The primary objective of this study is: To evaluate the real-world safety, specifically the incidence rates of hepatic toxicity, pyrexia, and resistance, of DCV/ASV dual therapy in Japanese patients chronically infected with HCV GT-1.

Time Perspective: Other - For patients who are treated before the contract between Bristol-Myers Kabushiki Kaisha (BMKK) and the treating physician is initiated, patient data will be collected retrospectively after the contract is signed. Data will be collected prospectively for patients who initiate DCV/ASV treatment after the contract is initiated

Patient Registry study - Yes; 48 weeks (Treatment: 24 weeks, Follow up: 24 weeks)

For more information regarding BMS clinical trial participation, please visit www.BMSStudyConnect.com

Inclusion Criteria:

• Patients who are initiating DCV and ASV treatment for the first time under the approved indications, dosage, and administration will be included in this study

University hospitals, General hospitals, and clinics that have relevant departments, such as Liver Internal medicine, Gastroenterological medicine, Internal medicine, etc, where the surveillance drug is mainly prescribed