviral Agents; Disease Outbreaks; Asia, Eastern; Humans; Phlebotomus Fever; Phlebovirus; Ticks; Viral Vaccines
PubMed: 31105134
DOI: 10.2222/jsv.68.41 -
Vector Borne and Zoonotic Diseases... Apr 2021Wuxiang virus was isolated from sandfly specimens collected in Wuxiang County, Shanxi Province, China in 2018, representing the first reported isolation of...
Wuxiang virus was isolated from sandfly specimens collected in Wuxiang County, Shanxi Province, China in 2018, representing the first reported isolation of sandfly-borne virus from sandflies collected in a natural environment in China. The local sandfly density, seasonal fluctuations, and temporal and spatial distributions of the virus in Wuxiang County remain unclear. Four fixed sandfly collection sites were set up in Wuxiang County and sandfly specimens were collected continuously from June to August 2019. All sandfly specimens were subjected to viral isolation and molecular biological analysis. The data on sandfly specimens collected in Wuxiang County from June to August 2019 showed a significant difference in the density of sandflies between June 26 and August 16 ( < 0.05). No statistical difference was found in sandfly density among collection sites ( > 0.05). A total of 33 virus isolates causing cytopathic effects in mammalian (BHK-21) cells were obtained from 7466 sandflies (91 pools) collected from June to August 2019. The results of molecular genetic evolution analysis of the nucleotide sequence of these isolates showed that the L and S genes (encoding NS and N proteins) of the 33 viruses isolated in 2019 are in the same evolutionary branch as the previously isolated Wuxiang virus. No significant difference was found in the virus isolation rate (the pool isolation rate of virus) among sandflies collected at different times from June to August ( > 0.05). The virus isolation rate of sandflies collected at different collection sites showed a statistically significant difference ( < 0.05). The results of this study suggest that the Wuxiang virus is a stable viral population in local sandflies. Strengthened research into Wuxiang virus infection of humans and animals and clarification of the public health hazards posed by Wuxiang virus to both humans and animals are urgently needed.
Topics: Animals; Base Sequence; Phlebotomus; Phlebovirus; Phylogeny; Psychodidae
PubMed: 33600240
DOI: 10.1089/vbz.2020.2702 -
Journal of Medical Virology Jul 2015Sandfly fever viruses are endemic in the Mediterranean region causing to humans asymptomatic or mild infections to severe neurological syndromes. In order to investigate...
Sandfly fever viruses are endemic in the Mediterranean region causing to humans asymptomatic or mild infections to severe neurological syndromes. In order to investigate the epidemiology of phlebovirus infections in Greece, samples from 499 patients with acute febrile illness (50.2% accompanied by neurological symptoms) were tested during 2010-2014 by serological and molecular methods. Phlebovirus infection was detected in 40 (8%) patients, 25 of them presenting acute neurological infection. Most cases were observed in the summer, with a peak in August. Increased number of cases was observed in 2013, and three of them were observed in Athens. Toscana virus lineage C RNA was detected in one encephalitis case, while the serological results showed that most cases were caused by phleboviruses belonging to the sandfly fever Naples virus serocomplex. This study provided the first insight into the epidemiology of phleboviral disease in Greece.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Female; Geography, Medical; Greece; History, 21st Century; Humans; Infant; Male; Middle Aged; Phlebotomus Fever; Phlebovirus; Phylogeny; Prevalence; RNA, Viral; Seasons; Young Adult
PubMed: 25733059
DOI: 10.1002/jmv.24163 -
Viruses Oct 2023Fermo virus is a that is increasingly reported in sand flies from northern Italy. The natural cycle is not fully understood, but the virus has been detected by direct...
Fermo virus is a that is increasingly reported in sand flies from northern Italy. The natural cycle is not fully understood, but the virus has been detected by direct methods only in sand flies. Although there is serological evidence that it can infect vertebrates, the virus has not been directly detected in animals or humans. Here, we have developed and reported a specific real-time PCR for Fermo virus. The availability of the described method will be useful to characterize the epidemiology of the FERV, ensuring, compared to previously available protocols, a more sensitive detection in insects and the possible detection in vertebrates to evaluate the presence of reservoirs and the pathogenic potential of the virus in humans or animals.
Topics: Animals; Humans; Phlebovirus; Real-Time Polymerase Chain Reaction; Psychodidae; Italy
PubMed: 37896859
DOI: 10.3390/v15102082 -
The Journal of General Virology Nov 2017Toscana virus (TOSV) is an arthropod-borne phlebovirus within the family Phenuiviridae in the order Bunyavirales. It seems to be an important agent of human...
Toscana virus (TOSV) is an arthropod-borne phlebovirus within the family Phenuiviridae in the order Bunyavirales. It seems to be an important agent of human meningoencephalitis in the warm season in the Mediterranean area. Because the polymerase of Bunyavirales lacks a capping activity, it cleaves short-capped RNA leaders derived from the host cell, and uses them to initiate viral mRNA synthesis. To determine the size and nucleotide composition of the host-derived RNA leaders, and to elucidate the first steps of TOSV transcription initiation, we performed a high-throughput sequencing of the 5' end of TOSV mRNAs in infected cells at different times post-infection. Our results indicated that the viral polymerase cleaved the host-capped RNA leaders within a window of 11-16 nucleotides. A single population of cellular mRNAs could be cleaved at different sites to prime the synthesis of several viral mRNA species. The majority of the mRNA resulted from direct priming, but we observed mRNAs resulting from several rounds of prime-and-realign events. Our data suggest that the different rounds of the prime-and-realign mechanism result from the blocking of the template strand in a static position in the active site, leading to the slippage of the nascent strand by two nucleotides when the growing duplex is sorted out from the active site. To minimize this rate-limiting step, TOSV polymerase cleaves preferentially capped RNA leaders after GC, so as to greatly reduce the number of cycles of priming and realignment, and facilitate the separation of the growing duplex.
Topics: Cells, Cultured; Epithelial Cells; Humans; RNA, Messenger; RNA, Viral; RNA-Dependent RNA Polymerase; Sandfly fever Naples virus; Transcription, Genetic
PubMed: 29022865
DOI: 10.1099/jgv.0.000941 -
Archives of Virology Jan 2022Ticks are blood-sucking arthropods that transmit many pathogens, including arboviruses. Arboviruses transmitted by ticks are generally referred to as tick-borne viruses...
Ticks are blood-sucking arthropods that transmit many pathogens, including arboviruses. Arboviruses transmitted by ticks are generally referred to as tick-borne viruses (TBVs). TBVs are known to cause diseases in humans, pets, and livestock. There is, however, very limited information on the occurrence and distribution of TBVs in sub-Saharan Africa. This study was designed to determine the presence and distribution of ticks infesting dogs and cattle in Ghana, as well as to identify the tick-borne or tick-associated viruses they harbour. A more diverse population of ticks was found to infest cattle (three genera) relative to those infesting dogs (one genus). Six phleboviruses and an orthonairovirus were detected in tick pools screened by RT-PCR. Subsequent sequence analysis revealed two distinct phleboviruses and the previously reported Odaw virus in ticks collected from dogs and a virus (16GH-T27) most closely related to four unclassified phleboviruses in ticks collected from cattle. The virus 16GH-T27 was considered a strain of Balambala tick virus (BTV) and named BTV strain 16GH-T27. Next-generation sequencing analysis of the BTV-positive tick pool detected only the L and S segments. Phylogenetic analysis revealed that BTV clustered with viruses previously defined as M-segment-deficient phleboviruses. The orthonairovirus detected in ticks collected from cattle was confirmed to be the medically important Dugbe virus. Furthermore, we discuss the importance of understanding the presence and distribution of ticks and TBVs in disease prevention and mitigation and the implications for public health. Our findings contribute to the knowledge pool on TBVs and tick-associated viruses.
Topics: Animals; Cattle; Dogs; Ghana; Phlebovirus; Phylogeny; Satellite Viruses; Tick-Borne Diseases; Ticks
PubMed: 34757503
DOI: 10.1007/s00705-021-05296-4 -
Acta Medica Portuguesa Oct 2021Toscana virus (TOSV) is an emerging sandfly-borne virus within the Phlebovirus genus. Although most infections caused by this virus present as asymptomatic or with...
INTRODUCTION
Toscana virus (TOSV) is an emerging sandfly-borne virus within the Phlebovirus genus. Although most infections caused by this virus present as asymptomatic or with minimal symptomatology, TOSV may emerge as a febrile disease or sporadic cases of neurological disease such as meningitis or meningoencephalitis. This pathogen is distributed throughout the Mediterranean basin, along with the spatial distribution of its recognized sandfly vector, Phlebotomus perniciosus. Portugal, after Italy, was the second country considered endemic for this virus, with the first case of acquired infection published in 1985. Although little is known about the circulation of this virus in Portugal, the laboratory diagnosis of TOSV is available at the Centre for Vectors and Infectious Diseases Research of the National Institute of Health Dr. Ricardo Jorge (CEVDI/INSA), since 2007. The aim of this study is to report the results of the diagnosis of TOSV at the CEVDI/INSA, between 2009 and 2018.
MATERIAL AND METHODS
The diagnosis of TOSV in the CEVDI/INSA is included in the arboviruses and vector-borne neurotropic viruses panels or can be performed, when specified, for TOSV only. Direct detection is made in cerebrospinal fluid samples and is available for TOSV by specific real-time reverse transcription polymerase chain reaction followed by conventional real-time reverse transcription polymerase chain reaction for sequencing purposes, if positive. For indirect diagnosis, performed in serum samples, an in-house immunofluorescence assay for the detection of IgM and IgG antibodies against TOSV is used. A commercial immunofluorescence assay consisting in a mosaic of four phleboviruses is also available, in which, in addition to TOSV, antibody detection for sandfly fever Naples virus, sandfly fever Sicilian virus and sandfly fever Cyprus virus can be done. All diagnostic tests requested by clinicians to the CEVDI/INSA for arboviruses, neurotropic viruses and/or TOSV between January 2009 and December 2018, were included in this study.
RESULTS
During the study period, the CEVDI/INSA received samples from 608 patients with diagnostic requests for TOSV. Five acute TOSV infections and one acute sandfly fever Sicilian virus infection were confirmed in serum samples. Three other patients had serological evidence of previous contact with the virus. Two of the six patients with acute infection developed febrile syndrome, and the other four presented with neurological disease: meningitis (n = 2), meningoencephalitis (n = 1) and severe depression of consciousness (n = 1). These infections were most likely acquired in the districts of Faro (3), Lisbon (2) and Setúbal (1).
DISCUSSION
In Portugal, the number of laboratory diagnostic requests for TOSV is low when compared to the numbers of requests for other less prevalent vector-borne viruses. The Faro district presented the highest number of TOSV-specific diagnostic requests which seems to indicate a higher level of recognition by clinicians in that region. Febrile syndrome and neurological disease were the clinical manifestations that were present in acute cases. In this study, in addition to the Faro district, recent infections were also detected in the districts of Lisbon and Setúbal. It is probable that TOSV may be distributed throughout the mainland territory since its main vector is present from north to south. In 2017, the sandfly fever Sicilian virus was associated for the first time with human disease in our country, thus alerting to the circulation of this phlebovirus.
CONCLUSION
Even though the number of identified cases in Portugal is low, TOSV circulates and causes disease in our country. The diagnosis of this and other phleboviruses should not be neglected in the differential diagnosis of febrile syndrome and viral meningitis and meningoencephalitis, especially during the warmer months, when the vector's activity is higher.
Topics: Antibodies, Viral; Diagnosis, Differential; Humans; Immunoglobulin G; Portugal; Sandfly fever Naples virus
PubMed: 34051876
DOI: 10.20344/amp.13308 -
Science Advances May 2022Endogenous viral elements (EVEs), accounting for 15% of our genome, serve as a genetic reservoir from which new genes can emerge. Nematode EVEs are particularly diverse...
Endogenous viral elements (EVEs), accounting for 15% of our genome, serve as a genetic reservoir from which new genes can emerge. Nematode EVEs are particularly diverse and informative of virus evolution. We identify Atlas virus-an intact retrovirus-like EVE in the human hookworm , with an envelope protein genetically related to G-G glycoproteins from the family Phenuiviridae. A cryo-EM structure of Atlas G reveals a class II viral membrane fusion protein fold not previously seen in retroviruses. Atlas G has the structural hallmarks of an active fusogen. Atlas G trimers insert into membranes with endosomal lipid compositions and low pH. When expressed on the plasma membrane, Atlas G has cell-cell fusion activity. With its preserved biological activities, Atlas G has the potential to acquire a cellular function. Our work reveals structural plasticity in reverse-transcribing RNA viruses.
Topics: Ancylostomatoidea; Animals; Humans; Phlebovirus; RNA Viruses; Viral Envelope Proteins; Viral Fusion Proteins; Virus Internalization
PubMed: 35544562
DOI: 10.1126/sciadv.abj6894 -
PLoS Neglected Tropical Diseases Aug 2021With global warming and lush forest change, vector-borne infections are expected to increase in the number and diversity of agents. Since the first report of severe...
With global warming and lush forest change, vector-borne infections are expected to increase in the number and diversity of agents. Since the first report of severe fever with thrombocytopenia syndrome (SFTS) in 2013, the number of reported cases has increased annually in South Korea. However, although tick-borne encephalitis virus (TBEV) was detected from ticks and wild rodents, there is no human TBE case report in South Korea. This study aimed to determine the seroprevalence of TBEV and SFTS virus (SFTSV) among forest and field workers in South Korea. From January 2017 to August 2018, a total 583 sera were obtained from the forest and field workers in South Korea. IgG enzyme-linked immunosorbent assay (ELISA) and neutralization assay were conducted for TBEV, and indirect immunofluorescence assay (IFA) and neutralization assay were performed for SFTSV. Seroprevalence of TBEV was 0.9% (5/583) by IgG ELISA, and 0.3% (2/583) by neutralization assay. Neutralizing antibody against TBEV was detected in a forest worker in Jeju (1:113) and Hongcheon (1:10). Only 1 (0.2%) forest worker in Yeongju was seropositive for SFTSV by IFA (1:2,048) and neutralizing antibody was detected also. In conclusion, this study shows that it is necessary to raise the awareness of physicians about TBEV infection and to make efforts to survey and diagnose vector-borne diseases in South Korea.
Topics: Adult; Aged; Aged, 80 and over; Antibodies, Neutralizing; Antibodies, Viral; Encephalitis Viruses, Tick-Borne; Encephalitis, Tick-Borne; Female; Forestry; Humans; Male; Middle Aged; Phlebovirus; Republic of Korea; Seroepidemiologic Studies; Severe Fever with Thrombocytopenia Syndrome; Vector Borne Diseases; Young Adult
PubMed: 34407077
DOI: 10.1371/journal.pntd.0009687 -
Antiviral Research Jan 2021Severe fever with thrombocytopenia syndrome virus (SFTSV) and Heartland virus (HRTV) cause viral hemorrhagic fever-like illnesses in humans due to an aberrant host...
Severe fever with thrombocytopenia syndrome virus (SFTSV) and Heartland virus (HRTV) cause viral hemorrhagic fever-like illnesses in humans due to an aberrant host inflammatory response, which contributes to pathogenesis. Here, we established two separate minigenome (MG) systems based on the M-segment of SFTSV and HRTV. Following characterization of both systems for SFTSV and HRTV, we used them as a platform to screen potential compounds that inhibit viral RNA synthesis. We demonstrated that the NF-κB inhibitor, SC75741, reduces viral RNA synthesis of SFTSV and HRTV using our MG platform and validated these results using infectious SFTSV and HRTV. These results may lead to the use of MG systems as potential screening systems for the identification of antiviral compounds and yield novel insights into host-factors that could play role in bandavirus transcription and replication.
Topics: Animals; Antiviral Agents; Chlorocebus aethiops; Drug Discovery; Genome, Viral; HEK293 Cells; Host-Pathogen Interactions; Humans; Inhibitory Concentration 50; NF-kappa B; Phlebovirus; THP-1 Cells; Ticks; Vero Cells
PubMed: 33296695
DOI: 10.1016/j.antiviral.2020.104993