GB virus C prevalence in blood donors and high risk groups for parenterally transmitted agents from Gauteng, South Africa

Investigating the etiologies of non-malarial febrile illness in Senegal using metagenomic sequencing

The worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata in a cross-sectional study of febrile patients and healthy controls in a low malaria burden area. Using 16S and untargeted sequencing, we detected viral, bacterial, or eukaryotic pathogens in 23% (38/163) of NMFI cases. Bacteria were the most common, with relapsing fever Borrelia and spotted fever Rickettsia found in 15.5% and 3.8% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosed Plasmodium, including one putative P. ovale infection. We developed a logistic regression model that can distinguish Borrelia from NMFIs with similar presentation based on symptoms and vital signs (F1 score: 0.823). These results highlight the challenge and importance of improved diagnostics, especially for Borrelia, to support diagnosis and surveillance.

Improving diagnosis of non-malarial fevers in Senegal: Borrelia and the contribution of tick-borne bacteria

The worldwide decline in malaria incidence is revealing the extensive burden of non-malarial febrile illness (NMFI), which remains poorly understood and difficult to diagnose. To characterize NMFI in Senegal, we collected venous blood and clinical metadata from febrile patients and healthy controls in a low malaria burden area. Using 16S and unbiased sequencing, we detected viral, bacterial, or eukaryotic pathogens in 29% of NMFI cases. Bacteria were the most common, with relapsing fever Borrelia and spotted fever Rickettsia found in 15% and 3.7% of cases, respectively. Four viral pathogens were found in a total of 7 febrile cases (3.5%). Sequencing also detected undiagnosed Plasmodium, including one putative P. ovale infection. We developed a logistic regression model to distinguish Borrelia from NMFIs with similar presentation based on symptoms and vital signs. These results highlight the challenge and importance of improved diagnostics, especially for Borrelia, to support diagnosis and surveillance.

Review of human pegivirus: Prevalence, transmission, pathogenesis, and clinical implication

Human pegivirus (HPgV-1), previously known as GB virus C (GBV-C) or hepatitis G virus (HGV), is a single-stranded positive RNA virus belonging to the genus Pegivirus of the Flaviviridae family. It is transmitted by percutaneous injuries (PIs), contaminated blood and/or blood products, sexual contact, and vertical mother-to-child transmission. It is widely prevalent in general population, especially in high-risk groups. HPgV-1 viremia is typically cleared within the first 1–2 years of infection in most healthy individuals, but may persist for longer periods of time in immunocompromised individuals and/or those co-infected by other viruses. A large body of evidences indicate that HPgV-1 persistent infection has a beneficial clinical effect on many infectious diseases, such as acquired immunodeficiency syndrome (AIDS) and hepatitis C. The beneficial effects seem to be related to a significant reduction of immune activation, and/or the inhabitation of co-infected viruses (e.g. HIV-1). HPgV-1 has a broad cellular tropism for lymphoid and myeloid cells, and preferentially replicates in bone marrow and spleen without cytopathic effect, implying a therapeutic potential. The paper aims to summarize the natural history, prevalence and distribution characteristics, and pathogenesis of HPgV-1, and discuss its association with other human viral diseases, and potential use in therapy as a biovaccine or viral vector.

Human pegivirus-1 infection in kidney transplant recipients: A single-center experience

Kidney transplantation is the treatment of choice for patients with end-stage renal disease. In the posttransplant period, the induced immunosuppression leads to an increased risk of developing infectious diseases, a leading cause of death after kidney transplantation. Human pegivirus-1 (HPgV-1) is considered a nonpathogenic human virus and is highly frequent in individuals parenterally exposed, however, its impact on kidney transplantation outcome is poorly understood. Given the scarcity of epidemiological data for this infection on organ recipients in Brazil, we conducted a study in a single center for kidney transplantation in Rio de Janeiro, aiming to determine HPgV-1 prevalence and genotypic distribution. Serum samples from 61 renal recipients, followed up for the first year after transplantation, were evaluated for viral RNA and genotypes were determined by sequencing of the 5'-untranslated region. HPgV-1 RNA was detected in 36.1% (22/61) of patients. Genotype 2 was the most commonly found (80.9%), followed by genotypes 3 (9.5%), 1, and 5, in 4.8% each. Statistical comparisons did not reveal any significant impact of HPgV-1 in patient outcome. Further epidemiologic studies are needed to understand if immunosuppression may interfere in HPgV-1 persistence rates and if viremia might impact graft dysfunction rates in kidney recipients.

Global prevalence of human pegivirus-1 in healthy volunteer blood donors: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

The local prevalence of HPgV-1 has been reported from different countries worldwide, but the global prevalence of HPgV-1 remains unknown. The aim of this systematic review and meta-analysis was to gather data from the literature to estimate the prevalence of HPgV-1 in healthy volunteer blood donors in the world.

MATERIALS AND METHODS

We searched PubMed, EMBASE, Scopus and Google Scholar databases for records up to January 2019 and included studies reporting HPgV-1 virus prevalence amongst healthy volunteer blood donors based on the detection of HPgV-1 RNA.

RESULTS

In all, we included 79 studies for the systematic review and 63 for the meta-analysis. Based on the random effect meta-analysis of 35 468 volunteer blood donors, we found the global prevalence of HPgV-1 to be 3·1% (95% CI, 2·4-4·1). The pooled prevalences of HPgV-1 were 1·7% (95% CI, 1·1-2·6) in North America, 9·1% (95% CI, 6·4-12·7) in South America, 2·3% (95% CI, 2%, 2·8) in Europe and 2·4% (95% CI, 1·4-4) in Asia. Subgroup analyses based on age, gender or risk factors were not possible.

CONCLUSION

Approximately 3 in 100 blood donations worldwide are positive for HPgV-1 increasing the risk of infection from transfusion of their components to subsequent recipients. Further research on virus pathogenicity is required before recommending routine screening of HPgV-1 for healthy volunteer blood donors.

Human pegivirus (HPgV) infection in sub-Saharan Africa-A call for a renewed research agenda

The human pegivirus (HPgV)-formerly GB virus C-has a beneficial impact on HIV disease progression that has been described in multiple studies. Given the high prevalence of HIV in sub-Saharan Africa and the continuing need to suppress HIV replication, this review provides a comprehensive overview of the existing data on HPgV infection in sub-Saharan Africa, with a particular focus on studies of prevalence and the circulating HPgV genotypes. This review also highlights the need for additional studies of HPgV conducted on the African continent and proposes a research agenda for evaluation of HPgV.

The Impact of Human Pegivirus on CD4 Cell Count in HIV-Positive Persons in Botswana

Background

Human pegiviruses (HPgV)-formerly known as hepatitis G virus or GB virus C (GBV-C)-are common single-stranded RNA viruses that may have a beneficial impact on slowing HIV disease progression. The data on HPgV in resource-limited regions such as Sub-Saharan Africa are scarce. Thus, we conducted the first study of HPgV in Botswana as part of a natural history study of HIV subtype C disease progression.

Methods

Plasma samples from 133 HIV-positive adults were evaluated for HPgV RNA, and the 5'UTR was sequenced to determine the HPgV genotype.

Results

HPgV RNA was detected in 41 (30.8%) individuals. While the presence of HPgV RNA had no impact on baseline HIV viral load, a significant difference in baseline CD4 cell count was observed. HPgV genotypes were determined for 27 individuals and included 5 individuals (18.5%) with genotype 1 and 22 (81.5%) with genotype 5. Baseline CD4 cell counts were significantly higher for persons infected with HPgV genotype 5 compared with genotype 1.

Conclusions

These data suggest that HPgV infection is common among HIV-positive individuals in Botswana and has a significant impact on CD4 cell count. This difference in CD4 cell count based on HPgV genotype suggests that HPgV genotype should be evaluated as a possible predictor of HIV disease progression and highlights the need for additional studies of this virus in resource-limited settings.

Detection and phylogenetic analysis of human pegivirus (GBV-C) among blood donors and patients infected with hepatitis B virus (HBV) in Qatar

Human Pegivirus (HPgV), formerly GB virus-C/Hepatitis G virus (GBV-C/HGV), collectively known as GBV-C, is widely spread and has been reported to be associated with non-A-E hepatitis. To our knowledge, no previous study was conducted about HPgV in Qatar. Thus, the objectives of this study were as follows: (i) to determine the rates of HPgV infection in Qatar among healthy blood donors and HBV-infected patients, and (ii) to determine the most predominant HPgV genotype in Qatar. A total of 714 blood plasma samples from healthy donors (612) and HBV-infected patients (102) were collected. RNA was extracted, reversed transcribed, and then subjected for HPgV detection by two round-nested PCR using primers amplifying a 208 bp of 5'-UTR of the HPgV. For genotyping, the 5'-UTR PCR products (from 25 randomly picked samples) were cloned and sequenced. The overall infection rate of HPgV in Qatar was 13.3%. There was no significant difference (P = 0.41) in the infection rates between healthy donor (13.7%) and in HBV-infected patients (10.7%). Moreover, we did not find any significant association between HPgV infection rates and nationality, sex, or age (P > 0.05). Sequence analysis of 40 5'-UTR PCR amplicons yielded the European genotype 2 as most predominant in Qatar, although other genotypes (5 and 7) were also present. Our results indicate that there is no strong correlation between HPgV infection rate, condition, nationality, age, and sex, and genotype 2 is most predominant in Qatar.

Intra-host diversity and emergence of unique GBV-C viral lineages in HIV infected subjects in central China

GB virus C (GBV-C), which is highly prevalent among HIV/AIDS, seemed to slow the HIV disease progression. The HIV/GBV-C co-infected individuals may represent an interesting model for the investigation of the role played by HIV infection and/or the immune system in driving the evolution of the GBV-C viral populations. The present study investigated the prevalence and population dynamics of GB virus C in HIV infected individuals representing 13 geographic regions of Hubei Province of China. Approximately 37% of HIV-1 infected individuals were infected with GBV-C and genotype 3 is appeared to be predominant. Utilizing the 196 complete E2 nucleotide sequence data from 10 HIV/GBV-C infected individuals and employing coalescence based phylogenetic approaches; the present study has investigated the intra-host dynamics of GBV-C. The results revealed patient-specific unique GBV-C viral lineages and each viral lineage showed the evidence of rapid population expansion in respective HIV-1 infected patients, thus suggesting HIV-1 was unlikely to have been inhibiting effect on the GBV-C viral replication. GBV-C in all patients has experienced intense purifying selection, suggesting the GBV-C viral invasion and subsequent expansion within the HIV-1 infected hosts without any modification of the functional epitopes at their membrane protein. The finding of within host GBV-C recombinant sequences indicated recombination was one of the significant forces in the evolution and divergence of GBV-C.

Frequency and genotypic distribution of GB virus C (GBV-C) among Colombian population with Hepatitis B (HBV) or Hepatitis C (HCV) infection

BACKGROUND

GB virus C (GBV-C) is an enveloped positive-sense ssRNA virus belonging to the Flaviviridae family. Studies on the genetic variability of the GBV-C reveals the existence of six genotypes: genotype 1 predominates in West Africa, genotype 2 in Europe and America, genotype 3 in Asia, genotype 4 in Southwest Asia, genotype 5 in South Africa and genotype 6 in Indonesia. The aim of this study was to determine the frequency and genotypic distribution of GBV-C in the Colombian population.

METHODS

Two groups were analyzed: i) 408 Colombian blood donors infected with HCV (n = 250) and HBV (n = 158) from Bogotá and ii) 99 indigenous people with HBV infection from Leticia, Amazonas. A fragment of 344 bp from the 5' untranslated region (5' UTR) was amplified by nested RT PCR. Viral sequences were genotyped by phylogenetic analysis using reference sequences from each genotype obtained from GenBank (n = 160). Bayesian phylogenetic analyses were conducted using Markov chain Monte Carlo (MCMC) approach to obtain the MCC tree using BEAST v.1.5.3.

RESULTS

Among blood donors, from 158 HBsAg positive samples, eight 5.06% (n = 8) were positive for GBV-C and from 250 anti-HCV positive samples, 3.2%(n = 8) were positive for GBV-C. Also, 7.7% (n = 7) GBV-C positive samples were found among indigenous people from Leticia. A phylogenetic analysis revealed the presence of the following GBV-C genotypes among blood donors: 2a (41.6%), 1 (33.3%), 3 (16.6%) and 2b (8.3%). All genotype 1 sequences were found in co-infection with HBV and 4/5 sequences genotype 2a were found in co-infection with HCV. All sequences from indigenous people from Leticia were classified as genotype 3. The presence of GBV-C infection was not correlated with the sex (p = 0.43), age (p = 0.38) or origin (p = 0.17).

CONCLUSIONS

It was found a high frequency of GBV-C genotype 1 and 2 in blood donors. The presence of genotype 3 in indigenous population was previously reported from Santa Marta region in Colombia and in native people from Venezuela and Bolivia. This fact may be correlated to the ancient movements of Asian people to South America a long time ago.

GB virus C infection in pregnancy: maternal and perinatal importance of the infection

OBJECTIVES

The more effective way of transmission of GB virus C (GBV-C) is parenteral, but sexual and vertical transmission seem to be the main way of spreading. We evaluated the prevalence and the effect of GBV-C infection on pregnant women, vertical transmission and viral effects on the newborn.

STUDY DESIGN

This study has consecutively enrolled 879 pregnant women. All patients had blood sampling to determine GBV-C RNA, serologic tests for chronic viral infections and seric tests of hepatic damage. The newborns from infected mothers had blood sampling to detect the presence of GBV-C at birth, and after 3 and 6 months. Positive babies were checked until 18 months.

RESULTS

36 (4.1%) women resulted GBV-C positive. Among the positive patients none presented complications during pregnancy. Neither embryonic-fetal abnormalities nor relevant differences in fetal birth weight and week of gestation at delivery were found. 20 out of 36 babies had a follow-up. At birth, 13 (65%) babies were positive. 4 out of 9 vaginal deliveries (44%) and 9 out of 11 cesarean sections (82%) resulted positive to GBV-C RNA. The risk of GBV-C vertical transmission was not significantly increased by type of delivery (p=0.274). At 3 months, 13 babies were GBV-C positive (65%) and 7 were negative (35%). At the end of the follow-up, 9 babies were positive (45%), while 11 were negative (55%).

CONCLUSION

The percentage of patients positive to GBV-C RNA was comparatively high (4.1%). This prevalence, in a population without particular risk factors, confirms that common ways of transmission, such as the sexual and vertical ones, might have an important role in viral diffusion. Our data suggest that the infection does not influence the course of pregnancy. The rate of transmission found in our study is high. Type of delivery does not seem to be actually involved in vertical transmission and the protective role of cesarean section has not been confirmed.

No association between GB virus C infection and disease progression in HIV-2-infected patients from the French ANRS HIV-2 cohort

Out of 183 HIV-2-infected patients tested in the ANRS CO8 HIV-2 cohort, 69 were exposed to GB virus C (GBV-C), yielding a prevalence of 38% (95% CI 30.7, 45.2). There was no significant difference between the CD4 cell count and HIV-2-RNA plasma viral load in patients exposed and not exposed to GBV-C. After adjusting for age and CD4 cell count, co-infection with GBV-C was not associated with clinical progression (hazard ratio 0.78; 95% CI 0.24-2.56, 16 clinical events).

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.

Hepatitis G Virus: Prevalence in Blood Donors in Armed Forces

BACKGROUND

A new RNA virus designated hepatitis G virus (HGV) was recently identified. Because HGV has less than 25% sequence or amino acid homology with hepatitis C virus (HCV) and other established Flaviviridae, it is considered to be a new genus in this growing family of hapatotropic viruses. Hepatitis G virus has been associated with hepatitis and is transmitted through parenteral and sexual route.

MATERIAL AND METHODS

A study comprising 500 healthy voluntary blood donors (service personnel) was under taken to find out prevalence of HGV. HGV RNA was detected by reverse transcriptase - polymerase chain reaction (RT-PCR). Hepatitis B surface antigen (HbsAg) and antibody to HCV were detected by Enzyme Linked Immunosorbent Assay (ELISA).

RESULTS

Thirteen donors (2.6%) were positive for HGV RNA. 17 donors (3.4%) were positive for antibody to hepatitis C virus (HCV) by ELISA. Co-infection of HGV with hepatitis B virus (HBV) was seen in 5 donors and with HCV infection in 2 donors. Co-infection of HGV, HBV and HCV was not seen in any donor.

CONCLUSION

So far there is no conclusive evidence that HGV produces hepatitis. But presence of HGV in hepatitis cases casts a doubt on this finding. Prevalence rate in blood donors may be helpful in future studies when the exact role of HGV is known.

Detection and genotyping of GBV-C virus in the United Arab Emirates

GB virus-C/Hepatitis G virus (GBV-C/HGV), collectively known as GBV-C, is spread widely and has been reported to be associated with non A-E hepatitis. The aim of the current project was to determine the rate of infection and genotypic characteristics of GBV-C in the United Arab Emirates (UAE). A total of 379 plasma/serum samples representing different populations in the UAE and comprising healthy as well as patients positive for HBV and HCV were screened using RT-PCR/nested PCR of the 5'-untranslated region (UTR). National subjects (n=168) and non-nationals residing in the UAE (n=211) were tested. The results obtained showed that the rate of GBV-C infection in healthy nationals, and those positive for HCV or HBV were 11.1%, 14.3%, and 5.7%, respectively, compared to 8.3%, 33.3%, and 8.6%, respectively, in non-nationals. No statistically significant correlation between infection with GBV-C and HCV or HBV (P>0.05) was found. Sequence analysis of the 5'-UTR using 37 and 46 clones from 8 and 6 healthy nationals and non-nationals, respectively, revealed the prevalence of the European/North American genotype 2 when compared to the five reference genotypes in GenBank.

GB virus C/hepatitis G virus infection in Indian blood donors and high-risk groups

The hepatitis G virus (HGV) or GB virus C (GBV-C) was discovered in 1995 as a putative agent of post-transfusion, non-A-E hepatitis. The present study was carried out with the aim to find the prevalence of this virus among various subject groups at risk for parenteral transmission as well as in healthy control subjects both individually and along with other parenterally transmitted hepatitis viruses. Of the 402 subjects tested, 6.22% were positive for the HBsAg surface antigen, 7.21% were positive for HCV RNA while only 2.24% were seen to be carriers of the HGV/GBV-C RNA. All the HGV/GBV-C positive cases were either multi-transfused thalassaemic subjects or hemodialysis patients. None of the healthy control subjects showed presence of the virus. Seven of the HGV/GBV-C positive subjects showed co-infection with one or more additional virological markers. Also, of the 9 HGV/GBV-C positive subjects, 5 showed elevated ALT levels while 4 showed elevated alkaline phosphatase levels. Overall our findings seem to indicate that HGV infections generally are asymptomatic, transient and self-limiting and the virus does not seem to show a very high prevalence among the Indian population.

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.

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.

Molecular investigation of GB virus C RNA in hemodialysis and thalassemics patients from Brazil

The GB virus C (GBV-C)/hepatitis G virus (HGV) is a member of the Flaviviridae family. Based on the clinical and epidemiological profiles, this virus could be acquired mainly by parenteral transmission through contaminated blood. We therefore investigated the presence of GBV-C/HGV and its relation with the other blood borne viruses as hepatitis B and C viruses (HBV, HCV) in hemodialysis and thalassemic individuals and blood donors from Ribeirão Preto-Brazil. Detection of blood borne virus markers including HBV surface antigen (HbsAg), HBV core antibody (anti-Hbc) and HCV antibody was carried out. HIV-1, HIV-2, HTLV-1 and HTLV-2 were also investigated. GBV-C/HGV RNA was detected by reverse transcriptase and polymerase chain reaction (RT-PCR). Ninety-four serum samples from patients with chronic renal failure were analyzed. GBV-C/HGV RNA was identified in 12 (12.8%) patients, anti-HCV antibodies in 28 (29.8%), anti-Hbc in 9 (9.6%), anti-HIV in 1 (1%), HBsAg in 33 (35.1%), and HBsAg/ anti-HBc was observed in 2 (2.1%) patients. Thirty-six (38.3%) samples were non-reactive. Seven of the 12 GBV-C/HGV RNA infected samples were co-infected with other viruses: 3 (25%) with HBsAg, 2 (16.7%) with anti-HCV and 2 (16.7%) with anti-HBc/anti-HCV/HBsAg. Among the 42 thalassemic patients GBV-C/HGV RNA was detected in 6/42 patients (14.2 %). Three patients presented GBV-C/HGV, with other blood borne markers. We also detected GBV-C/ HGV in 6/50 (12%) blood donors. In these GBV-C/HGV positive thalassemics patients, 50% (3/6) were young individuals (lesser 15 years old) and 67% (4/6) were female patients. The presence of GBV-C RNA in the absence of hepatitis B and C infection in the young patients and healthy donors could be indicate that this virus is capable of independent transmission and does not contribute to liver disease.

Investigation of HGV and TTV infection in sera and saliva from non-hepatitis patients with oral diseases

AIM: To determine the frequencies of HGV and TTV infections in serum and saliva samples of non-hepatitis patients with oral diseases in Hangzhou area, and to understand the correlation between detected results of HGV RNA and/or TTV DNA in sera and in saliva from the same patients.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection were performed in the serum and saliva samples from 226 non-hepatitis patients with oral diseases, and nucleotide sequence analysis.

RESULTS: Twenty-seven (11.9%) and 21 (9.3%) of the 226 serum samples were only positive for HGV RNA and TTV DNA, respectively. 10 (4.4%) and 9 (3.9%) of the 226 saliva samples were only positive for HGV RNA and TTV DNA, respectively. And 7 (3.1%) of the serum samples and 2 (0.9%) of the saliva samples showed the positive amplification results for both HGV RNA and TTV DNA. 12 saliva samples from the 34 patients (35.3%) with HGV or HGV/TTV viremia and 11 saliva samples from the 28 patients (39.3%) with TTV or HGV/TTV viremia were HGV RNA detectable, respectively, including two patients positive for both HGV RNA and TTV DNA in serum and saliva samples. No saliva samples from the 226 patients were found to be HGV RNA or TTV DNA detectable while their serum samples were negative for HGV or TTV. Homologies of the nucleotide sequences of HGV and TTV amplification products from the serum and saliva samples of the two patients compared with the reported sequences were 88.65%-91.49% and 65.32%-66.67%, respectively. In comparison with the nucleotide sequences of amplification products between serum and from saliva sample from any one of the two patients, the homologies were 98.58% and 99.29% for HGV, and were 98.65% and 98.20% for TTV, respectively.

CONCLUSION: Relatively high carrying rates of HGV and/or TTV in the sera of non-hepatitis patients with oral diseases in Hangzhou area are demonstrated. Parts of the carriers are HGV and/or TTV positive in their saliva. The results of this study indicate that dentists may be one of the populations with high risk for HGV and/or TTV infection, and by way of saliva HGV and TTV may be transmitted among individuals.

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.

High frequencies of HGV and TTV infections in blood donors in Hangzhou

AIM: To determine the frequencies of HGV and TTV infections in blood donors in Hangzhou.

METHODS: RT-nested PCR for HGV RNA detection and semi-nested PCR for TTV DNA detection in the sera from 203 blood donors, and nucleotide sequence analysis were performed.

RESULTS: Thirty-two (15.8%) and 30 (14.8%) of the 203 serum samples were positive for HGV RNA and TTV DNA, respectively. And 5 (2.5%) of the 203 serum samples were detectable for both HGV RNA and TTV DNA. Homology of the nucleotide sequences of HGV RT-nested PCR products and TTV semi-nested PCR products from 3 serum samples compared with the reported HGV and TTV sequences was 89.36%, 87.94%, 88.65% and 63.51%, 65.77% and 67.12%, respectively.

CONCLUSION: The infection rates of HGV and/or TTV in blood donors are relatively high, and to establish HGV and TTV examinations to screen blood donors is needed for transfusion security. The genomic heterogeneity of TTV or HGV is present in the isolates from different areas.

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.

A high frequency of GBV-C/HGV coinfection in hepatitis C patients in Germany

AIM: To detect infection rate of GBV-C/HGV in hepatitis C patients, to determine the methods of higher sensitivity and the primers of higher efficiency for GBV-C/HGV RNA detection and to study the dominant subtype and mutation of GBV-C/HGV.

METHODS: Quantitative RT-PCR for detection pf HCV RNA concentration in serum samples, RT-nested PCR with two sets of primers for detection of GBV-CRNA, RT-PCR ELISA with two sets of primers for detection of HGV RNA, nucleotide sequence and putative amino acid sequence analysis.

RESULTS: The positive rates of GBV-C RNA at the 5’-NCR and NS3 region in 211 serums amples from the patients with HCV infection were 31.8% and 22.8% respectively. The positive rates of HGV RNA at the 5’-NCR and NS5 region in the same samples were 47.9% and 31.8% respectively. The total positive rate of GBV-C/HGV RNA was as high as 55.5%. HCV copy numbers in the patients without GBV-C/HGV coinfection were statistically higher than that in the patients with GBV-C/HGV coinfection (P < 0.01). Frequent mutation of nucleotide residue was present in the amplification products. Frameshift mutation was found in two samples with GBV-C NS3 region nucleotide sequences. All nucleotide sequences from amplification products showed higher homology to HGV genome than to GBV-C genome even though part of the sequences were amplified with GBV-C primers.

CONCLUSION: A high frequency of GBV-C/HGV coinfection existed in the hepatitis C patients. RT-PCR ELISA was more sensitive than RT-nested PCR for detection of GBV-C/HGV RNA. The primers derived from the 5’-NCR was more efficient than those derived from the NS3 and NS5 regions. A reverse relationship was found to exist between HCV RNA concentration and GBV-C/HGV infection frequency. HGV was the dominant subtype of the virus in the local area. The major mutations of GBV-C/HGV genomes were random mutation of nucleotide residue.

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.

Sequence diversity in the 5'-UTR region of GB virus C/hepatitis G virus assessed using sequencing, heteroduplex mobility analysis and single-strand conformation polymorphism

GB virus C/hepatitis G virus (GBV-C/HGV) is a positive-sense RNA virus belonging to the Flaviviridae family identified recently. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect GBV-C/HGV RNA using nested primers designed to amplify 245 bp of the 5'-untranslated region (UTR). GBV-C/HGV RNA was detected in 20.7% of 101 HCV-RNA positive and 6.8% of 44 HCV-RNA negative specimens. Sequencing of the PCR products demonstrated they had between 84.3 and 100% nucleotide identity. Most of the diversity corresponded to two variable regions identified within the 5'-UTR. Phylogenetic analysis indicated that GBV-C/HGV subtypes present in Australia belonged to group 2 and were closest in evolutionary terms to isolates from the USA and Europe. All isolates were analysed using single-strand conformation polymorphism (SSCP) and heteroduplex mobility analysis (HMA) on 8% non-denaturing polyacrylamide gels. SSCP of the isolates identified a number of distinct conformation polymorphisms that corresponded with sequence-determined genetic diversity. HMA was developed to assess the amount of genetic diversity between isolates without the need for sequencing. The average difference between the predicted divergence of two isolates calculated from the mobility of the heteroduplex and the actual value (based on nucleotide sequence) was 2.3% in this sample of isolates, where the mean sequence divergence was 8.52%.

Hepatitis G virus: relevance to oral health care

OBJECTIVE

To review the current literature on the hepatitis G virus (HGV) infection, with particular attention to the aspects of interest for the dental staff.

MATERIAL AND METHODS

The authors searched for original research and review articles on specific aspects of the HGV infection including virology, epidemiology, transmission, natural history, and dental zaspects of HGV infection. The relevant articles were evaluated and reviewed.

RESULTS

HGV is a parenterally transmitted RNA virus that may cause acute, chronic, and fulminant liver disease; however, the real pathogenic potential of this virus and its possible effect on other hepatitic infections is still to be clarified. Preliminary studies have failed to demonstrate strong relationships between HGV infection and any oral disease. At present, data on the prevalence of HGV infection among health care workers are scarce. Nevertheless, in view of the potential transmission rates of HGV and the lack of effective immunization, HGV should be regarded as a potential occupational hazard for medical and dental staff.

CONCLUSION

Many virological, medical, and oral aspects of HGV infection need to be further investigated; nevertheless, until related data are available, HGV should be considered to be an infection that may be transmitted during dental care.

Prevalence of GB virus C/hepatitis G virus among blood donors in north-eastern Brazil

We tested 70 blood donors from Fortaleza (Ceara state, Brazil) for GB virus C/hepatitis G virus (GBV/HGV) infection by polymerase chain reaction and detection of antienvelope antibodies. Twenty-seven (38.6%) showed signs of an active or resolved infection. Sixty-four percent of those with indications of other blood-borne viral infections showed signs of GBV-C/HGV infection also.