five of the thermoplastic vibrators and four of the silicone ones.
The silicone vibrators responded better to the cleaning after 24 hours. The researchers did not detect the virus on any of the silicone vibrators a day after cleaning, but they did find HPV on two of the thermoplastic sex toys.
The difference could be related to the porosity of the material, Anderson said.
She noted that the presence of HPV DNA does not necessarily indicate the presence of an infection. Additional studies would be necessary to determine whether an infection could be transmitted through sex toys, she said.
Cleaning vibrators may reduce the frequency of HPV transmission, the authors write. They call for more research on sex-toy materials, design and cleaning methods to most effectively reduce the virus' spread.
Once hidden in X-rated novelty shops, sex toys now line the shelves of major stores. Women also buy the devices at parties formerly reserved for kitchen products.
"I agree with the author that we need to study and identify safe and effective ways to clean sex toys," Dr. Jeffrey Klausner told Reuters Health. He is an infectious disease specialist at the University of California, Los Angeles and was not involved in the current study.
"When people are intimate, they're going to share viruses and germs. The good thing is that HPV is vaccine-preventable. The bad thing is the vaccination rates are very low," Klausner said.
"It probably would make sense for people not to share their sex toys," he said. But he added, "I'm not sure how practical it is during sex to start washing your toys."
Dr. Vitaly Smelov, from the Karolinska Institute in Stockholm, Sweden, told Reuters Health in an email that doctors should advise patients to clean their sex toys, particularly those shared between both same-sex and heterosexual partners.
In prior studies, more than half of women between 18 and 60 years old reported using a vibrator, and more than 65 percent of bisexual women reported partnered sex toy use, the current study's authors write in Sexually Transmitted Infections.
The medical community once thought that women who have sex with women were at low risk for HPV. But studies have since shown HPV infections are common among these women.
Research also suggests some women who have sex with women, particularly adolescents and young women as well as women who have sex with both women and men, may be at increased risk for sexually transmitted infections.