Nina Fedoroff – TRANSCRIPT
Zika fever: our newest dread disease. What is it? Where’d it come from? What do we do about it? Well for most adults, it’s a relatively mild disease — a little fever, a little headache, joint pain, maybe a rash. In fact, most people who get it don’t even know they’ve had it. But the more we find out about the Zika virus the more terrifying it becomes. For example, doctors have noticed an uptick of something called Guillain-Barré syndrome in recent outbreaks. In Guillain-Barré, your immune system attacks your nerve cells it can partially or even totally paralyze you. Fortunately, that’s quite rare, and most people recover. But if you’re pregnant when you’re infected you’re at risk of something terrible. Indeed, a child with a deformed head.
Here’s a normal baby. Here’s that infant with what’s called microcephaly. a brain in a head that’s too small. And there’s no known cure. It was actually doctors in northeastern Brazil who first noticed, just a year ago, after a Zika outbreak, that there was a peak in the incidence of microcephaly. It took medical doctors another year to be sure that it was caused by the Zika virus, but they’re now sure. And if you’re a “bring on the evidence” type, check out this publication.
So where did it come from, and how did it get here? And it is here. Like many of our viruses, it came out of Africa, specifically the Zika forest in Uganda. Researchers at the nearby Yellow Fever Research Institute identified an unknown virus in a monkey in the Zika forest which is how it got its name. The first human cases of Zika fever surfaced a few years later in Uganda-Tanzania. The virus then spread through West Africa and east through equatorial Asia — Pakistan, India, Malaysia, Indonesia. But it was still mostly in monkeys and, of course, mosquitoes.
In fact in the 60 years between the time it was first identified in 1947 and 2007 there were only 13 reported cases of human Zika fever. And then something extraordinary happened on the tiny Micronesian Yap islands. There was an outbreak that affected fully 75 percent of the population. How did it get there? By air. Today we have two billion commercial airline passengers. An infected passenger can board a plane, fly halfway around the world before developing symptoms — if they develop symptoms at all. Then when they land, the local mosquitoes begin to bite them and spread the fever. Zika fever then next surfaced in 2013 in French Polynesia. By December of that year, it was being transmitted locally by the mosquitoes. That led to an explosive outbreak in which almost 30,000 people were affected.