The World’s Deadliest Animal: Zika Virus and the End of Mosquitoes

Mosquitoes are the worst. Nothing ruins a hike or a camping trip like a swarm of these blood-sucking, ear-buzzing, itch-inducing pests. Most of the world’s population will, at some point, be confronted with these horrid little animals and ask the inevitable question: do they even serve a purpose?

At their worst, mosquitoes go from being ridiculously annoying to horrifyingly dangerous. We may have a more palpable innate fear or sharks, lions, and snakes but let’s not forget that the deadliest animal on the planet is tiny and airborne. Mosquitoes spread disease like it’s their job. Malaria, Dengue Fever, West Nile, mosquitoes carry them all. It is an incredibly fortunate genetic quirk that they can’t spread HIV. For some reason, the virus dies when subjected to a mosquito’s internal environment, but if the day ever comes when a mutation changes that, then we could all be in big, big trouble.

The latest world health crisis is the spread of the Zika virus in Central and South America, brought to you (as you might have guessed) by these two-winged demons of the sky. Zika isn’t especially horrifying in its obvious symptoms. Whereas Ebola victims violently lose bodily fluids until their organs shutdown, 80% of people with Zika never suffer so much as a sniffle. For the one-in-five people who do get sick, things aren’t all that bad either as far as public health crises go. Most commonly, Zika will give you a rash and a fever that subsides in a week or so. At worst, you might get some dry, itchy eyes as well, but Zika is no worse than an afternoon at your aunt’s cat-infested bungalow if you happen to have an allergy.

The real threat from Zika is to pregnant women, or more specifically, their children. Zika has been linked to devastating birth defects, most famously microcephaly. Microcephaly is a condition where babies are born with small heads and brains. It is often responsible for severe mental deficits, which is what makes Zika so scary. A pregnant woman can pass the disease onto her baby without ever knowing she has it.

Zika is spread almost entirely by mosquitoes in tropical countries. A few cases have been linked to sexual contact between people, but the usual process is that a Zika-infected mosquito bites a person who becomes infected, and that person is bitten by more mosquitos, who in turn become infected and spread the disease to everyone else they bite. That means that Zika can spread rapidly and is very difficult to control. Health experts predict that eventually every country in the Americas, except for Chile and Canada, may become infected.

Researchers are doing their best to develop a vaccine, but the most effective method to fight Zika might be to target the mosquitoes themselves. If we decided that it were ethically justifiable to do so, we could potentially bring mosquitoes to the brink of extinction, using what we already know about genetics. Even before the current Zika outbreak, scientists had raised the question of wiping them of the face of the Earth. The method is shockingly simple. Genetically modified male mosquitoes are released into the wild to breed with females. The females lay eggs as normal, which hatch into the next generation. The only catch is that all of the offspring are sterile.

It may sound like a small-scale solution, but researchers are confident it could work. It has been estimated that genetically-altered males could wipe out 80% of the world’s mosquitoes in 36 weeks. Within a year, the world could be basically mosquito-free. It would be a canoeist’s paradise.

The problem is one of ethics and unforeseen consequences. First, should humans be allowed to wipe out another species just because we don’t like them and we are able to do it? What makes our existence so much more valuable than theirs? It’s especially troubling when you consider that humans, not mosquitoes, are the cause of much of what currently ails the world, from climate change to pollution to species extinction. Second, what if we’re missing something? What if mosquitoes play a vital role in our ecosystem that we don't yet understand and removing them brings it crashing down?

It may seem far-fetched, but consider the fact that the only reason most of the remaining rainforests in the world haven’t yet been cut down is because of the threat of mosquitoes, according to science writer David Quammen. If we wipe them out, who is to say that another Las Vegas won’t pop up along the banks of the Amazon, destroying one of the richest environments on Earth? These are big questions that require thought, but it is hard not to see the merit when you consider the pain one little pest can cause.