The primary objective of the study is to determine the number of adverse events (AEs) reported by chronic hepatitis C (CHC) patients receiving at least 1 dose of daclatasvir (DCV) and asunaprevir (ASV) at the 2 sentinel sites and that have been reported through the Mexican Health Authority's AE surveillance system during a specified 24-month study period. The secondary objective is to describe AEs reported by CHC patients receiving treatment with DCV and ASV treated by doctors at participating sentinel sites for the National Pharmacovigilance Center (CNFV) in Mexico during a specified 24-month study period.