ELISE HU, HOST:
It's what health officials have been preparing for for months. Investigators say they may have discovered the first cases of Zika being spread within the U.S. mainland. The cases are in Florida, and that means mosquitoes in the area could be spreading the virus. To find out more about the changing Zika story, we turn to NPR's Michaeleen Doucleff. She's from the Global Health team and has been following this outbreak. Michaeleen, tell us a little more about the cases in Florida.
MICHAELEEN DOUCLEFF, BYLINE: Well, Elise, right now, we don't know very much. Last week, health officials in Florida announced both of these cases. One of them is in Miami, and the other is north of Miami in Broward County, which is where Fort Lauderdale is. And what the Florida health department has said is that they don't know how these two people caught Zika. They could have gotten it when they traveled to another country, or they could have gotten it here in the U.S. And that means two things - that they either caught it through sexual transmission or mosquitoes in the area have picked up the virus and started spreading it.
HU: So this seems like a big mystery. How are investigators trying to solve it?
DOUCLEFF: Yeah. So the Florida health department has launched a big investigation. They are testing about 200 people in both communities for Zika to see who else is infected. They also have teams of epidemiologists and mosquito control, teams out there going door-to-door and collecting mosquitoes and looking for the virus to see if the mosquito population has picked up the virus and started spreading it. The CDC has also gotten involved. They have a medical epidemiologist that they've sent down to Florida, and they are also handing out Zika prevention kits to pregnant women.
HU: And I understand that, until last week, scientists thought there was only one mosquito that was spreading the virus. Now there's reports that another mosquito might be involved.
DOUCLEFF: Yeah. So up until last week, scientists thought that there was just one main mosquito that was spreading Zika. It's called Aedes aegypti, and it's common just at the southernmost edge of the U.S. It's not very widespread. But last week, researchers down in Brazil found Zika in another mosquito, which is called the southern house mosquito. And it's called that because it's really common in Southern homes in the U.S. So this new finding adds another layer of threat to the Zika situation here in the U.S. because we have two mosquitoes that could be carrying Zika.
Now, there's a big caveat to that. When we called up the CDC and we were talking to them about this last week, you know, they said that it doesn't change the situation that much right now because they don't know how important this new mosquito is to spreading Zika. And they think that this other mosquito, Aedes aegypti, is still the key one.
HU: That's NPR's Michaeleen Doucleff. Michaeleen, Thanks.
DOUCLEFF: Thank you, Elise. Transcript provided by NPR, Copyright NPR.