Patients participating in PACTG 219C are selected randomly to enroll into PACTG P1028S. Patients who agree to participate have a single blood draw for HCV antibody (Enzyme Immunoassay-EIA) testing and HCV RNA (Polymerase Chain Reaction-PCR) testing. An additional blood draw is necessary in the case of discordant results between the HCV EIA and HCV PCR. HCV-negative patients have 1 study visit. Patients with positive HCV test results have 2 visits. Patients with discordant HCV test results have 2 or 3 visits.