KELLY MCEVERS, HOST:
The Zika virus has not yet shown up in the Florida Keys, but the islands are on high alert against the particular mosquito that carries the disease. The area continually conducts an all-out war against mosquitoes. Right now, there's a proposed trial to use genetically modified mosquitoes in that war, and residents have a lot of concerns about it. From member station WLRN, Nancy Klingener reports.
NANCY KLINGENER, BYLINE: Billy Ryan visits Roy's Trailer Park on Stock Island every two months. It's part of his regular rounds as an inspector for the Florida Keys Mosquito Control District.
BILLY RYAN: Hey, I'm just checking on the yards for the mosquito control.
MARIE BAPTISTE: OK.
RYAN: OK? All right.
KLINGENER: People who live in the Keys, like Marie Baptiste, are used to seeing mosquito control inspectors in their yards. Since an outbreak of dengue fever in 2009, they've conducted house to house inspections in areas where the Aedes aegypti mosquito breeds. In the narrow side yard next to Baptiste's trailer, Ryan finds a plastic barrel with a couple of inches of water at the bottom. And he spots some mosquito larvae bouncing around, so he takes a sample.
RYAN: Here it is. This is a ideal breeding grounds for Aedes aegyptis.
KLINGENER: The mosquito inspector's tools are pretty simple. He's got a turkey baster, a dipper, which is a stick with a cup at end, and a plastic jar to collect samples. Ryan also has pellets of larvicide to treat areas where the mosquitoes breed. Ryan shows Baptiste what he found.
RYAN: You see the water?
RYAN: You see the larva?
RYAN: So I'm going to just flip this over, OK?
RYAN: If you ever see anything, like, holding water like this or any little buckets or anything, please turn them over because we don't want to get Zika or chikungunya or dengue fever, OK?
KLINGENER: This level of attention has been effective in the Keys. The last reported case of dengue was six years ago, but the Keys are considering a new, cutting-edge approach. The British company Oxitec wants to hold its first U.S. trial of genetically modified mosquitoes in Key Haven, not far from here.
The plan is to release about 3 million mosquitoes. According to Oxitec, in trials in other countries, that's reduced the population of Aedes aegypti by up to 90 percent. The U.S. Food and Drug Administration has tentatively said the tests should be safe. Oxitec's mosquitoes are bred with a gene that causes the offspring to die. The company releases mostly males, but Oxitec's Derek Nimmo acknowledges the sorting process isn't imperfect. About one in 10,000 of the released mosquitoes will be female. Only females bite.
DEREK NIMMO: Those females are still sterile, so their offspring inherit the gene and they will not survive. So there's no effect on survival or in the environment.
KLINGENER: At a mosquito control board meeting in the Keys this week, residents had lots of questions and concerns. Assurances from Oxitec were not enough to persuade resident Michael Kane that the test is safe. He's worried.
MICHAEL KANE: If they release the female mosquitoes and they live and they breed, those females are going to be biting us because they are going to adapt. All you're doing is making a super mosquito - genetically modified super mosquito. Nature always adapts. No matter how much you think you tweaked it, something else is going to happen. There's going to be unintended consequences.
KLINGENER: After all the questions, the mosquito control board decide this week to allow residents in Key Haven to vote in August whether to go forward with the Oxitec trial. For NPR News, I'm Nancy Klingener in Key West, Fla.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.