While condoms can help prevent other sexually transmitted diseases, evidence remains inconsistent as to whether or not they will prevent transmission of the human papillomavirus (HPV), a new report suggests. HPV, which can cause genital and anal warts and increase the risk of cancers of the cervix, vulva, vagina, anus, and penis, infects up to half of sexually active men and women ages 15 to 49 at some point in life, and as much as 60% of sexually active gay men. HPV is a particular problem for HIV-positive gay men, 90% of whom are estimated to carry the virus. Lisa E. Manhart and Laura A. Koutsky of the University of Washington-Seattle analyzed 20 previously published studies of condoms, genital warts, and HPV. Their full report, titled "Do Condoms Prevent Genital HPV Infection, External Genital Warts, or Cervical Neoplasia? A Meta-Analysis" and published in the November issue of Sexually Transmitted Diseases, showed that condom use did seem to protect against genital warts, though the effect was slightly stronger in men than women. But "complete protection from genital HPV infection may be impossible because infections may occur at... sites not covered by the condom," the researchers wrote.