A new international study finds that half of adult males in the United States and elsewhere may be infected with human papillomavirus (HPV), a sexually transmissible virus linked to cervical cancer and other tumors.
The finding could help public health experts determine the value of widespread HPV vaccination of males, the study authors say.
The study, which was funded by the U.S. National Cancer Institute and published in the March 1 online edition of The Lancet, also found that having multiple female or male sex partners greatly increased a man's risk of HPV infection and that, each year, about 6 percent of men are newly infected with HPV16, the virus that causes cervical cancer in women and also causes cancers in men.
In 2009, about 32,000 cases of cancers in American women and men were attributable to HPV infection, according to background information in the study. These included cancers of the cervix, vagina, vulva, penis, oral cavity, anal canal, and head and neck.
In recent years, HPV vaccination in teen girls and young women has become widespread. But HPV vaccination remains uncommon in males, even though HPV is easily transmitted from men to women and greatly affects women's risk of disease.
The cost-benefit ratio of vaccinating men against HPV in order to protect women has not been definitively established, Dr. Joseph Monsonego, of the Institute of the Cervix in Paris, France, noted in an editorial accompanying the study.