GB virus C/hepatitis G virus infection: clinical, histological and epidemiological aspects

GBV-C/HGV is a blood-borne virus related to the hepatitis C virus. We studied GBV-C/HGV infection in different populations, its transmission, and its association with liver disease. GBV-C/HGV viraemia was detected by PCR in 19/576 blood donors. Donors with normal and elevated ALT levels had similar rates of viraemia (1.6% vs. 4.1%; p = 0.20). Signs of resolved GBV-C/HGV infection (anti-E2 antibodies) were found in 13.5% of donors. In donors with isolated GBV-C/HGV viraemia, very mild portal inflammatory lesions were observed in 6/11 subjects. No other significant biochemical or histological abnormalities were noted.

In a case-control study of 66 donors exposed to GBV-C/HGV and 125 age- and sex-matched controls, GBV-C/HGV exposure was associated with multiple sex partners, history of a sexually transmitted disease, and previous endoscopy.

GBV-C/HGV markers were found in 35/62 blood donors deferred due to hepatitis C, but co-infection with GBV-C/HGV did not affect liver histology in these subjects. Exposure to GBV-C/HGV was more frequent in patients with chronic liver disease than in the general population (34% vs. 19%; p < 0.0001). Viraemia was uncommon in patients with cryptogenic disease. Apart from an increased occurrence of bile duct degeneration, GBV-C/HGV-viraemic patients did not display any biochemical or histological characteristics.

This thesis shows that GBV-C/HGV is common both among persons at high risk of parenteral exposure and in the general population. Besides via parenteral routes, transmission can occur by sexual contacts, and probably also nosocomially. GBV-C/HGV does not cause significant liver disease. Accordingly, blood donor screening for this virus is not warranted.