Antibodies to hepatitis C virus in community-acquired acute non-A, non-B hepatitis.

Circulating antibodies to the recently identified hepatitis C virus (anti-HCV) have been investigated by ELISA in a series of 129 adult Italian patients with acute, community-acquired non-A, non-B hepatitis. Anti-HCV was detected in 50 (38%) cases with a prevalence rate which increased from 19%, in sera taken during the first 2 weeks of illness to 52% in samples obtained 5-6 weeks after onset, indicating a rather late appearance of the antibody. Anti-HCV positivity was independent of risk factors in the clinical history, but correlated with the outcome of the disease. Eighteen (26%) of 68 patients who recovered were anti-HCV positive compared to 10 of 14 (71%) who progressed to chronicity (p less than 0.01). In this latter group the antibody persisted for more than 12 months after the onset of the illness. Conversely, in 12 (85%) of 14 serially tested patients who recovered, anti-HCV positivity was transient, lasting from a few weeks to a few months. These findings indicate that HCV is implicated in a consistent proportion of acute community-acquired non-A, non-B hepatitis cases, particularly cases which progress to chronicity. A large proportion of cases remained unclassified, however, and it will be important to define whether they represent cases of HCV infection with poor serologic response, or are due instead to other, as yet unidentified, non-A, non-B agents.