GBV-C/HGV genotypes: proposed nomenclature for genotypes 1-5

Interplay between HIV and Human Pegivirus (HPgV) Load in Co-Infected Patients: Insights from Prevalence and Genotype Analysis

Human pegivirus (HPgV) is transmitted through sexual or parenteral exposure and is common among patients receiving blood products. HPgV is associated with lower levels of human immunodeficiency virus (HIV) RNA and better survival among HIV-infected patients. This study aimed to investigate the prevalence of HPgV and determine its subtypes in HIV-infected individuals living in Istanbul, which has the highest rate of HIV infection in Türkiye. Total RNA extraction from plasma, cDNA synthesis, and nested PCR were performed for HPgV on plasma samples taken from 351 HIV-1-infected patients. The HPgV viral load was quantified on HPgV-positive samples. HPgV genotyping was performed by sequencing the corresponding amplicons. In the present study, the overall prevalence of HPgV RNA in HIV-infected patients was 27.3%. HPgV subtypes 1, 2a, and 2b were found, with subtype 2a being the most frequent (91.6%). Statistical analysis of HIV-1 viral load on HPgV viral load showed an opposing correlation between HIV-1 and HPgV loads. In conclusion, these data show that HPgV infection is common among HIV-positive individuals in Istanbul, Türkiye. Further comprehensive studies are needed to clarify both the cellular and molecular pathways of these two infections and to provide more information on the effect of HPgV on the course of the disease in HIV-infected individuals.

Viral Hepatitis in pregnancy

The global prevalence of viral hepatitis is very high and seems to be rising over the years. The infection can profoundly affect pregnant women causing significant maternal and perinatal morbidity and mortality with some strains much worse than others. Hepatitis A (HAV) and E (HEV) which are transmitted mainly through the faecal-oral route present as acute hepatitis during pregnancy and are responsible for most local epidemic outbreaks. HAV infection remains self-limiting during pregnancy, while HEV has a higher prevalence and causes significant morbidity. It is also associated with a very high maternal mortality rate (20 %) and requires special attention in endemic areas. HEV vaccines do exist, but the WHO has yet to approve them for general use. Hepatitis B is the most prevalent form and is part of the ante-natal screening program. The presence of HBeAg is associated with high viral loads and infectivity. Antiviral therapy, preferably tenofovir (TDF), is recommended for mothers with viral load ≥ 200,000 IU/mL₂), with the neonates receiving both active and passive immunisations. Hepatitis C and D are usually found as chronic infections in the pregnant and non-pregnant populations. Screening for hepatitis C during pregnancy and its subsequent management is still unsettled, but the introduction of direct-acting antiviral (DAA) drugs will change the picture if their safety is established in pregnancy. HDV is an incomplete virus linked to HBV and cannot establish an infection on its own. Controlling HBV is paramount to controlling HDV. HEV is quite prevalent and looked upon as hepatotropic. It seems to be quite prevalent in some blood donor populations and has a high co-infection rate with HCV. It has a high Mother-to-Child-Transmission (MTCT) but causes little or no illness in infected infants, and antenatal screening is not justified. This review summarises the prevalence, clinical picture, maternal, perinatal effects, and the management and prevention of hepatitis A, B, C, D, E and G viral infections during pregnancy.

Molecular and Clinical Profiles of Human Pegivirus Type 1 Infection in Individuals Living with HIV-1 in the Extreme South of Brazil

Human pegivirus type 1 (HPgV-1) infection has been associated with a beneficial effect on the prognosis of human immunodeficiency virus type 1 (HIV-1)-coinfected individuals. However, the mechanisms involved in this protection are not yet fully elucidated. To date, circulating HPgV-1 genotypes in HIV-1-infected individuals have not yet been identified in the extreme south of Brazil. The present study aimed to determine the genotypic circulation of HPgV-1 and the influence of HPgV-1 status and persistence time on the evolution of HIV-1 infection. A retrospective cohort of 110 coinfected individuals was analyzed. Samples were subjected to viral RNA extraction, cDNA synthesis, nested PCR, and genotyping. Genotypes 1 (2.8%), 2 (47.9% of subtype 2a and 42.3% of subtype 2b), and 3 (7%) were identified. In antiretroviral treatment-naïve subjects HPgV-1 subtype 2b was associated with lower HIV-1 viral load (VL) rates (p = 0.04) and higher CD4+ T-cell counts (p = 0.03) than was subtype 2a, and the positivity for HPgV-1 was associated with higher CD4+ T-cell counts (p = 0.02). However, there was no significant difference in HIV-1 VL between HPgV-1-positive and HPgV-1-negative subjects (p = 0.08). There was no significant association between the different groups in HPgV-1 persistence and median HIV-1 VL (p = 0.66) or CD4+ T-cell counts (p = 0.15). HPgV-1 subtype 2b is associated with better prognosis of HIV-1 infection. Although HPgV-1 infection is persistent, our data suggest that the time of infection does not influence HIV-1 VL or CD4+ T-cell counts in coinfected subjects.

Inhibition of HIV-1 infection by human pegivirus type 1-derived peptides is affected by human pegivirus type 1 genotype and HIV-1 coreceptor tropism

OBJECTIVE(S)

Up to 40% of HIV-1 infected individuals are coinfected with human pegivirus type 1 (HPgV-1). The majority of studies, but not all, have reported a beneficial effect of HPgV-1 coinfection on HIV-1 disease progression. So far, the impact of different HPgV-1 genotypes on different HIV-1 subtypes remains unclear.

METHODS

Peptides derived from HPgV-1 envelope protein E2, and representing different viral genotypes, were synthesized using Fmoc/t-Bu-based solid phase peptide synthesis. The inhibitory effect of these peptides on the infection of reporter cell lines was tested using an HIV-1 subtype panel representing clades A (n = 2), AG (n = 2), B (n = 6), C (n = 2), D (n = 2), F (n = 2), G (n = 1), G/H (n = 1), and group O (n = 2).

RESULTS

HIV-1 infection was blocked more efficiently by peptides derived from HPgV-1 GT2 than GT1 (P = 0.05). The HIV-1 subtype did not affect the degree of inhibition by a peptide derived from HPgV-1 GT2. All CXCR4-/dual-tropic isolates (n = 12), but only half (four out of eight) CCR5-tropic viruses were inhibited by this peptide (P = 0.014).

CONCLUSION

Our data indicate that the inhibitory effect of peptides derived from HPgV-1 E2 protein is dependent on the genotype, suggesting that coinfection with HPgV-1 GT1 is less likely to confer a beneficial effect on HIV-1 disease progression than GT2. The preferential suppression of more pathogenic CXCR4-tropic HIV-1 by peptides derived from HPgV-1 GT2 may explain the favorable effect in patients harboring these HIV-1 isolates. Consequently, HPgV-1 genotype and HIV-1 coreceptor tropism are likely determinants for the beneficial effect of HPgV-1 co-infection in HIV-1-infected individuals.

Recombination among GB virus C (GBV-C) isolates in the United States

GB virus C (GBV-C) is a non-pathogenic flavivirus that may play a role in modulating HIV disease. Multiple genotypes of GBV-C that have been identified to date that may differentially regulate HIV; however, the number of complete GBV-C sequences published to date is very limited. We sequenced full-length GBV-C genomes from four individuals with HIV/HCV co-infection in the United States. Intergenotypic recombination was evident in two of these individuals. Evaluation of additional full-length GBV-C genomes would facilitate the creation of full-length, replication-competent molecular clones of GBV-C to evaluate the phenotypic diversity of GBV-C genotypes and provide important molecular data on this understudied virus.

GB virus C coinfections in west African Ebola patients

In 49 patients with known Ebola virus disease outcomes during the ongoing outbreak in Sierra Leone, 13 were coinfected with the immunomodulatory pegivirus GB virus C (GBV-C). Fifty-three percent of these GBV-C(+) patients survived; in contrast, only 22% of GBV-C(-) patients survived. Both survival and GBV-C status were associated with age, with older patients having lower survival rates and intermediate-age patients (21 to 45 years) having the highest rate of GBV-C infection. Understanding the separate and combined effects of GBV-C and age on Ebola virus survival may lead to new treatment and prevention strategies, perhaps through age-related pathways of immune activation.

GB virus C infection in Indonesian HIV-positive patients

GB virus C (GBV-C), a human virus of the Flaviviridae family that is structurally and epidemiologically closest to hepatitis C virus (HCV), has been reported to confer beneficial outcomes in HIV-positive patients. However, the prevalence of GBV-C in HIV-positive individuals in Indonesia is unknown. Since GBV-C is more prevalent in anti-HCV positive patients than in anti-HCV negative subjects, transmission of GBV-C and HCV could be by the same method. This study examined the prevalence and molecular characteristics of GBV-C infection in HIV patients in Yogyakarta, Indonesia. The prevalence of GBV-C among HIV patients (n = 125, median age 31 years) based on the 5'UTR region was 111/125 (88.8%), including 39/48 (81.3%) and 72/77 (93.5%) HIV-infected patients with and without HCV infection, respectively. GBV-C isolates were of genotype 2a, 3 and 6 in 58.3%, 12.6% and 28.4% of patients, respectively. Patients with genotype 3 were significantly younger than those with genotypes 2a or 6 (P = 0.001 and P = 0.012, respectively). Genotypes 3 and 6 were significantly associated with injection drug use (P = 0.004 and P = 0.002, respectively) and HCV co-infection (P < 0.001 for both genotypes), indicating a shared transmission route with HCV. In conclusion, the prevalence of GBV-C among HIV-positive patients in Indonesia is high, and three genotypes were detected, namely genotype 2a, 3 and 6.

Deep sequencing identifies two genotypes and high viral genetic diversity of human pegivirus (GB virus C) in rural Ugandan patients

Human pegivirus (HPgV), formerly 'GB virus C' or 'hepatitis G virus', is a member of the genus Flavivirus (Flaviviridae) that has garnered significant attention due to its inhibition of HIV, including slowing disease progression and prolonging survival in HIV-infected patients. Currently, there are six proposed HPgV genotypes that have roughly distinct geographical distributions. Genotypes 2 and 3 are the most comprehensively characterized, whereas those genotypes occurring on the African continent, where HPgV prevalence is highest, are less well studied. Using deep sequencing methods, we identified complete coding HPgV sequences in four of 28 patients (14.3%) in rural Uganda, east Africa. One of these sequences corresponds to genotype 1 and is the first complete genome of this genotype from east Africa. The remaining three sequences correspond to genotype 5, a genotype that was previously considered exclusively South African. All four positive samples were collected within a geographical area of less than 25 km(2), showing that multiple HPgV genotypes co-circulate in this area. Analysis of intra-host viral genetic diversity revealed that total single-nucleotide polymorphism frequency was approximately tenfold lower in HPgV than in hepatitis C virus. Finally, one patient was co-infected with HPgV and HIV, which, in combination with the high prevalence of HIV, suggests that this region would be a useful locale to study the interactions and co-evolution of these viruses.

Role of GB virus C in modulating HIV disease

GB virus C (GBV-C) is a member of the Flaviviridae family and the most closely related human virus to HCV. However, GBV-C does not replicate in hepatocytes, but rather in lymphocytes. GBV-C has a worldwide distribution and is transmitted sexually, parenterally and through mother-to-child transmission. Thus, co-infection with HCV and HIV is common. Until now, no human disease has been associated with GBV-C infection. However, there are several reports of a beneficial effect of GBV-C on HIV disease progression in vivo. Different mechanisms to explain these observations have been proposed, including modification of antiviral cytokine production, HIV co-receptor expression, direct inhibition of HIV-1 entry, T-cell activation and Fas-mediated apoptosis. Further understanding of these mechanisms may open new strategies for the treatment of HIV/AIDS.

Prevalence and distribution of the GBV-C/HGV among HIV-1-infected patients under anti-retroviral therapy

Infection with GB virus C (GBV-C) or hepatitis G virus (HGV) is highly prevalent among HIV/AIDS patients. GBV-C/HGV viremia has not been associated with liver disease and seems to slow HIV disease progression. To study the GBV-C/HGV genotypes prevalence among HIV/AIDS patients and its association with HIV viral load (VL) and CD4+ lymphocyte counts. From February 2003 to February 2004, we analyzed 210 HIV-1-infected subjects who were on anti-retroviral therapy (ART). For 63 of them a PCR-nested to the non-coding 5' (5'NCR) region of the GBV-C/HGV was done, and for 49 a DNA direct sequencing was done. A phylogenetic analysis was performed by PHYLIP program. 63 (30%) of the HIV-1-infected patients were co-infected with GBV-C/HGV. The phylogenetic analysis revealed the following genotypes (and respective relative frequencies): 1 (10%), 2a (41%), 2b (43%), and 3 (6%). Co-infected patients presented lower HIV-1 VL and higher T CD4+ lymphocyte cells counts as compared with patients negative for GBV-C/HGV sequences (log=4.52 vs. 4.71, p=0.036), and T CD4+ lymphocyte counts (cells/mm(3)=322.6 vs. 273.5, p=0.081, respectively). T CD4+ cells counts equal to, or higher than, 200/mm(3) were significantly more common among co-infected patients than among HIV-infected-only patients (p=0.042). The lowest T CD4+ cells counts were associated with genotype 1 and the highest with genotype 2b (p=0.05). The GBV-C/HGV infection prevalence was 30% among HIV-1-infected subjects, and was associated with lower VL and higher CD4+ lymphocyte counts. GBV-C/HGV genotype 2b may be associated with better immunological response.

Hepatitis G virus infection in multitransfused Egyptian children

The purpose of this study was to identify the magnitude of the hepatitis G virus infection in 33 multitransfused cases and 20 matched controls. All were tested for liver biochemical profile, HBsAg, HCV-antibody, HGV-RNA, and antibody to envelop protein E(2). HGV was detected alone in 61% of the multitransfused cases and 15% of the controls. Hepatitis markers were negative in 21% of cases versus 70% of controls. HGV envelope antibody was detected in 12% of cases, and none of controls. Mean values of transaminases in HGV positives and negatives showed no significant differences. HGV infection is highly prevalent in Egyptian children with no impact in infected cases.

Hepatitis G virus

A number of new hepatitis viruses (G, TT, SEN) were discovered late in the past century. We review the data available in the literature and our own findings suggesting that the new hepatitis G virus (HGV), disclosed in the late 1990s, has been rather well studied. Analysis of many studies dealing with HGV mainly suggests the lymphotropicity of this virus. HGV or GBV-C has been ascertained to influence course and prognosis in the HIV-infected patient. Until now, the frequent presence of GBV-C in coinfections, hematological diseases, and biliary pathology gives no grounds to determine it as an “accidental tourist” that is of no significance. The similarity in properties of GBV-C and hepatitis C virus (HCV) offers the possibility of using HGV, and its induced experimental infection, as a model to study hepatitis C and to develop a hepatitis C vaccine.

A previously unrecognized sixth genotype of GB virus C revealed by analysis of 5'-untranslated region sequences

GB virus C (GBV-C) is a positive-strand RNA virus that infects a large proportion of the world's human population. It has been classified tentatively as a member of the Flaviviridae family and has been shown to exist as a group of five closely related genotypes. Recently, we reported the first full-length genome sequence of a genotype 5 isolate from South Africa. As part of the analysis of that sequence, a phylogenetic tree was elucidated from the 5'-untranslated region (UTR) that showed excellent congruence to the tree produced by analysis of complete open reading frame sequences. When 5'-UTR analysis was broadened subsequently to include additional isolates from around the globe, a heretofore unrecognized GBV-C genotype was discovered in Indonesia. When first reported in 2000, these isolates were described as constituting a novel fifth genotype. However, comparison to isolates from the then-known fourth and fifth genotypes (from Myanmar/Vietnam and South Africa, respectively) was not performed. A dataset of 121 GBV-C 5'-UTR sequences was complied and included representatives of the fourth and fifth genotypes as well as the "novel" Indonesian sequences and demonstrated, with strong support via bootstrap analysis, the existence of a sixth GBV-C genotype among infected individuals in Indonesia. The discovery of this sixth genotype emphasizes the diverse nature of GBV-C isolates and may have important implications for the interpretation of studies involving GBV-C/HIV co-infected individuals.

African origin of GB virus C determined by phylogenetic analysis of a complete genotype 5 genome from South Africa

GB virus C (GBV-C), a positive-strand RNA virus, currently infects approximately one-sixth of the world's population. This virus exists as a collection of genotypes whose global distribution correlates with geographical origin. Genotyping of GBV-C isolates by phylogenetic analysis has relied upon the use of 5'-untranslated region (5'-UTR) sequences, however, complete genome sequences are used to demonstrate definitively their existence and geographical correlation. Initial identification of the fifth genotype from South Africa was based upon phylogenetic analysis of the 5'-UTR. It was sought to confirm this classification by analysis of full-length E2 genes from South African isolates and by analysis of a complete genotype 5 genome. Analysis of full-length E2 genes from 28 GBV-C-infected South African individuals revealed the existence of a unique group of 18 isolates, distinct from the other four genotypes. Bootstrap analysis provided strong support (95 %) for this fifth group. The remaining isolates were either genotype 1 (n=8) or 2 (n=2). Analysis of human E2 gene sequences, with the E2 gene from the chimpanzee variant GBV-Ctro included as the outgroup, produced a tree rooted on the genotype 1 branch. The complete genome nucleotide sequence of South African genotype 5 isolate D50 was determined. Phylogenetic analysis of the 5'-UTR and open reading frame produced congruent trees that grouped the sequences into five major genotypes. Inclusion of the corresponding region of the chimpanzee isolate GBV-Ctro in the analysis produced trees rooted on the branch leading to the genotype 5 isolate D50, suggesting an ancient African origin of GBV-C.

Prevalence and genotypes of hepatitis G virus among hemodialysis patients in Eastern Anatolia, Turkey

OBJECTIVES

To study the prevalence and genotype distribution of hepatitis G virus (HGV) in hemodialysis patients in East Anatolia, Turkey.

SUBJECTS AND MATERIALS

Eighty-nine hemodialysis patients and 30 healthy individuals were analyzed by using reverse-transcriptase nested polymerase chain reaction with primers specific for 5' untranslated region. HGV genotyping was performed by PCR and three randomly selected HGV-positive samples were sequenced.

RESULTS

Of the 89 hemodialysis patients, HGV RNA was detected in 9 (10.2%). All of our isolates were assigned to genotype 2.

CONCLUSION

Our results showed that hemodialysis patients carry the risk for HGV infection in East Anatolia, Turkey.

GB virus C/hepatitis G virus infection in dialysis patients and kidney transplant recipients in Central Brazil

In order to investigate the prevalence of GB virus C (GBV-C)/hepatitis G virus (HGV) infection in dialysis patients and kidney transplant recipients in Central Brazil and also to analyze the virus genotypes distribution, a total of 123 patients including 98 on hemodialysis, 13 on continuous ambulatory peritoneal dialysis treatment, and 12 who received kidney transplantation were interviewed in one unit of dialysis treatment in Goiania city. Blood samples were collected and serum samples tested for GBV-C/HGV RNA by polymerase chain reaction. Genotypes were determined by restriction fragment length polymorphism (RFLP) analysis. Eighteen samples were GBV-C/HGV RNA-positive, resulting in an overall prevalence of 14.6% (95% CI: 9.2-21.7). A high positivity for GBV-C/HGV RNA was observed in patients who had received kidney transplant (16.7%), followed by those on hemodialysis (15.3%), and peritoneal dialysis (7.7%). RFLP analysis revealed the presence of genotypes 1, 2, and 3 of GBV-C/HGV; more precisely, 9 (50%) samples were found belonging to the 2b subtype, 4 (22%) to the 2a subtype, 3 (17%) to genotype 1, and 2 (11%) to genotype 3. The present data indicate an intermediate prevalence of GBV-C/HGV infection among dialysis patients and kidney transplant recipients in Central Brazil. Genotype 2 (subtype 2b) seems to be the most prevalent GBV-C/HGV genotype in our region.

Epidemiological and quantitative study of GBV-C infection in french polytransfused children

From 1999 to 2002, 246 serum samples taken from polytransfused children were tested for the presence of GB virus C (GBV-C) RNA using a real-time reverse transcription-polymerase chain reaction (RT-PCR) assay. This assay was based on the TaqMan technology and allowed viral load determination in infected children with a dynamic range from 10(3) to 10(7) genome equivalent (gEq) copies/ml. The limit of detection was estimated to 619 gEq copies/ml with a > or = 95% probability of a positive result. Thirty five sera were found to be GBV-C RNA positive, corresponding to a prevalence of GBV-C of 14.2%. The mean viral load was high, i.e., 6 +/- 1.4 log (range 3.22-7.42) gEq copies/ml, but low viral loads were also detected. Sequencing of the 5'-untranslated region (UTR) identified a majority of genotype 2 strains (82%) distributed into two subtypes, 88.5% genotype 2a and 11.5% genotype 2b. In conclusion, GBV-C active infection is very frequent in exposed populations such as polytransfused children. GBV-C RNA quantitation using real-time assay may be useful for diagnosis and follow-up of the natural history of GBV-C infection.

[Is GB virus C alias "hepatitis" G virus involved in human pathology?]

GB virus-C alias "hepatitis" virus G was discovered in 1995 as a putative causative virus of non A-E hepatitis. It is a very common virus found in 1 to 5% of eligible blood donors in developed countries. Numerous studies over seven years led to the exclusion of its role as a significant etiological agent of hepatitis. Its in vivo replication site is still unknown. Its direct involvement in the induction of significant hepatic or extra-hepatic diseases could not be demonstrated. However, coinfections with other viruses may contribute to changes in the evolution of both liver disease (negatively) and HIV/AIDS (favourably). Today, no country has decided to screen GBV-C in blood donors. However, more studies are necessary before the absence of influence of GBV-C infection on human health in the context of other viral infections could be confirmed definitely. This article is a review of the literature on a possible involvement of GBV-C in pathologies whether associated or not to other infections.

A novel subtype of GB virus C/hepatitis G virus genotype 1 detected uniquely in patients with hemophilia in Japan

GB virus C (GBV-C) or hepatitis G virus (HGV) has been transmitted to Japanese patients with hemophilia through the frequent use of unheated blood products. Sequence analysis showed that most of the viruses isolated from these patients belonged to GBV-C/HGV genotype 1, which is usually found in persons from Africa. This may point to the origin of this virus in Japanese patients with hemophilia. The phylogeny of 11 GBV-C/HGV isolates from Japanese patients with hemophilia was investigated by a detailed analysis with a fragment spanning from the 5' non-coding region to part of the E1 gene. Except for one that belonged to the genotype 3 cluster, all isolates were GBV-C/HGV type 1. Five main clades exist within the GBV-C/HGV genotype 1 sequences. These isolates are grouped in 2 defined clades. Three of the isolates are clustered in subtype 1c clade whereas the other 7 strains formed a new statistically well-supported monophyletic group (named subtype 1e). Our results suggest that GBV-C/HGV type 1 can at present be classified into at least 5 clades and in this group a majority of Japanese patients with hemophilia was infected with a GBV-C/HGV of a unique and newly described subtype within genotype 1.

Genotype distribution of the GB virus C in citizens of São Paulo City, Brazil

There has been several studies worldwide on phylogenetics and genotype distribution of the GB-virus C / Hepatitis G virus (GBV-C/HGV). However, in their great majority, those investigations were based on some epidemiologically linked group, rather than on a representative sampling of the general population. The present is a continuation of the first study in Brazil with such a population; it addresses the GBV-C/HGV phylogenetics and genotype distribution based on samples identified among more than 1,000 individuals of the city of S o Paulo. For this purpose, a 728 bp fragment of the 5 non-coding region (5 NCR) of the viral genome, from 24 isolates, was sequenced and subjected to phylogenetic analysis. Genotypes 1, 2a and 2b were found at 8.3% (2/24), 50% (12/24) and 41.7% (10/24), respectively. In conclusion S o Paulo displays a genotype distribution similar to the published data for other States and Regions of Brazil, endorsing the notion that types 1 and 2 would have entered the country with African and European people, respectively, since its earliest formation.

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.

High prevalence of GB virus C/hepatitis G virus RNA among Brazilian blood donors

The aim of this study was to investigate the presence of the Hepatitis G Virus on a population of blood donors from S o Paulo, Brazil and to evaluate its association to sociodemographic variables. Two RT-PCR systems targeting the putative 5'NCR and NS3 regions were employed and the former has shown a higher sensitivity. The observed prevalence of HGV-RNA on 545 blood donors was 9.7% (CI 95% 7.4;12.5). Statistical analysis depicted an association with race/ethnicity, black and mulatto donors being more frequently infected; and also with years of education, less educated donors presenting higher prevalences. No association was observed with other sociodemographic parameters as age, gender, place of birth and of residence. DNA sequencing of nine randomly chosen isolates demonstrated the presence of genotypes 1, 2 and 3 among our population but clustering of these Brazilian isolates was not detected upon phylogenetic analysis.

Prevalence of GB virus C/hepatitis G virus in Hungary

In 1995 a new flavivirus, GB virus C/hepatitis G virus (GBV-C/HGV), was discovered. The aim of this study was to determine the prevalence of the virus in healthy persons and hepatitis patients in Hungary. The sera of 408 healthy persons older than 60 years were tested for the presence of GBV-C/HGV antibodies, and 113 were positive (28%). Eight of the 71 healthy persons younger than 60 years and twenty of the 51 sera (39%) taken from patients suffering from hepatitis of unknown origin proved to be positive for GBV-C/HGV antibodies. Ten of the 124 sera (8%) of healthy persons and 36 of the 247 sera (14.6%) of hepatitis patients proved to be positive for GBV-C/HGV RNA. Eleven PCR products were sequenced, and the sequences were found to be different from each other and from the previously published ones. However, three sequences taken from the same patient at different times were identical. These results show that GBV-C/HGV is present in Hungary and cannot be considered rare.

Prevalence and genotypes of GB virus C/hepatitis G virus among blood donors in Central Brazil

A survey was conducted in a blood donor population of Central Brazil aiming to investigate the prevalence of GB virus C (GBV-C)/hepatitis G virus (HGV) infection and also to analyze the virus genotypes distribution. A total of 241 voluntary blood donors were interviewed at the State Blood Bank in Goiânia, State of Goiás, Brazil. Blood samples were collected and serum samples tested for GBV-C/HGV RNA by polymerase chain reaction. Genotypes were determined by restriction fragment length polymorphism (RFLP) analysis. Seventeen samples were GBV-C/HGV RNA-positive, resulting in a prevalence of 7.1% (95% CI: 4.2-11.1). A significant trend of GBV-C/HGV RNA positivity in relation to age was observed, with the highest prevalence in donors between 29-39 years old. Ten infected individuals were characterized by reporting parenteral (30%), sexual (18%), both (6%) and intrafamiliar (6%) transmission. However, 7 (40%) GBV-C/HGV RNA-positive donors did not mention any potential transmission route. RFLP analysis revealed the presence of genotypes 1 and 2 of GBV-C/HGV; more precisely, 10 (58.9%) samples were found belonging to the 2b subtype, 4 (23.5%) to the 2a subtype, and 3 (17.6%) to genotype 1. The present data indicate an intermediate endemicity of GBV-C/HGV infection among this blood donor population, and a predominant circulation of genotype 2 (subtype 2b) in Central Brazil.

Hepatitis G virus genotypes in a tertiary care centre in southern India

BACKGROUND

The association of GBV-C/HGV in patients at high risk of parenteral infection and those with chronic liver disease in southern India is unknown.

OBJECTIVES

To study the occurrence of GBV-C/HGV in three patient groups attending a tertiary care centre in Vellore and identify the prevailing genotype(s).

STUDY DESIGN

Two hundred and twenty-seven individuals were studied using an RT-PCR assay with primers specific for the 5'NCR and the NS5a-coding regions. Ten randomly selected samples were sequenced in the 5'NCR region of the GBV-C/HGV genome.

RESULTS

GBV-C/HGV RNA was detected in 37/70 (52.9%) of renal transplant recipients, 18/70 (25.7%) of patients with haematological disorders and in 9/87 (10.3%) patients with chronic liver disease. Nine of the ten sequences could be assigned to genotype 2a while the remaining sequence could not be assigned.

CONCLUSIONS

In this centre, GBV-C/HGV is widely prevalent in patients with high parenteral risk and in those with chronic liver disease. The predominantly circulating genotype among study patients is genotype 2a.

Using Live Pathogens to Treat Infectious Diseases: A Historical Perspective on the Relationship between Gb Virus C and HIV

Recent reports that co-infection with GB virus C (GBV-C) is associated with a reduced mortality in HIV-infected individuals, a slower progression to AIDS, and lower HIV viral loads, suggest a potential role of GBV-C as therapy for HIV infection. Although not known to cause any human disease, GBV-C was only recently discovered and prospective studies assessing long-term consequences of infection have not been completed. Our understanding of the host-viral interactions between humans and GBV-C is in its infancy. Further research into the intriguing relationship between GBV-C and HIV is needed before intentional inoculation of GBV-C into individuals infected with HIV should proceed. This essay explores the history of the once-popular treatment of paretic tertiary syphilis with the blood-borne pathogen Plasmodium vivax, providing a historical perspective on the current state of affairs between GBV-C and HIV. A brief review of GBV-C biology and human infection is followed by a discussion of the current challenges facing the use of this organism to treat HIV.

The serological and molecular epidemiology of GB virus C/hepatitis G virus infection in a hepatitis C and B endemic area

OBJECTIVES

To investigate the serological and molecular characteristics of GB virus C/hepatitis G virus (GBV-C/HGV) infection in the hepatitis C virus (HCV)/hepatitis B virus (HBV)-endemic areas in Taiwan.

METHODS

Sera from 200 residents from Masago, an HCV/HBV-endemic community in Taiwan, and 400 blood donors were tested for GBV-C/HGV RNA by using nested reverse transcription-polymerase chain reaction and for antibodies to GBV-C/HGV E2-protein (anti-E2) by an enzyme-linked immunosorbent assay. Phylogenetic analysis of GBV-C/HGV was performed.

RESULTS

The prevalence of GBV-C/HGV viraemia, anti-E2 and GBV-C/HGV exposure among residents of Masago was significantly higher than that among donors (17.0%, 25.5% and 39.5% vs. 3.3%, 7.5% and 10.3%, respectively; all P < 0.0001). In Masago, the prevalence of GBV-C/HGV exposure was significantly higher in residents exposed to HCV than in those without HCV exposure (45.8% vs. 24.1%;P< 0.005). Based on multivariate analyses, HCV viraemia was the only significant factor associated with elevated levels of alanine aminotransferase in Masago. Phylogenetic analysis showed all 34 GBV-C/HGV isolates from Masago clustered within genotype 3.

CONCLUSIONS

GBV-C/HGV was highly prevalent in Masago, an HCV/HBV-endemic community in Taiwan. HCV viraemia played the most important clinical hepatopathic role in the area. Infections with other hepatitis viruses did not influence the anti-E2 seroconversion from GBV-C/HGV infections.