Authorities in Dallas County, Tex. said they have confirmed the first case of the mosquito-borne Zika virus being acquired via sexual contact.

In a statement, the Dallas County Health and Human Services department said the patient was infected with the virus after having sexual contact with someone who visited a country where the virus is present.

Officials in Dallas said they were contacted by the Centers for Disease Control and Prevention, who said this was the first known case of someone being infected by the virus in the U.S.

Other cases in the country have all involved people who recently returned from Zika-affected regions.

“CDC has confirmed through laboratory testing the first U.S. case of Zika virus infection in a non-traveler in the continental United States,” the agency said in the statement.

Read more at The Washington Post,