Common aetiological agent for epidemic and sporadic non-A, non-B hepatitis.

Enterovirus-like particles have been reported in the acute phase of both epidemic and sporadic non-A, non-B (NANB) hepatitis. To examine whether these particles were the causative agent in the two types of disease, 29 patients with acute viral hepatitis in a north Indian epidemic outbreak and 9 with sporadic acute disease were investigated. 25 (86%) of 29 patients with epidemic hepatitis and 5 (56%) of 9 with sporadic disease were diagnosed as having enterically-transmitted-NANB hepatitis by exclusion. Virus-like particles (VLP) of 30-34 nm were detected in stool of 1 patient with epidemic and 1 with sporadic hepatitis. The VLPs crossreacted serologically and a specific IgM response was seen in acute epidemic and sporadic serum samples. After inoculation with infected stool rhesus monkeys had a mild rise in liver enzymes, and bile samples contained VLPs. These results suggest that the aetiological agent in epidemic and sporadic disease is the same.