(CNS): The Mosquito Research and Control Unit wasted no time Thursday morning with the controversial release of genetically modified Aedes aegypti. The planned release was put on hold for two weeks by the court during a judicial review, but after the stay was lifted Tuesday, some 20,000 of the bio-engineered mosquitoes were loose in West Bay. The legal challenge to the project was due to concerns that the MRCU has partnered with bio-engineering firm, Oxitec, in the pilot project to release millions of GM mosquitoes over the next few months before all of the risks to the environment and human health have been addressed.
The MRCU, however, seized the opportunity to press on with the full-scale trial that they hope will radically reduce and perhaps even eliminate the invasive disease-carrying mosquito.
Dr Renaud Lacroix from Oxitec said that they had taken an optimistic position on the court decision and had begun rearing the next batch of GM larvae in the hope that the stay would be lifted and they could begin the release immediately.
As West Bay is a hotspot for the Aedes aegypti, the release began there at 11:00am Thursday.
The team from the MRCU and Oxitec arrived behind the West Bay clinic with a cooler full of the bio-engineered insects and began opening 20 pots, each containing around 1,000 mosquitoes. As staff open the containers, the sterile male mosquitoes swarmed off on the hunt for wild females.
“The operation we are launching today in West Bay is the deployment of a tested technique,” said MRCU director Dr Bill Petrie. “It is a public health imperative that we control the Aedes aegypti mosquito, and that is exactly what we are undertaking to do.”
The MRCU and government believes the safety and efficiency of the technique has been demonstrated through field releases in East End in 2009 and 2010, as well as Brazil and Panama. The Aedes aegypti population was reduced by more than 90% in the areas where these releases took place, Oxitec have stated.
Dr Lacroix told CNS he was confident that the technique is very safe and that people do not need to be concerned. The vast majority of bugs released are male and don’t bite; they will go on to mate with wild females and then die, he said. The wild females will then produce larvae which will not reach adulthood.
He explained that the small percentage that may survive into adulthood would also die quickly but if they managed to mate, that would also lead to prodigy that will not survive.
The Oxitec scientist said that while a very small percentage of GM females are inevitably released, they will also produce sterile offspring and die quickly. Even if a female GM mosquito was to bite a human and transmit any virus to another, this would not be any different from a wild mosquito doing the same thing. He said this was demonstrated through years of research in the lab as well as testing in the field.
Although there has been a lot of talk about the need to press ahead with the release because of the increasing public health risk locally from Zika, dengue fever and chikungunya, the reality is that the success of the Cayman trial will have greater implications overseas. While the Aedes aegypti is certainly a pest here, the risk it poses to Caymanians is considerably lower than the public health threat it poses in its native Africa, as well as in other developing parts of the world, from Asia to Latin America.
If the technology proves to be as good as Oxitec believes it can be, after years of lab research and limited field tests, then the UK-based bio-tech firm will be seeking to use the genetically modified bugs in places where yellow fever, West Nile virus and Zika, among others, are prevalent and present very serious public health risks.
Cayman recently confirmed its third imported case of Zika, but there is no evidence of any local transmission. The regional outbreak has however, raised concerns and it is believed to have had an adverse impact on local tourism, despite the very recent and low number of cases here.
But having been given the greenlight by the court to begin the test, Dr Petrie said, “It is important that we are able to get on with the job as there is an urgency from the public health perspective.” he added, “We need to get the project back on track and put in place the preventative measures we have planned to reduce the risk of local transmission of mosquito-borne diseases.”
The World Health Organization has endorsed the pilot deployment under operational conditions to respond to the Zika crisis. The local project has the support of government and will be integrated with other control methods.
The treatment area in West Bay comprises 300 acres between Watercourse Road, Powell Smith Lane, Rev. Blackman Road and Hell Road. A hundred to 200 pots, each containing approximately a thousand genetically modified, non-biting male Aedes aegypti mosquitoes, will be released around three times a week from the specially adapted Oxitec van, which will blow the mosquitoes into the environment.
The treatment phase in West Bay is expected to last around nine months and then be rolled out to other areas of Grand Cayman, subject to the relevant approvals. Cayman Brac and Little Cayman are not affected by the Aedes aegypti mosquito, so there will be no release there.