Over the last few weeks, a previously obscure disease has been making headlines: the zika virus. If you glossed over early reports about the disease, you might now be wondering what all the fuss is about.
Some doctors in Brazil have been warning women not to get pregnant, and last week the Centers for Disease Control and Prevention issued travel advisories suggesting pregnant women postpone visits to a long list of destinations that look particularly appealing this time of year, like Mexico and Puerto Rico.
So what gives? Here's a quick and dirty low down on everything you need to know about zika.
What is zika and why is it in the news?
The zika virus is a tropical disease spread by some species of mosquitoes. It was first discovered in the 1940s, but wasn't heavily monitored or studied because it was never widespread and because the only reported symptoms were fairly mild. Many people infected didn't get sick at all, and those who did had mild flu-like fever and aches, lasting just a few days.
Zika spread to the Americas for the first time last spring, but it didn't really catch the attention of health agencies until late last year when Brazil reported a significant increase in the number of babies born with microcephaly, a rare and sometimes deadly brain deformity, correlating to zika's arrival. Tests on newborns and stillborns with microcephaly have found the virus, which makes doctors and researchers suspect a link between the virus and microcephaly.
Does the zika virus cause microcephaly?
Health experts are holding back from making this claim because we don't know for sure yet. But there's enough evidence of some kind of link to raise serious concerns. Even if there is a relationship between the virus and the brain deformity, we're not sure what it is or what the risks are—what percentage of pregnant women infected with zika might give birth to a baby with microcephaly, for example? For now, researchers are investigating and health officials are opting for a "better safe than sorry" tactic.
Why didn't we notice a possible link before now?
Since zika was not widespread, and since the reported symptoms were so mild, monitoring it was spotty at best.
"Most of the cases that have occurred have been in parts of the world where there's been less-than-active surveillance for zika and the resulting impact," explained Michael Osterholm, an epidemiologist and the director of the center for infectious disease research and policy at the University of Minnesota. "You don't know if it's really a new correlation or if it's just because we're looking for it better."
It could be that zika always had some relationship with microcephaly, we just never noticed it until it affected a large, well-monitored population like Brazil.
Will the virus migrate to the US and Canada?
It already has, in a way. Travellers who recently visited countries where zika is widespread have been returning to the states and reporting a handful of infection cases. The zika virus is carried and spread by Aedes species of mosquitoes, which migrate into the northern reaches of the continent in warmer weather, so there's a likely risk the virus will continue to spread north. In fact, these same kinds of mosquitoes were some of the ones responsible for the spread of West Nile, which gradually made its way to all of the continental US. Zika has already been reported in Puerto Rico and experts suspect it will turn up in the gulf states before long.
How do we stop it? Is there a vaccine or antidote?
Right now, we have neither a vaccine nor an antidote for zika, though now that researchers are more actively studying the virus there could be one in the future. In the meantime, our best bet for fighting the spread of zika is to fight the spread of mosquitoes. Vector control—common-sense tactics like destroying standing water where mosquitoes breed, wearing bug spray, and even widespread insecticide—is actually a really effective way of fighting the spread of mosquito-transmitted diseases. It's how we eliminated malaria in the US in the 1950s, and studies have shown it's effective against the spread of viruses like West Nile. This doesn't mean these techniques are guaranteed to eliminate zika, but they're our best option until we understand more about the virus.
Should pregnant women be worried?
Pregnant women should get informed and take precautions, according to the CDC. If you're pregnant and have recently travelled to any of the countries where zika is widespread—Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Suriname, Venezuela, and Puerto Rico—you should let your doctor know right away, especially if you felt sick at all during or after your trip.
If you're pregnant and living in one of the affected countries, do your best to avoid getting bitten: wear long sleeves, bug spray, and put screens on your windows. If you're pregnant and not living in any of the affected countries, it's still good practice to avoid mosquito bites during your pregnancy and let your doctor know if you're feeling unwell—and the CDC recommends postponing any travel plans to these areas.