%0 Journal Article %T Reduced acquisition and reactivation of human papillomavirus infections among older women treated with cryotherapy: results from a randomized trial in South Africa %A Sylvia Taylor %A Chunhui Wang %A Thomas C Wright %A Lynette Denny %A Wei-Yann Tsai %A Louise Kuhn %J BMC Medicine %D 2010 %I BioMed Central %R 10.1186/1741-7015-8-40 %X The impact of cryotherapy on newly detected hrHPV infections was examined among 612 women of known HIV serostatus, aged 35 to 65 years, who were negative for hrHPV DNA, and randomized to either undergo cryotherapy (n = 309) or not (n = 303). All women underwent repeat hrHPV DNA testing 6, 12, 24, and 36 months later.Among 540 HIV-negative women, cryotherapy was associated with a significant reduction in newly detected hrHPV infections. Women in the cryotherapy group were 55% less likely to have newly detected hrHPV than women in the control group (95% CI 0.28 to 0.71). This association was independent of the influence of changes in sexual behaviors following therapy (adjusted hazards ratio (HR) = 0.49, 95% CI 0.29 to 0.81). Among 72 HIV-positive women, similar reductions were not observed (HR = 1.10, 95% CI 0.53 to 2.29).Cervical cryotherapy significantly reduced newly detected hrHPV infections among HIV-negative, but not HIV-positive women. These results raise intriguing questions about immunological responses and biological mechanisms underlying the apparent prophylactic benefits of cryotherapy.Human papillomavirus (HPV), the causative agent of cervical cancer, is the most common sexually transmitted infection worldwide. Approximately 40% of women become infected with HPV within 2 years of initiating sexual intercourse, and nearly all women are infected at some point in their lifetime [1-5]. A small percentage of women infected with high-risk types of HPV (hrHPV) develop cervical intraepithelial neoplasia (CIN), which can act as a precursor to invasive cervical cancer. Multiple techniques are used to screen for and treat CIN lesions and early stage cervical cancers. Most developed countries have fairly extensive screening programs that primarily utilize cervical cytology as the screening method. Cytology-positive women are usually evaluated with colposcopy and if a high-grade CIN lesion is identified, undergo treatment using a variety of methods that include both %U http://www.biomedcentral.com/1741-7015/8/40