NEW YORK CITY — Three New Yorkers have contracted the Zika virus through sex — including the first known case in the world of a woman giving the virus to a man, officials said.
The city's Health Department recorded three known cases of sexually-transmitted Zika cases, including one man who caught it from his female partner who had just returned from abroad, according to the city Health Department and the Centers for Disease Control.
Officials say the man, who hadn't left the country for the past year, started to display Zika symptoms a week after having unprotected sex with a 20-year-old woman the day she returned from traveling to a country known to be a hotspot for the virus.
"This is an important development that highlights the fact that we continue to learn more about how this virus behaves," Dr. Oxiris Barbot, the city Health Department's first deputy commissioner, told reporters Friday.
The woman — who officials did not identify, but said was not pregnant — was experiencing Zika symptoms in the airport on the way home, including stomach cramps, and went on to develop other symptoms including headache and chills, CDC officials said.
Seven days later, her partner came down with similar symptoms, officials said. The city's Department of Health tested his blood and confirmed he had contracted Zika.
He told officials he had not had sex with anyone else, had not left the country in the year leading up to the infection, and had not been bitten by any mosquitos.
The case — which was diagnosed within in the last month, officials said — included several factors that made female-male-transmission more likely to occur, according to Dr. Jay Varma, deputy commissioner of the division of disease control for the DOH.
This includes the fact that the woman and her partner had sex while she was in the very early stages of the infection, when virus levels are high. she also had her menstrual period, and exposure to small amounts of blood "could have played a role" as well, Varma said.
Officials previously knew that the virus could be transmitted through sex from an infected man to an uninfected woman.
Officials did not say what country the woman had been traveling in.
But according to DOH statistics online, the most commonly-traveled countries associated with infection in NYC have been the Dominican Republic, which is connected to 190 reported infections, followed by Puerto Rico, Jamaica, Guyana and Colombia, all of which were linked to two dozen or less reported infections each.
There have been 127 reported cases of Zika in the Bronx, 66 in Manhattan, 58 in Queens, 57 in Brooklyn and 1 in Staten Island, DOH stats show. The Health Department has tested about 5,000 New Yorkers so far.
The news came as city officials revealed the number of those infected by Zika had increased to 309 people — all of whom were initially described on the Health Department's website Thursday as "All cases contracted Zika while visiting other countries."
The DOH revised their website Friday to list the number of people who had contracted the virus via sex, which they listed under "Travel Associated" with an asterisk, explaining the category includes "Travelers returning from affected areas, their sexual contacts, or infants infected in utero."
The two other cases of sexual transmission took place in June, officials said.
Health officials updated parts of their prevention protocol in the wake of this new case, now recommending that people use "barrier protection" during sex — they had previously used the word "condoms" — in order to expand to definition to include male condoms, female condoms and dental dams.
Women returning from affected regions are also now being told to use protection during sex for at least eight weeks after coming home, the same advice given to men.
Though there have been no documented cases of a woman transmitting the virus to another woman, Varma said it's "certainly possible."
Officials stressed that the number of sexually transmitted Zika infections are still small — three out of 309 cases in the city — and that the majority of people who contract the virus get it from a mosquito abroad.
There have been no reported cases of individuals contracting Zika from mosquitos in NYC, according to the DOH.
The CDC has encouraged those looking to protect themselves from Zika to use bug spray and avoid known areas with a Zika outbreak, particularly if they are pregnant or their health is compromised. They also recommend that those concerned about catching Zika only have protected sex.
"If you're a pregnant woman, don't travel [to Zika regions]," Barbot said. "If you're anybody else, take smart precautions."CORRECTION: An earlier version of this story incorrectly identified Jay Varma. He is a deputy commissioner at the city's Department of Health.