Direct-Acting Antiviral Treatment for Acute Hepatitis C in Japanese Patients: Clinical Course and Outcomes.

We diagnosed six cases of acute hepatitis C virus (HCV) infection at our hospital between October 2003 and December 2022. During the same period, we diagnosed 402 cases of chronic HCV infection and 636 cases of acute hepatic injury. Acute HCV infection cases accounted for 1.4% of all HCV infections and 0.9% of all acute hepatic injury cases. The acute HCV infection group was younger, had more severe hepatitis, and exhibited higher levels of bilirubinemia compared to the chronic HCV infection group. Two acute HCV infection cases achieved spontaneous viral clearance, while the remaining four cases progressed to chronic infection and were treated with direct-acting antivirals (DAAs). Liver enzyme elevation and liver function deterioration did not differ significantly between the acute HCV and other acute liver injury groups. Notably, DAA treatment was equally effective for acute and chronic HCV cases (75% vs. 90%, p = 0.34). Early DAA treatment in acute cases might contribute to interrupting viral transmission among high-risk populations, such as people who inject drugs or men who have sex with men. While there are currently no specific guidelines for acute HCV infection treatment in Japan, our findings suggest that DAA therapy should be initiated immediately following diagnosis. Further studies with larger patient cohorts are warranted to confirm these observations.