Hepatitis C and GB Virus C/Hepatitis G Virus Infection Among HIV-1-Infected Individuals in Hawaii and Puerto Rico

             GB virus C/hepatitis G virus (GBV-C/HGV), a recently described orphan flavivirus, composed of a positive-sense, single-stranded RNA genome of approximately 9.5 kb, is distantly related to HCV.  HCV has been implicated to cause hepatocellular carcinoma and HCV infection is highly associated with IDU, which is also a major risk factor for acquiring HIV-1 infection.  By contrast, the mode of GBV-C/HGV transmission is poorly understood.  Moreover, the prevalence and disease potential of HGV infection in HIV-1-infected individuals are unknown.  To begin to address these issues, we have amplified by reverse-transcription polymerase chain reaction a 334- and 218-nucleotide region spanning the 5â-untranslated segments of GBV-C/HGV and HCV, respectively, from plasma samples of 146 HIV-1-infected individuals from Hawaii (81 males and 65 females; mean age, 36 years; range, 5-60 years), classified in the following high-risk behavior groups: 61 (42%) homosexual sex, 39 (27%) high-risk heterosexual sex, 21 (14%) IDU, 4 (3%) blood transfusion or hemophiliac, and 21 (14%) unknown.  A statistically significant correlation was found between acquiring HGV infection in the homosexual group (26%), compared to the heterosexual (3%) or IDU (10%) groups (p < 0.001).  By contrast, the prevalence of HCV infection was highest in the IDU risk group.  The high prevalence of GBV-C/HGV infection in homosexual men suggests efficient transmission by the mucosal route.  Genetic and phylogenetic analyses reveal clustering of GBV-C/HGV strains according to the risk factors; for example, GBV-C/HGV from homosexuals and heterosexuals grouped together and HGV from IDU formed a monophyletic group.  These findings raise issues about selective and preferential mucosal transmission of HGV as opposed to parenteral transmission.

Nerurkar, V.R., Chua, P.K., Yamamura, Y., Woodward, C.L., Shikuma, C.M., and Yanagihara, R.:  Hepatitis C and GB virus C/hepatitis G virus infection among HIV-1-infected individuals in Hawaii and Puerto Rico.  Infection  (in preparation).

Nerurkar, V.R., Chua, P.K., Hoffmann, P.R., Dashwood, W-M., Shikuma, C.M., and Yanagihara, R.:  High prevalence of GB virus C/hepatitis G virus infection among homosexual men infected with human immunodeficiency virus type 1:  evidence for sexual transmission.  Journal of Medical Virology  1998;56:123-127.

Nerurkar, V.R., Chua, P.K., Shikuma, C.M., Dashwood, W-M., Milne, C., Woodward, C.L., Kobayashi, G., Peterson, J., and Yanagihara, R.:  Precipitous decline in IgG antibodies against GB virus C/hepatitis G virus in a patient with AIDS.  Hawaii Medical Journal 1998;57:11-12.

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