Occult hepatitis C virus infection in patients in whom the etiology of persistently abnormal results of liver-function tests is unknown. 

 Castillo I, Pardo M, Bartolomé J, Ortiz-Movilla N, Rodriguez-Iñigo E, de Lucas S, Salas C, Jiménez-Hefferman JA, Pérez-Mota A, Graus J, López-Alcorocho JM,Carreño V. J Infect Dis 2004; 189: 7-14.