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CSU Researchers Test Citrus To Stop The Spread Of Zika

By Kathy Walsh

FORT COLLINS, Colo. (CBS4)- With cold weather on the way, many in Colorado may not be concerned about the Zika virus.

But Colorado State University is at the forefront of Zika research, including testing an ingredient found in grapefruit to see if it can stop the mosquitoes that spread Zika.

(credit: CBS)

The study is sponsored by the National Institutes of Health. The ingredient is from a Swiss company, Evolva, the same people responsible for stevia and resveratrol.

CSU Research Associate Ashley Janich works with mosquitoes, aedes albopictus, mosquitoes that spread the Zika virus. Janich puts some in jars coated with the essence of grapefruit.

CSU researcher Ashley Janich (credit: CBS)

"You see how they're on their backs but they're still twitching their legs. It's not like they die immediately," she said.

But at CSU, researchers are finding that citrus ingredient is showing lethal potential.

Nootkatone (credit: CBS)

"It certainly seems to be killing mosquitoes at a certain concentration," CSU Associate Professor Brian Foy told CBS4 Health Specialist Kathy Walsh.

Foy explains that "it" is nootkatone, an ingredient found in grapefruit and Alaska yellow cedar trees. It is an FDA-approved fragrance and flavor enhancer.

(credit: CBS)

"It's actually in Squirt soda. It's in a lot of women's cosmetics," said Foy.

Some research already shows nootkatone can repel ticks. CSU is studying if it can both repel and kill Zika transmitting mosquitoes.

CBS4 Health Specialist Kathy Walsh interviews CSU Associate Professor Brian Foy (credit: CBS)

Using sheep's blood, researchers create two mosquito feeders in the lab. They smear one with nootkatone. In this case, they are testing aedes aegypti mosquitoes that also spread Zika. The insects ignore the feeder with nootkatone, but devour the other.

Foy believes the study results on nootkatone are promising, so far.


"I can't say it's going to be a magic bullet or a silver bullet, whatever you want to say. It's going to be another tool and we need more tools," said Foy.

The CSU research will help determine if nootkatone is the answer to battling mosquitoes and other pests naturally. Foy believes if it turns out to be a potent insecticide, nootkatone has the potential for use on mosquito nets in Africa to prevent malaria and even in Colorado to fight the West Nile Virus.

Kathy Walsh is CBS4's Weekend Anchor and Health Specialist. She has been with CBS4 for more than 30 years. She is always open to story ideas. Follow Kathy on Twitter @WalshCBS4.

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