West Nile experts say don't be scared, be careful

Dr. C.J. Peters, former chief of special pathogens at the federal Centers for Disease Control and Prevention

(CNN) -- The West Nile virus has killed nine people in New York and New Jersey since 1999. It looks like the virus is headed south: It turned up in a Florida man this month and dead birds carrying it were discovered in Florida, Georgia and Virginia.

For most people, the virus causes no more than a flu-like sickness. But it can kill people who are elderly or have weakened immune systems. CNN anchor Kyra Phillips talked with Dr. Helen Burns, head of the West Nile task force at the Pennsylvania Department of Health, and Dr. C.J. Peters, a former official for the Centers for Disease Control and Prevention in Atlanta, Georgia, for advice on avoiding the problem.

PHILLIPS: Should we be scared? It wasn't brought home to me until I heard about the hawk here in the Atlanta area that was found carrying the virus. So it's got a lot of people definitely worried -- do we need to fear this?

PETERS: I don't think you need to be scared at all. But I think you do need to be careful.

PHILLIPS: All right, so let's define being careful. Precautions?

PETERS: We know that these mosquitoes bite mainly at night so if you're out in the late afternoon and in the evening you should wear insect repellent. We know that insect repellent, in addition to this previous study, will keep mosquitoes away.

They've exposed people to intensely biting mosquitoes in a control. A person may get several hundred bites and a person wearing the repellent may only get one or two bites. So that works. Long sleeved shirts, socks, that sort of thing works. You screen your home and you stay inside.

Dr. Helen Burns, with the Pennsylvania Department of Health, talks with CNN's Kyra Phillips

PHILLIPS: Dr. Burns, any other ideas? You don't really want to stay inside, especially in our area, and bug repellent is sort of sticky and doesn't smell so great. Is there any other way to protect ourselves?

BURNS: Well, one of the important things is to remember to do whatever you can around your home to eliminate stagnant standing water. It's important to eliminate the habitat where mosquitoes can breed.

PHILLIPS: So we're talking baby pools...

BURNS: Well, it's important. Any type of container around the yard, wading pools, buckets, recycling bins, it's interesting to note that a small child's sand bucket can actually become the home to hundreds and hundreds of mosquitoes. So just being aware that any of the standing water around the home is a source for mosquitoes and eliminating that source reduces the risk for you and your family.

PHILLIPS: Tell us about this program you're involved with tracking the West Nile virus. What are you doing? How does it work?

BURNS: Pennsylvania has been very fortunate because we've had a governor who early on recognized the need to develop a statewide program, promoted that and received support from the general assembly to appropriate funds which created a program that coordinated the efforts of three state agencies and partnered with communities to focus on three major areas.

And that was to educate the public citizens about reducing their risk, to set up a system that would detect the presence of West Nile virus in Pennsylvania and establish procedures to control the mosquito population so that we could avoid spraying.

PHILLIPS: What's wrong with spraying? What are the effects of spraying?

BURNS: The effects of spraying are the end result of what we believe should be prevention activities up front. How to spray, the procedures to spray become issues that have to be dealt with and we believe that it's more important to do some of the upfront work and to prevent adult mosquitoes from developing.

PHILLIPS: Dr. Peters, do you want to add something to that first?

PETERS: Well, I was going to say not to mention the fact that spraying is of marginal utility compared to going out and getting into the sources where the mosquitoes are breeding. As soon as you spray and knock down the mosquitoes, they're hatching again. So the source reduction is very, very important and a good way to go.

PHILLIPS: What if someone finds a dead bird in their back yard?

PETERS: You should take it to your state health lab. You should take the bird, put it in a plastic bag. You can pick it up in a plastic bag. You should call your local health department and ask them how to get it into the surveillance system.

PHILLIPS: How is it that these viruses survive?

PETERS: This is an interesting question. It's something that I think the public needs to understand better. These viruses have their own strategy. They're very simple. They have no intelligence. They can't get around by themselves so they've evolved a partnership with birds and mosquitoes.

The mosquito puts its proboscis into a bird that has a lot of virus in its blood, it ingests this blood. The mosquito actually becomes infected. The virus infection spreads through the mosquito and gets into his salivary glands. Then when he bites another bird -- I should say she because only the female bites -- when she bites another bird, she puts her proboscis in looking for a little capillary to get some blood and injects the virus in that bird, who then develops the virus in his blood as he becomes infected. And it spreads bird-mosquito, bird- mosquito, bird.

So this is the cycle that we're trying to interrupt by knocking down the mosquitoes. Humans are only incidental to this. The bird, the virus, the mosquito, they don't really care about humans except it provides a blood meal for the mosquito and the human becomes incidentally infected.

PHILLIPS: And Dr. Burns, we don't even know still how this got to the United States, right?

BURNS: That's still one of the unanswered questions and probably the more relevant question now is now that we know the virus is in the United States, we need to find out how it's going to behave. And that's why it's important to have information systems developed that track that information on a real-time basis so that the information can be used in the decision-making and targeting the efforts across any state.