Check out this good-news story about a Florida A&M University professor and his work.
Article published Apr 19, 2007
Prof ponders mosquito mysteries
Why are some humans tastier?
By Daniela Velazquez
DEMOCRAT STAFF WRITER
PANAMA CITY-Why are some people more appetizing to mosquitoes than others?
And, once that's discovered, what further discoveries could be made?
That's what researchers are trying to find out at Florida A&M University's John A. Mulrennan Sr. Public Health Entomology Research & Education Center in Panama City.
“What makes one human a lot more attractive is a big mystery,” associate professor Jim Celik said.
With one whiff with their sensitive receptors, the pesky parasites can detect molecules of carbon dioxide, the gas we exhale after we breathe in oxygen, identifying their next meal, Celik said.
“Carbon dioxideÐemitting bag! Blood!” he described as the mosquito frame of mind when a mammal or bird comes into its proximity.
The Panama City researchers want to find a more potent substance that mosquitoes are attracted to in hopes of commercializing their research to help put more effective traps on the market.
The attractant is “trying to override the biological urge to get a blood meal,” Celik said. So far, very few mosquito traps on the market actually do tempt the parasites more than living hosts.
“Mosquitoes and other biting flies are responsible for transporting disease,” center director John Smith said. “When we work to control mosquitoes more effectively, we're basically working to protect public health by reducing their population levels so the probability of being bitten by an infected mosquito is reduced.”
But finding why the parasites pick one person or creature over another is a puzzle with as many solutions as there are molecules in the air.
“People's skin chemistry is different. There are 300 compounds on the skin of a human. Not only do we have a variety of hormones, we also have bacteria, and that produces smells. All of them work in concert. Research is trying to pick out the most primary ones from that chemical cocktail we all have.”
And the base of that chemical cocktail right now is a synthetic substance called Octenol, which was derived from the chemical composition of the breath of African oxen. Scientists wanted to study why the disease-carrying Tsetse fly flocked to the bovines.
FAMU researchers test three times a week what 24,000 mosquitoes are attracted to, Celik said. The center rears more than 100,000 mosquitoes a week for its research.
He tests two species, the Asian tiger mosquito - which populates just about every county in Florida, including Leon - and the Southern house mosquito, which is known for transmitting West Nile Virus.
He is working on the study funded by a $240,000 grant from the U.S. Department of Agriculture. The three-year grant that's designed to help historically black colleges and universities develop research, ends in September.
So far the study has some promising leads but no definitive answer about why mosquitoes feed like they do. The real future of the research lies in the "blends" made from mixing Octenol with other types of possible attractants such as lactic acid, a chemical that our muscles produce and mosquitoes gravitate to.
“You can go and spray yourself with DEET and there are some that are going to get through; they'll find a spot you missed,” Celik said.
He doesn't believe much in the word-of-mouth methods to make you less appetizing to the parasites.
"The anecdotal things of Vitamin B and garlic do not work. All you're going to do is limit your social life."
At his lab, you'll find Celik year-round in long sleeves and pants to avoid being bitten.