The hepatitis G virus, i.e. GB virus C, is a recently discovered flavi
virus that is clearly transmitted by the parenteral route. To date dem
onstration has only been possible by PCR. Spread among non-selected bl
ood donors is higher than for hepatitis viruses identified to date, an
d is estimated at around 2%. The virus is often detected in people at
increased risk of parenteral pathogen transmission (injecting drug use
rs, HIV patients, haemodialysis patients, haemophiliacs). Co-infection
s with the hepatitis G virus occur in about 10-20% of patients with he
patitis B and C. The clinical significance of a hepatitis G infection
is still unclear.