Prostate-specific antigen in vaginal fluid as a biologic marker of condom failure

Forty women participated in three clinic visits during which they were expo sed to their partner's semen (10 mu L, 100 mu L, and 1 ml). At each visit t hey took vaginal fluid samples before exposure to their partner's semen, im mediately after, and at 1, 24, and 48 h after exposure. PSA was measured wi th an enzyme-linked immunoassay. The mean PSA level for preexposure swabs r anged between 0.43 and 0.88 ng/mL. The mean PSA levels were 193 immediately after exposure to 10 mu L, 472 after 100 mu L, and 19,098 after 1 ml. The PSA levels declined within 1 h, and returned to background at 48 h. The fin dings confirm that our procedure is a sensitive and specific method for det ecting recent semen exposure, and indicate that PSA levels depend on exposu re intensity and time since exposure. Application of this method in condom efficacy studies provides objective evidence of condom failure that enhance s the interpretation of self-report. (C) 1999 Elsevier Science Inc. All rig hts reserved.