Zika has been in the news a lot over the past few years—during the recent outbreak of 2015-2016, the virus infected thousands of people in 60 countries throughout the Americas. You've probably heard about its most devastating effect: That the children of infected pregnant women are more likely to be born with microcephaly, a condition that causes the brain to develop abnormally.
As the disease spread, researchers hustled to learn more about it. There are still questions, but they've found a lot of answers, too.
Why did I only hear about Zika a few years ago? Is it new?
Nope. Zika was first discovered in 1947 in Uganda. In the decades since, there have been a few outbreaks, mostly in Africa. Between 2007 and 2014, however it spread to Asia, causing outbreaks on a some islands in the Pacific. Its genes indicate that it is most similar to the version that was circulating around the south Pacific, so scientists are pretty sure that's where it came from, though there are a few theories about how exactly it came to South America (one of them involves a canoeing competition).
How do you get zika?
The most common way to get Zika is through bite of an infected female mosquito from the Aedes family. The mosquito—which is common as far south as Argentina and as far north as the southern US—gets the virus into its system after feeding on the blood of an infected person. The virus then enters its saliva, which infects the new victim when he or she is bitten.
There's also evidence that Zika can be transmitted sexually, even when people don't have symptoms. Because Zika hangs out in bodily fluids like blood and vaginal secretions (and stays the longest in semen), it can be passed through vaginal, anal, or oral sex. Scientists don't know how commonly this happens, or how long the virus is transmissible from an infected person. Zika can also be passed from a pregnant mother to her child.
What does it do to you?
Four times out of five, it does nothing to adults—no symptoms. For those who do experience symptoms, they're not unlike the flu, or dengue—fever, rash, headache, pain in the joints and muscles. They usually clear up within a week or so. Some people develop a rare condition called Guillain-Barré syndrome, in which the immune system attacks the body's nerve cells, causing muscle pain and paralysis. A handful of Zika patients have died, but usually from concurrent illnesses affecting the immune system (such as Guillain-Barré syndrome).
For babies, the effect can be much more profound and long-lasting—the some 2,300 babies born with microcephaly from this outbreak will be affected for their whole lives. That number may even rise, as there have been some cases of babies born to Zika-infected mothers who initially didn't have microcephaly, but developed it as infants just a few months old.
How do you get rid of zika?
Because it's a virus, you kind of just have to let Zika run its course. People who experience symptoms should see them clear up in about a week. But because the virus can stay in bodily fluids a lot longer, and because of its effect on fetuses, the CDC recommends that men infected with Zika wait six months after exposure before they start trying to have a kid, and women should wait eight weeks before trying to conceive. There is an upside in all this: Once you have it, you're immune to future infection.
Since there's no treatment, prevention is the name of the game when it comes to Zika. If you're having sex with someone who has Zika, or has had Zika, or recently traveled to an area where Zika-carrying mosquitoes live, use protection. If you are traveling to a region where there's Zika, do your best to prevent mosquito bites by wearing long sleeves and insect repellant. Pregnant women, or women planning to become pregnant soon, should not travel to areas affected by Zika.
Last November, the World Health Organization declared the end of the Zika outbreak. But that doesn't mean the disease is no longer a threat; these prevention tactics are still useful, especially for pregnant women. For some, including the parents of children who developed microcephaly as a result of the virus, the impact of the outbreak will last a lifetime.
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