STEVE INSKEEP, host:

If you go to a picnic on this Labor Day, there is an excellent chance that mosquitoes will also attend the party. But of course you may have to wait until the quite of the night before you hear that one mosquito buzzing around your head.

(Soundbite of mosquito buzzing)

INSKEEP: People have battled against mosquitoes for more than a century, and we are not necessarily winning. Science writer Jennifer Kahn learned that on a trip to Thailand. She caught dengue fever from a mosquito bite and was ill on the flight home.

JENNIFER KAHN reporting:

The last thing I remember is going to back of the plane and lying down in the little narrow hallway between the airplane bathrooms, and waking up at one point and seeing all these people sort of just stepping over me going in and out of the bathroom.

INSKEEP: Jennifer Kahn spent 13 hours on the floor of that plane and several weeks at home recovering, which gave her plenty of time to think about the mosquitoes that carry that disease and many others.

KAHN: They're pretty incredible. They can fly about 30 miles. They've been known to cross from islands to the mainland across 30 miles of open ocean. And they can smell people from 50 yards away. So they also come equipped with this little sort of hypodermic snout on the front of their face that lets them inject basically directing into your bloodstream. They're pretty much like little tiny flying bags of disease.

INSKEEP: And what they do is they suck a little bit of your blood. Everybody knows that. But then when they go to the next person, what happens?

KAHN: Well, when they go to the next person they also suck their blood. But they inject a small anesthetizing fluid that also happens to contain - if they're infected - the parasites that they're carrying, whether it's malaria or dengue or yellow fever.

INSKEEP: Are you one of those people who gets bitten a lot?

KAHN: Unfortunately, I am. They've done the studies recently that seem to show that 20 percent of the people get 80 percent of the bites. And I'm convinced that I'm one of the 20 percent.

(Soundbite of laughter)

INSKEEP: You've always been that way all your life?

KAHN: Yeah. I'm not sure if this goes on the radio, but one of my early memories is on pulling down my pants in a jungle in South America when I was with my parents and immediately getting covered in about 80 bites on my little tiny girlish derriere.

INSKEEP: Oh this is going on the radio, I assure you.

(Soundbite of laughter)

INSKEEP: So when did the human war against mosquitoes begin?

KAHN: It began about 100 years ago, pretty much thanks to a British doctor who discovered that mosquitoes are actually the ones that carry malaria from person to person. Before that, they were just pests. And once we discovered that they actually were the vectors for disease, that's really when the gloves came off.

INSKEEP: Which means what?

KAHN: Which means that there started to be a series of programs - particularly escalating around World War II - eradication campaigns. People were draining swamps in Florida - you know, which really used to be a kind of a malarial hell hole before it was a charming retirement state - and dumping DDT and spraying it over ponds, dumping it from the air. There was quite a widespread effort just to, you know, rat out mosquitoes entirely.

INSKEEP: And are we winning?

KAHN: We're winning some battles. It's not very realistic to say that we're winning the war.

INSKEEP: Why not?

KAHN: They can breed anywhere. The species that carries malaria can breed in the little tiny bit of water that's left cupped between, you know, a plant stem and the leaf or in the water left behind in a hoof print in the dirt. So they're everywhere. They breed prolifically. And they all carry this disease, so it's pretty hard to annihilate them without blanketing the planet in an insecticide that would, as a side effect, kill pretty much every other insect.

INSKEEP: Are people obsessed with this war?

KAHN: Oh, yeah. A lot of people are very obsessed with this war. There are hundreds of scientists whose entire lives and careers have been devoted to working on mosquitoes to following their breeding habits, to understanding their sense of smell, to parsing their DNA. It's a field unto itself.

INSKEEP: Are there people who have just considered radical, radical solutions -utterly changing the environment to get rid of mosquitoes?

KAHN: Well, insecticides definitely are coming back into favor in a more moderate use. But now there's sort of a new modern version of the radical solution, which is for instance, tinkering with the mosquito genome to make it so that mosquitoes can't actually get malaria. It turns out that only very few mosquitoes actually get malaria. That most of them - it's a parasite. It's a disease. And most of them fight it off the way any of us would fight off the flu. And then a very small percentage have an immune system that can't fight it off. And so maybe it's, you know, at best a few in a hundred. And they're the ones that are responsible for spreading the disease.

INSKEEP: You even write here about some guy who has spent all of this time trying to breed mosquitoes that are sterile.

(Soundbite of laughter)

KAHN: That's right. Bart Knolls of the International Atomic Energy Agency - he's actually building a giant sterile male mosquito factory that will be used to breed a million sterile male mosquitoes a day, and then they'll be actually flown and air dropped over Sudan along the banks of the Nile. And the idea is you'll just produce so many sterile males that they'll outnumber the fertile males and your population will plummet.

INSKEEP: Shouldn't he be busy making sure that North Korea doesn't get any more nuclear weapons or something?

(Soundbite of laughter)

KAHN: You might think. Apparently this can actually work. The sterile insect technique is apparently pretty well known. To me it sounds, I confess it sounds a bit extravagant. It's one of the many methods that it seems almost like - I mean, there has to be a simpler way, one would think.

INSKEEP: Have you run across anybody focusing on this problem that started reminding you of Mr. Kurtz in Heart of Darkness? Kill, kill the brutes. Kill them all.

KAHN: Well, that was the thing. I was really convinced when I talked to folks that they would have sort of the scientist's love for their subject. You know, they'd sort of - although they're trying to kill mosquitoes, they would harbor a secret affection for them, that sort of thing. And in fact every single person I talked to I asked the question of whether they kind of, they got this Stockholm syndrome and started to kind of sympathizing with, you know, their captors. And every single one of them said no, they pretty much just hate mosquitoes.

(Soundbite of laughter)

INSKEEP: Is there a big anti-mosquito economy when you add up all the different sprays that people buy, or even public health programs where people spend to eradicate mosquitoes?

KAHN: Oh, yeah. This is a multi, multi-million dollar industry. I mean, partly there's the sprays and the nets and that sort of thing. But really, it's actually more in the research. The Bill Gates, you know, Foundation is heavily invested in preventing the transmission of malaria, and that takes some forms like a malaria vaccine. But it's also - a lot of the work is on mosquitoes. I'm sure that number has only gone up now that Warren Buffet has donated more money to the cause.

INSKEEP: What about the stuff that I might buy when I'm going on a camping trip, whether it's netting or some kind of spray? Is that worth the money?

KAHN: Well, a net will certainly help you out. The spray, you know, you might have good luck with DEET. It seems to work at least in my local area, in a California backyard. But I just had some friends who were on their honeymoon in Brazil, and they said that the, you know, the DEETs just seemed like barbecue sauce to the mosquitoes. They didn't stop them at all.

(Soundbite of laughter)

INSKEEP: Well, I suppose the mosquitoes might be developing immunity the way that microbes develop an immunity to antibiotics.

KAHN: Well, and that's actually one of the bigger problems in the mosquito war, is that almost anything you can come up with mosquitoes can adapt against. They're very able that way, and, you know, there's almost nothing - I mean, they develop immunities to insecticides. The malaria parasites develop immunity to the drugs that we develop like chloroquine and mefloquine. It's a very tricky problem.

INSKEEP: Jennifer Khan wrote an article for Outside Magazine called Itchy. Thanks for speaking with us.

KAHN: Thanks very much, Steve.

INSKEEP: Our interview with Jennifer Khan continues at npr.org, where you'll also find a link to her Outside Magazine article. This is MORNING EDITION from NPR News.

(Soundbite of mosquito buzzing)

INSKEEP: I'm Steve Inskeep.

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