What We Know About Zika, the Virus That's Freaking Everyone Out

Lab technician studying mosquitoes and Zika virua
Bloomberg/Bloomberg/Getty Images

The Zika virus, which has been spreading through the Western Hemisphere and Western news outlets since late last year, has prompted the World Health Organization to convene an Emergency Committee, and various American agencies to issue travel warnings. Now that Brazilian researchers have discovered yet another condition caused by Zika -- acute disseminated encephalomyelitis, which affects the central nervous system and can even lead to temporary paralysis -- the virus has been on the tops of many minds, and certainly on top of their Facebook newsfeeds. 

It's also freaked a lot of people out. Should you be freaking out?! A public health official, a medical doctor, and an epidemiologist are here to help you navigate all the warnings, contradictions, rumors, and whether you should stick with your Brazilian vacation plans, stock up on condoms and DEET, or move to mosquito-free Iceland.

What's this disease going to do to me?

For those (relatively few) people who do get sick, the result is basically a fever, pain in the joints, rash, and red eyes for a week or less. That means you might be totally oblivious to having gotten it, and the worst you can experience is that it’ll be like you’ve simultaneously contracted a cold, smoked weed, and had an allergic reaction -- but you’ll be fine in no time.

So that’s not the issue; the problem with Zika is its potential link to microcephaly. “The occurrence of severe congenital defects associated with Zika virus infection makes it different and of greater concern compared with other diseases,” Benjamin Schwartz, deputy chief for Acute Communicable Disease Control at the LA County Department of Public Health, says. "We haven’t had a new infectious disease cause of severe birth defects identified in over 50 years.” So that’s what all the fuss is about.

Zika mosquito on skin
Tacio Philip Sansonovski/Shutterstock

How will I get Zika, which doesn't sound all that bad because I'm not pregnant?

The virus can be spread through mosquito bites, through sexual contact, or through the blood. So if you’re not pregnant, not sleeping with someone who’s pregnant, not getting anyone pregnant, and not donating blood, go to Brazil (or one of the other active transmission countries), right? Except, see above, it still sucks and you never know, so use bug spray.

Does it definitely cause microcephaly or other birth defects?

It would be nice to blame microcephaly -- when an infant's head is smaller than expected, sometimes associated with developmental problems -- on something other than Zika. Then we could dismantle the committees, take down the travel warnings, and just call this whole thing off. Unfortunately, the link is seeming increasingly likely. At first, epidemiologists saw that the steep rise in microcephaly cases in Brazil happened right around the same time that the Zika virus began to appear there, but now there’s even more evidence.

“The genome of the Zika virus, as well as antibodies, were detected in the amniotic fluid of pregnant women with microcephalic fetuses. Zika virus genome was also detected in brain tissue from newborns with microcephaly who died,” explains Dr. Shirit Einav, of the Stanford School of Medicine. “These data indicate that at some point during the pregnancy the virus crossed the placenta.” And that’s unfortunately some pretty legit evidence.

Fogging mosquito to prevent Zika virus

Where the hell did this demon disease come from?

Carried by the Aedes mosquito (don’t drive yourself crazy pronouncing it, it’s just “'80s mosquito”), Zika has been around for almost 70 years in other regions. What makes it a big deal now is that it’s new in the Western Hemisphere. “In the Americas, the whole population, as far as we know, was naive. That means they’d never been exposed to Zika virus -- which means that everybody has the capacity to get it,” epidemiologist Aubree Gordon, PhD, of the University of Michigan School of Public Health, says. “When you have a large population where everybody can get it, that’s a situation where you can have a really large outbreak.”

The theory is that in Africa, by the time a woman is having children, she's probably already been exposed to the Zika virus and her body knows how to deal with it, whereas here it’s a different story. Basically, Westerners were kind of caught off guard with this Zika business.

Does the whole thing about sexual transmission mean it's an STD?

At this point, it’s pretty much a done deal that the Zika virus can spread through sex, based on that case in Texas, and more that the Centers for Disease Control (CDC) is looking at. In the US, this seems scarier than the mosquito thing because you’re probably more likely to have sex than go on a tropical vacation. That’s important, and the CDC gives advice on what to do. Basically, for heterosexual couples, it’s condoms or no fun for a while if the dude has traveled to one of the areas where Zika-infected mosquitos are active. And condoms are generally a good idea for everyone.

You have to be careful on an individual level, but as Dr. Gordon points out, sexual transmission isn’t likely to have a major impact on the US population: “One of the big things is that usually -- not always, but usually -- people don't have sex with that many people... in a short period of time.” She has lots of confidence in your game, folks! “Most sexually transmitted diseases, like HIV, syphilis, and gonorrhea, have adapted to that in that you are infectious for a very long period of time. With Zika, we still think it’s a short period of time that you’re infectious.”

So if you’re not getting it in all over the place during that probably short period (how long exactly is one of those maddening unknowns), you won’t be personally responsible for an epidemic. At least that’s good, right? “If you look at the epidemiology of the disease -- who gets it, where they get it -- it is more consistent with the mosquitos being by far the predominant way that the virus is spread, rather than through sex,” adds Dr. Schwartz.

Bottom line: don't freak out (yet)

As a recent Lancet article pointed out, no one's worried about Zika because scientists know too much about it. They're still trying to establish whether Zika is to blame for microcephaly, and during which part of pregnancy it’s most dangerous. As far as sex is concerned, the experts listed tons of questions yet to be answered. How long after picking up the virus can a guy spread the infection through semen? Is he contagious if he doesn’t have symptoms? Can women spread the infection, too? The public health people are shrugging their shoulders, but they’re on it.

International organizations, doctors, scientists, and health officials are up to their ears in Zika work, holding meetings, doing tests, creating models, conducting surveillance, and working on mosquito control. “No mosquitoes infected with Zika virus have been found in the US to date… [and] adequate vector surveillance and control should … prevent local spread,” Dr. Einav notes reassuringly.

There's probably no need to flee to Iceland, but condoms and a close eye on CDC updates, WHO news, and the travel advisories won’t hurt.

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Marina Komarovsky is a freelance writer for Thrillist, and she’s really over seeing close-up photos of mosquitos biting people. For more on health, follow her tweets: @MariKomarovsky.