Florida health officials declined to confirm reports Thursday that Zika has spread locally in Miami Beach, south Florida's thriving tourist and entertainment district.
The Miami Herald quoted sources as saying at least two cases not linked to travel had been traced to Miami Beach, which would make for a second center in Florida for the spread of the virus.
The state health department issued a statement late Thursday.
"By now you may have seen the various news reports regarding the Zika virus linked to Miami Beach. It is important to note that at this time the Department of Health has NOT confirmed any cases on Miami Beach, however we have been informed that cases are being investigated," it said.
Zika's confirmed to have infected 35 people locally in Florida, state health officials say - most of the cases in an area north of Miami called Wynwood.
Local cases were fully expected in Florida, which is home to the Aedes aegypti mosquitoes that spread Zika and also hosts many travelers to and from Zika-affected regions in Latin America.
Local outbreaks are caused when someone infected with Zika is bitten by a mosquito, which goes on to infect others. Only Aedes species of mosquitoes are known to spread Zika.
"Please feel confident in knowing that the city has been proactively focused on the elimination of potential breeding sites for months, and we are aggressively continuing these efforts. We are also working with Miami-Dade County as they are inspecting, and as needed, mitigating through techniques like clean ups, larvicides and targeted spraying," the Department of Health said.
Florida officials are keenly sensitive to the effect Zika outbreaks could have on tourism there. Most Zika information is being approved by Gov. Rick Scott's office before it's disseminated.
"While we still believe local transmissions are only occurring in an area that is less than one square mile in Wynwood, our state is committed to remaining vigilant in our Zika prevention, education and response efforts," Scott said in a statement released Thursday.
"Tourism is a driving force of Florida's economy and this industry has the full support of our state in the fight against the Zika virus," Scott added.
"Additionally, our Department of Economic Opportunity is working with businesses that may have been impacted to ensure they have everything they need to remain successful."
Florida reports 479 cases of Zika in people who traveled to other affected areas or who were infected by people who had traveled. Zika is spread by mosquitoes, but it can also be spread sexually.
The biggest danger is to pregnant women. Developing fetuses infected by Zika can suffer severe brain damage, and there's no known way to prevent it. Florida has had 63 pregnant women infected with Zika.
Zika's also known to cause Guillain-Barre syndrome, a rare paralyzing illness.
The Centers for Disease Control and Prevention is helping Florida investigate the outbreak, but it must defer to the state when it comes to giving out information.