GBV-C/HGV coinfection in HIV-1-positive men: frequent detection of viral RNA in blood plasma but absence from seminal fluid plasma

Discovery of a Novel Simian Pegivirus in Common Marmosets (Callithrix jacchus) with Lymphocytic Enterocolitis

From 2010 to 2015, 73 common marmosets (Callithrix jacchus) housed at the Wisconsin National Primate Research Center (WNPRC) were diagnosed postmortem with lymphocytic enterocolitis. We used unbiased deep-sequencing to screen the blood of deceased enterocolitis-positive marmosets for viruses. In five out of eight common marmosets with lymphocytic enterocolitis, we discovered a novel pegivirus not present in ten matched, clinically normal controls. The novel virus, which we named Southwest bike trail virus (SOBV), is most closely related (68% nucleotide identity) to a strain of simian pegivirus A isolated from a three-striped night monkey (Aotus trivirgatus). We screened 146 living WNPRC common marmosets for SOBV, finding an overall prevalence of 34% (50/146). Over four years, 85 of these 146 animals died or were euthanized. Histological examination revealed 27 SOBV-positive marmosets from this cohort had lymphocytic enterocolitis, compared to 42 SOBV-negative marmosets, indicating no association between SOBV and disease in this cohort (p = 0.0798). We also detected SOBV in two of 33 (6%) clinically normal marmosets screened during transfer from the New England Primate Research Center, suggesting SOBV could be exerting confounding influences on comparisons of common marmoset studies from multiple colonies.

Detection of GB virus C/hepatitis G virus in semen and saliva of HIV type-1 infected men

OBJECTIVE

To investigate the presence of the genome of GB virus C/hepatitis G virus (GBV-C/HGV) in semen and saliva from HIV-1-infected men.

METHODS

Samples of blood from 33 men seropositive for HIV-1 were tested for the presence of GBV-C/HGV markers of infection, RNA by RT-PCR, and anti-E2 antibodies by ELISA, respectively. The cell-free fractions of seminal fluid and saliva samples of the patients with positive blood samples for GBV-C/HGV RNA or anti-E2 antibodies were then analyzed for the presence of the RNA of this virus. In addition, six semen samples and 11 saliva samples from GBV-C/HGV-negative men were tested.

RESULTS

The GBV-C/HGV RNA tested by RT-PCR was recovered from blood in 11 patients of 33 (33.3%), and the antibodies to E2 envelope protein were detected in six patients (18.2%). Since no patient was positive for both markers, the overall prevalence of GBV-C/HGV infection was 51.5% in the studied population. Four-all belonging to the homosexual risk group-of the 17 men with markers to GBV-C/HGV in blood were found to be positive for GBV-C/HGV RNA in mucosal samples: two of them exhibited genomic RNA in both semen and saliva, and two others were positive for semen only. The absence of inhibitors of the PCR technique was confirmed in all mucosal fractions found negative for GBV-C/HGV RNA, except for one saliva sample and one seminal fluid sample.

CONCLUSION

These results confirm the high prevalence of GBV-C/HGV infection in patients infected with HIV-1 by sexual exposure and the presence of GBV-C/HGV RNA in seminal fluid and saliva of men with markers of this virus in the blood, suggesting that mucosal fluids could be a potential source for the spread of the GBV-C/HGV infection.

Investigation of saliva, faeces, urine or semen samples for the presence of GBV-C RNA

GBV-C/HGV has been demonstrated to be distributed worldwide with a prevalence in blood donors higher than HCV. This distribution in the general population probably requires an effective non-parenteral route of transmission. A previous study was performed to evaluate the presence of GBV-C/HGV in serum. Saliva, faeces and urine samples of 30 patients (15 males and 15 females) and 15 semen samples from patients whose serum gave a GBV-C/HGV RNA positive result were then tested by a sensitive polymerase chain reaction (PCR) test. Five semen supernatant samples (33.3%) tested positive--four of them belonged to HIV positive patients--and two saliva samples contained GBV-C/HGV sequences (6.6%)--one from a HIV-positive patient. An internal control was used to detect PCR nonspecific inhibitors in the samples. The data suggest possible non-parenteral routes of transmission from this virus. Its presence in body fluids other than serum has clinical implications other than possible hepatic damage that remain to be investigated.

GB virus-C infection in patients infected with the human immunodeficiency virus

Hepatitis virus infections are frequent in patients suffering from HIV infection due to similar transmission routes of these viruses. In addition, hepatitis virus infections lead to impaired survival in HIV positive patients. The recently discovered flavivirus GB virus C (alias Hepatitis G Virus) was initially believed to be another hepatitis virus. While there is still some minor discussion whether GB virus C (GBV-C) plays a role in fulminant hepatic failure, there is no evidence that this virus is responsible for chronic liver disease. Thus this 'orphan virus' still seeks its disease. In this review we concentrate on the published data concerning the co-infection of GBV-C and HIV. By summarizing the studies available, we show evidence for a beneficial influence of GBV-C on HIV infection. Many studies demonstrated a high prevalence of GBV-C infection in HIV positive patients due to its parenteral and sexual transmission. However, in contrast to the expectations, GBV-C does not aggravate the course of patients suffering from HIV infection. Even though not uniformly found, one often sees higher CD4 counts in patients with ongoing GBV-C viral replication. Likewise, a lower viral load appears to be accompanied by the presence of GBV-C RNA in the serum. In addition, longitudinal studies indicate that GBV-C infection slows down the progression to AIDS and eventually to death. GBV-C probably influences HIV infection associated disease by either directly inhibiting HIV replication or enhancing the immune competence to cope with HIV. Still the definitive mechanism how GBV-C could inhibit the progression to AIDS and eventually death needs to be identified.

Viruses in the mammalian male genital tract and their effects on the reproductive system

This review describes the various viruses identified in the semen and reproductive tracts of mammals (including humans), their distribution in tissues and fluids, their possible cell targets, and the functional consequences of their infectivity on the reproductive and endocrine systems. The consequences of these viral infections on the reproductive tract and semen can be extremely serious in terms of organ integrity, development of pathological and cancerous processes, and transmission of diseases. Furthermore, of essential importance is the fact that viral infection of the testicular cells may result not only in changes in testicular function, a serious risk for the fertility and general health of the individual (such as a fall in testosteronemia leading to cachexia), but also in the possible transmission of virus-induced mutations to subsequent generations. In addition to providing an exhaustive account of the data available in these domains, this review focuses attention on the fact that the interface between endocrinology and virology has so far been poorly explored, particularly when major health, social and economical problems are posed. Our conclusions highlight the research strategies that need to be developed. Progress in all these domains is essential for the development of new treatment strategies to eradicate viruses and to correct the virus-induced dysfunction of the endocrine system.

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.

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.