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Florida's governor has declared a public health emergency in five counties because of the Zika virus. Florida is one of several states where health authorities have found the mosquito-borne disease. All of the cases are in travelers who contracted the disease overseas, but NPR's Greg Allen reports health authorities say it's likely just a matter of time until Zika begins to show up in mosquitoes in Florida.
GREG ALLEN, BYLINE: Just 12 cases of Zika have been reported to health authorities in Florida, but Gov. Rick Scott says that's enough to declare a public health emergency.
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RICK SCOTT: We have to ensure that Florida is safe. Just like in a hurricane, what we always say to ourselves is, we're going to prepare for the worst and hope for the best. And we're going to do everything we can to stay ahead of the Zika virus.
ALLEN: Scott is asking the CDC to provide Florida at least 1,000 antibody test kits so it can check people who traveled abroad and had symptoms of Zika, especially pregnant women. So far, the Zika cases in Miami-Dade and four other counties are all when people recently returned from travel overseas, from Haiti, Venezuela, Colombia and El Salvador. With its mild climate, Florida is susceptible to mosquito-borne diseases. There have been sporadic outbreaks of dengue and chikungunya, other tropical diseases carried by a mosquito prevalent in Florida, the Aedes aegypti. That's a mosquito that also transmits Zika.
AMY VITTOR: I would like to bet money on the fact that we will see locally acquired cases.
ALLEN: Amy Vittor is an assistant professor who studies tropical diseases at the University of Florida. Vittor says Florida is unlikely to see the scale of the Zika outbreaks now sweeping through the Caribbean and Latin America in part because Sunshine State residents have far less exposure to the mosquitoes.
VITTOR: We get in from our air-conditioned house into our air-conditioned car in the garage and then drive to our air-conditioned office and then right back home.
ALLEN: Contrast that, she says, to someone who lives in a dense urban setting without air-conditioning or window screens, waste management or water sanitation.
VITTOR: You have a very different exposure risk.
ALLEN: Only about a fifth of the people with Zika ever display symptoms, and as tropical diseases go, those syndromes are relatively mild - a fever, rash, headaches, joint pain. But because it's been linked with microcephaly and other birth defects, Zika is especially worrisome. Those concerns may have played a role in Gov. Scott's decision to declare a public health emergency, something not done when Key West had nearly 90 cases of dengue fever in 2009 and 2010. Key West is the southernmost city in the continental U.S., a small, densely populated place in the subtropics. Beth Ranson is with the Florida Keys Mosquito Control District.
BETH RANSON: We are the perfect climate for aegypti mosquitoes and any mosquitoes. We are hot, and we are human.
ALLEN: Ranson says, so far, her agency isn't doing anything special to prepare for Zika, but on the other hand, day-to-day mosquito control in the Keys is pretty intense with a fleet of planes and helicopters and a couple dozen inspectors ferreting out the places mosquitoes breed. Even with that, the Keys Mosquito Control District is only able to eradicate about half of the Aedes aegypti. Ranson says that's why the district is looking at a new technology, one using genetically modified mosquitoes.
A British company, Oxitec, has developed genetically-modified aegypti mosquitoes that when they mate produce offspring that don't live to adulthood. Derek Nimmo, who's with Oxitec, says in trials in Brazil and other countries, the company has shown it can reduce the Aedes aegypti population by 90 percent.
DEREK NIMMO: Now, of course, Zika has gained prominence in the past few months with this link to microcephaly, and so there has been a much greater impetus in Brazil to look at how they can control this mosquito.
ALLEN: Oxitec is now waiting for the FDA to approve a trial release of the GMO mosquitoes in the Florida Keys. Oxitec is expanding trials in Brazil and hopes soon to receive permission there to begin marketing its GMO mosquitoes commercially. Greg Allen, NPR News, Miami. Transcript provided by NPR, Copyright NPR.