Cayman’s Mosquito Research and Control Unit and U.K. biotech company Oxitec tackled questions Tuesday night from West Bay residents concerned about the planned release of millions of genetically modified mosquitoes in their neighborhood.
At the first public meeting about the mosquito release, held at Sir John A. Cumber Primary School hall, residents questioned the scientists on the safety of the project and the apparent lack of public consultation leading up to the release, which is to begin next month.
The MRCU is planning a multi-phase rollout of Oxitec’s mosquito control solution, which involves releasing what they described as “friendly” Aedes aegypti male mosquitoes to help fight the mosquito that transmits diseases such as dengue, chikungunya and Zika. The rollout will begin in West Bay.
About 20 people attended the meeting.
“I am very disappointed that we are coming to a meeting of a foregone conclusion, that the public was not consulted in any way, shape or form, or certainly given any feedback about how we feel being inundated with … genetically modified mosquitoes,” Dwene Ebanks said at the meeting.
He and others at the meeting asked Oxitec representatives why Cayman was chosen for such a project.
Oxitec product development manager Derric Nimmo said the MRCU is “world-renowned” for assessing new technologies for mosquito control and that it is “very interested” in new methods because the current technology for dealing with Aedes aegypti mosquitoes is not working.
“This is a public health menace. It is also a real challenge for people to control,” MRCU Director Bill Petrie said.
Mr. Petrie explained that over the years the MRCU has looked at several methods to suppress the Aedes aegypti mosquito population, and he believes Oxitec’s solution will effectively suppress the species in Cayman.
“The essence of this technique is the use of effectively sterile male mosquitoes, which are released in the environment [and] then mate with the wild female Aedes aegypti mosquitoes, which are already out there. The progeny of those female mosquitoes then do not complete development, they all die, so they do not reach maturity,” Mr. Petrie explained. “If you do this over time, we have shown that you can significantly reduce the population of Aedes aegypti in the wild.”
Mr. Nimmo said that because Aedes aegypti mosquitoes live in and around homes and can breed in very small amounts of water, the species is very difficult to control by conventional means. The species has also become resistant to many types of insecticides.
“This technology reaches where other tools cannot,” he said.
Mr. Ebanks also expressed concerns about the technology, and asked Mr. Nimmo whether residents should be concerned about ingesting the mosquitoes, and whether they would have to wear masks when walking outside.
Mr. Nimmo said residents should not be concerned about the possibility of accidentally ingesting a genetically modified mosquito, as it is no more harmful than accidentally ingesting a normal mosquito.
Those at the meeting also expressed concerns about the possibility of female mosquitoes being accidentally released along with the male mosquitoes.
“We do release a small percentage of females … [among] one out of every 10,000 males is a female, so there is a chance that you could get bitten by one of these females,” Mr. Nimmo said. “There is no difference getting bitten by a GM female mosquito than the wild mosquito.”
The U.S. Food and Drug Administration’s Center for Veterinary Medicine came to the same conclusion in its preliminary “Finding of no Significant Impact” in March.
“Based on the data and information presented, FDA concluded that the immunological response in humans and animals to OX513A female mosquito bites is not expected to be different from the immunological response to bites by wild type Ae. aegypti mosquitoes,” the agency said in the statement.
The FDA report was in response to a proposed plan to release Oxitec Aedes aegypti mosquitoes for an investigational trial in the Florida Keys.
Similar releases by Oxitec have been carried out in Panama, three locations in Brazil, and in Cayman’s East End in 2009.
Mr. Nimmo noted that while the GM female mosquito, like its wild counterpart, can carry diseases, “lab” females do not live as long as wild female mosquitoes.
Beginning in June, the genetically modified mosquitoes will be deployed initially to treat an area of about 300 acres, with 1,800 residents, in West Bay. Mosquitoes will be released three times a week, with between 100,000 to 200,000 mosquitoes per release. About 1,000 mosquitoes will be released every 50 to 100 meters along a road.
Mr. Nimmo said those numbers may “sound like a lot,” but after 30 seconds, those 1,000 mosquitoes quickly disappear from sight as they disperse to nearby yards and gardens.
Several mosquito traps will also be set so that weekly monitoring of the rollout can be done.
Mr. Nimmo added that the current mosquito control efforts by the MRCU will continue as normal while the GM mosquito release project is under way.