Men with penile
human papillomavirus (HPV) infection have an increased risk of acquiring HIV, investigators report in
the online edition of AIDS. This
increase in risk was irrespective of circumcision status.
indicate that HPV infection is an important risk factor for HIV acquisition in
men that needs to be explored further and accounted for in HIV-prevention
studies,” comment the authors.
It has already
been shown that cervical HPV is associated with increased HIV
risk for women. Investigators wished to see if penile HPV infection similarly
increased the risk of HIV acquisition for men, and if this risk was modified by
circumcision status. They therefore designed a prospective cohort study
involving approximately 2500 men in Kisumu, Kenya, who were enrolled in the
randomised-controlled trial designed to evaluate the impact of circumcision
status on HIV risk.
All the men were
HIV negative at baseline and aged between 19 and 24 years. Every six months, the study participants had penile swabs to check for HPV infection and they were also
screened for HIV.
Over a median of
30 months of follow-up, 61 men (2.4%) acquired HIV. Men
randomised to be circumcised were significantly less likely to acquire HIV than men who remained uncircumcised.
Penile HPV infection
was present in 61% of the men who seroconverted for HIV and 46% were infected
with HPV types associated with a high risk of ano-genital cancers.
The authors’ first
analysis showed that men infected with any HPV type had over twice the risk of
acquiring HIV compared to HPV-uninfected men (HR = 2.55; 95% CI, 1.51-4.32). Men
infected with high-risk HPV types (HR = 2.74; 95% CI, 1.66-4.79) were also over
twice as likely to become infected with HIV compared to men who were
status did not significantly alter these findings.
for potential confounders, there was an association just short of significance
between penile infection with any HPV type (aHR = 1.72; 95% CI, 0.94-3.15) and
penile infection with high-risk HPV types (aHR = 1.92; 95% CI, 0.96-3.87) and
acquisition of HIV.
The more HPV types
detected on the penis of an individual, the higher his risk of acquiring HIV.
Each additional type increased the risk of HIV acquisition by over a quarter
(aHR = 1.27; 95% CI, 1.09-1.48). Men with three or more HPV types had over
three times the HIV risk compared to HPV-uninfected individuals.
Men infected with HPV
types 16/18 only (both of which are covered by two licensed HPV vaccines) had
the highest risk of acquiring HIV. However, the authors were unsure if this
finding was of significance to HPV vaccination strategies. They explain: “Men
with only HPV-16/18 were twice as likely to acquire HIV infection compared to
men who were HIV-negative. But these men represent a minority of our
population. Most HIV seroconverters had only non-16/18 genotype infections or
had HPV-16/18 in addition to other HPV types.”
An increased risk
of HIV was observed in men who had cleared all HPV infections, had persistent
HPV infections, or who had both cleared and persistent infections.
“Incidence of HIV
was highest among men with persistent and/or recently cleared HPV infections,”
conclude the authors. “We found no clear evidence that circumcision modifies
the association between penile HPV infection and the risk of HIV acquisition.”