Abstract
The cloning of the hepatitis C virus (HCV)1 established that important human pathogens, which could not be seen microscopically, grown in cell culture, or detected serologically, could nonetheless be discovered through the power of molecular amplification. Using similar methods, scientists have discovered the hepatitis E virus (HEV) and, most recently, have cloned the hepatitis G virus (HGV)2 and the GB agent (HGBV).3 First, I will try to clarify the nomenclature of what has become a complex alphabet soup of hepatitis agents. Hepatitis viruses A, B, C, D, and E are all well-characterized, molecularly defined agents with unequivocal disease associations. The . . .