The Centers for Disease Prevention and Control is now urging condom use to prevent the spread of the Zika virus after health officials in Texas reported that a Dallas resident contracted the virus through sex.
Dallas County Health and Human Services officials told NBC5 that the patient got infected after having sex with an infected person who recently returned from a trip to Venezuela.
"A person who recently traveled to an area with Zika virus transmission returned to the United States and developed Zika-like symptoms. The person later tested positive for Zika, along with their sexual partner, who had not traveled to the area," a statement from the CDC said.
The once-obscure disease is now spreading in the Americas and has been linked to hundreds of cases of babies with brain damage in Brazil.
In a statement after an emergency meeting of health experts Monday, World Health Organization chief Dr. Margaret Chan declared a suspected causal link between the Zika virus and cases of Microcephaly, a disease that causes babies to be born with abnormally small brains, to be a "Public Health Emergency of International Concern."
"The experts agreed that a causal relationship between Zika infection during pregnancy and microcephaly is strongly suspected, though not yet scientifically proven. All agreed on the urgent need to coordinate international efforts to investigate and understand this relationship better," noted Chan.
"I am now declaring that the recent cluster of microcephaly cases and other neurological disorders reported in Brazil, following a similar cluster in French Polynesia in 2014, constitutes a Public Health Emergency of International Concern," she said.
"A coordinated international response is needed to improve surveillance, the detection of infections, congenital malformations, and neurological complications, to intensify the control of mosquito populations, and to expedite the development of diagnostic tests and vaccines to protect people at risk, especially during pregnancy," she added.
Dozens of other Zika cases have surfaced in the U.S., according to The Washington Post, but they have involved people who became infected with the mosquito-borne virus while traveling to Zika-affected countries.
"Now that we know Zika virus can be transmitted through sex, this increases our awareness campaign in educating the public about protecting themselves and others," Zachary Thompson, the DCHHS director, told the local NBC station. "Next to abstinence, condoms are the best prevention method against any sexually-transmitted infections."