Living with the West Nile threat

October 2, 2002

NASHVILLE, Tenn. – The West Nile virus is here to stay, but there is no reason for panic.

That is the message from Larry Zwiebel, assistant professor of biological sciences, who is an expert on mosquito biology. He recently received a grant of $50,000 from Vanderbilt University to study the mechanisms that allow the Culex mosquito, which carries the virus, to track and identify human hosts.

“There are two important things to keep in mind,” says Zwiebel. “One is that infections with West Nile virus are still rare events and represent a relatively small risk to individuals. The second is that most of the people who get West Nile don’t have much of a problem: the symptoms are equivalent to a severe bout of flu. It is the very young, the very old and those with compromised immune systems who are primarily at risk.”

Zwiebel applies advanced genetic techniques to study the mosquitos’ sensory systems. This week one of his papers appears in a special issue of the journal Science that reports the sequencing of the genome of the malaria mosquito, Anopheles gambiae. In the paper, he and his colleagues identify 276 genes in the Anopheles genome that code for a class of proteins that plays a critical role in almost every aspect of the insect’s life cycle, including its ability to see, taste, touch and smell.

The researcher hopes that these studies will provide the basis for effective new mosquito repellants and attractants in the next five years. Meanwhile, there are a number of practical steps people can take to reduce their risk of infection. “There are a number of very simple precautions against mosquitos that are common sense in most of the world that we have largely ignored,” he says.

These measures include:

· Keep your house screened. Don’t open any windows without screens.
· At all costs, avoid standing water around your house because that is where mosquitos breed. That includes cleaning your gutters regularly.
· Wear long-sleeved shirts and long pants when you are going out at dusk and dawn when mosquitos are biting.
· Use mosquito repellant that contains DEET, which is effective to a degree.
· If you see an unusual number of dead birds in your neighborhood, call your local health authority so it can collect and test them. Culex normally bites birds, so dead birds of any kind are a good indication that mosquitos in the area may be infectious.
· If you have a flu-like illness that persists longer than normal, see your doctor.

Zwiebel lab:

Contact: David Salisbury, 615-322-NEWS,

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