Fury over plan to release 750 million genetically engineered mosquitoes

The move in Florida Keys to kill insects carrying Zika and yellow fever has been branded by locals as a 'Jurassic Park experiment' that could create superbugs

Some residents of the Florida Keys are furious over plans to release more than 750 million genetically modified mosquitoes in the region to combat disease.

The Florida Keys Mosquito Control District gave final approval Tuesday to the plan, which will be rolled out in 2021 and 2022.

The transgenic insects, classified as OX5034, have been modified to help cull the population of Aedes aegypti, a mosquito known to carry Zika, malaria, dengue, yellow fever and other illnesses.

However, residents and local wildlife groups worry the 'Jurrasic Park experiment' could just introduce a new breed of mosquito. State officials have attempted to calm their fears, stating the transgenic bugs will provide a safer, cheaper alternative to spraying the Aedes aegypti with insecticides.

The mosquitoes are all male, altered so that any female offspring they produce die in the larval stage well before they are big enough to bite and spread disease. Only females mosquitoes bite for blood, which they need to mature their eggs. Male offspring would pass along the 'defective' gene.

Dengue fever results in 390 million infections per year, according to the World Health Organization, with a more-than-30-fold increase in reported cases the last 50 years. The disease causes high fever, severe headaches and joint pain and can result in lethal complications - it kills up to 25,000 people every year.

The Florida Keys faced major dengue outbreaks in 2009 and 2010, with smaller ones reported this year. But residents and environmental groups say not enough is known about these transgenic mosquitoes. They worry the programme could just introduce a new breed of mosquito that's more resistant to insecticides.

The transgenic Aedes aegypti has also been approved for release in Harris County, Texas, next year. These mark the first time genetically modified mosquitoes will be used in the US.

But scientists monitoring a similar effort in Brazil say it has backfired. Researchers from Yale University investigated the impact of Oxitec's transgenic mosquitoes in Jacobina, a popular ecotourism destination.

In a study published last year in Nature journal Scientific Reports, they found 'clear evidence' that the genetically modified mosquitoes gave rise to new generations of hardier, hybrid insects.

'The claim was that genes from the release strain would not get into the general population because offspring would die,' said senior author Jeffrey Powell, an ecologist and evolutionary biologist at Yale. 'That obviously was not what happened.'

Oxitec slammed the study as 'false, misleading and speculative' and said it had 'successfully provided significant suppression of the wild Aedes aegypti in Brazil.'