In the aftermath of the devastation of buildings and infrastructure and the toxic marinade of floodwaters by Hurricanes Harvey and Irma, Mother Nature is literally hatching another hazard: disease-carrying mosquitoes that will find new breeding grounds in the innumerable pools of standing water from torrential rains and storm surges.
Aedes aegypti, the mosquito species that carries the viruses that cause Zika, yellow fever, dengue and chikungunya, is of particular concern to public health authorities. We might have been able to martial an innovative approach to controlling the mosquitoes, were it not for dysfunctional and dilatory government regulation.
Far better to control mosquitoes would be a non-toxic biological approach, several of which are in development. The first of these to be developed has been stymied by years of dysfunction at the Food and Drug Administration (FDA), of all places.
The FDA aggressively expropriated the control of genetically engineered animals in 2009 with publication of a "guidance" document that required all “genetically engineered” animals, from whales to mosquitoes, to be regulated by its Center for Veterinary Medicine like “new animal drugs” such as antibiotics, pain relievers or flea medicines. The rationale was that "intentionally altered genomic DNA" that is in a genetically engineered animal “and is intended to affect the animal's structure or function meets the definition of an animal drug.”
Until that policy, no one — certainly not members of Congress or officials at other regulatory agencies — had conceived of FDA claiming oversight of the breeding of pets, farm animals or indeed any other animal. For example, FDA did not evaluate greyhounds bred by conventional techniques to enhance (DNA-mediated) traits that make them faster runners; cats that are better mousers; or even animals that have been modified with molecular genetic engineering techniques for scientific research, which includes hundreds of lines of rodents.
Operating under this dubious policy, the FDA unnecessarily and inexplicably delayed small-scale field trials of an innovative approach to controlling Aedes aegypti: the release of a novel, self-destructing, genetically modified male Aedes aegypti, which was created by a company called Oxitec.
Because of the presence of a newly-introduced, inherited genetic defect (a conditional-lethal mutation) which causes the insects to die in the absence of a certain supplement, after the mosquitoes are released and mate, their offspring die before reaching maturity. That results in a marked reduction in the mosquito population.
Because male mosquitoes don’t bite, they present no health risk, and because their progeny die before they can reproduce, none should persist in the environment. This approach has been successfully tested in several countries, with up to greater than 90 percent suppression of the wild population of Aedes aegypti mosquitoes. Brazil's National Technical Commission for Biosecurity has granted permission for commercial releases.
FDA took an unconscionable five years (2011-2016) to approve a single small-scale field test of the Oxitec mosquito, and that came only after mounting pressure from the growing Zika threat and the consequent need to control Aedes aegypti. In August 2016 the FDA finally approved a single field trial in Key Haven in the Florida Keys, some 160 miles from the Zika outbreak in Miami, a trial that has yet to begin because of local opposition. The locals might feel differently now.
Because the FDA regulated the genetic insert in the Oxitec mosquito as a new animal drug, like other “drugs” in order to be marketed it would have to be shown to be safe and effective for the animal. This presented a regulatory conundrum: Regulators would have to conclude that the genetic material that causes a male mosquito to self-destruct after producing defective, doomed offspring is safe and effective for the mosquito. The FDA would have found itself tied up in legal knots if its ultimate approval of the insect were challenged in court by environmentalists and anti-genetic-engineering activists.
Since we first pointed out the “safe and effective” impossibility in a Wall Street Journal op-ed last year, the FDA in January 2017 announced that it was ceding the regulation of mosquitoes to EPA, an agency which does have the statutory authority to regulate insecticides. The ball is now in EPA's court to, at long last, get the small-scale field trial under way.
In its oversight of a related mosquito-control innovation, EPA has done better at reviewing field trials proposed by a company called MosquitoMate for non-genetically engineered strains of mosquitoes to control Aedes albopictus (Asian Tiger mosquitoes) by interfering with the reproduction of the insects.
This is achieved by infecting Aedes albopictus with Wolbachia, a common bacterium that occurs naturally in up to 60 percent of all insect species. The strategy involves producing mosquitoes infected with a particular strain of Wolbachia and releasing the males into the environment. When they mate with wild females that don’t carry the same strain of the bacteria, the resulting fertilized eggs fail to hatch.
Thus, as infected male mosquitoes continue to be released in large numbers and breed with wild partners, fewer progeny appear and the mosquito population decreases. According to the company, “MosquitoMate completed successful trials in Lexington, Kentucky, California, and New York. Trials have demonstrated a greater than 80 percent reduction of the biting mosquito population.”
FDA’s callous failures in both policy formulation and in the actual review of the genetically engineered mosquito have resulted from empire-building, a lack of scientific expertise, and deference to political pressure. Moreover, the government neglected to utilize the expertise of USDA, which regulates agents to control pests that affect animals.
USDA has a long history with genetically altered biocontrol agents, most notably the innovative screw-worm fly produced with sterile-insect techniques that was successfully developed by USDA more than 70 years ago to eradicate a devastating agricultural pest. Since then, USDA has performed, funded, and overseen the testing and commercialization of a variety of control agents created with sterile-insect techniques. When released in large numbers, insects made sterile, usually by irradiation, mate but don’t produce progeny, and thereby reduce wild insect populations.
Largely because of the irrationality and unpredictability of U.S. regulation, government research-funding agencies and industry have not been eager to invest in these important new genetic approaches to pest control. As we’re seeing in Florida and South Texas, safe new methods for controlling mosquitoes could be the Next Big Thing, if they were not shackled by excessive and misguided government regulation.
John J. Cohrssen is an attorney who has served in a number of government
posts in the Executive and Legislative Branches of the federal government,
including Associate Director of President George H.W. Bush’s Council on
Competitiveness and Counsel for the House Energy and Commerce Committee.
Henry I. Miller, a physician, is the Robert Wesson Fellow in Scientific Philosophy
and Public Policy at Stanford University’s Hoover Institution. He was the founding
director of the Office of Biotechnology at the FDA.