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Genetically modified killer mosquitoes may attack Florida Keys — to target other killer mosquitoes

A genetically modified Aedes aegypti mosquito. (AP Photo/Oxitec, Derric Nimmo)

The Florida Keys are a sun-kissed land of endless spring breaks and girls and guys gone wild — a lazy Margaritaville where Ernest Hemingway’s six-toed cats lounge in the sun.

Thanks to climate change and globalization, the Keys are also increasingly home to killer tropical diseases such as dengue fever and chikungunya spread by Aedes aegypti, a tiger-striped mosquito that originated in Africa. Just last year, a few dozen people in the Sunshine State were infected with these formerly exotic illnesses as they made their way up the Gulf Coast.

“The threat is greater than I’ve seen in my lifetime,” Walter Tabachnick, director of the Florida Medical Entomological Laboratory, said last year. “Sooner or later, our mosquitoes will pick it up and transmit it to us. That is the imminent threat.”

The solution? A private company has geneticially modified the Aedes aegypti, creating a mosquito that fights for the good guys and, pending Food and Drug Administration approval, will be unleashed in the Keys ASAP.

“This is essentially using a mosquito as a drug to cure disease,” Michael Doyle, executive director of the Florida Keys Mosquito Control District, told the Associated Press.

Dengue and chikungunya — also charmingly called “break-bone” fever — are no joke. About 50 million people contract dengue each year — more than 2 percent die. Chikungunya is less widespread, but has already done damage in the Caribbean after afflicting 1 million people there in 2014.

The Aedes aegypti, meanwhile, is a formidable foe. Though Florida is routinely soaked with insecticide, these mosquitoes have developed resistance to more than half of the chemicals designed to kill them.

But where virologists saw disaster, a British pest control company called Oxitec saw opportunity. The company patented a method for modifying Aedes aegypti with an unappetizing stew of herpes simplex virus and E. coli bacteria as well as genes from coral and cabbage.

The Frankenstein mosquitoes Oxitec created don’t moan or accidentally drown little girls in ponds. But when they breed with good old fashioned mosquitoes, the resulting larvae die. Release enough into the wild and voila: Aedes aegypti is toast.

“Using advanced genetics Oxitec breeds and releases ‘sterile’ males of the damage-causing species,” the company’s Web site reads. “This highly targeted form of biological control is safe to other species, causes no lasting impact on the environment and is cost-effective.”

The company said only genetically modified males would be released — not females, who bite. But even if someone somehow was bitten by a modified Aedes aegypti, it wouldn’t matter. No genetically modified DNA would enter the bloodstream, the company said.

Moreover, Oxitec has done this before. In 2012, the company released 3.3 million modified mosquitoes in the Cayman Islands. The impressive result: 96 percent of targeted mosquitoes eradicated.

But reasonable arguments and successful precedent aside, does anyone want millions of genetically modified mosquitoes swarming around Florida?

“What Oxitec is trying to spin is that it’s highly improbable that there will be negative consequences of this foreign DNA entering someone that’s bitten by an Oxitec mosquito,” Phil Lounibos, who studies mosquito control at the Florida Medical Entomology Laboratory, told the AP. “I’m on their side, in that consequences are highly unlikely. But to say that there’s no genetically modified DNA that might get into a human, that’s kind of a gray matter.”

It’s not so much that the project is bad, Lounibos said. It just sounds bad.

“It’s not even so much about the science — you can’t go ahead with something like this if public opinion is negative,” he said.

The company’s first target: Key Haven, a neighborhood of more than 400 homes “closely clustered on a relatively isolated peninsula at the north end of Key West,” as the AP put it. Residents have also responded positively in polling about the test.

But one resident told the AP that, since dengue and chikungunya have not been seen in Key Haven, there’s little point to the experiment.

“If I knew that this was a real risk and lives could be saved, that would make sense,” Marilyn Smith said. “But there are no problems. Why are we trying to fix it? Why are we being used as the experiment, the guinea pigs, just to see what happens?”

Oxitec stands by its mosquitoes.

“We are confident of the safety of our mosquito, as there’s no mechanism for any adverse effect on human health,” company spokesman Chris Creese said. “The proteins are non-toxic and non-allergenic.”

Meanwhile, the FDA told the AP that said no field tests will be allowed until the agency has “thoroughly reviewed all the necessary information.”