Florida Keys plan killer insect attack on disease-carrying mosquitoes

6 months ago 33
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ORLANDO, June 18 (UPI) -- The Florida Keys is close to adding a new weapon to help control a mosquito-borne disease -- genetically modified mosquitoes that produce dead offspring.

Outbreaks of dengue fever in the Keys in recent years prompted local authorities to consider the genetically modified bugs because the Aedes aegypti mosquito, which spreads the disease and others, has shown resistance to pesticides.

At stake is the potential for a large public health crisis in the tourism-dominated region. A reduction in the amount of pesticide use would be a side benefit.

"Ultimately, the name of the game is public health," said Chad Huff, public information officer for the Florida Keys Mosquito Control District. "We have seen outbreaks of dengue fever. The last significant one was in 2010, but the effectiveness of the pesticides declines."

The new mosquitoes, engineered by British company Oxitec, were released in trials in Brazil. Studies by Oxitec and other scientists said the program resulted in significant population declines for the disease-carrying insect.

"We have shown that the release of mosquitoes in a neighborhood results in 95 percent suppression compared to areas with no release," said Nathan Rose, director of regulatory affairs at Oxitec.

The U.S. Environmental Protection Agency has approved the release, and Florida officials announced state permits on Tuesday. Final approval is required by board members for the Florida Keys Mosquito Control District.

The mosquito district's board plans an online workshop to hear from Oxitec at 1 p.m. on Tuesday. The district hasn't set a date for another workshop to gather more input from the public.

Oxitec is capable of deploying the mosquitoes quickly, but has not offered a timeline for release pending final approval. Releases are possible along the entire 125-mile chain of islands.

The altered mosquitoes, which the company calls Oxitec Friendly, are male. Only female mosquitoes bite people or animals for blood meals before they lay eggs.

The altered males mate with female Aedes aegypti, and the female offspring then carry a protein that kills them as tiny, barely visible larvae. The result is a steady reduction in population, according to the company.

Oxitec said it spent 18 years of public-private collaboration with universities, governments, global foundations and more than 200 scientists from over 20 countries developing the program.

But environmental groups are not convinced the mosquitoes and believe more study is needed, according to a petition circulated by the non-profit Florida Keys Environmental Coalition. The group cites concerns about potential impact on bats or other animals that eat mosquitoes.

One study of Oxitec's mosquito release in Brazil found that the altered mosquitoes mated with some other species, according to the findings published in the journal Nature in September by researchers from Yale University.

The result was hybrid mosquito offspring, which the researchers said could be hardier and pose unknown problems for mosquito control.

But Oxitec found no impact on the environment. The gene edit disappears after a few generations, the company's Rose said.

"We did experiments to show that there's no impact on predators that eat mosquito larvae," he said. "Because Aedes aegypti is invasive, from Central Africa, it's not a significant part of the food chain in Florida."

He said the Keys is a good place to demonstrate the program in the United States since it is isolated and a potential home for the spread of mosquito-borne disease because of tourism and climate.

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