Circumcision not only protects against HIV in heterosexual men, but it also helps prevent two other sexually transmitted infections, a large new study found. Circumcised males reduced their risk of infection with HPV, or human papillomavirus, by 35 percent and herpes by 28 percent. However, researchers found circumcision had no effect on the transmission of syphilis.
Landmark studies from three African countries including Uganda previously found circumcision lowered men's chance of catching the AIDS virus by up to 60 percent. The new study stems from the Uganda research and looked at protection against three other STDs. The findings are reported in Thursday's New England Journal of Medicine.
"Evidence now strongly suggests that circumcision offers an important prevention opportunity and should be widely available," Drs. Matthew Golden and Judith Wasserheit of the University of Washington wrote in an accompanying editorial.
Worldwide, only about 30 percent of men are circumcised. The figure is higher in the United States, where about 79 percent of men are circumcised, according to surveys by the National Center for Health Statistics.
An international team of researchers who conducted the study said circumcision, the surgical removal of the foreskin from the penis, should be an accepted method to reduce sexually transmitted infections among heterosexuals.
"It must be emphasized that protection was only partial, and it is critical to promote the practice of safe sex," they wrote.
HPV can cause cervical cancer and genital warts. Herpes greatly increases the chances of infection with HIV.
The American Academy of Pediatrics previously said there was not enough evidence to recommend routine circumcision of infants. The doctor's group is reviewing its position based on recent studies. About 2,800 herpes cases in newborns occur in the U.S. every year transmitted from mothers to infants that can lead to disability or death.
The latest research involved 3,393 HIV-negative heterosexual adolescent boys and men from Uganda who were part of the original HIV study. About half were randomly selected to undergo circumcision right away while the rest had the procedure 2 years later. All had physical exams and were offered voluntary HIV counseling and condoms.
After two years, herpes infection was detected in 114 circumcised men compared with 153 uncircumcised men. HPV was detected in 42 circumcised men compared with 80 uncircumcised men. There was no significant difference between the two groups on rate of syphilis infections. The researchers considered condom use, number of sex partners and other factors to calculate the risk reductions.
Why circumcision may reduce the risk of infection is not entirely known. But researchers think cells in the foreskin of the penis may be susceptible to HPV and the herpes virus.
The study was funded by the National Institutes of Health and the Bill and Melissa Gates Foundation. It was conducted by the Rakai Health Sciences Program and Makerere University in Uganda, Johns Hopkins Bloomberg School of Public Health and a division of the National Institutes of Health.
The results were similar to two recent studies from South Africa that found circumcision reduced HPV and herpes by up to a third.
Researchers plan to study whether circumcision reduces the spread of HPV to female sex partners.