HPV infection heightens HIV risk in men

The human papillomavirus (HPV) vaccine could be a useful tool in HIV prevention, according to a study, which found that Kenyan men infected with HPV were more likely than uninfected men to contract the HI virus.



"Within [the study] population of young men at a high risk for HIV acquisition in Kenya, HPV infection was very common, so preventing HPV infection could potentially be another tool for HIV prevention," the authors said.



HPV is a common sexually transmitted infection (STI) that can cause genital warts; some types of HPV can also cause cervical cancer.



Published in the 1 June edition of the Journal of Infectious Diseases, researchers found that of 2,168 uncircumcised men aged between 18 and 24, nearly half were infected with HPV at the start of the study. Over the next 42 months, 5.8 percent of those men contracted HIV, compared with 3.7 percent of the HPV-negative men.



The study was part of a wider clinical trial conducted between February 2002 and December 2006 in Kisumu, western Kenya, which showed that male circumcision significantly reduced the risk of HIV acquisition.



A 2009 study of men who have sex with men in the United States also found that anal HPV infection raised the risk of HIV infection.



According to Kawango Agot, of the Universities of Nairobi, Illinois, and Manitoba (UNIM) Project in Kisumu, HPV prevention could have wide-reaching benefits.



"The use of both male circumcision and HPV vaccination would further lower men's risk of contracting HIV," she said.



This was substantiated by a finding that among uncircumcised men infected with HPV, the estimated incidence of HIV infection was 3.9 percent over a two-year period, against 0.8 percent among circumcised men without HPV.



Agot noted that while the country's male circumcision rollout had been very successful among younger men, the programme had struggled to persuade older men in stable relationships to undergo the procedure. This was despite the fact that most HIV infections in Kenya occur within stable relationships.



"Between 80 and 90 percent of people coming for male circumcision are under the age of 30," she said. "Even as we try to convince other age groups to volunteer for it, we must accept that not everyone will be willing to be circumcised - the HPV vaccine could help to lower such people's chances of contracting HIV."



Kenya's male circumcision programme has proved a useful tool in identifying and tackling STIs in men volunteering for the procedure. Research shows that STIs such as herpes, Chlamydia and gonorrhoea make people more susceptible to HIV infection.



"Vaccinating men against HPV would also mean they would not pass it on to women, reducing their female sexual partners' cervical cancer risk," Agot added.



Vaccination for HPV in Kenya remains very low, despite the fact that cervical cancer is the most frequent cancer among women in the country. The Kenya Pharmacy and Poisons Board approved the sale of an HPV vaccine in 2007, but its availability is extremely limited and it is still prohibitively expensive for most Kenyans.



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