A U.S. health official warned Monday it's possible the Zika virus could spread to other Gulf states because of the area's semi-tropical weather and the difficultly in controlling the mosquito population.
And that means areas in Louisiana already hard hit by flooding need to be vigilant about taking measures to fight off mosquitoes, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said in an interview with CNBC's "Closing Bell."
"Whenever you have a flood, it isn't during a flood that the mosquitoes flourish. You tend to get rid of them during the flood. It's when the flood recedes and you have standing water that you have a lot of mosquito activity, because that's where they lay their eggs," he said.
There are about 2,000 people in the United States who have been diagnosed with Zika, with approximately 500 of those cases in Florida, Fauci said.
Of the cases in the state, 36 are locally transmitted. Florida also now has two clusters of the mosquito-borne illness, including in Miami Beach.
"I would not be surprised at all if we saw individual cases and perhaps even some clusters arise in other areas of Florida as well as in other of the Gulf Coast states," Fauci said. "There certainly is that possibility. That would not surprise us because the conditions are there for that to happen."
The disease has spread rapidly through the Americas since it was first detected in Brazil last year. It can cause the rare birth defect microcephaly, marked by abnormally small heads and developmental problems.
Fauci said the locally transmitted cases occur when a mosquito bites someone who has a travel-related case and then bites someone who never left the country.
"Mosquito control is the most important thing to do to prevent outbreaks of Zika," said Fauci.
— Reuters contributed to this report.