Virus circulating in the bloodstream is difficult precipitate with antibody to immunoglobulins, but can precipitated with antibody to apolipoproteins. Since no hypervariable regions have yet been identified in the envelope proteins of HGV, the lipoprotein coat may help the virus evade immune surveillance and contribute to its persistence. How this high prevalence is maintained is unknown, but this does suggest that sub-clinical infection is common. Therefore, HGV infection is probably much more frequent than studies of the prevalence of HGV RNA suggest. The majority of patients infected with HGV by blood transfusion do not develop chronic hepatitis, but viremia frequently persists without biochemical evidence of hepatitis.
Viruses are obligate intracellular parasites.