Preventing HPV infection could slow HIV epidemic, say researchers

Men infected with human papillomavirus (HPV) are at greater risk of becoming infected with human immunodeficiency virus (HIV) than men who are not HPV positive, according to researchers at the University of North Carolina at Chapel Hill.

Preventing HPV infection could be a way to slow the HIV epidemic, the researchers said in a study published online recently in the Journal of Infectious Diseases.

"Finding a vaccine to prevent HIV is the greatest hope for curbing the world's AIDS pandemic, but so far there is no such vaccine," said Jennifer S. Smith, Ph.D., research associate professor of epidemiology in the UNC Gillings School of Global Public Health and lead author of the study. "However, there is a vaccine to prevent specific types of HPV infection, and vaccinating young men before they become sexually active could potentially help prevent the spread of HIV."

The study was conducted between 2002 and 2006 in men aged 18 to 24 in Kisumu, a city in western Kenya. The main trial, conducted by University of Illinois at Chicago researcher Robert Bailey, Ph.D., and colleagues, aimed to determine the effectiveness of male circumcision in reducing the incidence of HIV infection. The 2,168 men who participated in the HPV part of the trial were - at the time of their first study visit - uncircumcised, did not have HIV and were sexually active. The men were tested for HPV infections at the start of the trial and over 24 months; most were followed for 42 months.

At the outset, researchers found that half of the men (1,089 out of 2,168) were infected with HPV on the skin of their penis. They speculated that since HPV can cause penile lesions and affect immune responses, it may enhance susceptibility to HIV infection. After 42 months, 5.8 percent of the men who were HPV positive at the beginning of the trial were HIV positive, compared to 3.7 percent of the men who did not have HPV.

"Even when we controlled for circumcision status, herpes and other sexual and sociodemographic risk factors, men infected with HPV at the first study visit were at greater risk for HIV infection than men without HPV," Smith said. "If our findings are confirmed in other studies, then HPV prevention could become an effective tool for HIV prevention."

Carcinogenic types of HPV are the leading cause of cervical cancer, both globally and in the United States. HPV vaccination is routinely recommended for females aged 11 to 12, by agencies including the U.S. Advisory Committee on Immunization Practices, the Centers for Disease Control, and Prevention and the National Cancer Institute. Cervical cancer screening is still necessary for women following vaccination.

HPV infects both young females and males. The quadrivalent HPV vaccine is also approved in the U.S. for young men. HPV can cause other diseases, including genital warts and other cancers.

SOURCE Journal of Infectious Diseases