Press Briefing Transcript

CDC Telebriefing on West Nile Virus Update

Wednesday, August 29 at Noon ET

• Audio recording (MP3, 9.9MB)

OPERATOR: Welcome.  Thank you for standing by.  At this time, all participants are in a listen-only mode until the question and answer session of today's conference.  At that time, you may press star one to ask a question.  Today's conference is being recorded.  If you have any objection you may disconnect at this time.  I would now like to turn the conference over to Lola Russell.  You may begin. 

LOLA RUSSELL: Thank you so much for joining us today on the Centers for Disease Control and Texas department of state health services update on the West Nile virus numbers and we'll provide you also with the update on the situation in Texas. The national perspective and what's going in particular in Texas, where you know nearly half of the volume of cases of neuroinvasive of West Nile disease is taking place there.  Our lineup includes Dr. Lyle Petersen who is the director of the division of vector-borne infectious diseases here at the Centers for Disease Control and Prevention.  As well as Dr. Lakey, who is the commissioner for the Texas Department of State Health Services.  Dr. Petersen will begin with a statement followed by one by Dr. Lakey and we'll take one question and follow-up from reporters after both doctors have given their statements.  Dr. Petersen? 

LYLE PETERSEN: Thank you and good afternoon and thank you for all of you joining us.  This is the second national telebriefing we have held this month to release information about the current West Nile virus outbreak in the United States.  This information was posted this morning on the CDC website at www.cdc.gov/westnile.  I want to thank our partners nationwide who regularly provide CDC with their updated numbers and thus make it possible for us to track what's happening with the epidemic.  As we have reported in recent weeks that the number of people reported with West Nile virus continues to rise.  We have seen this trend in previous West Nile epidemics and so the increase we report today is not unexpected.  In fact, we think the reported numbers that will get higher through October.  We recognize that people are worried about the threat of West Nile virus this season.  And we want to assure you that we're working closely with state and local governments to contain the outbreak. 

As of August 28th, 2012, a total of 48 states have reported West Nile virus infections in people, birds or mosquitoes. Only Alaska and Hawaii have reported no West Nile virus activity.  Forty-three states have reported at least one human case of West Nile virus disease. CDC received reports of 1,590 cases of West Nile virus disease in people, including 66 deaths. Of these, 889 (56 percent) were classified as neuroinvasive disease, such as meningitis or encephalitis; and 701 (or 44 percent) were classified as non-neuroinvasive disease.  These numbers represent a 40 percent increase over last week’s report of 1,118 total cases, 629 neuroinvasive disease cases, and 41 deaths.  The 1,590 cases reported thus far in 2012, is the highest number of West Nile virus disease cases reported to the CDC through the last week in August since West Nile virus was first detected in the United States in 1999.  More than 70 percent of the cases have been reported from 6 states, which in descending order are Texas, South Dakota, Mississippi, Oklahoma, Louisiana, and Michigan.  Nearly half of the cases are from Texas. 

We cannot accurately predict how many human cases will be reported this year.  However, based on current reports, we think the numbers may come close to or even exceed the total number reported in the epidemic years of 2002 and 2003, when about 3000 cases of neuroinvasive disease and more than 260 deaths were reported each year.  Because cases of West Nile fever (or “non-neuroinvasive disease”) are very underreported, we think that cases of neuroinvasive disease are the best measure of the severity of the epidemic.  From what we’ve seen in West Nile epidemics in previous years, we expect that this year’s epidemic will peak in mid- to late-August.  The incidence of Infection may peak earlier in southern states than in northern ones.   

And now I’d like to say a few words about Hurricane Isaac and the question of how it might affect the spread of West Nile virus.  Previous experience has shown that floods and hurricanes do not typically result in increased transmission of West Nile virus.  Thus, we expect Hurricane Isaac will likely have no noticeable effect on the current West Nile epidemic.  Nevertheless, small increases in the numbers of West Nile cases were noted in some areas of Louisiana after Hurricane Katrina.  These were thought to be due to increased outdoor exposure that occurred when houses were severely damaged and during recovery efforts.  CDC has reached out to health departments in Louisiana, Mississippi, Alabama, and Tennessee to alert them of the situation and offer assistance.  In light of the ongoing risk for West Nile virus infection, it's important for people to protect themselves from mosquito bites. 

We encourage everyone to use insect repellent when you go outdoors, wear long sleeves and pants.  Use air conditioning if possible.  Empty stands water from items outside your home, such as gutters, kiddie pools and birdbaths.  In response to this year's outbreak, CDC works closely with state and local health departments particularly in areas hardest hit by the epidemic.  As I noted earlier, nearly half of this year's West Nile virus cases have occurred in Texas.  A majority of the cases there have been in the Dallas area.  CDC has had the privilege of working with the Texas department of state health services in Dallas County and other county departments to help protect people from the West Nile virus. They’ve done a great job. Dr. Lakey is going to give an update about the situation in Texas.  Dr. Lakey? 

DAVID LAKEY: Thank you, Dr. Petersen.  Again, I want to thank the CDC for their support for the state of Texas as we're working through the major outbreak and the media for their involvement.  They have been critical to getting the key to getting the message out in the state of Texas.  Here in the state of Texas continue to be very concerned about the disease and the disease that we're seeing here in Texas.  And other parts of the United States.  I'll focus on the data.  But, again, we understand that it's more than just the data, that there have been a large number of people whose lives have been changed related to the outbreak of this event.  One of the issues that a lot of people, have we peaked in Texas or not?  At this time, as I look at the data, I’m not convinced we have peaked.  We may have plateaued.  I'm not convinced yet that we have peaked.  Intensifying our efforts to make sure we control the disease, especially when seeing increased disease in a different part of the state.  I'm going to go through some of the data and again, kind of comparative from where we are now verses last week.  Some of these data, pieces of data are lagging indicators as we talked about the neuroinvasive disease and deaths.  That doesn't necessarily indicate increased disease transmission right now.  Those are lagging indicators related to the activity that has occurred over the last month in the state of the Texas. 

As we look at the data statewide in Texas, as of this morning, we have 783 state confirmed cases of West Nile disease.  That's up 197 from last time we talked last week.  And we have had 31 deaths, that's up 10 from our discussion last week.  We have had 416 cases of West Nile neuroinvasive disease, and again, that's up 93 from this time last week.  Those numbers are going to continue to go up.  I think we have a lot of reports that are being entered right now and those numbers will be updated this afternoon.  We know that there will be additional cases and deaths entered later today.  Assuming normally disease progression, it looks like it's going to be our worst year with West Nile.  We have 416 cases of West Nile neuroinvasive cases.  2003, we had 439.  Looking at the progression, this will be on our worst year.  In 2003, we had 40 deaths.  Again, we're at 31 so far this year.  So we're closely evaluated the disease incidents from all counties in the state of the Texas, but focusing on certain counties that have been hardest hit.  If you want specific data for any county in the state of Texas I would direct you to www.tx.westnile.org.   

Again, on that website, we have the counties-specific data.  Let me focus in on two areas.  One is the Dallas situation, as of this morning, Dallas city health department have reported 309 cases.  152 of those were the West Nile neuroinvasive disease and Dallas County, alone, has 12 deaths.  Now, we completed our aerial spraying in Dallas County.  We completed it last Thursday night.  We sprayed 437,500 acres twice.  So a total of 875,000 acres were sprayed in the course.  The aerial spraying was just part of the overall response.  A combination of aerial are spraying and ground spraying.  In Denton County, has a smaller population but their incidents have been at the top of the state.  The local health department there, has reported 38 cases of West Nile virus neuroinvasive disease.  They have had two deaths.  We're working with Denton County right now, the cities within Denton County to determine -- we offered aerial spraying, some cities want aerial spraying and some have decided not to have aerial spraying.  30 cities of Denton County have opted into aerial spraying.  We're polling resources today.  That spraying activity will begin tomorrow night. 

A lot of our focus has been in Dallas and north Texas.  We're mindful that the disease is impacting other parts of the state, so we're working closely with several parts of the state of Texas making sure they're getting the support they need to confront this outbreak.  We're in close communication with health departments across our state.  Again, I want to thank the CDC for their ongoing and thank the media, they have been a critical partner as we have outlined the preventive measures that the people of state of Texas need to do in order to prevent their families and loved ones from getting infected.  I'll stop there and I’ll be open for any questions. 

LOLA RUSSELL:  Jennifer, we're ready for the first questions. 

OPERATOR: If you would like to ask a question please press star one.  Record your name.  One moment.  And our first question comes from Maryn McKenna from Wired Magazine.  Your line is open. 

MARYN MCKENNA:  Thanks for all doing this.  I wonder if the CDC or the Texas representative could give us a bit more detail about the neuroinvasive cases, are these milder or serious cases, anything like that. 

LYLE PETERSEN:  Hi, this is Dr. Petersen.  The neuroinvasive disease cases are three things, people with meningitis.  People with encephalitis which is an actual infection of the brain itself and people with acute paralysis, which is largely due to an infection of the virus of the spinal cord.  But other parts of the brain as well.  People with meningitis, generally are hospitalized.  But in the long run, do fairly well.  People with encephalitis, are often left with severe, often left with some neurological deficit over the long run and about 10 percent of the people, of those people will succumb to the infection.  The people with paralysis, will, about a third of them will recover nearly completely, a third will be left with some residual weakness and about a third will have very little recovery from the virus.  So the neuroinvasive disease cases, in general, are severe.  And, people are often left with long-standing neurological problems. 

MARYN MCKENNA:  So, following up, can you give us any kind of breakdown within the neuroinvasive cases especially in Texas?  In other words, do they conform to those, those rough categories that you just laid out, is there any kind of case count for the more severe ones? 

LYLE PETERSEN:  I can't speak for Texas.  But on the national level, I don't have those data in front of me, although we can get that data for you. 

DAVID LAKEY:  This is David Lakey.  The data that we have about 95 percent of these individuals end up being hospitalized.  40 percent have ended up in the intensive care unit.  In the Dallas area, I think we're too early to know the long term consequences of the outbreak that's taking place right now.  Our expectations would be the same as Dr. Petersen has just laid out. 

OPERATOR:  Our next question comes from Richard Knox of National Public Radio.  Sir, your line is open. 

RICHARD KNOX: What would be the earliest time that you would expect to see any impact from the spraying, especially in Dallas County, if it does the impact you want? 

LYLE PETERSEN:  This is Dr. Petersen, I can answer that and maybe Dr. Lakey can fill in more if necessary.  Generally, Dr. Lakey indicated that human case reporting is a lagging indicator, because it takes time for somebody to get infected, to develop symptoms, and then to go to the doctor, to get diagnosed and then report it.  So, even if we stop wells Nile virus transmission tomorrow, you would continue to see many, many cases reported over the coming weeks and even months, possibly.  So, human cases are lagging indicators.  So, we will not expect to find, to be able to evaluate the effect on human cases for some time.  And in the short run, what we're looking for is a decrease in mosquito counts.  After the spraying and that evaluation is currently being done right now.  In conjunction with local, state CDC team that's in the Dallas area and we hope to get some data on that in the upcoming days. 

RICHARD KNOX: Does Dr. Lakey have anything to say about that? 

DAVID LAKEY: This is David Lakey.  Again, my comments would be very similar to Dr. Petersen.  I think, you know, this is a disease that has an incubation period of 2 to 14 days.  We think we'll see more individuals presenting with this disease.  There's a lag from someone presents until they end up in the hospital.  The data ended up in the hospital ends up in the health department, so that human data is going to be several more weeks before we have that indication.  On the mosquitoes, though, our folks are looking at that data right now with the CDC team to see if we can have early indications that the number of mosquitoes has been decreased and I think we'll have that, again, I don't want to jump out, I think it was a week or so we'll have some of that mosquito data. 

LYLE PETERSEN: This is Dr. Petersen, I would also like to emphasize that there's a reasonably extensive medical literature on the effects of spraying on West Nile virus and related kinds of vector-borne diseases.  And what has been noted in fairly well conducted studies is that after these spray events, when all is said and done, it has shown a marked decrease in human cases compared to areas that have not been sprayed. 

LOLA RUSSELL:  Next question, please. 

OPERATOR: Our next question comes from Elizabeth Weiss from USA today.  Your line is open. 

ELIZABETH WEISS: Thank you so much for taking my call.  I had a question about the point that was made earlier, looking at the hurricane, you said that there had historically been an uptick, is that right after?  You assume because there was so much standing water, the services that might have gone to mosquito abatement may have been used elsewhere, an uptick later do you mean never or later? 

LYLE PETERSEN: What has been observed in the past, we have had a lot of experience with vector-borne diseases and hurricanes and floods?  What has been observed in the past that these don't really have a big impact on overall incident of disease.  The reason is, because, it's because, these hurricanes and flood events tend to disrupt the entire ecology of the area and interrupt this natural transmission cycle between birds and mosquitoes.  The virus normally exists in.  And so, the end result is, really hurricanes and floods don't have a major impact on our virus transmission.  But, naturally, before the hurricane happened, there were plenty of West Nile virus infected mosquitoes out there in the environment.  And so, what happens -- what was observed in Louisiana, was, after Katrina, was that, people who were out, houses were destroyed.  They were living out in the elements; there were a lot of workers out there and homeowners taking care of downed trees and the like.  Outdoors and exposed to the West Nile virus-infected mosquitos already there.  In some areas, where it was looked at, there was a small transient increase in West Nile virus transmission following hurricane Katrina, but if you look at the overall picture the hurricane really is not expected to have a major impact at all on what's happening across the country. 

LOLA RUSSELL:  Next question, please. 

OPERATOR: Our next question comes from Sherry Jacobson of Dallas Morning News.  Your line is open. 

SHERRY JACOBSON:  Hello.  I'm curious on why it's taking so long to figure out the effects on the mosquitoes here in Dallas county, simply because, it's been a whole week, actually, it has been two weeks since the first spraying and I’m so wondering, what exactly  you're looking for and why you won't know for another week? 

DAVID LAKEY: This is David Lakey.  I think we'll have data before the end of the week.  They're just doing some complex analyze with the CDC, the state and local making sure we have good sampling in the right areas.  The sampling that took place, you know, before the mosquito companies sprayed and after, that data looks promising to us.  They need to compare that with the overall data throughout that area before a hard statement of the effectiveness of it taking place.  The data looks promising.  It looks like there was -- with those companies, it looks like they were effective, but we want to make sure we're using that in conjunction with the other data, working with the CDC to make sure we have a good analysis of that data.  And I think that complete analysis will take a couple more days, at least, before we have that. 

SHERRY JACOBSON: Could I just do a quick follow-up, are you looking for pregnant mosquitos who are actually carrying the West Nile virus or a certain mosquito that's capable of carrying the virus? 

DAVID LAKEY:  They look at the traps as you talked about, they have the co2 traps that pull in other mosquitoes and they have to look to identify, what type of mosquito it is and vector carrying it.  They said that the mosquito and test pulled by, to see the virus is in those mosquitos.  So it's a combination of those tests. 

LOLA RUSSELL:  Next question, please. 

OPERATOR:  Our next question comes from John Gever from of Medpage Today. 

JOHN GEVER: Thank you.  You probably have answered this question before, but, what's different this year, having more mosquitoes, are there changes in the viral genome or are human social factors different. 

LYLE PETERSEN:  That's an excellent question, actually, and one we're very interested in, clearly, but, this has to be put in the perspective of arbor diseases.  Not only from West Nile but from other kind of viruses across the world.  It turns out that these outbreaks are very difficult to predict and they're trying to figure out what caused them.  Because the ecology of these viruses in nature is incredibly complex and influenced by many, many factors that all interact with each other, it's a really confluence of environmental factors that are important in determining whether an outbreak will occur and some of these factors are very difficult to measure, for example, one factor that's important is how many birds you have and how many immune birds you have or how many susceptible birds you have and that kind of data generally isn't available.  Factors are important.  That we can't easily measure.  Now, there's been a lot of speculation about the heat wave this year and could this have caused, or at least partially caused this outbreak?  And the answer is yes.  The heat wave could have had an important effect on whether this outbreak on curse.  We have seen previously, that large outbreaks have occurred during heat waves such as occurred in 2002 and 2003.  Other heat waves didn't produce outbreaks.  Due to a complicated system, the short answer to your question is, we don't know.  But, the heat wave this year could have been an important contributing factor. 

JOHN GEVER: Follow-up, have you looked at the viral genome has there been any evolution over time? 

LYLE PETERSEN:  This is an R and A virus, a type of virus that is known to mutate all the time.  R and a viruses do mutate rather rapidly.  From looking at the West Nile virus over a number of years in the U.S. that the virus is continuously changing.  Now, whether it is changed and has caused some difference is unknown.  This is something that we're looking at.  But, it's a complicated process and you won't get answer right away but it is something that we are looking at, we have no evidence right now, at this point in time, to suggest that this outbreak was caused by a change in the virus itself. 

LOLA RUSSELL:  Next question, please. 

OPERATOR: Our next question comes from Kathleen Doherty of WebMD.  Your line is open. 

KATHLEEN DOHERTY: Thank you.  Gentlemen, can you speculate on why the number of neuroinvasive cases is over half and have you tracked that through the years, is the percent of neuroinvasive cases getting higher and if so, why? 

LYLE PETERSEN: Right.  I'm glad you asked this question and it's a very confusing one.  Actually, but let me start out with the short answer.  The short answer is neuroinvasive disease cases, those people almost invariably end up in the hospital and are diagnosed.  And so, neuroinvasive disease cases are the best measure of what's actually happening with the epidemic.  Because these cases are reasonably well reported.  Or diagnosed and reported.  With the non-neuroinvasive cases, West Nile virus fever, the symptoms can range from no symptoms at all, to very mild, to actually quite severe and debilitating.  So, because of that range of illness, most people actually are not even -- they may go to the doctor and the doctor may say, well, you know, i think you got West Nile virus there's no treatment and that person is never tested.  Or the person may never come to the doctor at all.  The symptoms may be mild enough that they stay home.  Only about 2 percent to 3 percent of people with West Nile fever are diagnosed and reported to national surveillance.  And another factor is that we don't recommend routine testing for people with suspected West Nile fever since there's no specific treatment.  So, what the ratio of -- of encephalitis or neuroinvasive disease cases to West Nile fever, is an art fact, actually, there are many, many cases of West Nile fever that are not reported.  So, that ratio doesn't really have -- is not terribly meaningful.  Does that answer the question? 

KATHLEEN DOHERTY: Sort of.  A quick follow-up, to focus in on the neuroinvasive, is the likelihood of the neuroinvasive cases getting higher through the years? 

LYLE PETERSEN:  You mean, after somebody gets infected? 

KATHLEEN DOHERTY: Are you more likely if you're infected in 2012 to get neuroinvasive than in 1999 for instance? 

LYLE PETERSEN: We have no evidence that that's the case.  We, we think that the ratio of neuroinvasive disease cases to infections is relatively constant number.  We have no evidence that that is changing. 

LOLA RUSSELL: Next question, please. 

OPERATOR: Our next question comes from Miriam Falco from CNN Medical News Atlanta.  Your line is open. 

MIRIAM FALCO: Thank you for taking the question.  One basic question, can you tell me what the age range of the deaths of the 66 total deaths and then, also, the subsequent pooling of water that can be expected after Isaac dumps water could be contributing to more mosquitos, correct?  Standing water is an outcome.  I'm just a little confused about what you were saying earlier on that. 

LYLE PETERSEN: Right.  First thing to answer your question about the age range of the -- you asked about the age range of neuroinvasive cases and the deaths. 

MIRIAM FALCO: That and the 66 people who have died so far?

LYLE PETERSEN: If you could contact the press office afterwards, they will get you that data; I just don’t have the information in front of me.  The question about the flooding, the mosquitos that spread West Nile, which are called culex mosquitoes, they breed in small nutrient-rich pools of water, they like small pools of water like you might find in a tire. Water in a tire in somebody’s backyard. Now, so, what happens is, when you get a big rainfall event, many of those small pools of water are simply washed away.  So huge floods can certainly eliminate, or heavy rainfall can certainly eliminate breeding sights rather than create them.  On the other hand, if the water has been sitting around for a long time and then creates small pools of water it evaporates, certainly that can promote mosquito breeding sites.  So it's actually a very complicated process.  But in the end, what we have observed is, we don't see a huge effect on West Nile virus transmission.  Because some mosquito breeding sights are eliminated and others are created. 

MIRIAM FALCO: Okay, if I can follow-up with Dr. Lakey, just again, what specifically has been happening in Dallas that's contributing -- has Dallas had more water than usual, why are so many cases from an environmental perspective in the Dallas area? 

DAVID LAKEY: I don't think we know yet.  I think there have been several theories.  I think Dr. Petersen laid out some of those that we agree with related to drought, followed by rain in that area.  You know, we continue to preach a lot of those messages of making sure you're draining your yards.  Why the outbreak has occurred there in the north Texas area?  I don't think we have a full understanding of that yet.  Related to your question just a little bit ago about age range, we have had, you know from the neuroinvasive disease, predominantly it's been in the older individuals with rates per 100,000 much higher in the 70s, 79, a rate of 6.3 for those 80 and above, 7.3.  We have had cases in all age rangers.  So, for 10 to 19 years old, we’ve had an incidence rate of .3 per 100,000. For 20 to 29, a .6. From 30 to 39 year old individuals, a 1.2. For 40 to 49, an incidence rate of 1.6.  From 50 to 59, of 2.9.  And from 60 to 69, 3.2. 

LOLA RUSSELL:  Another question, next question. 

OPERATOR: Next question comes from Robert Lowes with Medscape Medical News. 

ROBERT LOWES: I have a question what is the status of developing both a vaccine for West Nile virus and also a treatment for it, I have wondered since this virus has been, you know, has been here or detected since '99, why don't we have a vaccine, why don't we have a treatment?  Are there any intrinsic barriers to developing either treatment or a vaccine?  So, talk about the status of developing that and whether there's any barrier to developing those two things. 

LYLE PETERSEN: Yeah, let me start -- with -- this is Dr. Petersen.  Let me start out with the vaccine issue, there are four licensed vaccines for horses.  So, we know that, at least, excuse me, at least in horses, that we can create an effective vaccine, using a variety of technologies.  There has been a few of those vaccines, or related vaccines to the horse vaccines that have been conducted in early vaccine clinical trials in phase one and two trials which have actually been successful.  The problem has been, with instituting a phase three vaccine is that we're dealing with a low incidence disease, most years.  Of cases that are widely dispersed and so, the thought of trying to produce a phase three clinical trial to show efficacy is fairly daunting.  In addition to the fact, we can't totally predict what's going to happen with West Nile virus incidence in upcoming years.  Tremendous market risk to a vaccine manufacturer.  For those reasons, there's been no vaccine that's been taken to a phase three clinical trial. 

Now, as far as the treatment goes, there are two issues, one issue is, even with related diseases like Japanese encephalitis which have a much higher incidence in endemic areas, there has been no treatment that has been shown to be effective in randomized clinical trials.  West Nile virus is not Japanese encephalitis, the bottom line is, it's difficult to make a drug that you can prove that's going to be efficacious for this type of virus.  The second problem is the numbers of clinical trials have been started.  Randomized clinical trials, but none of them has been able to take on the completion because of -- of low patient enrollment.  And for the same reasons, you have problems with doing clinical trials with vaccines, you have the same problem with trying to prove that a drug is effective and that this is a low-incidence disease, that cases are widely dispersed.  And so, you end up having to enroll hundreds of hospitals trying to get enough cases.  And, some years are low-incidence years and some years are high-incidence years.  It turns out trying to get enough patients in a randomized clinical trial is difficult because you can't predict where the disease is going to occur.  In addition, West Nile is largely a rural and suburban disease and where patients show up or present to hospitals aren't the ones traditionally that do clinical trials.  And so, there are a number of logistic problems that have made clinical trials for treatment very, very difficult in practice. 

ROBERT LOWES: I have one follow-up question, can you expand on why it's hard to make a drug that can prove to be effective for this kind of virus?  You compared this virus to Japanese encephalitis. 

LYLE PETERSEN: Part of the problem is that, by the time patients present, in the ones that you're concerned about are with ones with neuroinvasive disease. By the time someone has come in with neuroinvasive disease, the virus has already invaded their central nervous system and that makes it very difficult, both from a drug delivery standpoint, because it has to enter the central nervous system in high concentrations or at least in sufficient concentrations to take care of the infection, because some neurological damage has probably already been done since the virus has already invaded the central nervous system and we know that these infections progress rather rapidly in most people and so, the combination of that in practice, has it made it very difficult to try and find an efficacious drug.  As you know, there aren't a lot of drugs in our pharmaceutical that are anti-viral.  Lot of more antibacterial than antiviral. 

LOLA RUSSELL:  Next question, please. 

OPERATOR: Our next question comes from David Nogueras, with Oregon Public Broadcasting. 

DAVID NOGUERAS: Hi, Thank you so much for taking my question.  Here in Oregon, we had our first two human cases of West Nile virus confirmed yesterday.  I wonder from the perspective of the public here that's following the news, following the work of reporters that may be on this call and they see all of the activity in Texas, I wonder if they would be less likely to buy bug spray than somebody in Dallas.  What should a member of the public in some of these states like ours that have relatively few cases, what should they conclude about their risk of contracting West Nile and getting sick from it? 

LYLE PETERSEN: One thing to remember is that the virus is endemic, at this point, throughout most of the United States.  Certain areas high in the Rocky Mountains may not have it.  But most of the country has endemic virus, it circulates every year.  It's just a matter of how much.  And so, what we have observed is a very high rate of transmission in certain states this year.  Less transmission in other states, but it doesn't mean that people aren't -- there's no risk in other areas.  There's a risk almost everywhere in the U.S.  We're certainly, in areas where they had outbreaks or having high number of cases, we're certainly emphasizing that people follow the recommended precautions.  In other areas, the risk may be lower but it's still not zero.  And West Nile virus isn't the only mosquito-borne virus out there as well.  So, I think it's prudent to follow the precautions no matter where you are. 

DAVID NOGUERAS: No follow-up from me.  Thank you. 

LOLA RUSSELL:  Next question. 

OPERATOR: Our next question comes from Maggie Fox of NBC News.  Your line is now open. 

MAGGIE FOX: Hi.  I just wanted to ask did everybody get all the numbers, can we have all the numbers on the age ranges and Dr. Lakey, you threw out some really interesting numbers there, and if we can get those somewhere there on your website which is really good, by the way, that would help taking it down shorthanded it's a built difficult. 

DAVID LAKEY: I understand that.  My public information officer will have that data and we'll make sure that's available to folks. 

MAGGIE FOX: That's great.  Thank you. 

LOLA RUSSELL:  We'll be talking our last question now. 

OPERATOR: Our last question comes from Lyndsey Knecht of KERA News. Your line is now open.  Disconnected.

LOLA RUSSELL:  Do we have anyone else in queue? 

OPERATOR: We do.  Don Finley of San Antonio Express News. 

DON FINLEY: Thank you.  We have been hearing about transplant patients may be at higher risk of developing neuroinvasive disease.  I was wondering if other immunocompromised groups like cancer patients might be at similar risk or something unique about transplants? 

LYLE PETERSEN: The answer to your question is, there are a variety of conditions that that have been an increased risk of West Nile.  People with kidney disease, for example.  People with cancer or other immune-compromising conditions certainly have been shown to be at increased risk.  It often times hard to define exactly the degree of risk.  There's a different strata within those broad category of immunocompromised.  But, certainly, kidney disease was actually one of the things that we discovered was a risk factor.  Cancer is another risk factor.  People who have had transplants are another risk factor as you the point because they're taking immunosuppresants.  People who may take immunosuppresants for other reasons such as rheumatoid arthritis or some other conditions may also be at increased risk. 

DON FINLEY: Thank you. 

LOLA RUSSELL:  We would like to thank everyone for their participation today.  We'll have an audio file as well as a transcript after we have closed this telebriefing today.  If you have questions for the media direct to the CDC you can call your office at the news media branch.  If you have questions that are specific for Texas and Dr. Lakey, you can reach out to Carrie Williams who's his press officer or press director.  That's 512-776-7119.  Again, thank you for your participation today. 

OPERATOR: That concludes today's conference.  Thank you for your participation.  You may disconnect at this time.  

###
U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES