Description of a viral agent found in blood obtained from patients with infectious hepatitis

A small, double-stranded deoxyribonucleic acid viral agent (agent Y) has been found in blood from patients with infectious hepatitis. The agent was propagated in chimpanzee liver tissue culture which had been grown and maintained on unheated agamma calf serum. A causal relationship between this agent and the occurrence of human disease cannot be determined from the data presented.