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CNN Sunday Morning

Weekend House Call: West Nile Virus

Aired August 17, 2003 - 08:30   ET

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.


DR. SANJAY GUPTA, CNN MEDICAL CORRESPONDENT: Good morning and welcome to WEEKEND HOUSE CALL and today we're talking about the West Nile virus. It's been such a wet summer much of the U.S. and mosquitoes are worse than ever. Of course that means the West Nile virus is entering its peak period, which is now. There have been 470 human cases reported so far, ten deaths, two in Alabama, two in Texas, and six in Colorado. That's the state that's been hit hardest so far.
(BEGIN VIDEOTAPE)

GUPTA (voice-over): The West Nile virus is now in full throttle. The number of human cases tripled a week ago, and is nearly tripled again this week. That case number is far ahead of where it was this time last year. And there are other differences in 2003. The average age for West Nile victims this year is younger, about 45 years old versus age 55, last year. And the mosquito born disease is hitting hard in new areas, like Colorado where there already 200 victims, they had just 14 human cases last year. But, some things are the same.

ANNOUNCER: Have you heard the buzz about West Nile virus?

GUPTA: The CDC, again, this year is taking the lead in trying to educate the public especially in states dealing with West Nile for the first time.

UNIDENTIFIED FEMALE: No, you can't solve this problem with a single measure. It takes everything from knowing where the next area to be hit is going to be, and we do that through our monitoring systems, taking care of the mosquito larva through larvacide programs, spraying where there are cases and we can't control it anyway, but most importantly individual people can take the steps they need to take to protect themselves.

GUPTA: The Centers for Disease Control recommend: Get rid of standing water in your yard, organize a mosquito control program if there isn't one already, use a repellent containing the chemical DEET, wear long pants and sleeves and spray your clothing with a spray containing DEET or permethrin. And keep this in mind: According to the CDC, 80 percent of those who get West Nile don't get sick at all, they're perfectly fine, 20 percent have mild symptoms such as a fever or a headache, less than 1 percent become severely ill. The most vulnerable? The elderly and those with suppressed immune systems. So, the best strategy -- prepare for the worse, but know chances are the worse will probably never happen to you.

(END VIDEOTAPE) GUPTA: And again, important to remember 80 percent of the people with West Nile virus with won't show any symptoms at all. Up to 20 percent of the people infected will display mild symptoms including fever, headache, body aches, nausea, vomiting, sometimes swollen lymph glands -- which are over here, or a skin rash on the chest, stomach, or back. Symptoms, typically, last only a few days.

Now, about 1 in 150 people or so infected with the West Nile virus will develop a more serious illness. Those symptoms can include high fever, headache, neck stiffness, stupor disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, paralysis. Lots of different symptoms, there, not to scare you, but there are many things to look out for. Those symptoms can last several weeks. Neurological effects may be permanent, again though, very rare.

We want to hear from you and want to answer your questions about West Nile virus, so call us at 1-800-807-2620 or e-mail us at housecall@CNN.com.

To help wade through all these question, we're joined by a very special guest, Dr. Anthony Marfin -- Marfin, sorry, he joins us from Fort Collins, Colorado, this morning.

Good morning, sir.

DR. ANTHONY MARFIN, CENTERS FOR DISEASE CONTROL: Good morning, Dr. Gupta.

GUPTA: I should point out, he's a deputy director of the CDC's Vector-Borne Infectious Disease Division.

Dr. Marfin -- you know, it's interesting, you're in the hardest hit state, which is Colorado. Why is West Nile so bad in Colorado this year?

MARFIN: Well, we're comparing it to last year and, as you noted in the piece that went on just a few minutes ago, there were only 14 cases that occurred in Colorado. But, we have to remember that this virus only spread into Colorado at the end of this season. This year, the virus started early it's been here the entire season and it may have found a very favorable vector -- mosquito vector in terms of the Culex tarsalis, which tends to occurs in many of the areas around Colorado.

GUPTA: OK, and all mosquitoes are not the same, clearly.

Listen, Dr. Marfin, we got -- we got a call on the line -- El from Florida who actually has West Nile virus and she's down in Florida.

El, welcome to HOUSE CALL.

EL, BRADENTON, FLORIDA: Hi, how are you?

GUPTA: I'm -- we're doing well. What's your question? You have West Nile, is that right?

EL: Right. I tested positive for West Nile on 7/14, on July the 14th.

GUPTA: OK, and how's things been going for you?

EL: Not very well at all.

GUPTA: Tell us about it. Most people hear about West Nile, but you're somebody who actually has it. First of all, would you mind telling us how old you are?

EL: I'm 47.

OK, so right around the average age, this year, Dr. Marfin. And, have you been getting treatment?

EL: No, I haven't. I was hospitalized for four days and they never diagnosed me or never did any blood cultures or never -- or geared towards anything neurological. They kind bypassed all those symptoms, the blood cell counts -- you know, the headaches, everything. They, I guess, assumed it was something different.

GUPTA: And how did they figure it out? What prompted them to finally get the test?

EL: Actually four weeks after I was out of the hospital I was still experiencing low-grade fever, hand tremors, difficulty in articulating, and I just, you know, my legs were bruising, just all kinds of symptoms that said it's got to be something in my blood. Fortunately there was one doctor and she's an endocrinologist and an absolutely dedicated doctor, and she listened to me. I only see her one time a year. She's not even my doctor. I asked her to order the test and he did and I came out positive for both IGG and IGM.

GUPTA: All right. Well El, this is an important story, actually, and Dr. Marfin, she's 47-years-old, sounds like she had quite a course, there, before she actually got diagnosed. So, is that typical, No. 1 and No. 2, what should she do at this point for treatment?

MARFIN: I don't -- I'm not sure that that is typical. When people come into the hospitals in areas where there's lots of, either animal activity or previous human cases, most physicians tend to be very, very aware and sending off the West Nile virus antibiotic test is one of the very first things that they do. In this case it sounds like there may have been other things that led them away from that and eventually the test did -- was done and came back as positive.

As to what one does after that is very difficult to say. When we treat West Nile virus, there is no specific virus treatment. It is not -- does not cause chronic disease, but there is no treatment, so we mostly support people. If they're severely ill with severe neuralgic illness that sometimes requires ventilation, you support them through that. If there is fever and more of the body aches type of illness, the West Nile favor, that we support with antipyretics. But, one thing to really emphasize is when one does have anti-bodies to West Nile virus, that they are on the other side of the disease, they're recovering and the virus is being eliminated from their system.

GUPTA: Okay. Well, you know, and I think it's an important point. I want to talk more about this, as well. But, El's story is an important one, 47-years-old, she has West Nile virus. A lot of people, I think, sit at home and think -- we're never -- I'm never going to get this. The average age has actually decreased from 55 to about 45 and people are fairly getting it. Lots of questions and lots of interest, let's go to one of our e-mails.

Now, we've gotten an e-mail from Dan in Pennsylvania who asks, "I thought only the elderly were threatened by this virus. Do healthy younger people need to be concerned, as well?"

And again, Dr. Marfin, we've been talking about this. What do you say to Dan?

MARFIN: Well, when you look at the infection rate you see that people of all ages are about equally at risk to be infected, and this has been shown in several studies, but if you look at the people that actually developed illness, the older you are, the more likely you are to develop symptoms. And, the older you are, the more likely you are to develop serious symptoms. That is not to say we have not had very young people that have developed encephalitis or meningitis, because that has happened, but in fact, overall the rate is very low. As pointed out, in the preceding piece, only 1 out of 150 people actually develop the severe neuralgic infection and that does tend to occur in older people. But, it is very difficult to predict who is going to develop the neuralgic and so it is good for people to take precautions at all ages.

GUPTA: All right. I'm going to ask all of our callers to stand by. We're going to take a quick break, here, but when we come back: How much DEET is enough to keep the mosquitoes away? And, can you use too much? We're also going to find out about those expensive mosquito zappers. Do they actually work? We'll take your phone calls and your e-mail questions, as well. So, call us, 1-800-807-2620 or e-mail us, housecall@CNN.com. We'll be right back.

(COMMERCIAL BREAK

(BEGIN VIDEOTAPE)

ANNOUNCER: You have heard the buzz about West Nile virus? Protect yourself and your family from the mosquito bites that spread the virus. Use mosquito repellants when you go outside. When possible wear long long-sleeved shirt and pants. Remove standing water where mosquitoes breed. Most people who get West Nile virus don't feel sick, but it may cause serious illness. Fight the bite, tell mosquitoes to buzz off.

(END VIDEOTAPE)

GUPTA: All right, you may have seen some of those commercials on television. "Fight the bite," that's the premise, there. This is WEEKEND HOUSE CALL and we're talking about fighting the West Nile virus. We want to answer your questions, we want to talk to you directly, keep the phone calls coming. You can reach us, 1-800-807- 2620 or e-mail us at housecall@CNN.com.

Now, while we get to your questions -- when we get those lined up, let's check our "Daily Dose Health Quiz."

Today's question: Can your pet contract the West Nile virus?

We'll have the answer in 30 seconds.

(COMMERCIAL BREAK)

GUPTA: Checking our "Daily Dose" quiz now, we asked, "Can your pet contract the West Nile virus?"

Well, while it's not common, it has happened. In terms of who mosquitoes want to bite, cats and dogs are very low on the list. But, if you're concerned, practice caution by keeping your animal inside from dusk to dawn, if you can, keep dogs away from marines and ponds. Insect repellent is not recommended, however though, for household pets.

Some vets say feeding your pooch a B vitamin or garlic can work. And, there's also a dog mosquito repellent on the market.

This is WEEKEND HOUSE CALL. We're talking about the West Nile virus. Dr. Anthony Marfin is from the CDC and he joins us from Colorado.

Dr. Marfin, you know, we just talked about house pets. Can they also transmit the West Nile virus to humans, if your dog or cat get is it, for example?

MARFIN: No. We -- human beings primarily get their infections are from mosquitoes. They're mosquitoes that predominantly feed on birds, that's something that we sometimes lose track of during -- during epidemic years, that this is a virus that affects birds. There other mammals, like horses, like humans, like dogs, like cats, that may become infected, but we're really not the intended target most of the time for those mosquito species.

GUPTA: OK. Well let's go to our -- we got a lot of e-mails and phone calls coming in on this, incidentally. Let's go next to our e- mail question from Lisa in Texas.

She asks, "There are different concentrations of DEET that can be found in several over-the-counter repellents products. What are the health risks and repellent differences that we, the public, should be aware of before buying 100 percent DEET products, for example, rather verses 12-25 percent?"

Important point, Dr. Marfin, because, I think -- you know, a lot of times folks are saying -- 30 percent DEET was recommended for adults, 10 percent for children. Is that still the recommendations or is that changing, as well?

MARFIN: I think that is a changing a little bit. To come back to the 100 percent, thought, I don't think there's ever really a reason to wear 100 percent DEET.

When we talk about DEET, we, usually talk about the higher the concentration, the longer it will last. So, there's a role for 30 percent, there's a role for 20 percent, there's a role for 7 percent. If you're going to have a short exposure, say a half hour to an hour, you can wear something that has 7 to 10 percent DEET and it will be effective during that entire time. If you have a longer exposure we encourage people to use higher concentrations up to 30 and in some situations up to 50 percent. With regards to children, it used to be the rule that it was 10 percent. But, in fact, you can look on some of the Web sites for the American Academy of Pediatrics, they'll a have a full discussion of DEET, and you can see that, in fact, we -- there are times where you would use a higher concentration.

GUPTA: All right, so an important point. So, as far as DEET goes the longer you're going to be outside, the longer the exposure is going to be the higher concentration. But, you're not going to get a better protection with the higher percentage or DEET. That's good advice.

We got another e-mail question, as well.

Don from Michigan writes, "I have two questions. First, is it possible to get a mild case of West Nile virus and not know it? Second, once someone has caught West Nile, can it be caught again?"

Do you somehow protect yourself, there Dr. Marfin?

MARFIN: That's a good question. The -- as has been pointed out earlier in this program, you know, the vast majority of people are -- do not have any symptoms at all of about every 150 to 200 infections, you only have one person who develops serious, serious neuralgic illness. Then, there's a small group, maybe about 20 to 30 people out of that 150, that will develop West Nile fever. The fever, maybe a mild headache and muscle ache. But, all of the rest of the people will have no symptoms at all. Regardless of the clinical manifestation or the clinical syndrome you develop, you will develop the antibody and this antibody is presumed to be protective for your whole life.

GUPTA: OK, that's interesting. So, if you get, you're -- protected for your whole life.

We got our phone callers up again, Pam from Pennsylvania. Welcome to HOUSE CALL.

PAM, PARKER, PENNSYLVANIA: Hi.

GUPTA: What's your question?

PAM: I've got two questions.

GUPTA: OK.

PAM: Are they working on a serum for a vaccination for it? And, the ones that have had it and survived it, can't they take some of their antibodies and make a serum out of it, to get vaccinated?

GUPTA: That's a good question, Pam. Dr. Marfin, first of all, it's sort of surprising about the vaccine. There's a vaccine for horses, but not humans, yet. And then Pam's second question, sort of, dealing with taking existing antibodies from humans how've been exposed to the virus.

MARFIN: Those are very important questions, right now, Pam, and the question often comes up -- why do we have a horse vaccine, but not a human vaccine. There's different quality -- or there's different standards for the development of a veterinary vaccine than a human vaccine. What we ask for in a human vaccine is the safety and efficacies. In fact, there are several groups, both in the private industry NIHN at CDC that are working on a West Nile virus vaccine. But, it is likely that we are years away, because we do demand that it be effective and safe.

With regards to the question about using antibody from people who have survived their illness, in fact that is a very, very viable way of treating the infection. As to whether it's effective or not is still a question and in fact, there are going to be some randomized clinical trials run by the National Institutes of Health, this year, in which a serum that contains West Nile virus antibody will be used to treat people who develop the illness.

OK, and real quick, just a one word answer. How long do you think before a vaccine then, Dr. Marfin?

MARFIN: I can't say. I've heard people say as short as two years. I've heard people say as long as ten years and that's all been in the past week...

GUPTA: OK.

MARFIN: ...that I've heard that.

GUPTA: You'll be happy to know, lots of people interested in this topic, lots of phone calls, e-mails coming in. We'll take another phone call, now. Dean from Florida.

Welcome to HOUSE CALL, Dean.

DEAN, TAMPA, FLORIDA: Yes, good morning, gentlemen. First, a question -- a comment regarding the spread of the West Nile virus, seems to me it would be a perfect case study for bio-terrorism, as that we've seen it spread across the country, hopefully we'll learn something from that. My question is regarding the nation's blood supply and prescreening of donors. What is being done as far that and in relation to the fact that of 80 percent of the people do not have symptoms, so are we actually screening the blood supply, at all, so for as blood donations? GUPTA: This is interesting. And, Dr. Marfin, this has been one of the victories in the fight against West Nile, hasn't that? The blood screening that is?

MARFIN: Yes. You know, it wasn't until last year that it was even identified that West Nile virus could be transmitted in transfusions and in an extremely short time the FDA, the blood banking industry, the test developers, and CDC have been all working together to get it -- a test out there and being used. Since early July, all of the blood banks in the United States do screen blood for West Nile virus. Looking for the virus itself, not antibody, but looking for the virus itself. When that is found those blood units are removed from circulation and will no longer pose a risk because they will not be given to anyone.

GUPTA: OK. All good information and there's so much more to come, still. We've got to take a quick break, now. Phone callers, stand by, but when we come back: Mosquitoes and kids. A lot of people concerned about that. What are the best tips from keeping your kids from getting bit. And, if you're outside should you put the sunscreen on first or the insect repellent on first. Just basic questions, we'll have good answers for you when HOUSE CALL continues. Stay with us.

(COMMERCIAL BREAK)

(NEWSBREAK)

(COMMERCIAL BREAK)

GUPTA: All right. Mosquitoes are already out in full force, this year, and here's some good tips avoid getting bitten, that's the real essence of it. First of all use insect repellent containing DEET, look at the label and make sure it actually contains this product, DEET. Also, cover up wearing long-sleeve shirts and long pants when you're outdoors, if possible. Minimize the time spent outdoors during dusk and dawn, that's when mosquitoes are out in their fullest force. Also, remove any standing water around your home, that's where mosquitoes like to breed. An, take care your yard, don't leave clippings or piles of leaves around where mosquitoes can breed.

To help us work through some of your questions, Dr. Anthony Marfin of the CDC is our guest, this morning.

Dr. Marfin, first of all, you know, one thing I had a question about, was just these mosquito zappers. You know, you see a lot of advertisements for those on television. Do these things actually work? Are they a good investment do you think?

MARFIN: Well, you can always see the zappers, in fact, kill mosquitoes, but all zappers are based on attracting mosquitoes to the area that you are sitting. So, in that way, we do not encourage them as a good preventative measure and really much more strongly encourage the use of DEET.

GUPTA: All right. Yeah, and they're pretty expensive, as well. Lots of phone calls coming in. Stacy from Ohio, I believe, is our next caller.

Welcome to HOUSE CALL, Stacy.

STACY, AUSTINTOWN, OHIO: Good morning, Doctors. Thank you for taking my call. My concern is I have a 2-year-old and a 5-year-old and they play outside quite a bit and I am concerned about the chemical DEET. Do the benefits from the insect repellent outweigh the possibility of getting West Nile virus?

GUPTA: Really practical question, Dr. Marfin. 2 and 5-years- old, they're going to be outside, maybe even at dusk and dawn, probably not wearing long sleeve clothing in this heat. What do you tell someone like Stacy?

MARFIN: I think, Stacy, that the benefits of DEET are outweighed -- the risk of DEET. So, the question that you have to ask is, is my community at risk? And if, in fact, there is virus that is either causing infections in animals or other humans, then you know that your children are at risk for infection. And, although it is highly, highly unlikely they'll develop serious illness, we cannot say that with certainty. So, I think that you do apply the DEET and you try to match the concentrations of the DEET to the length of their exposure. As, we had talked earlier, the higher the exposure the longer the effect and there are DEET products out there with 7 and 10 percent, but we can go higher in kids, now, and that's something we hadn't suggested in previous years.

GUPTA: Good practical advice. And, Dr. Marfin, you'll be surprised we're 25 minutes into the show. We're going to take quick break now, but we want to get a final thought from you -- a final piece of advice from you, when we come back in just a moment.

(COMMERCIAL BREAK)

GUPTA: All right. If you'd like more information on the West Nile virus check out the CDC Web site, go to www.CDC.gov and click on the West Nile virus link. We've been joined today, with all your questions, by Dr. Marfin from Colorado, he's with the CDC.

Dr. Marfin, a final quick thought, please?

MARFIN: Well, because there is no specific anti-viral treatment and there is no vaccine, there's a great deal of emphasis on the us of personal protections here, because there's only one way to reduce the number of cases and that's by preventing mosquito bites. You can't tell which mosquitoes are infected and which not, so it does put a lot of emphasis on both the individual, the family, and neighborhoods to reduce mosquito bites for everyone.

GUPTA: We're in charge of our own health to some degree. Dr. Marfin, thank you so much for joining us early in the morning in Colorado.

MARFIN: Thank you, Dr. Gupta. GUPTA: You've giving us a lot of good information.

Well, that's all the time we have for today. Join us next weekend for another edition of HOUSE CALL, that's at 8:30 in the East, Saturday and Sunday. Watch CNN, also for all your medical news. This we're going to be covering stories on heart disease, most cases are 80 to 90 percent preventable, we're also going to take a closer look at the human growth hormone controversy, you're not going to want to miss that, as well.

Thanks fro watching, today. I'm Dr. Sanjay Gupta.

CNN SUNDAY continues, now.

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Aired August 17, 2003 - 08:30   ET
THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.
DR. SANJAY GUPTA, CNN MEDICAL CORRESPONDENT: Good morning and welcome to WEEKEND HOUSE CALL and today we're talking about the West Nile virus. It's been such a wet summer much of the U.S. and mosquitoes are worse than ever. Of course that means the West Nile virus is entering its peak period, which is now. There have been 470 human cases reported so far, ten deaths, two in Alabama, two in Texas, and six in Colorado. That's the state that's been hit hardest so far.
(BEGIN VIDEOTAPE)

GUPTA (voice-over): The West Nile virus is now in full throttle. The number of human cases tripled a week ago, and is nearly tripled again this week. That case number is far ahead of where it was this time last year. And there are other differences in 2003. The average age for West Nile victims this year is younger, about 45 years old versus age 55, last year. And the mosquito born disease is hitting hard in new areas, like Colorado where there already 200 victims, they had just 14 human cases last year. But, some things are the same.

ANNOUNCER: Have you heard the buzz about West Nile virus?

GUPTA: The CDC, again, this year is taking the lead in trying to educate the public especially in states dealing with West Nile for the first time.

UNIDENTIFIED FEMALE: No, you can't solve this problem with a single measure. It takes everything from knowing where the next area to be hit is going to be, and we do that through our monitoring systems, taking care of the mosquito larva through larvacide programs, spraying where there are cases and we can't control it anyway, but most importantly individual people can take the steps they need to take to protect themselves.

GUPTA: The Centers for Disease Control recommend: Get rid of standing water in your yard, organize a mosquito control program if there isn't one already, use a repellent containing the chemical DEET, wear long pants and sleeves and spray your clothing with a spray containing DEET or permethrin. And keep this in mind: According to the CDC, 80 percent of those who get West Nile don't get sick at all, they're perfectly fine, 20 percent have mild symptoms such as a fever or a headache, less than 1 percent become severely ill. The most vulnerable? The elderly and those with suppressed immune systems. So, the best strategy -- prepare for the worse, but know chances are the worse will probably never happen to you.

(END VIDEOTAPE) GUPTA: And again, important to remember 80 percent of the people with West Nile virus with won't show any symptoms at all. Up to 20 percent of the people infected will display mild symptoms including fever, headache, body aches, nausea, vomiting, sometimes swollen lymph glands -- which are over here, or a skin rash on the chest, stomach, or back. Symptoms, typically, last only a few days.

Now, about 1 in 150 people or so infected with the West Nile virus will develop a more serious illness. Those symptoms can include high fever, headache, neck stiffness, stupor disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, paralysis. Lots of different symptoms, there, not to scare you, but there are many things to look out for. Those symptoms can last several weeks. Neurological effects may be permanent, again though, very rare.

We want to hear from you and want to answer your questions about West Nile virus, so call us at 1-800-807-2620 or e-mail us at housecall@CNN.com.

To help wade through all these question, we're joined by a very special guest, Dr. Anthony Marfin -- Marfin, sorry, he joins us from Fort Collins, Colorado, this morning.

Good morning, sir.

DR. ANTHONY MARFIN, CENTERS FOR DISEASE CONTROL: Good morning, Dr. Gupta.

GUPTA: I should point out, he's a deputy director of the CDC's Vector-Borne Infectious Disease Division.

Dr. Marfin -- you know, it's interesting, you're in the hardest hit state, which is Colorado. Why is West Nile so bad in Colorado this year?

MARFIN: Well, we're comparing it to last year and, as you noted in the piece that went on just a few minutes ago, there were only 14 cases that occurred in Colorado. But, we have to remember that this virus only spread into Colorado at the end of this season. This year, the virus started early it's been here the entire season and it may have found a very favorable vector -- mosquito vector in terms of the Culex tarsalis, which tends to occurs in many of the areas around Colorado.

GUPTA: OK, and all mosquitoes are not the same, clearly.

Listen, Dr. Marfin, we got -- we got a call on the line -- El from Florida who actually has West Nile virus and she's down in Florida.

El, welcome to HOUSE CALL.

EL, BRADENTON, FLORIDA: Hi, how are you?

GUPTA: I'm -- we're doing well. What's your question? You have West Nile, is that right?

EL: Right. I tested positive for West Nile on 7/14, on July the 14th.

GUPTA: OK, and how's things been going for you?

EL: Not very well at all.

GUPTA: Tell us about it. Most people hear about West Nile, but you're somebody who actually has it. First of all, would you mind telling us how old you are?

EL: I'm 47.

OK, so right around the average age, this year, Dr. Marfin. And, have you been getting treatment?

EL: No, I haven't. I was hospitalized for four days and they never diagnosed me or never did any blood cultures or never -- or geared towards anything neurological. They kind bypassed all those symptoms, the blood cell counts -- you know, the headaches, everything. They, I guess, assumed it was something different.

GUPTA: And how did they figure it out? What prompted them to finally get the test?

EL: Actually four weeks after I was out of the hospital I was still experiencing low-grade fever, hand tremors, difficulty in articulating, and I just, you know, my legs were bruising, just all kinds of symptoms that said it's got to be something in my blood. Fortunately there was one doctor and she's an endocrinologist and an absolutely dedicated doctor, and she listened to me. I only see her one time a year. She's not even my doctor. I asked her to order the test and he did and I came out positive for both IGG and IGM.

GUPTA: All right. Well El, this is an important story, actually, and Dr. Marfin, she's 47-years-old, sounds like she had quite a course, there, before she actually got diagnosed. So, is that typical, No. 1 and No. 2, what should she do at this point for treatment?

MARFIN: I don't -- I'm not sure that that is typical. When people come into the hospitals in areas where there's lots of, either animal activity or previous human cases, most physicians tend to be very, very aware and sending off the West Nile virus antibiotic test is one of the very first things that they do. In this case it sounds like there may have been other things that led them away from that and eventually the test did -- was done and came back as positive.

As to what one does after that is very difficult to say. When we treat West Nile virus, there is no specific virus treatment. It is not -- does not cause chronic disease, but there is no treatment, so we mostly support people. If they're severely ill with severe neuralgic illness that sometimes requires ventilation, you support them through that. If there is fever and more of the body aches type of illness, the West Nile favor, that we support with antipyretics. But, one thing to really emphasize is when one does have anti-bodies to West Nile virus, that they are on the other side of the disease, they're recovering and the virus is being eliminated from their system.

GUPTA: Okay. Well, you know, and I think it's an important point. I want to talk more about this, as well. But, El's story is an important one, 47-years-old, she has West Nile virus. A lot of people, I think, sit at home and think -- we're never -- I'm never going to get this. The average age has actually decreased from 55 to about 45 and people are fairly getting it. Lots of questions and lots of interest, let's go to one of our e-mails.

Now, we've gotten an e-mail from Dan in Pennsylvania who asks, "I thought only the elderly were threatened by this virus. Do healthy younger people need to be concerned, as well?"

And again, Dr. Marfin, we've been talking about this. What do you say to Dan?

MARFIN: Well, when you look at the infection rate you see that people of all ages are about equally at risk to be infected, and this has been shown in several studies, but if you look at the people that actually developed illness, the older you are, the more likely you are to develop symptoms. And, the older you are, the more likely you are to develop serious symptoms. That is not to say we have not had very young people that have developed encephalitis or meningitis, because that has happened, but in fact, overall the rate is very low. As pointed out, in the preceding piece, only 1 out of 150 people actually develop the severe neuralgic infection and that does tend to occur in older people. But, it is very difficult to predict who is going to develop the neuralgic and so it is good for people to take precautions at all ages.

GUPTA: All right. I'm going to ask all of our callers to stand by. We're going to take a quick break, here, but when we come back: How much DEET is enough to keep the mosquitoes away? And, can you use too much? We're also going to find out about those expensive mosquito zappers. Do they actually work? We'll take your phone calls and your e-mail questions, as well. So, call us, 1-800-807-2620 or e-mail us, housecall@CNN.com. We'll be right back.

(COMMERCIAL BREAK

(BEGIN VIDEOTAPE)

ANNOUNCER: You have heard the buzz about West Nile virus? Protect yourself and your family from the mosquito bites that spread the virus. Use mosquito repellants when you go outside. When possible wear long long-sleeved shirt and pants. Remove standing water where mosquitoes breed. Most people who get West Nile virus don't feel sick, but it may cause serious illness. Fight the bite, tell mosquitoes to buzz off.

(END VIDEOTAPE)

GUPTA: All right, you may have seen some of those commercials on television. "Fight the bite," that's the premise, there. This is WEEKEND HOUSE CALL and we're talking about fighting the West Nile virus. We want to answer your questions, we want to talk to you directly, keep the phone calls coming. You can reach us, 1-800-807- 2620 or e-mail us at housecall@CNN.com.

Now, while we get to your questions -- when we get those lined up, let's check our "Daily Dose Health Quiz."

Today's question: Can your pet contract the West Nile virus?

We'll have the answer in 30 seconds.

(COMMERCIAL BREAK)

GUPTA: Checking our "Daily Dose" quiz now, we asked, "Can your pet contract the West Nile virus?"

Well, while it's not common, it has happened. In terms of who mosquitoes want to bite, cats and dogs are very low on the list. But, if you're concerned, practice caution by keeping your animal inside from dusk to dawn, if you can, keep dogs away from marines and ponds. Insect repellent is not recommended, however though, for household pets.

Some vets say feeding your pooch a B vitamin or garlic can work. And, there's also a dog mosquito repellent on the market.

This is WEEKEND HOUSE CALL. We're talking about the West Nile virus. Dr. Anthony Marfin is from the CDC and he joins us from Colorado.

Dr. Marfin, you know, we just talked about house pets. Can they also transmit the West Nile virus to humans, if your dog or cat get is it, for example?

MARFIN: No. We -- human beings primarily get their infections are from mosquitoes. They're mosquitoes that predominantly feed on birds, that's something that we sometimes lose track of during -- during epidemic years, that this is a virus that affects birds. There other mammals, like horses, like humans, like dogs, like cats, that may become infected, but we're really not the intended target most of the time for those mosquito species.

GUPTA: OK. Well let's go to our -- we got a lot of e-mails and phone calls coming in on this, incidentally. Let's go next to our e- mail question from Lisa in Texas.

She asks, "There are different concentrations of DEET that can be found in several over-the-counter repellents products. What are the health risks and repellent differences that we, the public, should be aware of before buying 100 percent DEET products, for example, rather verses 12-25 percent?"

Important point, Dr. Marfin, because, I think -- you know, a lot of times folks are saying -- 30 percent DEET was recommended for adults, 10 percent for children. Is that still the recommendations or is that changing, as well?

MARFIN: I think that is a changing a little bit. To come back to the 100 percent, thought, I don't think there's ever really a reason to wear 100 percent DEET.

When we talk about DEET, we, usually talk about the higher the concentration, the longer it will last. So, there's a role for 30 percent, there's a role for 20 percent, there's a role for 7 percent. If you're going to have a short exposure, say a half hour to an hour, you can wear something that has 7 to 10 percent DEET and it will be effective during that entire time. If you have a longer exposure we encourage people to use higher concentrations up to 30 and in some situations up to 50 percent. With regards to children, it used to be the rule that it was 10 percent. But, in fact, you can look on some of the Web sites for the American Academy of Pediatrics, they'll a have a full discussion of DEET, and you can see that, in fact, we -- there are times where you would use a higher concentration.

GUPTA: All right, so an important point. So, as far as DEET goes the longer you're going to be outside, the longer the exposure is going to be the higher concentration. But, you're not going to get a better protection with the higher percentage or DEET. That's good advice.

We got another e-mail question, as well.

Don from Michigan writes, "I have two questions. First, is it possible to get a mild case of West Nile virus and not know it? Second, once someone has caught West Nile, can it be caught again?"

Do you somehow protect yourself, there Dr. Marfin?

MARFIN: That's a good question. The -- as has been pointed out earlier in this program, you know, the vast majority of people are -- do not have any symptoms at all of about every 150 to 200 infections, you only have one person who develops serious, serious neuralgic illness. Then, there's a small group, maybe about 20 to 30 people out of that 150, that will develop West Nile fever. The fever, maybe a mild headache and muscle ache. But, all of the rest of the people will have no symptoms at all. Regardless of the clinical manifestation or the clinical syndrome you develop, you will develop the antibody and this antibody is presumed to be protective for your whole life.

GUPTA: OK, that's interesting. So, if you get, you're -- protected for your whole life.

We got our phone callers up again, Pam from Pennsylvania. Welcome to HOUSE CALL.

PAM, PARKER, PENNSYLVANIA: Hi.

GUPTA: What's your question?

PAM: I've got two questions.

GUPTA: OK.

PAM: Are they working on a serum for a vaccination for it? And, the ones that have had it and survived it, can't they take some of their antibodies and make a serum out of it, to get vaccinated?

GUPTA: That's a good question, Pam. Dr. Marfin, first of all, it's sort of surprising about the vaccine. There's a vaccine for horses, but not humans, yet. And then Pam's second question, sort of, dealing with taking existing antibodies from humans how've been exposed to the virus.

MARFIN: Those are very important questions, right now, Pam, and the question often comes up -- why do we have a horse vaccine, but not a human vaccine. There's different quality -- or there's different standards for the development of a veterinary vaccine than a human vaccine. What we ask for in a human vaccine is the safety and efficacies. In fact, there are several groups, both in the private industry NIHN at CDC that are working on a West Nile virus vaccine. But, it is likely that we are years away, because we do demand that it be effective and safe.

With regards to the question about using antibody from people who have survived their illness, in fact that is a very, very viable way of treating the infection. As to whether it's effective or not is still a question and in fact, there are going to be some randomized clinical trials run by the National Institutes of Health, this year, in which a serum that contains West Nile virus antibody will be used to treat people who develop the illness.

OK, and real quick, just a one word answer. How long do you think before a vaccine then, Dr. Marfin?

MARFIN: I can't say. I've heard people say as short as two years. I've heard people say as long as ten years and that's all been in the past week...

GUPTA: OK.

MARFIN: ...that I've heard that.

GUPTA: You'll be happy to know, lots of people interested in this topic, lots of phone calls, e-mails coming in. We'll take another phone call, now. Dean from Florida.

Welcome to HOUSE CALL, Dean.

DEAN, TAMPA, FLORIDA: Yes, good morning, gentlemen. First, a question -- a comment regarding the spread of the West Nile virus, seems to me it would be a perfect case study for bio-terrorism, as that we've seen it spread across the country, hopefully we'll learn something from that. My question is regarding the nation's blood supply and prescreening of donors. What is being done as far that and in relation to the fact that of 80 percent of the people do not have symptoms, so are we actually screening the blood supply, at all, so for as blood donations? GUPTA: This is interesting. And, Dr. Marfin, this has been one of the victories in the fight against West Nile, hasn't that? The blood screening that is?

MARFIN: Yes. You know, it wasn't until last year that it was even identified that West Nile virus could be transmitted in transfusions and in an extremely short time the FDA, the blood banking industry, the test developers, and CDC have been all working together to get it -- a test out there and being used. Since early July, all of the blood banks in the United States do screen blood for West Nile virus. Looking for the virus itself, not antibody, but looking for the virus itself. When that is found those blood units are removed from circulation and will no longer pose a risk because they will not be given to anyone.

GUPTA: OK. All good information and there's so much more to come, still. We've got to take a quick break, now. Phone callers, stand by, but when we come back: Mosquitoes and kids. A lot of people concerned about that. What are the best tips from keeping your kids from getting bit. And, if you're outside should you put the sunscreen on first or the insect repellent on first. Just basic questions, we'll have good answers for you when HOUSE CALL continues. Stay with us.

(COMMERCIAL BREAK)

(NEWSBREAK)

(COMMERCIAL BREAK)

GUPTA: All right. Mosquitoes are already out in full force, this year, and here's some good tips avoid getting bitten, that's the real essence of it. First of all use insect repellent containing DEET, look at the label and make sure it actually contains this product, DEET. Also, cover up wearing long-sleeve shirts and long pants when you're outdoors, if possible. Minimize the time spent outdoors during dusk and dawn, that's when mosquitoes are out in their fullest force. Also, remove any standing water around your home, that's where mosquitoes like to breed. An, take care your yard, don't leave clippings or piles of leaves around where mosquitoes can breed.

To help us work through some of your questions, Dr. Anthony Marfin of the CDC is our guest, this morning.

Dr. Marfin, first of all, you know, one thing I had a question about, was just these mosquito zappers. You know, you see a lot of advertisements for those on television. Do these things actually work? Are they a good investment do you think?

MARFIN: Well, you can always see the zappers, in fact, kill mosquitoes, but all zappers are based on attracting mosquitoes to the area that you are sitting. So, in that way, we do not encourage them as a good preventative measure and really much more strongly encourage the use of DEET.

GUPTA: All right. Yeah, and they're pretty expensive, as well. Lots of phone calls coming in. Stacy from Ohio, I believe, is our next caller.

Welcome to HOUSE CALL, Stacy.

STACY, AUSTINTOWN, OHIO: Good morning, Doctors. Thank you for taking my call. My concern is I have a 2-year-old and a 5-year-old and they play outside quite a bit and I am concerned about the chemical DEET. Do the benefits from the insect repellent outweigh the possibility of getting West Nile virus?

GUPTA: Really practical question, Dr. Marfin. 2 and 5-years- old, they're going to be outside, maybe even at dusk and dawn, probably not wearing long sleeve clothing in this heat. What do you tell someone like Stacy?

MARFIN: I think, Stacy, that the benefits of DEET are outweighed -- the risk of DEET. So, the question that you have to ask is, is my community at risk? And if, in fact, there is virus that is either causing infections in animals or other humans, then you know that your children are at risk for infection. And, although it is highly, highly unlikely they'll develop serious illness, we cannot say that with certainty. So, I think that you do apply the DEET and you try to match the concentrations of the DEET to the length of their exposure. As, we had talked earlier, the higher the exposure the longer the effect and there are DEET products out there with 7 and 10 percent, but we can go higher in kids, now, and that's something we hadn't suggested in previous years.

GUPTA: Good practical advice. And, Dr. Marfin, you'll be surprised we're 25 minutes into the show. We're going to take quick break now, but we want to get a final thought from you -- a final piece of advice from you, when we come back in just a moment.

(COMMERCIAL BREAK)

GUPTA: All right. If you'd like more information on the West Nile virus check out the CDC Web site, go to www.CDC.gov and click on the West Nile virus link. We've been joined today, with all your questions, by Dr. Marfin from Colorado, he's with the CDC.

Dr. Marfin, a final quick thought, please?

MARFIN: Well, because there is no specific anti-viral treatment and there is no vaccine, there's a great deal of emphasis on the us of personal protections here, because there's only one way to reduce the number of cases and that's by preventing mosquito bites. You can't tell which mosquitoes are infected and which not, so it does put a lot of emphasis on both the individual, the family, and neighborhoods to reduce mosquito bites for everyone.

GUPTA: We're in charge of our own health to some degree. Dr. Marfin, thank you so much for joining us early in the morning in Colorado.

MARFIN: Thank you, Dr. Gupta. GUPTA: You've giving us a lot of good information.

Well, that's all the time we have for today. Join us next weekend for another edition of HOUSE CALL, that's at 8:30 in the East, Saturday and Sunday. Watch CNN, also for all your medical news. This we're going to be covering stories on heart disease, most cases are 80 to 90 percent preventable, we're also going to take a closer look at the human growth hormone controversy, you're not going to want to miss that, as well.

Thanks fro watching, today. I'm Dr. Sanjay Gupta.

CNN SUNDAY continues, now.

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