Flaviviridae: A family of RNA viruses, many of which cause disease in humans and domestic animals. There are three genera FLAVIVIRUS; PESTIVIRUS; and HEPACIVIRUS, as well as several unassigned species.Flaviviridae Infections: Infections with viruses of the family FLAVIVIRIDAE.Flavivirus: A genus of FLAVIVIRIDAE containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is YELLOW FEVER VIRUS.Diarrhea Viruses, Bovine Viral: A group of viruses in the genus PESTIVIRUS, causing diarrhea, fever, oral ulcerations, hemorrhagic syndrome, and various necrotic lesions among cattle and other domestic animals. The two species (genotypes), BVDV-1 and BVDV-2 , exhibit antigenic and pathological differences. The historical designation, BVDV, consisted of both (then unrecognized) genotypes.GB virus A: A species of virus (unassigned to a genus) in the family FLAVIVIRIDAE, that have been identified in at least six species of New World monkeys. They do not cause HEPATITIS in the host or other susceptible species.Flavivirus Infections: Infections with viruses of the genus FLAVIVIRUS, family FLAVIVIRIDAE.Pestivirus: A genus of FLAVIVIRIDAE, also known as mucosal disease virus group, which is not arthropod-borne. Transmission is by direct and indirect contact, and by transplacental and congenital transmission. Species include BORDER DISEASE VIRUS, bovine viral diarrhea virus (DIARRHEA VIRUS, BOVINE VIRAL), and CLASSICAL SWINE FEVER VIRUS.Saguinus: A genus in the subfamily CALLITRICHINAE consisting of 12 species and found in Panama as well as South America. Species seen most frequently in the literature are S. oedipus (cotton-top marmoset), S. nigricollis, and S. fusicollis.West Nile virus: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.Encephalitis Virus, St. Louis: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE), which is the etiologic agent of ST. LOUIS ENCEPHALITIS in the United States, the Caribbean, and Central and South America.Viral Nonstructural Proteins: Proteins encoded by a VIRAL GENOME that are produced in the organisms they infect, but not packaged into the VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.GB virus C: A species of virus (unassigned to a genus) in the family FLAVIVIRIDAE. It is genetically heterogeneous, of human origin, and transmitted by blood or blood products. Despite its alternate name (Hepatitis G virus), its pathogenicity remains controversial.Classical swine fever virus: A species of the PESTIVIRUS genus causing exceedingly contagious and fatal hemorrhagic disease of swine.Nucleoside-Triphosphatase: An enzyme which catalyzes the hydrolysis of nucleoside triphosphates to nucleoside diphosphates. It may also catalyze the hydrolysis of nucleotide triphosphates, diphosphates, thiamine diphosphates and FAD. The nucleoside triphosphate phosphohydrolases I and II are subtypes of the enzyme which are found mostly in viruses.Encephalitis, St. Louis: A viral encephalitis caused by the St. Louis encephalitis virus (ENCEPHALITIS VIRUS, ST. LOUIS), a FLAVIVIRUS. It is transmitted to humans and other vertebrates primarily by mosquitoes of the genus CULEX. The primary animal vectors are wild birds and the disorder is endemic to the midwestern and southeastern United States. Infections may be limited to an influenza-like illness or present as an ASEPTIC MENINGITIS or ENCEPHALITIS. Clinical manifestations of the encephalitic presentation may include SEIZURES, lethargy, MYOCLONUS, focal neurologic signs, COMA, and DEATH. (From Adams et al., Principles of Neurology, 6th ed, p750)Culex: A genus of mosquitoes (CULICIDAE) commonly found in tropical regions. Species of this genus are vectors for ST. LOUIS ENCEPHALITIS as well as many other diseases of man and domestic and wild animals.Dengue Virus: A species of the genus FLAVIVIRUS which causes an acute febrile and sometimes hemorrhagic disease in man. Dengue is mosquito-borne and four serotypes are known.RNA Helicases: A family of proteins that promote unwinding of RNA during splicing and translation.Hepatitis, Viral, Animal: INFLAMMATION of the LIVER in animals due to viral infection.Arboviruses: Arthropod-borne viruses. A non-taxonomic designation for viruses that can replicate in both vertebrate hosts and arthropod vectors. Included are some members of the following families: ARENAVIRIDAE; BUNYAVIRIDAE; REOVIRIDAE; TOGAVIRIDAE; and FLAVIVIRIDAE. (From Dictionary of Microbiology and Molecular Biology, 2nd ed)Encephalitis Virus, Japanese: A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE), which is the etiological agent of Japanese encephalitis found in Asia, southeast Asia, and the Indian subcontinent.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Yellow fever virus: The type species of the FLAVIVIRUS genus. Principal vector transmission to humans is by AEDES spp. mosquitoes.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.West Nile Fever: A mosquito-borne viral illness caused by the WEST NILE VIRUS, a FLAVIVIRUS and endemic to regions of Africa, Asia, and Europe. Common clinical features include HEADACHE; FEVER; maculopapular rash; gastrointestinal symptoms; and lymphadenopathy. MENINGITIS; ENCEPHALITIS; and MYELITIS may also occur. The disease may occasionally be fatal or leave survivors with residual neurologic deficits. (From Joynt, Clinical Neurology, 1996, Ch26, p13; Lancet 1998 Sep 5;352(9130):767-71)Arbovirus Infections: Infections caused by arthropod-borne viruses, general or unspecified.RNA Replicase: An enzyme that catalyses RNA-template-directed extension of the 3'- end of an RNA strand by one nucleotide at a time, and can initiate a chain de novo. (Enzyme Nomenclature, 1992, p293)Hepacivirus: A genus of FLAVIVIRIDAE causing parenterally-transmitted HEPATITIS C which is associated with transfusions and drug abuse. Hepatitis C virus is the type species.Culicidae: A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.Hepatitis, Viral, Human: INFLAMMATION of the LIVER in humans due to infection by VIRUSES. There are several significant types of human viral hepatitis with infection caused by enteric-transmission (HEPATITIS A; HEPATITIS E) or blood transfusion (HEPATITIS B; HEPATITIS C; and HEPATITIS D).Bovine Virus Diarrhea-Mucosal Disease: Acute disease of cattle caused by the bovine viral diarrhea viruses (DIARRHEA VIRUSES, BOVINE VIRAL). Often mouth ulcerations are the only sign but fever, diarrhea, drop in milk yield, and loss of appetite are also seen. Severity of clinical disease varies and is strain dependent. Outbreaks are characterized by low morbidity and high mortality.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Serine Endopeptidases: Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.Aedes: A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Viral Envelope Proteins: Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Dengue: An acute febrile disease transmitted by the bite of AEDES mosquitoes infected with DENGUE VIRUS. It is self-limiting and characterized by fever, myalgia, headache, and rash. SEVERE DENGUE is a more virulent form of dengue.Viral Proteins: Proteins found in any species of virus.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Hepatitis C: INFLAMMATION of the LIVER in humans caused by HEPATITIS C VIRUS, a single-stranded RNA virus. Its incubation period is 30-90 days. Hepatitis C is transmitted primarily by contaminated blood parenterally, and is often associated with transfusion and intravenous drug abuse. However, in a significant number of cases, the source of hepatitis C infection is unknown.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Nucleic Acid Conformation: The spatial arrangement of the atoms of a nucleic acid or polynucleotide that results in its characteristic 3-dimensional shape.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

Carriage of GB virus C/hepatitis G virus RNA is associated with a slower immunologic, virologic, and clinical progression of human immunodeficiency virus disease in coinfected persons. (1/233)

The prevalence of GB virus C (GBV-C) infection is high in human immunodeficiency virus (HIV)-infected persons. However, the long-term consequences of coinfection are unknown. HIV-positive persons with a well-defined duration of infection were screened on the basis of their GBV-C/hepatitis G virus (HGV) RNA status and studied. GBV-C/HGV viremia was observed in 23, who carried the virus over a mean of 7.7 years. All parameters (survival, CDC stage B/C, HIV RNA load, CD4 T cell count) showed significant differences in terms of the cumulative progression rate between persons positive and negative for GBV-C/HGV RNA. When GBV-C/HGV RNA-positive and -unexposed subjects were matched by age, sex, baseline HIV RNA load, and baseline CD4 T cell count, HIV disease progression appeared worse in GBV-C/HGV RNA-negative subjects. The carriage of GBV-C/HGV RNA is associated with a slower progression of HIV disease in coinfected persons.  (+info)

High prevalence of hepatitis G virus (HGV) infections in dialysis staff. (2/233)

BACKGROUND: Patients on renal replacement therapy, haemodialysis (HD), or after kidney transplantation (TX), are known to be at risk of acquiring blood-borne infections (HBV, HCV). GBV-C/Hepatitis G virus (HGV) has been described recently and is considered to cause blood-borne infections. The aim of this study was to analyse the risk for the medical staff of HD and TX patients to acquire HGV infection. METHODS: Eighty-five HD patients and 86 TX recipients were compared with 49 health-care workers and 64 blood donors as controls. The HGV prevalence was determined by RT-PCR and antibodies to E2 protein. RESULTS: A high prevalence of HGV was found in the medical staff (24%) which nearly corresponded to the prevalence of the patients (TX 36%, HD 25%) but not to the controls (9%). In contrast, the prevalence of HCV was low in the medical staff (2%) and controls (0%) but high in HD (13%) and TX (13%). Age and duration of employment in the department did not significantly influence the HGV prevalence in staff. The number of viraemic subjects in staff was high, possibly indicating a more recent infection. CONCLUSION: An occupational risk for HGV exists in medical staff of dialysis and transplant patients. Further routes of transmission than only parenteral may play a role in this setting.  (+info)

Sequence heterogeneity within three different regions of the hepatitis G virus genome. (3/233)

Two sets of primers derived from the 5'-terminal region and the NS5 region of the hepatitis G virus (HGV) genome were used to amplify PCR fragments from serum specimens obtained from different parts of the world. All PCR fragments from the 5'-terminal region (5'-PCR, n = 56) and from the NS5 region (NS5-PCR, n = 85) were sequenced and compared to corresponding published HGV sequences. The range of nucleotide sequence similarity varied from 74 and 78% to 100% for 5'-PCR and NS5-PCR fragments, respectively. Additionally, five overlapping PCR fragments comprising an approximately 2.0-kb structural region of the HGV genome were sequenced from each of five sera obtained from three United States residents. These sequences were compared to 20 published sequences comprising the same region of the HGV genome. Nucleotide and deduced amino acid sequences obtained from different individuals were homologous from 82.9 to 93. 6% and from 90.4 to 99.0%, respectively. Sequences obtained from follow-up specimens were almost identical. Comparative analysis of deduced amino acid sequences of the HGV structural proteins and hepatitis C virus (HCV) structural proteins combined with an analysis of predicted secondary structures and hydrophobic profiles allowed prediction of processing sites within the HGV structural proteins. A phylogenetic sequence analysis performed on the 2.0-kb structural region supports the existence of three previously identified HGV genetic groups. However, phylogenetic analysis performed on only small DNA fragments yielded inconsistent genetic grouping and failed to confirm the existence of genetic groups. Thus, in contrast to HCV where almost any region can be used for genotyping, only large or carefully selected genome fragments can be used to identify consistent HGV genetic groups.  (+info)

RNA-Stimulated ATPase and RNA helicase activities and RNA binding domain of hepatitis G virus nonstructural protein 3. (4/233)

Hepatitis G virus (HGV) nonstructural protein 3 (NS3) contains amino acid sequence motifs typical of ATPase and RNA helicase proteins. In order to examine the RNA helicase activity of the HGV NS3 protein, the NS3 region (amino acids 904 to 1580) was fused with maltose-binding protein (MBP), and the fusion protein was expressed in Escherichia coli and purified with amylose resin and anion-exchange chromatography. The purified MBP-HGV/NS3 protein possessed RNA-stimulated ATPase and RNA helicase activities. Characterization of the ATPase and RNA helicase activities of MBP-HGV/NS3 showed that the optimal reaction conditions were similar to those of other Flaviviridae viral NS3 proteins. However, the kinetic analysis of NTPase activity showed that the MBP-HGV/NS3 protein had several unique properties compared to the other Flaviviridae NS3 proteins. The HGV NS3 helicase unwinds RNA-RNA duplexes in a 3'-to-5' direction and can unwind RNA-DNA heteroduplexes and DNA-DNA duplexes as well. In a gel retardation assay, the MBP-HGV/NS3 helicase bound to RNA, RNA/DNA, and DNA duplexes with 5' and 3' overhangs but not to blunt-ended RNA duplexes. We also found that the conserved motif VI was important for RNA binding. Further deletion mapping showed that the RNA binding domain was located between residues 1383 and 1395, QRRGRTGRGRSGR. Our data showed that the MBP-HCV/NS3 protein also contains the RNA binding domain in the similar domain.  (+info)

Identification of a novel genotype of hepatitis G virus in Southeast Asia. (5/233)

Hepatitis G virus (HGV) isolates obtained from 20 Myanmarese and 10 Vietnamese subjects were analyzed. A cluster of isolates not belonging to any known genotype of HGV was found in five Myanmarese subjects and three Vietnamese subjects by phylogenetic analysis, and we classified this new genotype as type 4. These results revealed that the HGV genome can be classified into at least four major genotypes.  (+info)

Seroprevalence of hepatitis B virus, hepatitis C virus and GB virus-C infections in Siberia. (6/233)

We studied the seroprevalence of hepatitis B virus (HBV), hepatitis C virus (HCV) and GB virus-C (GBV-C) infections in 348 Siberian natives who lived in the Kamchatka Peninsula of Russia. Of 348 samples studied, the seroprevalence of HBsAg and anti-HBs were 11.8% (41 of 348 samples) and 35.9% (125 of 348 samples), respectively. The prevalence of HCV infection was 1.4% (5 of 348 samples), and that of GBV-C RNA, using RT-PCR methods, was 7.5% (26 of 348 samples). In Siberia, the prevalences of HBV and GBV-C infections were about tenfold higher than those in Japan. The prevalence of HBsAg in subjects under 50 years of age was significantly higher than that in those over 50 years old (P < 0.05). Because HBV infection is highly endemic in Siberia, we propose that the community-based mass immunization must be conducted as soon as possible in this area.  (+info)

Analysis of hepatitis G virus (HGV) RNA, antibody to HGV envelope protein, and risk factors for blood donors coinfected with HGV and hepatitis C virus. (7/233)

Serologic, biochemical, and molecular analyses were used to study hepatitis G virus (HGV), antibody to the HGV envelope protein (anti-E2), risk factors, clinical significance, and the impact of HGV on coexistent hepatitis C virus (HCV). Among 329 donors with confirmed HCV infection, 12% were HGV RNA-positive and 44% were anti-E2-positive (total exposure, 56%). HGV RNA and anti-E2 were mutually exclusive except in 9 donors (1.5%); 8 of 9 subsequently lost HGV RNA but anti-E2 persisted. HGV had little impact on alanine aminotransferase, aspartate aminotransferase, or gamma-glutamyl transpeptidase in donors with HGV infection alone or those coinfected with HCV. A multivariate analysis showed that intravenous drug abuse was the leading risk factor for HGV transmission, followed by blood transfusion, snorting cocaine, imprisonment, and a history of sexually transmitted diseases. In summary, HGV and HCV infections were frequently associated and shared common parenteral risk factors; HGV did not appear to cause hepatitis or to worsen the course of coexistent hepatitis C.  (+info)

Early acquisition of TT virus (TTV) in an area endemic for TTV infection. (8/233)

TT virus (TTV) is widely distributed, with high frequencies of viremia in South America, Central Africa, and Papua New Guinea. The incidence and timing of infection in children born in a rural area of the Democratic Republic of Congo was investigated. TTV viremia was detected in 61 (58%) of 105 women attending an antenatal clinic and in 36 (54%) of 68 infants. Most infants acquired the infection at >/=3 months postpartum. Surprisingly, TTV infection was detected in a large proportion of children with TTV-negative mothers (13 [43%] of 30). Nucleotide sequences of TTV-infected children were frequently epidemiologically unlinked to variants detected in the mother. These three aspects contrast with the maternal transmission of hepatitis G virus/GB virus C in this cohort and suggest an environmental source of TTV infection comparable to hepatitis A virus and other enterically transmitted infections.  (+info)

  • We demonstrated that vertebrates and mosquitoes genomes are under very distinct lineage-specific constraints, and Flaviviridae viruses which specifically infect these lineages appear to be subject to the same evolutionary pressures that shaped their host coding regions, evidencing the lineage-specific coevolutionary processes between the viral and host groups. (uni-bielefeld.de)
  • NTPase/helicase of Flaviviridae: inhibitors and inhibition of the enzyme. (edu.pl)
  • they can be used in clinical practice as prognostic markers of the course and outcomes of infection with the Flaviviridae, as well as of the response to treatment. (nsu.ru)
  • Most cladograms of Flaviviridae focus on specific lineages and ignore outgroups, hampering the efficacy of the analysis to test ingroup monophyly and relationships. (cdc.gov)
  • These data provide evidence that RNA chaperoning-possibly mediated by intrinsically disordered protein segments-is conserved in Flaviviridae core proteins. (nih.gov)
  • The enzymatic activities of a NTPase/helicase were also detected in the carboxyl-terminal non-structural protein 3 (NS3) of members of the Flaviviridae family. (edu.pl)
  • Here, we review the new findings that connect the inflammatory pathways to cellular stress sensors and the strategies of Flaviviridae members to counteract these cellular mechanisms and escape immune response. (frontiersin.org)
  • Virus-host coevolution: common patterns of nucleotide motif usage in Flaviviridae and their hosts", PLoS One , vol. 4, 2009, pp. e6282. (uni-bielefeld.de)
  • West Nile virus (WNV) is a Flaviviridae most often transmitted by mosquitos. (itjem.org)