Scientists Find Zika Might Be Transmitted by Oral Sex

It’s possible the Zika virus can be transmitted by oral sex, scientists said in a letter to the New England Journal of Medicine on Thursday.

In a case reported in France, a 24-year-old woman was infected with the virus after having sex with a 46-year-old man who had just returned to Paris from Rio de Janeiro, a hot zone for Zika, the New York Times reported. The pair had sex several times between Feb. 11 and Feb. 20, involving vaginal sex without ejaculation and oral sex with ejaculation. The woman became ill on Feb. 20, and both were tested on Feb. 23, the Times reported.

While the test results showed the man had high levels of the virus in his semen and urine, he had none in his blood or saliva. The woman, on the other hand, had the virus in her urine and saliva, but a vaginal swab tested negative.

Read more: 10 Zika Facts You Need to Know Now

Scientists had already confirmed cases of sexually transmitted Zika, leading the U.S. Centers For Disease Control and Prevention to release guidelines on prevention in February.

“I don’t think this changes anything, but it shows you how elaborate the number of avenues of possible transmission can be,” said Dr. William Schaffner, head of preventive medicine at Vanderbilt University Medical School, in an interview with the Times.