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Scientists have genetically engineered a fungus to produce a spider venom. They hope this modified microbe will help fight one of the world's biggest health problems - malaria. NPR health correspondent Rob Stein explains.
ROB STEIN, BYLINE: Hundreds of millions of people get malaria every year, and hundreds of thousands die - mostly children. And Raymond St. Leger of the University of Maryland says it's a huge problem, especially in sub-Saharan Africa.
RAYMOND ST LEGER: Most of the people it infects don't necessarily die of it, but they're enfeebled. They have these periodic fevers. And so those who don't die are grievously weakened by the disease.
STEIN: So St. Leger and his colleagues decided to try to find a new way to kill the mosquitoes that spread the malaria parasite - a fungus that only infects mosquitoes. But there was one catch - the fungus kills slowly.
ST LEGER: So that doesn't suit our purposes. We want the fungus to kill the insect quickly, the mosquito quickly before it can transmit disease.
STEIN: So St. Leger's team modified the genes of the fungus.
ST LEGER: We put into the fungus this specific gene from a spider which produces a toxin. But it only makes it when the fungus is swimming in insect blood. This fungus lands on the mosquitoes. It bores through the mosquito, acts like a hypodermic syringe. It expresses the toxin in the blood of the insect, and the insect dies quickly.
STEIN: And then the scientists wanted to see how the modified fungus works, so they went to the African country of Burkina Faso and built a mosquito sphere.
ST LEGER: So think of a very, very large greenhouse. Instead of glass, there's mosquito netting.
STEIN: To keep the modified microbe from escaping before scientists have done more safety tests. Inside the mosquito sphere, there were huts. The scientists contaminated some of the huts with the toxic fungus and released mosquitoes inside to see what happened.
ST LEGER: The transgenic fungus would collapse a mosquito population. Within two generations, the mosquitoes are basically gone. They're finished.
STEIN: St. Leger says the engineered fungus could provide a powerful new weapon to fight malaria.
ST LEGER: If it just reduced the transmission of malaria by 5%, that would still be hundreds of thousands of lives that benefited. And I think it can do quite a bit better than that.
STEIN: Others agree.
MARCELO JACOBS-LORENA: I think it's an important step forward.
STEIN: Marcelo Jacobs-Lorena is at the Johns Hopkins Bloomberg School of Public Health.
JACOBS-LORENA: We need something new to combat malaria. We are at standstill at the moment. This shows an alternative way to kill the mosquito using this fungus that was engineered to be a very effective killer.
STEIN: But others aren't so sure.
NNIMMO BASSEY: Fighting malaria is something that everybody should do, but fighting malaria through genetic engineering, I think, is dangerous, risky.
STEIN: Nnimmo Bassey is with the Health of Mother Earth Foundation, an advocacy group based in Nigeria. He fears the fungus could run amok, kill other creatures and upset fragile ecosystems.
BASSEY: I'm heavily worried that Africans are the preferred guinea pigs for experimentation. And Africa is going to become a large laboratory for risky experimentations. We don't want this to happen.
STEIN: St. Leger says the fungus only kills mosquitoes and spares other insects such as bees. But a lot more research is needed to make sure the modified microbe is safe and would really work. And St. Leger stresses the new fungus would only be released if people in places afflicted by malaria are on board. Rob Stein, NPR News.
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