Low frequency of NS5A relevant resistance-associated substitutions to Elbasvir among hepatitis C virus genotype 1a in Spain: a cross-sectional study oleh Claudia Palladino, Marta Sánchez-Carrillo, Irene Mate-Cano, Sonia Vázquez-Morón, Ma Ángeles Jimenez-Sousa, Mónica Gutiérrez-Rivas, Salvador Resino, Verónica Briz