Adenovirus type 5 was isolated from blood clots from 27 of 30 sporadic cases of infectious hepatitis. Only one isolation of virus, also adenovirus 5, was made from blood clots from 70 persons with no known contact 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.

Adenovirus type 5 was isolated from blood clots from 27 of 30 sporadic cases of infectious hepatitis. Only one isolation of virus, also adenovirus 5, was made from blood clots from 70 persons with no known contact with infectious hepatitis.