BY JOHN L. GUERRA
Konk Life Staff Writer
Michael Doyle watched a scientist spray mosquitoes flying around the inside of a clear container and waited for them to die.
They didn’t, and that’s the problem.
“All of our chemicals are ineffective against Aedes egypti,” said Doyle, referring to the indestructible — or at least tough to kill — mosquitoes in the Keys that can carry dengue and yellow fever.
As executive director of the mosquito control district, it’s his job to create a battle plan to prevent Chikungunya (pronunciation: \chik-en-gun-ye) from spreading in Monroe County. The new mosquito-borne disease threat resembles dengue, which already checked in to Key West lodgings about two years ago.
Like dengue, chik (for ease of pronunciation) is transmitted to people when a mosquito carrying the virus bites another human. The most common symptoms, according to the Centers for Disease Control and Prevention in Atlanta, are fever and joint pain. Other symptoms may include headache, muscle pain, joint swelling or rash. Outbreaks have occurred in Africa, Asia, Europe and the Indian and Pacific Oceans. In late 2013, it hit the Caribbean.
“We’re watching it pretty closely,” Doyle said. “In December there was one case in the Caribbean, but it took off like wildfire and now 190,000 people in the Caribbean have it.”
And just after the New Year, it arrived in Florida.
“There are about 80 cases in the United States, including in half the counties in Florida,” Doyle said.
Doyle, the scientists, and the engineers of the Mosquito Control District are preparing for the arrival of chik in several ways. The first task is to come up with the combination of chemicals and spray consistency that will kill the carriers. The mosquitoes are in the Keys, chik so far is not.
“We use plant-based chemicals, such as pyrethrins and pyrethroids, which are made from the oil from a chrysanthemum flower,” Doyle said. “We found out through spraying during the dengue arrival that out local egyptii is resistant to almost all those. We have to be careful which chemicals we use, otherwise it’s like spraying them with water.”
The engineers are working on new spray equipment, including older techniques such as bringing back truck-mounted sprayers. The size of the drops in the older system may make a difference, creating better coverage and more effective penetration, he said.
Even the U.S. Navy is getting involved in the fight with Mosquito Control; the service uses the hand-held system in South America and has agreed to introduce the district to the devices up here.
“About 20 years ago, you could put out larger drops, it didn’t make a large cloud, but it was just as effective,” Doyle said. “We’re also looking into using hand-held thermal foggers, to hit areas the truck-mounted sprayers cannot reach. Most of the egypti hide under houses and under sheds, places like that, and using the thermal fogger we’ll be able to put fog underneath buildings and it will hang for quite a while.”
Other allies in the fight: Restaurant owners, hotel managers, “a whole variety of people to make sure we spray around their areas,” Doyle said.
Including the public. When the wastewater management folks visit homes, they put a sticker on the doors asking homeowners to walk their yards to pick up anything that might hold water, including bottle caps, upended bicycles, paper cups, “even a crunched up Fritos bag, which can hold tiny pockets of water,” Doyle said. “That’s enough for mosquitoes to raise a family.
The Mosquito District spent $900,000 to increase its spraying and other efforts in 2010 after tests showed that some Key West residents showed exposure to dengue, Doyle said.
“That was in addition to our budget,” he said.
“There was a lot of overtime. We bought more chemicals — those are the two main things we’re spending money on now,” he said. “Helicopter spraying was stepped up; the aircraft cost $700 an hour to run. But we have about a year and a half of reserves left until the next budget cycle.”
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