LINDA WERTHEIMER, HOST:
This is WEEKEND EDITION from NPR News. Rachel Martin's away. I'm Linda Wertheimer. The Food and Drug Administration now says all U.S. blood donation centers must screen for the Zika virus. News about the first cases of local transmission in Florida have raised fears among women who are pregnant or want to start a family. But what are the odds of contracting the Zika virus, and what does that virus really do? Joining us now to talk about this is NPR health correspondent Rob Stein. Rob, welcome.
ROB STEIN, BYLINE: Nice to be here.
WERTHEIMER: So now we've heard a lot about how Zika causes this terrible birth defect called microcephaly. What do we know about how much of a risk there really is or does it matter how much risk there is if something as catastrophic as microcephaly might happen?
STEIN: Yeah, so the first thing I ought to say, Linda, is that with most things about Zika at this point, unfortunately there's still more questions than definitive answers. It's so new that there isn't really a lot that we know for sure. One thing we do know, though, is that it's pretty clearly been shown that Zika can cause microcephaly in babies that are born to women who get infected when they're pregnant. Now, how often that occurs, we still don't really know. But there are some estimates, and they range from anywhere from about 1 percent to about 13 percent of cases in which the woman gets infected during her first trimester. But there is also increasing evidence that the virus probably poses a risk no matter when a woman gets infected during her pregnancy. And there's probably no time when the pregnancy is completely safe.
WERTHEIMER: What kind of damage does the virus do?
STEIN: It can be really devastating. In fact, there's some new research that just came out. Some researchers published brain scan images from dozens of Brazilian babies who were born to women who got infected when they were pregnant. Whole portions of these babies and fetuses' nervous systems are just missing, like parts of their brain stem, parts of their spinal cord. And in some cases, there are babies that are born whose brains - they seem like they're OK, but after they're born, they realize that parts of their brain or the ventricles were filled up with fluid, sort of puffed up their brains so they looked normal, but, in fact, they were severely damaged.
WERTHEIMER: Now, I know you spent some time with some of these babies when you were in Brazil earlier in the year. Can you tell us anything about what these babies need, how they can be cared for, what it was like to be around them?
STEIN: Yeah, so, you know, some of these babies seem, you know, pretty much like normal babies. I mean, their heads looked a little small, but otherwise, they seemed like your typical baby. Other babies, it was more clear that they had severe problems. They were starting to have seizures. They were starting to have problems eating. Some of them seemed like they were developing OK, but then they stopped eating, started losing weight and started, like, losing ground developmentally. And one of the things that really strikes you is how these babies sound. They often cry way more than normal babies, and their cries can sound really disturbing in some ways. They're much more kind of pained and anguish sounding than a normal baby's cry, and it's much more difficult for the mothers or anyone else to soothe these babies.
WERTHEIMER: So, Rob, we've had cases of the Zika virus appear in Florida. It's at the end of the summer. We have all of next summer to look forward to. How serious is this? How frightened should we be?
STEIN: You know, it's definitely something to be concerned about and keep an eye on, but we just don't know yet how bad it will get. And public health people tell me that, look, we've had other diseases like this. We've had dengue, chikungunya. They're spread by the same mosquitoes. They're very similar viruses. They've come into this country, and we haven't had widespread outbreaks. We've had little clusters pop up that die off very quickly, and the same thing could happen with Zika. And so it could end up being not a huge problem in this country. We just don't know yet.
WERTHEIMER: NPR health correspondent Rob Stein, thank you.
STEIN: Thank you.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.