HPV Infection in Men
Abstract & Commentary
By Dean L. Winslow, MD, FACP, FIDSA
Chief, Division of AIDS Medicine, Santa Clara Valley Medical Center; Clinical Professor of Medicine, Stanford University School of Medicine.
Dr. Winslow serves as a consultant for Siemens Diagnostics, and is on the speaker's bureau for Boehringer-Ingelheim and GSK.
This article originally appeared in the December 2007 Infectious Disease Alert. It was edited by Stan Deresinski, MD, FACP, and peer reviewed by Connie Price, MD.
Synopsis: Genital HPV infection is common, and is often found at multiple sites in young heterosexual men. Risk factors for HPV infection in men include number of female sex partners (FSP), condom use, and smoking. Multiple anatomic sites should be sampled in heterosexual men to optimize detection of HPV.
Sources: Partridge JM, et al. Genital human papillomavirus infection in men: Incidence and risk factors in a cohort of university students. J Infect Dis. 2007;196:1128-1136; Nielson CM, et al. Risk factors for anogenital human papillomavirus infection in men. J Infect Dis. 2007;196:1137-1145; Giuliano AR, et al. The optimal anatomic sites for sampling heterosexual men for human papillomavirus (HPV) detection: The HPV detection in men study. J Infect Dis. 2007;196:1146-1152.
These three studies published back to back in the Journal of Infectious Diseases serve to better characterize HPV infection in heterosexual men. The first study from the group in Seattle followed a cohort of 240 heterosexually-active male university students from 2003 until 2006 and obtained genital samples at 4-month intervals for HPV-DNA analysis by PCR while the students maintained a web-based log of their sexual activity. By 24 months, the cumulative incidence of new infection with HPV was 62.4%. Report of a new sex partner in the preceding 8 months approximately doubled the relative risk of acquiring infection. A history of smoking increased the risk of acquiring infection with HPV by a factor of 1.6.
The second study conducted under CDC auspices recruited 463 men 18-40 years old from Tucson and Tampa and also used HPV detection by PCR and completion of a self-administered questionnaire at one time point only. Prevalence in this slightly older population of HPV infection of any type was 65.4%, 29.2% for oncogenic types, and 36.3% for non-oncogenic types. Lifetime and recent number of Femme Sex Partners (FSPs), condom use, and smoking were modifiable risk factors associated with HPV infection.
The third paper was a more in-depth analysis of technical factors associated with detection of HPV DNA derived from the dataset of the CDC study described above. Bottom line results from this study demonstrated that, at minimum, the penile shaft and glans penis/coronal sulcus should be sampled in heterosexual men, and that for optimal detection, scrotal, perianal and anal samples should be obtained as well.
Beginning in the 1970s, the association between oncogenic types of HPV infection and cervical cancer became well established. By the 1990s, increasingly sensitive molecular diagnostic techniques were available for the detection and typing of HPV in clinical samples. Appropriately, these techniques were generally initially applied in the clinical setting in young women. While genital malignancy can be associated with HPV infection in heterosexual men, HPV infection in men is mainly of importance to the extent that men provide a reservoir of infection and their sexual behavior affects women's risk of cervical cancer. Previously available information regarding penile HPV infection has been limited by the fact that it was derived from 3 sources: 1) studies of male partners of women with cervical cancer; 2) small cross-sectional studies of select populations such as men being treated for STDs or military recruits; or 3) small prospective studies.
The 3 studies described above greatly expand our knowledge of the true prevalence of HPV infection in men and our understanding of risk factors for acquisition. The high rates of HPV infection in men should be considered when developing strategies for the prevention of HPV infection in female adolescents and young women.
While not addressed in these studies, the state of knowledge regarding the natural history of anorectal HPV infection in gay/bisexual men is very limited as well. Despite the increasing acceptance of periodic performance of anorectal Pap smears in this population (especially in the San Francisco Bay Area), the utility and cost effectiveness of this practice remains unestablished, and will remain so until larger and more in-depth studies of HPV infection anorectal cancer are made in gay men as well.