April 17, 2003
In the current study, researchers assessed the prevalence and type distribution of HPV in an ethnically diverse group of men ages 18-70 attending an STD clinic in Tucson, Ariz., between July 2000 and January 2001. Clinical examinations were performed by physicians and midlevel clinicians experienced in STD detection. All clinicians working on the study were trained in specimen collection.
Approximately 69 percent of the 645 patients who were approached elected to participate, resulting in the enrollment of 443 participants. Those declining most commonly cited as reasons time constraints and lack of interest. Compared with non-participants, participants were more likely to be of "other" race/ethnicity, a category including Native Americans, Pacific Islanders, and men of Asian or South Asian descent, and were more likely to be ages 25-29. Participants also had significantly higher prevalence of STDs, including nongonococcal urethritis, chlamydia, genital warts and genital herpes.
Participants' mean (±SD) age was 30.9 (±10.3) years, with a range of 18-70 years. The majority of participants were either white (42.1 percent) or Hispanic (39.2 percent), with 75.1 percent born in the United States and 15.7 born in Mexico. Most were single (63.1 percent), 75.6 percent were currently employed, and 90.3 percent were heterosexual. Neither age nor marital status was significantly associated with HPV infection. Men who reported bisexual activity had a higher prevalence of HPV (50 percent) than did men who reported having sex with only women or only men, but this difference was not statistically significant.
The prevalence of HPV among the 393 participants was 28.2 percent (111 patients). Oncogenic HPV types were found in 12 percent of participants; nononcogenic types were found in 14.8 percent of participants; multiple types were found in 6.1 percent (24) of participants; and unknown types were found in 5.9 percent (23) of participants. The most prevalent subtypes were nononcogenic 6 (3.8 percent), 53 (3.1 percent) and 84 (2.8 percent). Among oncogenic types, the most common were 16 (2.3 percent), 52 (1.8 percent), and 59 (2.3 percent).
Statistically significant associations with HPV infection were observed with ethnicity and educational level. Participants of Hispanic or "other" nonwhite race/ethnicity and those reporting fewer years of education had higher HPV prevalence. HPV positivity was not associated with age. Genital warts were the only STD to be associated with penile HPV detection. A fairly strong correlation was noted between HPV types 6 or 11 and the presence of genital warts. Of the 15 men positive for HPV type 6, seven (46.9 percent) had genital warts. Both men with HPV 11 had genital warts (100 percent). Overall, nine (52.9 percent) of 17 men with HPV types 6 or 11 had genital warts at their visit. Only 46 percent of men with genital warts tested positive for HPV, demonstrating a low sensitivity for this method of collection.
In this investigation, nononcogenic HPV types occurred more frequently in men than did oncogenic types, in contrast to studies of HPV infection in women. These results, the study authors reported, indicate that HPV infection among men at high risk is common but that characteristics of male HPV infection may differ from those of female infection. "These findings have implications for public health and cancer prevention. Both prevalence and natural history data are needed to ensure the success of HPV vaccination efforts and other future public health endeavors; more research, especially prospective cohort studies of HPV in men, is needed."
Journal of Infectious Diseases
04.01.03; Vol. 187, No. 7, P. 1064-70; Susie B. Baldwin; Danelle R. Wallace; Mary R. Papenfuss; Martha Abrahamsen; Linda C. Vaught; Janet R. Kornegay; Jennifer A. Hallum; Stacey A. Redmond; Anna R. Giuliano