Background: For over a decade we have known of an epidemic of sexually transmitted hepatitis C virus (HCV) infection among human immunodeficiency virus (HIV)-infected men who have sex with men (MSM), but there still remains significant controversy over which bodily fluid(s) are responsible for HCV transmission in these men.
Methods: We enrolled HIV-infected MSM with recent and chronic HCV infection and quantified HCV from rectal fluid obtained by blind swab. We compared the rectal HCV viral load (VL) with paired blood HCV VL.