The Centers for Disease Control and Infection reported the first confirmed case of Zika transmitted from a woman to a man during sex. Previously, they thought that the disease was only likely to be sexually-transmitted from a male to female or male to male. The CDC will soon update their advisory "for sexually active people in which the couple is not pregnant or concerned about pregnancy and for people who want to reduce personal risk of Zika infection through sex." From CNN:
A non-pregnant woman in her 20s had unprotected vaginal sex with a male partner on the day she returned from travel to a country where Zika is circulating. The next day, she came down with Zika-like symptoms, including fever, rash, fatigue and muscle pain, along with numbness and tingling in her fingers and toes. On day three, she visited her primary care doctor, who took blood and urine samples, and sent them off to the NYC health department. Both tested positive for the virus.
On day seven after intercourse, her male partner, also in his 20s, began to show the same typical signs of Zika, such as fever, rash, joint pain and red eyes, despite the fact that he had not traveled outside the United States for more than a year…
While this is the first documented case of female to male sexual transmission, it's not the first clue that the Zika virus might be hiding in the female genital tract. A case report published this week in The Lancet Infectious Diseases journal tells the story of a 27-year old Guadeloupean woman who came down with Zika in May. Even though Zika was absent from her blood and urine 11 days after she fell ill, her cervical mucus still tested positive for the virus. And recently, a study on rhesus monkeys showed that the virus remained in the vaginal fluid of three non-pregnant females.