Atlanta, February 5 (RHC)-- U.S. government health officials are warning that the spread of the Zika virus to the country could get worse, a day after the state of Florida declared a public health emergency over the virus.

The warning by the Atlanta-based U.S. Centers for Disease Control and Prevention (CDC) on Thursday came as the mosquito-borne virus has generated increasing concern in the United States.

Zika is spreading rapidly in the Americas, and has been linked to a spike in birth defects in thousands of babies in Brazil. "There's a huge amount of travel to countries that have mosquito-borne transmission from Zika virus," said Dr. Steve Redd, director of the CDC's Office of Public Preparedness and Prevention.

"I think we should expect that as travelers return they'll be tested, and there are going to be many states that have returning travelers that have the infection," Redd said.

The current Zika virus outbreak originated in Brazil in May of 2015. Since then, it has spread to more than 30 countries in Central and South America. The virus is spread primarily by mosquitoes. It appears to be most dangerous for pregnant women because it can cause birth defects.

Florida Governor Rick Scott declared a public health emergency over the Zika virus on Wedesday. Florida's warm climate and nearly year-round mosquito season makes it particularly vulnerable to spreading, although so far all of the state's cases were acquired abroad, officials said.

Georgia health officials confirmed on Wednesday the first Zika case in the state. On Tuesday, authorities in the U.S. state of Texas said a person in the city of Dallas had become infected with Zika after having sex with another person who had traveled in Venezuela.