Shortly after the World Health Organization announced the Zika virus an international public health emergency on Monday, a case of Zika virus infection transmitted by sex, as opposed to a mosquito bite, was confirmed in Texas on Tuesday. Today in Florida, Governor Rick Scott declared a public health emergency in four Florida counties due to a total of nine travel-associated Zika cases.

The Centers for Disease Control and Prevention has since confirmed the case in Dallas, according to The New York Times. Health officials there say the person infected during sex had not left the United States, and there was no documented transmission of the virus by mosquitos in the city. The case involved a patient who had had sex with an infected traveler who recently returned from Venezuela.

“America's hospitals are working closely with their local public health officials and with the CDC. Important steps are being taken now by public health agencies to identify and share effective strategies for reducing the likelihood that the virus will spread to the United States and to prepare hospitals to correctly diagnose and treat any who may have become infected,” said John Combes, M.D., chief medical officer of the American Hospital Association, in a statement.

“Hospitals will continue to partner with public health officials to spread the word about the dangers of this virus and to share strategies individuals, particularly pregnant women, can use to avoid becoming infected.”

Parkland Health & Hospital System announced that it had assembled multidisciplinary teams comprising specialists in infectious diseases, infection prevention, pathology, obstetrics, pediatrics, nursing, patient safety and risk, and offered reassurance that the risk of infection in this country is currently low. “There is no concern for Zika virus in individuals who have not traveled to, or in those who have not had sexual contact with an individual who has traveled to a Zika virus-affected country,” said Pranavi Sreeramoju, M.D., Parkland’s chief of infection prevention and associate professor in medicine–infectious diseases at the University of Texas Southwestern Medical Center, in a news release.

The CDC said that it will provide guidance on sexual transmission soon, telling Medscape Medical News that “sexual partners can protect themselves by using condoms to prevent spreading sexually transmitted infections.”

However, it is important to note that the majority of transmission involves a bite from a mosquito, but sexual transmission adds a new challenge for detecting and preventing Zika from spreading.