High prevalence of GBV-C hepatitis G virus infection in a rural South African population

A novel virus, GBV-C/hepatitis G virus (GBV-C/HGV), has been cloned and characterised recently. GBV-C/HGV global epidemiology and risk factors for acquisition are currently unclear. We aimed to establish the determinants of this infection in a rural South African (SA) population. The study population included two samples, namely a community-based sample, and consenting persons from a nonspecialist outpatient department in the same district. A questionnaire regarding demographic details and putative risk factors was administered; blood samples were taken on which a polymerase chain reaction (PCR) was performed for both 5′NCR and NS5a regions of GBV-C/HGV using commercially available primers and probes. Two hundred and forty-nine people were studied with a mean GBV-C/HGV prevalence of 10.4%. Outpatient department and community prevalences differed significantly (18.0% and 6.3%, respectively, P = 0.004). GBV-C/HGV infection was associated with excessive alcohol consumption (P = 0.02; OR, 4.18) and a lack of waterborne sewerage (P = 0.04). PCR amplification of the NS5a region of all but two South African GBV-C/HGV positive samples showed poor reactivity. The prevalence of GBV-C/HGV in rural SA appears to be higher than that reported from Europe and North America. Infection appeared to be associated with excess alcohol intake and a history of previous blood transfusions. The discrepant NS5a and 5′NCR PCR sensitivity in this study raises the possibility of genetic differences in southern African GBV-C/HGV. J. Med. Virol. 53:225–228, 1997. © 1997 Wiley-Liss, Inc.     

Amplification of GB virus-C/hepatitis G virus RNA with primers from different regions of the viral genome

GB virus-C/hepatitis G virus (GBV-C/HGV) is a newly identified RNA virus. The aim of the study was to compare three primer pairs from the 5′ untranslated region (5′UTR), envelope region 2 (E 2) and nonstructural region 3 (NS 3) of GBV-C/HGV genome for their ability to detect GBV-C/HGV RNA by polymerase chain reaction (PCR) assays. By using PCR with primers from different regions of the viral genome, serum GBV-C/HGV RNA was assayed in 200 at-risk individuals. The sensitivity of this assay was assessed by a titration experiment, and nucleotide sequences of the amplified products were determined directly. Of 200 serum samples, 43 (21.5%) were positive for GBV-C/HGV RNA with at least one of the primer pairs. The positive rates by 5′UTR, NS 3, and E 2 primers were 100%, 98%, and 84%, respectively, and the sensitivity of PCR assays using 5′UTR primers was 10 to 100 times more likely to detect GBV-C/HGV RNA than that of NS 3 and E 2 primers. The average homology of amplified targets to the prototype HGV genome was 89%, 80%, and 85% and the similarity between each amplified target was up to 100%, 90%, and 92% in the 5′UTR, E 2, and NS 3 regions, respectively. Therefore, the 5′UTR of GBV-C/HGV genome is highly conserved and primers deduced from this region can provide a sensitive and specific PCR assay for GBV-C/HGV RNA. J. Med. Virol. 51:284–289, 1997. © 1997 Wiley-Liss, Inc.     

Genetic heterogeneity and molecular epidemiology of GB virus C/hepatitis G virus in China

OBJECTIVE: The inter- and intrapatient genetic variation of GB virus C (GBV-C)/hepatitis G virus (HGV) was investigated to characterize the molecular epidemiologic profile of GBV-C/ HGV infection in China, an area endemic for viral hepatitis. The intrapatient variation of hepatitis C virus (HCV) from the same patients was compared to that of GBV-C/HGV. STUDY DESIGN/METHODS: GB virus C/HGV RNA was amplified by polymerase chain reaction in 88 patients with hepatitis C, hepatitis B or presumed non-A-E hepatitis from three cities in China. Five clones of the GBV-C/HGV NS3 region were sequenced from each GBV-C/HGV RNA-positive patient. The corresponding region of HCV was also sequenced from patients co-infected with HCV. Representative sequences of the GBV-C/HGV NS3 region from each patient and those of isolates from other continents were subjected to phylogenetic analyses. RESULTS: GB virus C/HGV was detected in 22 (25.25%) of 88 patients: 9 (21.4%) of 42 patients with presumed non-A-E hepatitis, 10 (27.7%) of 36 patients with hepatitis C, 3 (30.0%) in 10 patients with hepatitis B and C, and in none of 60 volunteer blood donors. The extent of nucleotide variation was less between Chinese isolates (2.4-17%; median, 10.4%) than between Chinese isolates and seven isolates from outside China (10.5-19.5%; median, 15.3%). Intrapatient sequence variation ranged from 0 to 1.75%, with a mean of 0.57 +/- 0.51%. Phylogenetic analysis grouped most Chinese isolates into four geographically specific clusters with a divergence of 10% to 16% from each other. The ratio of nonsynonymous to synonymous substitutions of GBV-C/HGV (Ka/Ks 0.019) was much lower than for HCV (0.071) in the same patients. CONCLUSION: Chinese isolates of GBV-C/HGV are genetically distinct. There are local strains as well as shared strains between different locales. The extent of amino acid sequence conservation suggests strong selection against nonsynonymous substitutions in the GBV-C/HGV genome.     

用逆转录—套式聚合酶链反应检测我国不同临床型肝？…

目的 为了研究庚型肝炎病毒（ＨＧＶ）在我国的感染状况。方法 概括已发表的ＨＧＶ的５‘端非编码区（５’－ＵＴＲ区）及螺旋酶区（ＮＳ３区）两段高度保守的基因序列分别设计两套引物，用逆转录－套式聚合酶链式反应检测ＨＧＶＲＮＡ。结果 从北京、秦皇岛、河南等地采集各种肝病患者及职业献血员血清３５４份，ＨＧＶＲＮＡ阳性９７份，阳性率为２２．３％。其中已确定的临床型肝炎／肝病患者２５４例，ＨＧＶＲＮＡ阳性者为５     

Lack of anti-GOR antibody among subjects with GB virus C/hepatitis G virus RNA

Homologies were sought between the putative amino acid sequences of GB virus C/hepatitis G virus (GBV-C/HGV) and the GOR epitope or the liver/kidney microsome-1 (LKM-1) epitope, which share partial sequence identity with the hepatitis C virus (HCV) polyprotein. Anti-GOR antibody (anti-GOR) was assayed among 100 subjects with GBV-C/HGV RNA. Twenty-one and 25 subjects were coinfected with hepatitis B virus (HBV) or HCV, respectively. Homologies were found between the NS5 or E2 polyproteins of GBV-C/HGV and the GOR epitope or the LKM-1 epitope, respectively. These segments of GBV-C/HGV polyproteins sharing identity with the GOR or the LKM-1 epitope were well conserved among three genotypes of GBV-C/HGV. However, only 1 of 55 subjects (1.8%) with GBV-C/HGV RNA, but not with HBV or HCV, was positive for anti-GOR. The positivity for anti-GOR among the group with GBV-C/HGV RNA alone was significantly lower than that among the groups with HCV RNA (P < 0.01 and P < 0.05, respectively). Only 2 of 55 subjects (3.6%) with GBV-C/HGV RNA alone exhibited elevation of alanine aminotransferase. The incidence of liver dysfunction among the group with GBV-C/HGV RNA alone was significantly lower than the incidence among the groups with GBV-C/HGV RNA and hepatitis B surface antigen (HBsAg) or HCV RNA (P < 0.01 and P < 0.01, respectively). These data indicate that 1) there is no association between GBV-C/HGV infection and the presence of anti-GOR, and 2) GBV-C/HGV infection is not related to chronic liver dysfunction. J. Med. Virol. 55:129–133, 1998. © 1998 Wiley-Liss, Inc.     

High prevalence of GB virus C/hepatitis G virus in Kinshasa, Democratic Republic of Congo: a phylogenetic analysis

A prevalence of 10.3% of GB virus C (GBV-C)/hepatitis G virus (HGV) carriers was found in 97 pregnant women from Kinshasa, Congo (formerly Zaire), while prevalences of 1%, 4.1%, and 0% were found for hepatitis C virus, human immunodeficiency virus, and human T-lymphotropic virus respectively. Phylogenetic analysis of the ten GBV-C/HGV positives based on the 5' non-coding region using three different methods identified consistently three GBV-C/HGV genotypes. Four main clades were found within the type 1 sequences. All the Congolese isolates are GBV-C/HGV type 1 in two different clades. The clustering of seven Congolese isolates was inconsistent in different methods. Further likelihood-mapping analysis showed a well-resolved phylogeny, confirming the clustering of the seven Congolese isolates with a Belgian strain representing a new clade in the GBV-C/HGV type 1 sequences.     

High prevalence of GB virus C/hepatitis G virus genotype 3 among autochthonous Venezuelan populations

GB virus C or hepatitis G virus (GBV-C/HGV) is highly prevalent among population groups at risk of parenterally transmitted viral agents, but it has also a worldwide distribution in other non-risk population groups. GBV-C/HGV RNA and antibodies against its envelope protein (anti-E2 Abs) were found in 3/86 (3%) and 7/89 (8%) of biomedical science personnel (BSP), in 31/453 (7%) and 37/200 (19%) of blood donors (BD), and in 6/64 (9%) and 26/59 (44%) of hemodialysis patients (HD) from Caracas, Venezuela. A significant gradient of GBV-C/HGV exposure (anti-E2 Abs and/or GBV-C/HGV RNA) was found between BSP (lowest prevalence), BD, and HD (P < 0.001). GBV-C/HGV RNA and anti-E2 Abs were also found in 2/69 (2.9%) and 2/44 (4.5%) of individuals from a rural community, in 9/162 (5.5%) and 2/40 (5%) of West Amerindians, and in 14/56 (25%) and 4/53 (7.5%) of South Amerindians. Socioeconomic and cultural factors may have contributed to the relatively high risk of exposure to GBV-C/HGV in BD and Amerindians. Whereas GBV-C/HGV genotypes 1 (n = 1), 2 (n = 6), and 3 (n = 22) were present in Venezuela, only the Asiatic genotype 3 was found infecting Amerindians and rural populations (n = 16). Genotype assignment based on the 5' noncoding region of the GBV- C/HGV genome was corroborated in some isolates by genetic analysis of the E2 region. This report confirms the circulation of the Asiatic genotype of GBV-C/HGV among Amerindians, suggesting an old origin of GBV-C/HGV. This might be associated with the apparently low pathogenesis of this virus.     

GB virus C/hepatitis G virus and TT virus infections among high risk renal transplant recipients in India.

BACKGROUND: GB virus C/hepatitis G virus (GBV-C/HGV) and TT virus (TTV) have been widely reported in patients with high parenteral risk such as haemodialysis and renal transplant recipients. The occurrence of these agents in association with hepatitis B virus (HBV) and hepatitis C virus (HCV), in Indian renal transplant recipients, is yet unreported. STUDY DESIGN: Molecular and serological markers of GBV-C/HGV and TTV were examined in addition to those for HBV, HCV and hepatitis D virus (HDV) in a selected group of seventy renal transplant recipients. HGV RNA detection was achieved using primers specific for the 5'NCR and NS5a regions of the genome. Anti-GBV-C/HGV antibody was detected using the mu plate anti-HG env kit (Roche, Germany). TTV DNA PCR was performed using primers specific for the coding region (method A) of the genome. In 50% of patients, TTV DNA was also tested for using primers specific for the non-coding region (method B). Host related factors such as age, alanine aminotransferase (ALT) levels, number of transfusions, haemodialysis sessions, and months following transplantation were also studied. RESULTS: Exposure rates to GBV-C/HGV, TTV (method A), HBV, HCV and HDV were 58.6, 32.9, 52.9, 54.3 and 2.9%, respectively. 'Active' infection as measured by viraemia and/or virus-specific antigenaemia for GBV-C/HGV, TTV, HBV and HCV was 52.9, 32.9, 15.7 and 52.9%, respectively. The majority of GBV-C/HGV and TTV infections were seen as co-infections with other hepatitis viruses. Single infection with GBV-C/HGV and TTV was seen in ten (14.2%) and eight (11.4%) patients, and was not associated with ALT elevation when compared to uninfected blood donors. Using univariate analysis, GBV-C/HGV RNA was significantly associated with > or =20 haemodialysis sessions. TTV DNA occurrence was not associated with any risk factors. CONCLUSIONS: There is a high occurrence of GBV-C/HGV and TTV in this select group of renal transplant recipients in India. These viruses mostly occurred in the context of co-infections with other hepatitis viruses. Long term effects of multiple hepatotropic viral infections need to be carefully documented in such transplant populations.     

Profiles of GBV-C/hepatitis G virus markers in patients coinfected with hepatitis C virus.

GBV-C/Hepatitis G virus (GBV-C/HGV) is a newly discovered viral agent, found widely among healthy blood donors and among individuals at risk of parenterally transmitted infections. GBV-C/HGV is found frequently in coinfection with HCV. A population of 109 HCV positive patients was examined for the presence of GBV-C/HGV RNA and antibodies to E2. Of the 109 patients, 23 (21%) had serum GBV-C/HGV RNA in serum, 39 (36%) had only antibodies to E2 and 8 (7%) were positive for both markers, with an overall prevalence of 64%. Different serologic and virological patterns were observed in GBV-C/HGV exposed patients according to their infection status. Active infection was characterized by positive RT/PCR signal with primers for both the 5'UTR and NS5 genomic regions, viremia levels above 10(4) copies/mL by real time quantitative RT/PCR and absence of detectable anti-E2. In the transition phase between active infection and recovery, GBV-C/HGV RNA was only detectable by RT/PCR using primers from the 5' untranslated region and viremia levels were below 10(4) copies/ml by quantitative PCR, with or without simultaneous presence of anti-E2 antibodies. Resolved infection was characterized by absence of detectable viremia and, in most patients, by the presence of anti-E2.     

利多组套式引物的测庚型肝炎病毒RNA

利用庚型肝炎病毒ＮＳ３－５区序列合成了四组套式引物，建立了灵敏，特异的 型肝炎病毒ＲＮＡ双扩增聚合酶链反应检测方法，用此方法检测了１０份庚型肝炎病毒抗体阳性患者血清及１０份阴性的健康人血清。前者不同组引物的检出率为ＮＳ３（１）引物９份了是性，ＮＳ３（２）引物８份阳性，ＮＳ４引物４份阳性，ＮＳ５（１）引物５份阳性，ＮＳ５（２）引物９份阳性；后者各组引物匀为阴性。结果表明，庚型肝炎病毒不同区域引物用于