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Florida Keys: Sunshine, blue skies and genetically-modified mosquitoes?

This photo provided by Oxitec shows a genetically-modified <em>Aedes aegypti</em> mosquito in a U.K. lab. The Food and Drug Administration is deciding whether to approve experiments in Florida using the non-biting male mosquitoes in an effort to kill off other mosquitoes that can carry dengue and chikungunya. (Oxitec via AP)

If federal regulators sign off on the idea, millions of genetically-modified mosquitoes could soon be buzzing around the Florida Keys, mingling with the tourists who flock to the southernmost point in the United States.

The Associated Press reports that British researchers are awaiting approval from the Food and Drug Administration — and have been for some time — to begin experiments using lab-engineered mosquitoes to kill their natural counterparts carrying worrisome diseases such as dengue and chikungunya. Here's the outline of how it works, according to the AP:

Insecticides are sprayed year-round from helicopters and door-to-door in charming and crowded neighborhoods throughout the Keys. But because Aedes aegypti [mosquitoes] don't travel much and are repeatedly doused with the same chemicals, they have evolved to resist four of the six insecticides used to kill them.

Enter Oxitec, a British biotech firm launched by Oxford University researchers. They patented a method of breeding Aedes aegypti with fragments of proteins from the herpes simplex virus and E. coli bacteria as well as genes from coral and cabbage. This synthetic DNA has been used in thousands of experiments without harming lab animals, but it is fatal to the bugs, killing mosquito larvae before they can fly or bite.

Oxitec's lab workers manually remove modified females, aiming to release only males, which feed on nectar and don't bite for blood like females do. The modified males then mate with wild females whose offspring die, reducing the population.

Oxitec has built a breeding lab in Marathon and hopes to release its mosquitoes this spring in Key Haven, a neighborhood of 444 homes closely clustered on a relatively isolated peninsula at the north end of Key West."

It's not the first time scientists have tried the approach. Oxitec said it has conducted similar experiments in the Cayman Islands and in Brazil in recent years, and that both countries are considering larger-scale projects because the tests were effective in suppressing disease-carrying mosquitoes and reducing the overall mosquito population.

But plenty of skepticism remains. Never before have bugs with genetically-modified DNA been released so close to a U.S. neighborhood, or set loose in the wild in such numbers. Worries about the unknown consequences of such an action have led to protest against the Florida experiments, the AP notes:

Dengue and chikungunya are growing threats in the U.S., but some people are more frightened at the thought of being bitten by a genetically modified organism. More than 130,000 signed a petition against the experiment.

Even potential boosters say those responsible must do more to show that benefits outweigh the risks.

'"I think the science is fine, they definitely can kill mosquitoes, but the GMO issue still sticks as something of a thorny issue for the general public," said Phil Lounibos, who studies mosquito control at the Florida Medical Entomology Laboratory. "It's not even so much about the science — you can't go ahead with something like this if public opinion is negative."

The FDA, which is evaluating the project along with other agencies such as the Centers for Disease Control and Prevention and the Environmental Protection Agency, has said it will not allow field tests until it has reviewed any potential risks.

On the ground in Florida, officials from the local mosquito control district and from Oxitec have held public meetings in recent months to answer questions from wary residents. They have argued that the genetically-modified mosquitoes pose no significant threat to humans and could actually fight the risk of some deadly diseases. They also have said the approach could save money, given that the district spends a sizable chunk of its budget in a perpetual battle with the Aedes aegypti mosquitoes. But according to the AP account, some residents have remained unswayed:

Key Haven resident Marilyn Smith still wasn't persuaded. The Keys haven't experienced a dengue outbreak in years, and no chikungunya cases have been reported here, she said.

"If I knew that this was a real risk and lives could be saved, that would make sense,' 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?"