Bacteria-Infected Mosquitoes Tested As A Way To Control Population

Apr 20, 2017
Originally published on April 20, 2017 5:31 am
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Pretty interesting science happening in the Florida Keys. Researchers there are battling mosquitoes carrying the Zika virus. The weapon they're using - other mosquitoes. They're releasing tens of thousands of male mosquitoes that are infected with bacteria, and they hope this will reduce the population of the Zika mosquitoes by as much as 80 percent. NPR's Greg Allen has been checking out this research. He joins us. Hey, Greg.

GREG ALLEN, BYLINE: Good morning, David.

GREENE: So what exactly are scientists doing here?

ALLEN: Well, they're conducting trials over the next week of releasing a mosquito that's infected with a type of bacterium called Wolbachia.


ALLEN: And that's a bacteria that's - that will help control this mosquito population. And as you mentioned, it's - mosquito carries not just Zika but also dengue and chikungunya. The Aedes aegypti mosquito is the mosquito they're concerned about. It's a domesticated mosquito that likes people a lot, and it's spread Zika in Miami to more than 280 people. So it's a real problem.

GREENE: I have so many questions here. The first one is, like, why releasing just male mosquitoes that are infected and why does that somehow help here?

ALLEN: Well, males don't bite people. Only female mosquitoes bite, so they're not a problem per se. And when you release these males with Wolbachia, when they mate with females, because of the bacteria, the offspring don't survive to adulthood. So that would bring down the population. Now, this has been tried around the world. This method has been tried elsewhere. It's been used in California last year as a trial. The mosquito agency in the Florida Keys want to see how well it's going to work there. And it's important to get new methods to spraying because spraying is just not working to control these mosquitoes.

GREENE: So if you're a resident of the Florida Keys, do you like hearing news that they're, like, releasing infected mosquitoes into the environment (laughter)?

ALLEN: Well, people in the Florida Keys have been very concerned about another trial, a different type of trial, using genetically modified mosquitoes, and that's been a big concern. This trial uses these naturally occurring bacterium that's already found in insects. So for that reason, I think a lot of people down there think that this is kind of a more natural alternative to the genetically modified trials. But that said, the Florida Keys Mosquito Control District is getting ready to conduct these trials of the genetically modified Aedes aegypti mosquitoes. The FDA has already given approval last year. They're waiting now to get approval to release it in another community, the community that - the original community voted against it in a referendum. And so now they found a new place. They're waiting for the FDA to give approval. And they're going to go ahead soon with this other trial, these genetically modified mosquitoes.

GREENE: Greg, I feel like Zika has been out of the headlines recently. I mean, you might know that as well as anyone since you spent so much time reporting on it. But is it still a major concern in Florida?

ALLEN: Oh, it certainly is. You know, it's really about the time of year. We're in the dry season now throughout the southeast, certainly in Florida. And so we don't see mosquitoes as much now. But scientists say they believe Zika is here to stay in south Florida. And the Aedes aegypti mosquito, which is the main carrier so far for this disease, are found throughout the southeast. Local transmission also happened last year in south Texas. So it's not just Florida. This mosquito can be elsewhere and can carry Zika elsewhere. This year, they're gearing up for spending more money to get ready for - to control this disease with - and to work on mosquito control. And they're working on better testing. But right now, we've not had any local Zika this year, but it's really just a matter of time is what scientists and health officials say. So we're just kind of waiting and watching and doing our best.

GREENE: NPR's Greg Allen in Miami. Greg, thanks as always.

ALLEN: You're welcome. Transcript provided by NPR, Copyright NPR.