Prevalence and diversity of Beta-papillomavirus in anogenital and oral samples of males from the HIM study

Abstract

HPV is primarily transmitted by sexual contact and infection by these viruses is strongly associated with the development of tumors in the cervix, vulva and anus in women, cancer of the penis and anus in men, as well as tumors in the head and neck in both genders. Case-control studies conducted in women with cervical cancer showed that male partners' sexual behavior influences the risk of women of developing this neoplasia. However little is known about the natural history of HPV infection in the male genital region. Since 2005 an International prospective study in men (HPV Infection in Men - HIM, Brazil, Mexico, United States) is being conducted following-up approximately 4,500 men every 6 months for 4 years. For viral genotyping of the samples, a methodology capable of identifying 37 HPV types commonly detected in female genital samples is being used. Initial analysis of the HIM study revealed an HPV prevalence of 65.2%, of which 14.7% were categorizes as unclassified infections, ie without positive type defined. Among these non-classified scrotum/penile and anal samples, high prevalence of beta-HPV types was further observed using a PCR-sequencing protocol. In addition, a subset of 17 samples was analyzed using a bead-based multiplex genotyping methodology and multiple infections by different b-HPV types were unraveled in most specimens suggesting that the PCR-sequencing protocol used may be underestimating the real prevalence of "cutaneous" HPV types among these smears. In order to better understand the significance of these viral types in the natural history of HPV infection, our aim is: (1) Determine the frequency of individual beta-HPV types detected among 800 matched oral/penile/anal samples; (2) Identify factors independently associated with the acquisition, persistence and clearance of these HPV types in different anatomical sites of men participating in the HIM study. To achieve these objectives, we will use the sensitive bead-based multiplex genotyping methodology (Luminex suspension array technology) currently well established for detecting and typing beta-HPV types in DNAs extracted from anogenital/oral specimens.