“The level of alarm is extremely high,” said the head of the World Health Organization on Thursday, describing the spread of Zika virus around the world. As well it should be: The disease, which seems likely to be causing birth defects, could affect millions of people in several dozen countries. And the virus may be on its way into the US. As of Friday morning, no fewer than five New York residents have been diagnosed as Zika positive.
But New Yorkers, like everyone else in the United States, can take solace in two simple facts. The first is that Zika virus can’t easily be transmitted from one person to another. The second is that the bugs that carry the disease—in particular, two species of mosquito, Aedes aegypti and Aedes albopictus—are not very active in the winter, and do not pose a major risk in communities with ample screens and air conditioning. According to the commissioner of New York’s Department of Health, “There is virtually no risk of acquiring Zika virus in New York State at this time.” Other experts, too, have told Americans that there isn’t cause to panic. So what’s this hotness in my face, this shortening of breath? It’s not panic, I assure you. It’s more like rage. I’m angry at this Zika epidemic, starting with the ratty little flavivirions that are doing so much harm. But to rail against the virus doesn’t make much sense. It has no animal intentions; it isn’t even quite a full-fledged living thing. My wrath is focused on a different target—not the virus but the vector. I hold a special reservoir of bile for the flying hypodermic needles that harbor this pathogen, the flies that shuttle it from one country to another, spreading bioterror in their wake. I’m mad at the mosquitoes, and it’s time to give ’em hell. Who would stand against me? Events of recent years—outbreaks of dengue and chikungunya, the continued devastation of malaria—have not done much to burnish the mosquito’s already-suspect brand. Indeed, these sweat-sniffing, bloodsucking parasites might reasonably be counted among the greatest fiends in human history. Consider the statistics: Mosquito-borne diseases kill hundreds of thousands of people every year. Malaria alone claims the lives of 6 million people per decade, mostly small children. The economic costs are similarly staggering, likely in the tens of billions of dollars every year. When researchers totaled up the losses caused by a single mosquito-related illness (dengue fever) in a single mosquito-ridden country (Brazil), it came out to $1.35 billion annually, not including the $1 billion that must be spent to control the spread of dengue-infected flies. You might’ve thought that news about the Zika outbreak would have convinced humanity to crush the mosquito. But all we keep hearing are proposals to take the battle to the virus, not its host. We’re told that scientists must work hard to find a new vaccine, as if that would be the best solution to the problem. The hunt for a Zika cure could take a decade—and in the meantime we’re left to wait and watch swarms of evil on the wing, mating in midair, and landing on our shores. An enemy has made its way to the nation’s borders. Now is not the time for soft responses. It’s time to kill all the mosquitoes. It’s time for mass mosquito-cide. It’s true that we already try to keep the critters in control. We spray their breeding sites with pesticides. When the bugs are in their larval stage, we try to poison them with bacteria. If they make it to the pupal stage, we can suffocate them in a film of oil. But each of these modes of warfare leaves room for activism and dissent.
The chemicals may drift into areas where humans live, or else they do their job too broadly and too well, killing species that we actually like. Public health officials have their own technocratic way of describing all this collateral destruction, worrying over problems such as “adulticide drift” and “nontarget insect mortality.”
So they hedge their bets and do their best to strike a balance between mosquito death and ecosystem health. They use what’s called “Integrated Mosquito Management,” a euphemism for doing lots of little things at once: keeping track of where mosquitoes breed, spraying them with chemicals, fixing broken drains and picking up discarded tires, eliminating swamps. It’s all quite responsible and safe. One might even brand it ecologically correct. But the recent spread of arboviruses has me convinced that we can’t win this fight with our repellent-coated hands tied behind our backs. Enough of the politeness: The ugly situation on the ground does not call for Integrated Mosquito Management; it demands a program of Total Mosquito Destruction. And here’s the thing: For the first time in human history, that dream could be realized. We have a better way to kill mosquitoes—a nuclear option—but up until this point we’ve been too afraid to use it. The approach I’m thinking of has its origins in the 1930s, when a man named Edward F. Knipling had an idea. Faced with the problem of a deadly cattle pest, the screwworm fly, the US Department of Agriculture researcher thought to turn the bugs against themselves. By breeding and releasing sterile males into the wild, he figured that he might interfere with screwworm breeding and shrink their numbers. “The general reaction ranged from skepticism to ridicule,” he later wrote.
But in 1953, Knipling used an Army X-ray machine to sterilize some flies and released them on Florida’s Sanibel Island. The experiment worked. Then it worked again, on the island of Curaçao. Within a few months, Knipling had exterminated the island’s native screwworm population—a full-blown screwworm massacre. By 1959, the fly was gone from all Southeastern states. Not long after that, it had disappeared from the US as a whole. Knipling won the World Food Prize for his work and was named to the Cattlemen’s Association Hall of Fame. His “sterile insect technique” appealed not just to ranchers but to environmentalists. In 1962, Rachel Carson published Silent Spring, her epochal broadside against the chemical industry. In the final chapter of that book, called “The Other Road,” Carson singles out some “new, imaginative, and creative approaches to the problem of sharing our earth with other creatures.” Chief among those was Knipling’s method—“a triumphant demonstration of the worth of scientific creativity,” she wrote, “aided by thorough basic research, persistence, and determination.” So why haven’t scientists tried to use the same approach in the fight against mosquitoes? Actually, they have. The problem was that mosquitoes proved too fragile for the X-rays: Instead of turning sterile, the bugs just died. But in recent years, the sterile insect technique has been revived.
One researcher, Luke Alphey, used genetic engineering to design a sterile strain of Aedes aegypti mosquito—the kind that carries Zika, dengue, and yellow fever. Alphey’s technique is very clever: The bugs hold a gene that kills them at the larval stage, unless they’re reared in the presence of tetracycline, a common antibiotic. That means it’s possible to breed large numbers of the flies in the lab, but when they’re released into the world, they cannot reproduce.
This article was first published in the slate.com.