GMO mosquitos aren’t the answer to Zika


Zika is one of the most dangerous emergent diseases we’ve seen in awhile.

And, in a bid to stop the spread of the disease, health experts around the world are considering some very unorthodox approaches.

One of those is particularly controversial. Mostly because it’s a new type of genetically-modified organism—a GMO. But, unlike previous GMOs, this one doesn’t take aim at plants. This one goes right at the mosquitos themselves.

A dangerous disease.

As you’ve probably heard, Zika emerged in Brazil in 2014.

Well, that’s not entirely true—Zika has been around awhile. And we never paid it much mind, because it was relatively benign.

But recently, a new strain of Zika was linked to birth defects—specifically, microcephaly. In microcephaly, you get children with brains that don’t develop normally. They’re often undersized and underdeveloped, as is the child’s head.

Zika also has been linked to Guillain-Barré Syndrome, a little-understood disorder that can cause paralysis and death.

And Zika is now spreading like wildfire, including here in the U.S. We had our first native cases in Florida earlier this year, and that’s unlikely to be the end of it.

That’s because the breed of mosquito that carries Zika—the Aedes aegypti—is particularly well suited to modern living. Unlike other breeds, a. aegypti needs only a small puddle in which to breed.

The sort of standing water that’s common in cities—from overturned tires to clogged gutters.

And that’s exactly where the GMO attack comes in.


Here’s the basic idea: Scientists genetically create mosquitos that have a self-destruct gene embedded in their DNA.

They release males with this gene, which then go out and mate with the females.

The males—which don’t bite humans naturally—die off quickly, thanks to their self-destruct gene. And all their offspring die quickly as well—before they reach the adult stage.

And that crashes the population.

In limited tests, the mosquito population in small areas has been taken down 80-95%. And when the numbers crashed, cases of diseases carried by the mosquitos—like dengue fever—also went down.

Of course, there’s a catch. These GMO mosquitos aren’t cheap. And the moment you stop releasing them, mosquito populations quickly rebound, as females find healthy males.

There’s also the question of tinkering with nature.

These mosquitos are actually an invasive species from Africa, so removing them from the ecosystem doesn’t present the same ethical challenges as taking on a native species.

But, at the same time, another breed of mosquitos could take over the same space—and, for all we know, it might be worse.

And there’s no way to know exactly what will happen long-term with these GMO mosquitos. Their very short life-span theoretically limits potential damage—but theory sometimes runs into trouble when it is carried out in practice.

There’s even a rumor that the GMO mosquitos helped bring in the outbreak of Zika, since the Zika outbreak occurred only 400 miles from a GMO mosquito test site.

That seems unlikely to me—there’s no known way that genes from a mosquito could affect the genes of a virus. But the rumor persists, and there’s still plenty we don’t know about genetic manipulation.

Too great a risk

In the end, because there’s so much that we don’t understand about genetic modification, I’m against using GMO mosquitos in this case.

Especially when testing has been so limited. We simply don’t know what will happen when these genetically-modified insects are released into the wild.

We don’t think that they’ll spread their modifications, but we don’t know that as a certainty. We may think that it will only affect this particular breed of mosquitos, but who knows? What might happen if a spider eats a GMO mosquito? Or a bird, or bat?

When you’re dealing with a complete unknown, the Law of Unintended Consequences grows exponentially more powerful—and more dangerous.

Zika is a health menace. But we’ve successfully fought illnesses like this before, and we will again.

Attacking the virus—not the environment—is the solution.



Last Updated: August 16, 2018
Originally Published: July 6, 2016