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The Zika virus is spreading explosively in the Americas. That's the description today from the World Health Organization. And the WHO is calling an emergency meeting next week to decide what measures should be taken to address it. Zika has been linked to thousands of cases of birth defects in Brazil. NPR's Jason Beaubien reports.
JASON BEAUBIEN, BYLINE: In her first major address on the Zika outbreak, the head of the World Health Organization, Margaret Chan, said the mosquito-borne virus has gone from being a mild threat to one of alarming proportions. Chan today said the world needs answers about the outbreak quickly.
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MARGARET CHAN: I have asked the emergency committee to reconvene on Monday so that, you know, the world's scientists come together, working with the countries who are reporting outbreaks like Brazil and others. Then we look at the evidence.
BEAUBIEN: The big question that still hasn't been definitively proven is whether the sharp rise in birth defects in Brazil is a direct result of the Zika outbreak. The first report of Zika in the Americas was in Brazil in May of 2015. A few month later, doctors in Brazil started to see hundreds of babies being born with smaller-than-normal heads and underdeveloped brains. Scientists say the timing of this strongly suggests that the virus was involved.
Since then, Zika has spread rapidly to 22 countries in this hemisphere, including 31 cases imported into the U.S. All of the reported cases of birth defects, however, have come from Brazil. Most Zika infections only have mild flu symptoms if they have any symptoms at all. WHO officials say there may be some complicating factor in Brazil, like being infected with dengue at the same time, that's causing this surge in birth defects. The one thing WHO officials are expressing with certainty is that this outbreak is moving fast.
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SYLVAIN ALDIGHIERI: Definitely the Zika virus in the American region is circulating with very high intensity at this moment.
BEAUBIEN: Dr. Sylvain Aldighieri is with the WHO's Epidemic Alert and Response Unit. He predicts that over the next 12 months, there will be 3 to 4 million Zika infections in this hemisphere possibly spread from the Southern United States to Northern Argentina. He's basing this on the geographical distribution of this dengue, which is transmitted by the same mosquitoes as Zika. Aldighieri says countries in other parts of the world that have had large dengue outbreaks, including India and China, should also be on the lookout for Zika. Jason Beaubien, NPR News.