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The World Health Organization Just Declared the Zika Virus a Global Public Health Emergency

The Zika virus, which reportedly can cause serious birth defects if it infects pregnant women, has spread rapidly from Africa and Asia to the Americas.

A mosquito feeding on a human. Photo via the Centers for Disease Control

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On Monday, the World Health Organization (WHO) designated the Zika virus a "public health emergency of international concern." This is a major step: The three previous times WHO declared such an emergency were for the swine flu in 2009, the Ebola virus in 2014, and the reemergence of polio in Syria also in 2014.

The virus, which spreads primarily through mosquitos, was first discovered in 1947, and has been common in parts of Africa and Asia for decades. However, it recently spread to more than 20 countries in the Americas, which has caused politicians and experts to worry that the United States will also face an epidemic in the summer.

Typically, Zika sufferers have no symptoms or just have something resembling the flu. In countries where it is endemic, people generally get the virus at a young age, like chicken pox. But in places where it is rare, pregnant women are at risk of first-time exposure. After it spread to the Americas, doctors realized it's correlated with microcephaly, or babies born with small heads and potential brain damage. Causation hasn't been proven, but in one Brazilian state the number of infants with the condition went from an average of nine per year to more than 600 in 2015, according to the New York Times.

Margaret Chan, the director general of the WHO, said at a news conference in Geneva that studies on the connection between Zika and microcephaly will begin in the next couple of weeks. Reuters reported last week that a vaccine is in the works and might be ready by the end of 2016. Meanwhile, the WHO will try to coordinate funding from governments and organizations all around the world to combat Zika. The WHO was widely criticized for not acting quickly enough to combat the Ebola outbreak.

"Can you imagine if we do not do all this work now and wait until all these scientific evidence to come out, people will say why didn't you take action?" Chan said.

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