Prostate-Specific Antigen to Ascertain Reliability of... : Sexually Transmitted Diseases (original) (raw)

Article

Prostate-Specific Antigen to Ascertain Reliability of Self-Reported Coital Exposure to Semen

Gallo, Maria F. PhD*; Behets, Frieda M. PhD§; Steiner, Markus J. PhD†; Hobbs, Marcia M. PhD§; Hoke, Theresa Hatzell PhD‡; Van Damme, Kathleen MD∥; Ralimamonjy, Louisette MD**; Raharimalala, Leonardine MD††; Cohen, Myron S. MD¶

From *Family Health International (FHI), Research Triangle Park, North Carolina; †Clinical Research and ‡Health Services Research, FHI, Research Triangle Park, North Carolina; the Departments of §Epidemiology and ¶Medicine, Microbiology, and Epidemiology, ∥University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; the **Institut de Sante Publique et Communautaire, Antananarivo, Madagascar; and ††Hopital Kely, Ministere de la Sante Publique, Tamatave, Madagascar

The authors thank Jane Parker, Kimberly Rich, Dana Lapple, and Cynthia Kwok for valuable technical assistance. The authors also thank Prof. Rasamindrakotroka and the Madagascar Ministry of Health for their support of the project.

This work was supported by the Microbiology Core Laboratory of the North Carolina Sexually Transmitted Infections/Topical Microbicide Cooperative Research Center funded by U.S. National Institutes of Health (NIH) contract U19 AI031496 and the Sexually Transmitted Diseases Clinical Trial Unit funded by U.S. NIH contract N01 AI075329. The U.S. Agency for International Development (cooperative agreement #AID/CCP-3079-A-00-5022-00) also supported this work. The views expressed in this document, however, do not necessarily reflect those of the funding agencies.

Correspondence: Maria F. Gallo, PhD, Centers for Disease Control and Prevention, Division of Reproductive Health, 4770 Bulford Highway NE, Mail Stop K-34, Atlanta, GA 30333. E-mail: [email protected].

Received for publication August 2, 2005, and accepted November 29, 2005.

Objective:

The objective of this study was to assess the validity of women’s reports of recent unprotected sex by testing for prostate-specific antigen (PSA) in vaginal samples.

Study Design:

The authors conducted prospective research with 332 female sex workers attending 2 public dispensaries in Madagascar.

Results:

Among women who reported no sex or protected sex only within the past 48 hours, 21% and 39%, respectively, tested positive for PSA. Among those testing positive for PSA, no differences in PSA concentrations were found among those reporting no sex, protected sex only, or at least one unprotected act.

Conclusions:

The substantial disagreement between self-reports and measurement of a biologic marker of semen exposure in vaginal specimens substantiates that self-reports of sexual behavior cannot be assumed to be valid measures. Future sexually transmitted infection/HIV and pregnancy prevention studies should confirm the validity of self-reports or use end points that do not rely on self-reported data.