ORIGINAL CONTRIBUTION Prevalence of HPV Infection Among Females in the United States

HUMAN PAPILLOMAVIRUS(HPV) is estimated to be themost common sexuallytransmitted infection in the United States.1 HPV prevalence has been found to be highest among young per-sons within the first few years after sexual debut.2-6 However, there are no data on the prevalence of HPV among women across a broad age range and representative of the US population. Genital HPV types are categorized ac-cording to their epidemiological asso-ciation with cervical cancer. Infec-tions with low-risk types, such as HPV types 6 and 11, can cause benign or low-grade changes in cells of the cervix, genital warts, and recurrent respira-tory papillomatosis. High-risk HPV types can cause cervical, anal, and other genital cancers. High-risk HPV types are detected in 99 % of cervical cancers, and worldwide approximately 70 % of cer-vical cancers are due to HPV types 16 and 18.7,8 Although HPV infection is common, studies suggest approxi-mately 90 % of infections clear within 2 years.9,10 A highly efficacious prophylactic vaccine against HPV types 6, 11, 16, and 18 was licensed in June 2006 and recommended for routine use in females aged 11 to 12 years in the United States.11-14 Clinical studies of the quadrivalent HPV vaccine demon-strated close to 100 % efficacy in pre-venting infection and disease (cervical cancer precursors, genital lesions) associated with types included in the vaccine in analyses restricted to those women who were naive to HPV types 6, 11, 16, or 18 (either by HPV DNA or HPV antibodies). Representat ive data on type-specific prevalence of HPV DNA detection in the United States could provide a baseline estimate to mea