Shared sex toys between two women and between women and men could have traces of the human papillomavirus even after they’ve been cleaned. According to a study published in the journal Sexually Transmitted Infections, researchers from the Division of Infectious Diseases at the Indiana University School of Medicine found that women could be potentially putting their partners at risk.

"Sex toys used between partners within the same sexual encounter have the potential for transmitting HPV," Dr. Teresa Anderson said, Reuters Health reported. "Cleaning the sex toy has the potential to decrease the amount of HPV DNA we can detect and so can potentially decrease the risk of transmission."

HPV is one of the most commonly sexually transmitted diseases, approximately 79 million Americans are currently infected with the disease, and that number increases by 14 million each year. It can lead to a number of other diseases such as cancers of the cervix, vulva, vagina, anus, and penis. While there is no cure for HPV, the virus may sometimes clear on its own.

The study focused on women between the ages of 18 and 29 who had been in sexual relationships with both a man and a women in the prior year. They gave each woman a cleaning product, one vibrator made of thermoplastic elastomer, and another made out of soft silicone. The participants were asked to swab the vibrations after vaginal use, immediately after cleaning, and 24 hours later. Anderson pointed out that she was unaware if any of these women had already been vaccinated for the HPV virus.

The authors found that in 75 percent of vagina samples (9 out of 12), HPV was detected. In the nine vibrators from the HPV-positive women, 85 percent (8) of showed signs of the virus; after cleaning, 56 percent (5 of the 9) had traces of HPV. Two hours after cleaning the contaminated vibrators, 40 percent (2 out of the 5) of the swabs were still positive.

They also found that silicone vibrators had a lower detection rate 24 hours after cleaning.

The authors say that this information supports the potential for HPV transmission through the use of shared sex toys. This data also adds to the range of sexual behaviors associated with HPV transmission as well as the need for sex toy cleaning recommendations.