2017-04-06 17:14:02
Close to Half of American Adults Infected With Genital HPV, Study Finds

More than 42 percent of Americans between the ages of 18 and 59 are infected with genital human papillomavirus, according to the first survey to look at the prevalence of the virus in the adult population.

The report, published on Thursday by the National Center for Health Statistics, found that high-risk strains of the virus — a cause of cervical and vaginal cancers, and cancer of the penis, as well as cancers of the anus and throat in both sexes — infect 25.1 percent of men and 20.4 percent of women.

The virus is transmitted by skin to skin contact; people who are infected may pass the virus to sexual partners.

“One of the most striking things that we really want people to know is that high-risk HPV is common — common in the general population — these are not people who are marginalized,” said the lead author, Geraldine McQuillan, an epidemiologist at the Centers for Disease Control and Prevention and the lead author of the new report.

She and her colleagues also found that 7.3 percent of Americans aged 18 to 69 are infected with oral HPV, and 4 percent are infected with the high-risk strains that can cause cancers of the mouth and pharynx.

There are more than a hundred strains of this virus, and 40 of them are sexually transmitted. The body usually manages to rid itself of HPV, but for unclear reasons the infection can become chronic in certain individuals.

Many of the sexually transmitted strains do not cause serious health problems, but HPV-16 and -18 are the cause of almost all cervical cancers. Even low-risk strains cause warts, including genital warts.

Two vaccines are effective in preventing sexually transmitted HPV infection, and the researchers stressed that they should be used far more often.

“If we can get 11- and 12-year-olds to get the vaccine, we’ll make some progress,” Dr. McQuillan said. “You need to give it before kids become sexually active, before they get infected. By the time they’re in their mid-twenties, people are infected and it’s too late. This is a vaccine against cancer — that’s the message.”

There are significant differences in rates of high-risk genital HPV infection by race and ethnicity.

The highest rate, 33.7 percent, was found among non-Hispanic blacks; the lowest, 11.9 percent, among Asians. The prevalence of genital HPV infection is 21.6 percent among whites and 21.7 percent among Hispanics.

Men generally have somewhat higher rates than women, but among Asian and Hispanic men, the infections are not significantly more common. The reasons for these variations are not known.