GB virus-C/hepatitis G virus infection in prostitutes: Possible role of sexual transmission

The modes of transmission of GB virus-C/hepatitis G virus (GBV-C/HGV) other than by blood transfusion are largely unknown. The prevalence of GBV-C/HGV viremia and the associated risk factors in 145 female prostitutes were examined. The seroprevalence of hepatitis B surface antigen (HBsAg), antibodies to hepatitis C virus (anti-HCV), and GBV-C/HGV RNA were 14%, 18%, and 11%, respectively. The demographic characteristics were similar between subjects with and without HBsAg. In contrast, those with HCV or GBV-C/HGV infection had practised longer as prostitutes and received blood transfusion more frequently. Moreover, the prevalence of GBV-C/HGV RNA and anti-HCV tended to increase in parallel with the duration of prostitution. These results suggest that like HCV, sexual transmission of GBV-C/HGV occurs and the risk increased with prolonged duration of exposure. The transmission efficiency between GBV-C/HGV and HCV appears to be similar. J. Med. Virol. 52:381–384, 1997 , © 1997 Wiley-Liss, Inc.     

Sexual transmission of GB virus C/hepatitis G virus

Although it is established that infection with GB virus C (GBV-C) or hepatitis G virus (HGV) can be transmitted parenterally, the prevalence of GBV-C/HGV viremia in the general population (2–5%) is relatively high compared with other parenterally borne viruses such as hepatitis C virus. To investigate the possibility of sexual transmission of GBV-C/HGV, we determined the frequency of viremia by the polymerase chain reaction and serological reactivity to the E2 protein by ELISA in samples collected from individuals at risk for sexually transmitted diseases attending a city genitourinary medicine clinic. GBV-C/HGV viremia was detected in 27 of 87 male homosexuals (31%) and 9 of 50 prostitutes (18%), frequencies significantly greater than those in matched controls (2/63) and local blood donors (2.3%). Among nonviremic individuals, a high frequency of serological reactivity to the E2 protein of GBV-C/HGV was also observed in the risk groups (male homosexuals: 14/60; prostitutes: 11/41), although these figures are likely to be underestimates of the frequency of past infection as detectable anti-E2 reactivity may attenuate rapidly over time following resolution of infection. Infection with GBV-C/HGV was more frequent among those coinfected with human immunodeficiency virus type 1. Among male homosexuals from whom retrospective samples were available, evidence for de novo infection was found in 9 of 22 individuals over a mean sampling time of 2.9 years, predicting an annualized incidence of GBV-C/HGV infection of approximately 11% in this group. The high prevalence and incidence of GBV-C/HGV infection in these individuals and prostitutes provides strong evidence for its spread by sexual contact. Further studies are required to investigate the mechanism of its transmission and the clinical significance of acute and persistent infection in these risk groups. J. Med. Virol. 55:203–208, 1998. © 1998 Wiley-Liss, Inc.     

GB virus C genotype determination in GB virus-C/HIV co-infected individuals

Several recent studies have indicated that patients infected with human immunodeficiency virus (HIV) exhibit a beneficial effect of co-infection with GB virus C (GBV-C). The benefit is demonstrated by slower progression to acquired immunodeficiency syndrome (AIDS) and prolonged survival time after the development of AIDS. In some but not all studies, a significant association between GBV-C/HIV co-infection and increased CD4(+) cell counts has been reported. To understand further the possible role that GBV-C might play in the reduced morbidity and mortality among HIV-infected patients, we sought to examine the presence of different GBV-C genotypes in a cohort of co-infected patients. PCR products derived from the 5'-untranslated region (5'-UTR) and the second envelope gene (E2) were sequenced directly and genotyped by phylogenetic analysis. While 5'-UTR analysis delineated the major type, analysis of the complete E2 gene was required for identification of group 2 subtypes, designated 2a and 2b. Among 35 patients tested, GBV-C genotype was determined for 33: two patients were infected with genotype 1, 12 with type 2a, and 19 with type 2b. Clinical data were available for 25 genotyped patients: one infected with genotype 1, nine with genotype 2a, and 15 with type 2b. CD4 cell counts tended to be lower in patients infected with genotype 2a compared with those with genotype 2b (310 +/- 136 vs 430 +/- 199, P = 0.054). Additional studies with larger cohorts from separate geographical regions are needed to determine whether a particular GBV-C genotype is associated with reduced morbidity or mortality among HIV co-infected patients.     

Identification of a novel GB type C virus/hepatitis G virus subtype in patients with hematologic malignancies

The existence of four GB C virus/hepatitis G virus (GBV-C/HGV) subtypes has been reported. The subtype was determined in 16 multitransfused GBV-C/HGV infected patients prior to bone marrow transplantation by comparing the 5′ untranslated region (5′ UTR) sequence with 39 available sequences. Phylogenetic and bootstrap analyses were carried out with PHYLIP package 3.5c. In the samples with undefined subtype, the whole 5′ UTR was cloned and sequenced. Comparison of distances showed that the isolates from 12/16 and 4/16 patients belonged theoretically to subtypes 2a and 2b, respectively. The phylogenetic tree and bootstrap analyses confirmed this result in only 11/16 samples. Analysis of the entire 5′ UTR from the remaining five samples with undefined GBV-C/HGV subtype revealed genomic variability within the isolates from each patient and between the isolates of different patients. Evolutionary distances, phylogenetic tree, and bootstrap showed that the isolates from these samples were grouped in a separate branch, different from the published subtypes. In conclusion, a novel GBV-C/HGV subtype was found in a group of multitransfused patients with GBV-C/HGV infection. J. Med. Virol. 57:80–84, 1999. © 1999 Wiley-Liss, Inc.     

Effects of GB virus-C/hepatitis G virus on hepatitis B and C viremia in multiple hepatitis virus infections

Summary.  We found that patients with dual HBV and GBV-C/HGV infection had comparable serum HBV DNA positivity and mean virus concentration compared with age-matched HBV carriers, and those with triple infection had a significantly lower HBV DNA positivity. Serum HCV RNA positivity and mean virus titer were similar between HCV carriers with or without GBV-C/HGV co-infection, and those with GBV-C/HGV co-infection seemed to have a lower serum ALT level. These data suggest that GBV-C/HGV infection exerts no significant suppression on levels of chronic hepatitis B or hepatitis C viremia. Accepted December 4, 1997 Received September 8, 1997     

Prevalence of GB virus-C/hepatitis G virus infection in an antenatal population

It is difficult to explain the high levels of infection seen with GBV-C/HGV if transmission relies on the parenteral route. A group of young women was investigated in order to establish the prevalence of infection in this age group of the general population and perhaps indicate other possible routes of infection, searching for both GBV-C/HGV RNA and HGV E2 antibodies. Evidence of infection was found in 11.8%. This is a higher prevalence than that found in blood donors but lower than in prostitutes. Evidence is accumulating from various groups that sexual/ close contact may result in transmission of this virus.     

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.     

Molecular evidence of father-to-child transmission of hepatitis B virus

At present in Japan, only high-risk infants born to chronic hepatitis B virus (HBV)-infected mothers are given HBV vaccine. However, children can contract the virus from other HBV-infected family members, including fathers. The aim of this study is to present substantial and unequivocal evidence of father-to-child transmission of HBV infection using techniques including homology analysis and phylogenetic analysis. Thirteen chronic HBV-infected members of five families that included eight children and their respective fathers were enrolled in this study. Homology analysis and phylogenetic analyses of 2 coding region, the S gene and X gene, from the HBV genome were performed comparing the 13 nucleotide sequences from the 13 subjects. The nucleotide homology among the five sets of fathers and children was quite high (99.3-100%). A phylogenetic tree constructed on the 13 nucleotide sequences showed that all 5 sets of fathers and children were grouped into the same cluster with high bootstrap values. These results strongly indicate that father-to-child transmission is an important route of HBV infection in Japan and it is recommend that universal vaccination against HBV infection be instituted immediately in Japan for all children, in accordance with the WHO recommendation of 1997.     

Occupational transmission of hepatitis C virus resulting from use of the same supermarket meat slicer

Tracing risk factors for acquiring hepatitis C virus (HCV) in an HCV-infected patient, the only identified risk was working at the same butcher's counter of a supermarket as another HCV-infected patient, using a common ham cutting machine, with frequent bleeding hand injuries. A phylogenetic analysis showed a high percentage of nucleotide homology between the two patients’ strains.     

Frequencies of GB virus C/hepatitis G virus genomes and of specific antibodies in German risk and non-risk populations

The prevalence of the new flavivirus GB virus C/hepatitis virus G (GBV-C/HGV) in different German populations was investigated by detection of viral genomes and anti-E2 antibodies. While blood donors had an overall prevalence of 10.4% there were increased rates for hemophiliacs (54.7%), hemodialysis patients (30.2%), male homosexuals (30.2%) and intravenous drug users (74.4%). Most GBV-C/HGV positive samples were either viral genome positive or antibody positive, exclusively. Samples with the rare constellation “positive for both GBV-C/HGV genome and specific antibody” originated in almost all cases from patients who were additionally infected with HIV or HCV. Probable transmission of GBV-C/HGV by PCR-positive blood transfusions was observed in 5 of 6 cases approximately six months after transfusion. J. Med. Virol. 53:218–224, 1997. © 1997 Wiley-Liss, Inc.     

Etiology of sporadic acute viral hepatitis in Taiwan: the role of hepatitis C virus, hepatitis E virus and GB virus-C/hepatitis G virus in an endemic area of hepatitis A and B.

The etiology of sporadic acute hepatitis was studied in 334 consecutive patients from Taiwan (237 men and 97 women, aged 16-81 years), with emphasis on the role of hepatitis C virus (HCV), hepatitis E virus (HEV), and GB virus-C/hepatitis G virus (GBV-C/HGV) in acute non-A, non-B (NANB) hepatitis and in HBsAg carriers with superimposed acute hepatitis. According to the conventional diagnostic criteria, there were 12 cases (3.6%) of acute hepatitis A, 17 cases (5.1%) of acute hepatitis B, 128 cases (38.3%) of acute NANB hepatitis, and 177 cases (53.0%) of acute hepatitis in HBsAg carriers (those who were HBsAg positive but IgM anti-HBc negative). Among 128 cases of acute NANB hepatitis, 70 (54.7%) had acute hepatitis C (HCV RNA positive), 5 (3.9%) had acute hepatitis E (IgM anti-HEV positive), and the other 53 (41.4%) were presumably acute hepatitis non-A-E. The prevalence of acute hepatitis A, B, E, and non-A-E showed no significant sex difference, whereas acute hepatitis C was significantly more prevalent in females. The prevalence of acute hepatitis A and B decreased and that of acute hepatitis C increased significantly with increasing age. In contrast, acute hepatitis E and non-A-E showed no significant age predominance. Of 177 HBsAg carriers with acute hepatitis, 64 (36.1%) demonstrated non-B hepatotropic virus superinfection, with HCV being the most common (60.9%), followed by hepatitis D, E, and A viruses, and the other 55 (31.1%) and 58 (32.8%) were presumed to have acute exacerbation of chronic hepatitis B or superimposed acute hepatitis non-A-E, respectively. Serum GBV-C/HGV RNA was detected in 3-4% of acute hepatitis non-A-E cases, suggesting its limited role in these cases.     

Intrafamilial transmission of hepatitis C virus

HCV infection is a major public health problem worldwide. Several studies reported that HCV infection might cluster in families or households. Horizontal intrafamilial transmission of the virus has been demonstrated previously. Whether horizontal transmission makes any significant contribution to the global burden of HCV infection is still controversial and data about epidemiology and routes of transmission are uncertain. The certain diagnosis of horizontal intrafamilial transmission of HCV is based on the simultaneous presence of specific laboratory criteria, the temporal association between intrafamilial exposure and infection and the exclusion of all the potential extrafamilial routes of transmission of the infection. This review summarizes the current knowledge of epidemiology, risk factors and molecular biology of horizontal intrafamilial transmission of HCV infection. J. Med. Virol. 85:608–614, 2013. © 2013 Wiley Periodicals, Inc.     

GB virus C/hepatitis G virus (GBV-C/HGV): still looking for a disease

GB Virus C and Hepatitis G Virus (GBV-C/HGV) are positive, single-stranded flaviviruses. GBV-C and HGV are independent isolates of the same virus. Transmission via the blood-borne route is the commonest mode, although vertical and sexual transmission is well documented. GBV-C/HGV is distributed globally; its prevalence in the general population is 10 fold higher in African countries than in non-African countries. High prevalences of GBV-C/HGV have been found in subjects with frequent parenteral exposure and in groups at high risk of exposure to blood and blood products. The clinical significance of human infection with GBV-C/HGV is currently unclear. The virus can establish both acute and chronic infection and appears to be sensitive to interferon. Only some 12-15% of chronic Non-A, B, C hepatitis cases are infected with GBV-C/HGV. A direct association with liver pathology is still lacking and it is not yet clear as to whether GBV-C/HGV is indeed a hepatotropic virus. Current evidence suggests that the spectrum of association of GBV-C/HGV infection with extrahepatic diseases ranges from haematalogical diseases, aplastic anaemia, human immunodeficiency virus (HIV)-positive idiopathic thrombocytopenia and thalassemia, through to common variable immune deficiency and cryoglobunemia.     

Mother-to-infant transmission occurs more frequently with GB virus C than hepatitis C virus

Summary.  A total of 107 hepatitis C virus (HCV)-infected pregnant women were screened for GB virus C (GBV-C) RNA in their sera, and 11 (10.3%) were positive. Among 11 infants born to these HCV/GBV-C co-infected mothers, GBV-C RNA was detected in 7 (63.6%) while HCV RNA was found in 1 (9.1%) within 1 year after birth: this difference was statistically significant (p = 0.023). The mothers of infected infants had significantly higher serum titers of GBV-C RNA than those of uninfected infants: 10^6.7±0.5 vs 10^4.0±1.0 copies/ml in average (p=0.001). The baby in whom HCV RNA was found was also positive for GBV-C RNA, and had an elevation in serum transaminase levels, whereas all the other GBV-C infected infants showed no evidence for hepatitis. A family study, performed on 2 of the 7 infected cases, revealed that all the elder siblings of the index infants were also GBV-C RNA-positive. Nucleotide sequence of GBV-C RNA, amplified by PCR from an NS3 region, was completely identical between the mother and the infant within each family, but varied significantly across different families. These results suggest that GBV-C is more easily transmitted from mother to infant than HCV, although hepatitis is not caused thereby. Aaccepted August 26, 1997 Received July 30, 1997     

Molecular analysis of transmission of hepatitis C virus in a nurse who acquired acute hepatitis C after caring for a viremic patient with epistaxis

A 23‐year‐old nurse (HC‐IP) developed acute hepatitis C. Intrafamilial transmission of hepatitis C virus (HCV) was suspected initially because her parents were carriers of HCV of the same genotype (1b) as that of Patient HC‐IP. However, the HCV isolate from Patient HC‐IP and those from her parents shared identities of only 92.4–92.7% in the 1,087‐nucleotide (nt) sequence within the NS5B region. It was then suspected that she contracted HCV infection during medical practice. Sixteen patients with antibodies to HCV (anti‐HCV) were hospitalized 1–3 months before she became positive for anti‐HCV. Upon analysis of stored serum samples, 14 of the 16 patients were found to be positive for HCV RNA, and 9 of the 14 viremic patients had genotype 1b HCV. Although the shared identities between the HCV isolate from Patient HC‐IP and those from eight of the nine patients were merely 90.6–93.9% within the 1,087‐nt NS5B sequence, the HCV isolate from the remaining one patient (HC‐P12) was 99.7% identical to that from Patient HC‐IP. Upon analysis of the E1 and E2 junctional region including hypervariable region 1 (283 nt), there was a close relationship (99.3–100%) between clones obtained from Patients HC‐IP and HC‐P12. Although the nurse HC‐IP had a finger injury, she took care of Patient HC‐P12, a 70‐year‐old man with HCV‐related cirrhosis and recurrent epistaxis, occasionally without wearing protective gloves. This study indicates the occurrence of HCV transmission by exposure of nonintact skin to blood in health care settings. J. Med. Virol. 81:1363–1370, 2009. © 2009 Wiley‐Liss, Inc.