Entering their fourth month of fighting a local outbreak of Zika, Miami-Dade officials are considering releasing thousands of genetically engineered mosquitoes in Miami Beach and Miami’s Little River neighborhood to reduce the numbers of insects and help stop the virus’s spread, county officials said this week.
Miami Beach commissioners were the first to propose using genetically engineered mosquitoes in September, when they were faced with throngs of protesters opposed to the county’s aerial spraying of the pesticide naled over sections of the city to reduce the number of insects that carry the virus.
Since then, Miami-Dade officials, who oversee mosquito control in Miami Beach and Miami, also have taken an interest in the genetically engineered insects bred and sold by the biotechnology company Oxitec, which has been collaborating with the Florida Keys Mosquito Control District for a potential trial release in Monroe County. The proposed trial release became so controversial in the Florida Keys that the question was placed on the Nov. 8 ballot for a non-binding county vote.
Oxitec representatives are scheduled to meet with county mosquito control and Miami Beach officials on Nov. 17, said Mike Hernandez, a spokesman for Miami-Dade Mayor Carlos Gimenez, who is running for re-election on Tuesday.
“We need to listen to any potential solution or vehicle that could mean fewer mosquitoes in Miami-Dade County, which means we would have a lower risk of disease transmission again next season,” Hernandez said, adding that county officials want to understand the regulatory requirements, costs and public opinion on the possible use of Oxitec’s mosquitoes.
If Miami-Dade and Oxitec decide they want to collaborate, the company will submit an application, including an environmental assessment, to the Food and Drug Administration for a trial release.
“We are eager to discuss our solution with any Florida county that is seeking alternate solutions,” Derric Nimmo, Oxitec’s project coordinator in the Keys, said in a written statement.
Oxitec researchers say their genetically engineered mosquitoes have helped reduce mosquito populations by as much as 90 percent during trial releases in regions of Brazil, Panama and the Cayman Islands. Any release of genetically engineered mosquitoes would be integrated with more traditional methods of mosquito control, including spraying and reducing breeding sites, Nimmo said.
For the proposed trial in Monroe, Oxitec would breed mosquitoes from eggs in the company’s laboratory in Marathon and then release the non-biting males in the designated area about three times a week, Nimmo said. Once released, the genetically engineered mosquitoes mate with females, producing offspring that die before reaching adulthood.
Before moving ahead with a release, however, Monroe County residents will vote Tuesday in a straw poll to determine the level of support for a trial in Key Haven, an affluent island east of Key West. Key Haven residents also will vote in their own local poll.
Three of the five members of the local mosquito control district board have pledged to act in accordance with the results, which aren’t binding, Nimmo said.
Miami-Dade mosquito control has been spraying pesticides — by air, truck, and handheld foggers — reducing breeding sites and raising public awareness about the local spread of Zika since August, after state officials identified a one-square-mile area of Miami’s Wynwood neighborhood as the first place in the continental United States with mosquito-borne transmission of the virus.
Since then, local cases have also been reported in Broward, Palm Beach and Pinellas counties, but Miami-Dade remains the only county with sustained outbreaks of the disease, including in most of South Beach and Middle Beach, and in the newest Zika zone, a one-square-mile section of Miami’s Little River neighborhood identified in October.
Miami Beach Commissioner Kristen Rosen Gonzalez first proposed using Oxitec’s genetically engineered mosquitoes in September, sponsoring a resolution authorizing the city manager to begin exploring the possibility.
Gonzalez also has proposed releasing bats, a natural predator of mosquitoes, and said she wants to exhaust all options for ridding Miami Beach of Zika.
Aerial spraying of naled hasn’t done the job, she said.
“People would like a solution and they would like a non-toxic solution,” Gonzalez said. “I wouldn’t like to use naled anymore given the fact that even after we sprayed we still continue to have locally transmitted cases. I would prefer to find another option.”
The county has said it expects spend up to $12 million combating Zika by the end of mosquito season in December.
In September, Miami Beach City Manager Jimmy Morales sent a letter to the U.S. Department of Health and Human Services requesting that the FDA approve the “emergency use” of Oxitec’s genetically engineered mosquitoes.
FDA Commissioner Robert Califf responded that any local governments in Florida interested in a trial release of Oxitec’s mosquitoes should contact the company so it could submit the required information.
The FDA in August cleared the way for Oxitec and the Florida Keys Mosquito Control District to release genetically engineered mosquitoes in Monroe County after finding that a field trial would not significantly harm the region’s environment. But the plan has met significant resistance from Florida Keys residents and others opposed to the release, including Mila de Mier, a realtor and mother of three who lives in Key West.
De Mier led a petition drive that she said has gathered about 170,000 signatures opposing the release. She said she doesn’t trust Oxitec’s data and that the FDA should require the consent of residents before allowing a trial release.
De Mier said she also worries that genetically engineered mosquitoes could open the door to unforeseen consequences, like antibiotic resistant bacteria
“It could really be opening a huge problem that’s not even talked about,” she said.
Miami-Dade officials said they will be watching results of the Monroe County referendum to inform their decision about whether to use Oxitec’s mosquitoes in Miami Beach and Miami.
“The county is not taking a position for or against,” Hernandez said. “We’re listening.”
Hernandez said mosquito counts have remained relatively low in the sections of Miami-Dade where health officials have confirmed local spread of Zika, with per trap averages of 4.8 in Wynwood; 1.6 in Little River; 0.47 in South Beach; and 1.25 in Middle Beach — all as of Wednesday.
Still, Zika continues to spread in other areas of Miami-Dade. On Thursday, the Florida Department of Health reported two more mosquito-borne Zika infections outside of the transmission zones in Miami Beach and Miami, requiring an epidemiological investigation to determine the source of exposure.
A total of 1,120 Zika infections have been confirmed in Florida this year, with 207 mosquito-borne cases and 907 travel-related cases, including 131 pregnant women. An additional six cases have been ruled “undetermined” after state investigators failed to identify the source of exposure.
Zika cases confirmed in Florida as of Nov. 3
Number of Cases
Total cases not involving pregnant women
Cases involving pregnant women regardless of symptoms*
* Counties of pregnant women not disclosed
** Does not include local cases
Source: Florida Department of Health