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Press Briefing Transcripts

CDC Telebriefing on Investigation of Human Cases of H1N1 Flu

May 15, 2009, 1:30 p.m. ET

  • Audio recording (MPEG) MP3 audio file

Operator: Welcome, and thank you all for standing by.  At this time, I would like to remind parties that your lines are on a listen-only mode until the question and answer session, at which time you can press star one to ask a question.  Today′s call is being recorded.  If you have any objections, you may disconnect at this time.  I will now turn the meeting over to Glen Nowak. Thank you, sir, you may begin.

Dave Daigle: Hi, this is actually Dave Daigle, from CDC’s Media Relations.  Today we′re going to have Dr. Dan Jernigan, who is the deputy director for the CDC′s influenza division,  update us on novel influenza, H1N1 virus, that′s circulating.  Dr. Jernigan will provide a short statement and then take questions.

Dan Jernigan: Thanks a lot.  The novel H1N1 virus continues to circulate in the United States and people continue to be ill and to be hospitalized.  Today we had our fourth death reported from Maricopa County in Arizona.  There are 22 U.S. states that are reporting widespread or regional influenza activity, which is something that we would not expect at this time.  There are, again, more deaths and hospitalizations that we′re monitoring.  There is increased amount of flu-like illness in New York City, in schools and in Houston in schools as a result of many children becoming sick with influenza-like illness that we presume will be the H1N1 virus.  There are at least, in terms of our case counts, over 4,700 probable and confirmed cases in the United States.
That number is one that we′re continuing to follow.  We will continue to get those numbers from the states that report to us, but the numbers are becoming less important as we move through the increasing numbers of cases.  And so we are monitoring the influenza through other surveillance systems that the CDC and state health departments maintain.  What we′re seeing is there is geographic variation in H1N1 flu activity, and that is the activity appears to be highest in the Pacific Northwest and in southwest and in other areas of the country.  So we expect, just as with seasonal flu, that the flu will appear in different places.  It will come, it will go, so we′re trying to monitor that.  But overall, we′re seeing increased activity. 

There are four known fatalities, like I mentioned.  There are 173 hospitalizations that have been reported to CDC so far.  Most of the cases that we have, again, remain among younger people in the ages of 5 to 24 years old.  But unlike seasonal flu, we′re still seeing relatively few cases in older individuals, and that may be just a matter of time until the virus is capable of getting to those populations, or maybe that it is a reflection of a difference that this particular virus has in the populations that are affected. 

Internationally, the World Health Organization is reporting over 7,500 confirmed cases in 34 countries.  We worked -- we′re continuing to work very closely with our southern hemisphere partners to monitor influenza activity as we expect that it will increase over the next months during their flu season in the southern hemisphere.  In Mexico, there continues to be disease.  It is just as in the United States, appearing in different places at different times.  Some areas being more significantly affected than others. 

The estimates of the number of confirmed and probable cases in the United States are probably not the best indicator of transmission at this point because of the effect of testing, that is early on, a lot of tests were done but now the amount of testing is more targeted.  And so they likely are underestimates of the actual number of people infected.  And so we do know that in some places there are reporting thousands of suspect cases, and so as we know more, especially as we know more from the field teams that are doing household surveys and so forth, we will be able to have better estimates of the numbers of cases that we estimate are actually caused by influenza, the outpatient kind of illness. 

There has been some discussion about the virus mutating.  We′re working very closely with W.H.O., with other countries and with academics and other collaborating centers around the globe to look at these viruses, to look at the gene sequences in them.  And so far, we′re not seeing significant evidence of any mutation towards more virulence in the U.S.  However, we′re continuing to look at these things, trying to see whether or not there might be different kinds of illness that is caused by them.  But at this point, nothing that we are able to say about any change that has occurred in the virus. 

In terms of CDC′s response, we have more than 100 CDC staff that are in the field.  Also in terms of helping to detect the H1N1 virus around the globe, we are working with the World Health Organization to distribute test kits.  We distributed to 95 laboratories in all 50 states in the U.S. and to 237 laboratories in 107 countries.  And we hope that having those very sensitive tests out around the globe, we will be able to get a good sense early on about where the virus is occurring.  At this point, we′re not seeing the seriousness of illness that was initially reported in Mexico, in the United States, but this certainly does not mean that the outbreak is over.  The H1N1 virus is not going away.  We know that the outbreak is not localized but is spreading and appears to be expanding throughout the United States. 

So, this is an ongoing public health threat and continued vigilance and action is needed.  And for the upcoming fall flu season, it is critically important for everyone now to be prepared and to follow with us and if you have illness, to see your doctor.  If you′re sick, stay home.  Use those appropriate hygiene that we have described and follow with us on our website regarding the numbers of cases, the amount of illness and the guidance that′s being developed at

Dave Daigle: Thank you, Dr. Jernigan.  Operator, at this time, we will take the first question.

Operator: The first question is from Robert Lowes, MedScape Medical News.  Your line is open.

Robert Lowes: Thank you, Dr. Jernigan.  Now, The New York Times reported that a researcher investigating cases in Mexico found that one-third of the hospitalized patients from this flu did not have fever, which is odd in his view because that is typically a symptom of seasonal flu, and one-third of the patients he looked at didn′t have that symptom.  Is that also something that you have discovered in the United States?  And if so, what does that say about the virus and screening for it? 

Dan Jernigan: Well, the report indicated that a number of people did not have fever.  That is not what we have seen so far in the United States.  Of those that are hospitalized, all of those that we have been following have had fever except for those who might not be expected to have it, those older individuals might not have it, and some that are severely ill may not be able to mount a fever.  But as a significant symptom or sign that is associated with this particular virus, we are not seeing the absence of fever as a prominent component.

Dave Daigle: Thank you, Robert.  Next question, please, operator.

Operator: The next is from Rob Stein, Washington Post.  Your line is open.

Rob Stein: Yeah, Hi, thank you very much for taking my question.  I had a couple of questions.  First was, do you have any more information about the -- the latest death in Arizona?  And where the other three were just to remind us.  And also, I had a question about a vaccine.  There was an announcement today that one of the manufacturers was planning to go ahead and proceed with an adjuvant vaccine.  I was wondering if that was something that the United States would be -- would be able to -- and interested in using if they go ahead with that.  

Dan Jernigan: In terms of your first question regarding deaths, I would refer you to the Maricopa county and Arizona state health departments for further information on that.  They have put out some press releases and have some information on their web.  The other sites that deaths have occurred, there are two in Texas and one in Washington state so far.  In terms of the adjuvant vaccines, that is something in other countries they have used adjuvant vaccines for seasonal influenza.  There were early on some trials of adjuvant vaccines for the Avian influenza pre pandemic vaccine but in the United States, it′s not something that has been approved for use by FDA but we look forward to seeing how well that vaccine works and the potential for its use here. 

Dave Daigle: Thank you.  Next question, please, operator.

Operator: The next is from Donald McNeil, The New York Times.  Your line is up.

Donald McNeil: Hi, Dr. Jernigan.  There′s a growing gap between the usefulness of that 4,714 confirmed and probable cases and the actual number of cases around the country.  I know the teams aren′t all in yet but do you have any sort of estimate at all about how many cases we′re talking about across the country?  Is it 10,000, 20,000, 30,000?  Any sense at all of what the real number is like? 

Dan Jernigan: Yeah, I agree with you regarding the utility of the numeric figure for influenza.  And for that reason, we don′t enumerate the numbers of individual cases each year in the United States.  Somewhere between 7 to 10 percent of the U.S. population each year gets influenza, which is maybe 21 to 30 million people a year.  And so with the amount of activity that we′re seeing now, it′s a little hard to make an estimate about what that means in terms of the total number of people with flu out in the community.  But if we had to make an estimate, I would say that the amount of activity we′re seeing with our influenza-like illness network is probably upwards of maybe 100,000, but that′s something we will have a much better estimate of once we get the information back from the field teams that are collecting that data.

Dave Daigle: Thanks, Don. Next question, please, operator?

Operator: The next is from Helen Branswell, The Canadian Press.  Your line is up.

Helen Branswell: Hi, thank you very much for taking my question.  I was just looking at flu watch for this week, or FluView, excuse me.  And it′s really kind of interesting to see there seems to be quite a spike in activity not just for the new H1N1 but for a bunch of different types of flu.  Is that an artifact of the fact that more testing is being done now than would normally be done this time of the year, or is something weird going on? 

Dan Jernigan: I can with great certainty say that that is a reflection of the amount of testing that′s going on.  For those of you that follow this kind of thing, if you′re looking at the curves, you will see that there′s a nice bell shape to our season from last year -- from this past season, rather.  And that significant increase at the end of the season, that significant increase is a reflection of this profound amount of testing that has gone on in the last few weeks.  The interesting thing, as you point out is that when we start testing everyone that looks like they have flu, we find a number of them that do have flu and what we′re finding is only about half of those have the h 1 -- the new h1 virus.  The others have the circulating seasonal kinds of viruses.  And so what that means is that there is even at this end of the usual season, the regular season, a fair amount of regular viruses that are circulating in addition to these from h1.  But I think the important message is that we would be expecting to see the season to be slowing down or almost completely stopped from the kinds of surveillance systems that we normally monitor.  But what we′re seeing is that there are some areas that actually have reports of the amounts of respiratory disease that are coming into their clinics that are equivalent to peak influenza season, and so that′s an indicator to us that there′s something going on with the amount of influenza disease out there.  But in terms of us enumerating that, we′re not able to do that at this point.

Dave Daigle: Thank you, Helen.  Next question please, operator.

Operator: The next is from John Cohen, Science Magazine.  Your line is open.

John Cohen: Hi.  Thanks for taking my call.  I wanted to clarify something that Helen Branswell just asked and also ask a question about vaccines.  There′s a report that several European countries have secured purchase with Glaxo of H1N1 novel, H1N1 for next year.  If the U.S. makes that decision, who makes that?  Is that an HHS decision?  Is that a CDC decision?  Who actually makes it?  And is there a time line cutoff date when the decision will be made?  The other question -- I can wait until you answer the first one.  Thanks. 

Dan Jernigan: Yeah, I think vaccine decisions are made through an inner agency group within the federal government, predominantly through HHS.  So that inner agency group is actively engaged right now and they are working through these issues and the key decisions are likely to be made soon regarding the U.S. plans.
Dave Daigle: The time line? 

Dan Jernigan: The time line, I don′t have a time which that is but it is as soon as possible.  There are a number of factors that you know about manufacturing and so forth that require these decisions to be made very quickly. 

Dave Daigle: John, what was your question about the FluView? 

Dan Jernigan: He had a second question.

Dave Daigle: Yes. 

Dave Daigle: Operator, I think we might have lost John.

John Cohen: I′m here. 

Dave Daigle: Excellent.

John Cohen: I′m here.  

Dave Daigle: John, did you have a second question about FluView? 

John Cohen: I did.  You′re saying there′s increased activity from normal surveillance but it′s confusing given that there′s so much more surveillance, how do you factor out whether it′s the increased surveillance that′s leading to this abnormal activity when 50 percent of what you′re seeing is seasonal flu? 

Dan Jernigan: Right.  I think it′s a difference between the types of surveillance systems.  So one of them is the -- what we call viral logic surveillance.  It′s where we actually collect the viruses and enumerate them, characterize them, et cetera.  And so that′s one that is completely dependent upon people sending in specimens where they can be appropriated tested and characterized.  And that′s where you see that tremendous increase at the end of this season.  The other is an influenza illness network of 4,500 clinicians and other providers that tell us how many people are coming into their clinics for all causes and also tell us how many of those people are coming in with fever and influenza-like illness symptoms.  And so that one is going to be less affected by media and by other factors and is not one that we stimulate through any kind of public health activity but would be in part, perhaps, reflective of some media interest.  But even in the time that the interest has waned, we see that those folks are still coming in.  And what we also see is that those upticks in certain regions are consistent with anecdotal reports and other reports we get of school closures and of increased illness in communities. 

Dave Daigle: Thank you, John.  Next question, please, operator.

Operator: The next is from David Brown, Washington Post.  Your line is open.

David Brown: Yes, Hi, thanks.  There′s a report that there is a -- yet another new H1N1 virus that has been found in the states of Durango, Zacatecas and Jalisco in Mexico that is distinct from both this -- this swine H1N1 and the seasonal Brisbane H1N1.  Have you heard of this?  And can you tell us anything about this?
Dan Jernigan: We′ve heard of some reports about that, but I have not had any direct information about the specifics of that case.  So there′s ongoing dialogue between us and the folks that are in Mexico and so as we know more about that, we will be able to let people know.

Dave Daigle: Thank you, David.  Next question, please, operator.

Operator: The next is from Stacey Singer, Palm Beach Post.  Your line is open.

Stacey Singer: Hi.  Thanks for taking my call.  My question is in the serious cases where we′re seeing hospitalizations in this country and in Mexico and the deaths as well, has the cytokine storm frequently play a role in the deaths?  What are people dying of when they′re dying? 

Dan Jernigan: The issue of cytokine storm is one that clearly is something that influenza has been associated with in the past.  We have every reason to believe that could be a part of the cause here.  The numbers of individuals that have died that we actually have appropriate tissues and enough information to study is still pretty small.  We have seen that some individuals do appear to have what looks like viral pneumonia.  And so that is a direct infection of the lower respiratory track by the flu virus.  And so as we learn more, I think we′ll be able to say if there are unique features about the H1N1, but what we are seeing so far are the kinds of outcomes that have been previously described for influenza, but that′s something that we are very interested in and we want to learn more about.

Dave Daigle: Thank you, Stacey.  Next question, please, operator.

Operator: The next is from Michelle Merrill, Hospital Employee Health.  Your line is open.

Michelle Merrill: Thank you very much.  I had a couple of questions.  One is, do you have any idea as to how many health care workers have been infected either in the community which could pose a threat to patients in the hospital, or due to occupational exposure?  And I also have a second question about your respiratory protection guidance.  While that guidance has remained the same, state and local health departments around the country have differing guidance.  And I′m just wondering what you think about that situation in which, you know, does that create a confusion because depending on where you live, you have different guidance about the level of respiratory protection.

Dan Jernigan: Right.  I think there are a number of issues that have to be taken into account.  And you′re very aware of all of them regarding protection of the workers and the ability to -- to do your work given all of the protective equipment and other requirements for worker protection.  At this point there have been no changes to the guidance that′s on our website.  The discussions that we′re having are with NIOSH and with OSHA and with others to try to identify what is the most appropriately science based guidance to offer protection in this setting. 
In terms of the numbers, your question was also about the variation in guidance.  When the guidances are written, in general, of course, they are all interim guidance at this point but those guidances are intended to have or offer some flexability so that some localities based on the context can make some decisions.  And so for various guidance on our web, we allow for there to be some flexibility so that states can take into account the unique activities and the unique amount of disease in those activities -- in those jurisdictions and come up with the appropriate guidance.  In terms of the numbers of confirmed or probable health care personnel, there are 56 confirmed or probable that we know of in 20 states.  And that represents about 1.4 percent of all currently reported cases.  In terms of where their exposures occurred and whether or not they traveled to someplace or had exposures elsewhere and brought it into the health care setting, those are things that our investigative teams are now working through.  Because we think that′s very important information that we want to help to inform decision-making but the numbers of case that we have that we can ask those questions of may be too small for us to get some of the important questions answered at this time.

Dave Daigle: Thank you, Michelle.  Next question, please, operator.

Operator: The next is from Kate Trainor, AJHP.  Your line is open.

Kate Trainor: Hi.  Thank you for taking my question.  I know CDC has said you′re going to be looking very closely at the southern hemisphere for what develops down there.  So I was wondering if you can tell us what specific signs you might be looking for that severe disease might or might not be coming this way in the fall.  And sort of on the other side of that, how do you weigh that information against the fact that the harder you look, the more stuff you′re going to find, kind of similar to what′s going on here as far as finding both the seasonal and new H1N1 flu in the northern hemisphere? 

Dan Jernigan: Right, well over the last few years, the CDC and other public health agencies have been working with folks in the southern hemisphere and in tropical areas to try to characterize with the baseline what the amount of influenza is through their seasons.  For many countries in the southern hemisphere, their seasons are just now starting and will peak in the next month to two.  So we want to be able to work there to identify a couple of things in particular.  We want to look at severity and we want to look at the spread of infection.  So there are different ways to do that.  We work with the laboratories down there to characterize the viruses that are circulating.  That will tell us if viruses thats we have chosen for a vaccine are still good or the right ones that are likely to come back.  It will also tell us if there′s changes in the virus and also if there′s development of antiviral resistance.  The next thing we would want to look at is people who are admitted for severe acute respiratory illness, and so there are protocols and processes that have been worked out over the last few years that will be implemented through our partners in those regions to try to characterize that.  And then finally there are estimates of the amount of influenza-like illness in the community, that we’ll be working with them as well.

Dave Daigle: Thank you, Kate.  Next question, please, operator.

Operator: The next is from Kafi Drexel, New York 1.  Your line is open.

Kafi Drexel: Hi, how are you?  Earlier today in New York City′s press conference regarding the latest cluster of H1N1 at an intermediate school here, the question was posed kind of, why has this been happening in schools?  And our outgoing health commissioner himself commented that it′s a little surprising to them because they usually don′t see this in a regular flu season where there are situations where 20 or 30 kids at a time come in with high fever on a single day.  And, also, it doesn′t seem like this is impacting as many older adults as usual at this point.  So do you have any further insight as to why some of these clusters may be happening more in school environments?  Are you looking at whether or not H1N1 is acting differently in younger people?  And then also, regarding the vaccine, if you could talk a little bit more specifically on where the CDC is as far as what′s happening with that and what the thinking is as far as going ahead and developing that for fall.  Looking ahead. 

Dan Jernigan: Yes.  I think you′re pointing out an important feature of influenza, and that is that younger people are often more affected.  If we look at who gets influenza each year, the predominance, if you want to call it reservoir of influenza is in the school-aged children′ so, schools therefore are a place where those younger children congregate and then can share their influenza viruses amongst themselves and then that often then allows then for other folks to become infected as well.  For this particular H1N1, it′s following along seasonal flu in that sense.  But when we look at the blood of people who have -- that we have collected over the past few years, we′re able to see that the older you are, the more likely you might have some evidence that you could respond somewhat to the H1N1 novel virus that′s circulating.  And so what that suggests to us is that not only are kids as usual affected more, there is a chance that they may be completely naive or immune, not have any immunity to the virus.  So that suggests that we want to do something to make sure that we protect them.  And so while in the usual season, we may not close schools.  Now it may make sense to do that.  But, my understanding is in New York City these school closures have occurred because of the staffing issues and the number of peoples affected, and I believe that was their decision.  In terms of the vaccine, as you know, there′s many steps involved with producing a flu vaccine.  And we′re working with under HHS agencies and vaccine manufacturers to go through those steps as fast as possible.

Dave Daigle: Thank you.  Next question, please, operator.

Operator: The next is from Donald McNeil, The New York Times.  Your line is open.

Don McNeil: Hi.  Thank you for taking a second one.  I wanted to ask about infection control in schools.  We′re seeing pictures now in New York City of the custodians wiping down door handles and washing the schools but if the schools are being closed for a week and the virus dies in 48 hours, that seems like a cosmetic exercise and I′m wondering -- I don′t notice any infection guidelines, infection control guidelines for school on the CDC website or any other.  I wonder if you have suggestions or plans for schools and what they would be and what do you do when the students come back into the school so you don′t get a resurgence? 

Dan Jernigan: In terms of environmental infection control issues, there are different guidances that are not on the H1N1 influenza swine -- excuse me -- site.  However, those guidances are on our infection control site and can be found there.  But in particular here, the closing of the schools is in addition to allow for time so that transmission among those folks who are not in school can either burn out or get -- have an opportunity to not be spread within the school environment.  In terms of the specific guidance for infection control in schools, we do not have that on our website, but there are places on the CDC website that get out issues of environmental cleaning.
Dave Daigle: Thank you, Don.  Next question, please, operator.

Operator: The next is from Helen Branswell, The Canadian Press.  Your line is open.

Helen Branswell: Hi.  Thanks for coming back to me as well.  Dan, I′m clear about your answer to me and to John Cohen about the amount of activity that′s going on now.  Do you think that there is more activity than would be normally seen at this time of year, or is it just more testing is being done?  Is something weird going on?  Is there an interplay of these viruses? 

Dan Jernigan: I think the simple answer is yes, we think there is more activity.  We are seeing it anecdotally, we are seeing it in our surveillance systems and we have a novel virus that has emerged for which there is no immunity in the fair amount of the population.  So everything at this point suggests that there is ongoing activity and we′re seeing that in other countries as well, in this western hemisphere.

Dave Daigle: Thank you, Helen. I have just been handed a late breaker, so we will have Dr. Cetron make a short announcement.

Marty Cetron: I just wanted to indicate that later today, CDC would likely be posting a downgrade to the travel warning that is currently up regarding Mexico, which is at a level four alert that suggests folks defer non essential travel to Mexico.  That will be downgraded to a travel precaution.  And this will focus on providing particular precautionary advice to those individuals who are at high risk for complications of influenza.  As Dr. Jernigan has probably already discussed in his brief, very high proportion of our hospitalizations are occurring among those who have underlying health conditions that put them at risk for complications, and our travel precaution will be particularly providing advice to those individuals regarding seeing their physician and getting specific advice on the feasibility and reasonableness for them.  But the overall travel alert will be lowered from a warning to a precaution in that regard.  And this information that we expect will be on the -- on the CDC website later, by the end of the day today.

Dave Daigle: Dr. Martin Cetron, is the Director of the Global Migration and Quarantine Division.  We do not plan a briefing right now pending any major developments for Saturday and Sunday.  I want to thank everybody for joining us.  Thanks very much.  Good-bye. 




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