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Press Briefing Transcripts

CDC Briefing on Investigation of Human Cases of H1N1 Flu

May 7, 2009, 12 noon EST

  • Audio recording (MP3) MP3 audio file


Operator: At this time all lines on listen only.  During the question and answer session, you may press star one to ask a question.  At this time, I'll turn the call over to Mr. Glen Nowak, you may begin, sir.

Glen Nowak: Thank you, thank you all for come calling in for today's press briefing as well as being here.  Today's update will be conducted again by Dr. Richard Besser, acting director of the CDC, I'll turn the podium over to Dr. Besser. 

Richard Besser: Thanks very much, Glen.  Thanks for joining today's briefing.  This continues to be a dynamic situation.  What I want to do today is provide an update on the current situation, but also talk about some of the studies going on to identify information gaps, to provide better information for guidance.  First thing I would like to talk about though is our school guidance.  And we issued changed modified guidance a couple of days ago.  In this guidance, we called on an approach that focused on individuals who are sick and called on personal responsibility so that if a child was sick or if a grown-up was sick, they stayed home for seven days so that their illness would run its course and they wouldn't put other people at risk.  I want to address the issue of these children returning to school.  And I know that people are concerned well, what if they're still sick, what if they put my child at risk?  You know, I think we should flip this around and congratulate these children and their families for doing the right thing, for following the recommendations for keeping their children home when they're sick.  We know that most children shed this virus for seven days.  And that staying home for that period staying home at least one day past symptomatic if you're symptomatic for seven days will greatly reduce the risk of transmission.  We want to encourage children at that point to return to schools an encourage schools and families to welcome them back.  We're doing additional studies to look at viral shedding and I'll talk about that in a moment.  An update on diagnostic test kits, I've mentioned these have gone out around the country so states have these kits.  There is a ramp-up here from when a state receives the kit to when they get skilled in using that kit and get validation.  While states can report a suspect probable case where they have that validation, that validation step is very important and many states are holding on that validation before reporting their own results.  Much of the confirmatory testing is still being done at CDC.  We're working very hard to try and keep up with that testing.  We've had requests for diagnostic kits from around the world.  And we feel it's an important role of CDC to meet some of that demand and we have received requests from 131 countries and so far have been able to provide kits to 78 countries we're working to meet the other requests as well. 

Moving on to today's case update.  These numbers are as of 11:00 A.M. today.  We are reporting 1,823 probable and confirmed cases in 44 states.  This is an increase of around 330.  We are reporting 896 confirmed cases in 43 states, that's an increase of 254 cases and around 925 probable cases.  Again, I want to reiterate that as soon as I say the numbers, they're wrong because ongoing testing is taking place at CDC; it takes place in every state.  And so as you go to states, you will come up with numbers than are on our website.  That is expected.  The work continues.   The median age remains 15.  The range is one month to 87 years.  12 of the cases are under age one.  So I do want to remind you that individuals of all ages can acquire this virus.  Only about 10% of confirmed cases have a travel history from Mexico.  This indicates as well ongoing transmission in communities.  We would expect as this travels more around the country, that we're going to see that number go down further.  So that while there may have been introduction from travel to Mexico, the spread that's ongoing does not require travel to Mexico.  58% of our confirmed cases are under 18 years of age.  5% have been hospitalized.  That's 42 of the 896 confirmed cases.  And two individuals died from this disease.  The W.H.O. numbers from earlier today, 1,893 cases in 23 countries.  They use different time periods, so it's very hard to look and see the numbers line up by country, but we report the W.H.O. numbers once a day based on their reporting scheme.  The case counts in Canada and Spain continue to increase by large numbers.  In terms of what's going on in Mexico, there are 949 confirmed cases and 29 confirmed deaths.  What they're seeing in Mexico is very similar to what we're seeing here and that's a series of outbreaks at different stages of progression around the country.  And that's what you expect.  Just like we see here with seasonal flu, you'll see seasonal flu occurring at different stages around the country.  They're seeing that in Mexico.  Businesses are reopening around Mexico, country-wide today and that's going to be followed by their school's reopening next week.  I really want to recognize the collaboration that's been taking place in Mexico.  They have been very open to working as part of a trinational effort and inviting experts from Canada and United States to participate.  This is really, I think, a remarkable model and example for the global community.  When you see a new emerging infection, you really need to bring to bear in the place that it's occurring the best scientists around.  And so the World Health Organization, the Pan American Health Organization, Mexico, U.S., Canada, all working there together to try and understand the situation.  What we've learned in Mexico has been incredibly important to our response efforts here in the United States and I want to personally thank the public health community there for welcoming us as part of that effort.  Again, I want to put the numbers into context.  We expect to see a large increase in those numbers over the coming days.  There are still backlogs in most states in terms of testing and as those backlogs are taken care of, the case numbers are going to go up.  Another point I want to make is that when it comes to testing, there's usually a priority put on the sickest individuals.  And so you may see in certain states higher -- what appears to be higher rates of severity and that is usually a testing artifact.  So what people will do is test hospitalized patients first, test sicker individuals second and then work to see what is going on in the community as a whole.  As we move forward, we will be moving to much more of a system like we used with seasonal flu.  And those of you who have followed the seasonal flu picture and have looked at our website, we tend to report on flu activity.  So at some point reporting on individual cases no longer has value from a public health perspective but knowing where in the country we're seeing a large amounts of flu activity does remain important.  So we will transition into that kind of a system.  Right now, we can say that the virus is continuing to spread both domestically and around the world. 

Let me talk about some of the public health actions and just give you a heads up on a couple publications.  Later today, the New England Journal of Medicine will be posting online two studies, one is looking at the first 241 U.S. cases providing detailed information on those.  The second study looks at over the past four years, the ten cases of swine associated H1N1 disease.  So this looks at the picture that we had been seeing and provides some insight into that.  Later today, we're also publishing an update on the MMWR, the Morbidity and Mortality Weekly Report, that will be reporting object global picture of H1N1 and what's being seen around the world.  It really summarizes a lot of the information that we've been talking about here over the past two weeks.
I mentionedat the beginning, I wanted to talk about some of the studies that are going on to give you a flavor of the type of work that takes place during an outbreak investigation.  We are undertaking multiple field studies in conjunction with states.  One is looking at the evaluation of a rapid diagnostic test.  Whenever you a new emerging infection, you look to develop diagnostic tests that can be used very quickly to provide information.  So there's a study that is looking at can we have a rapid diagnostic test that performs as well as the PCR test, which is the gold standard.  We're looking at viral shedding.  The question of how long do individuals shed this virus?  So we would be looking at different age groups to see how long individuals shed this either in the respiratory secretions or in their stool.  We'll look to see what the impact of antivirals is.  Does that have any impact on shedding of the virus?  We'll be looking at -- we are looking at virus transmission related studies.  Looking at transmission within households.  How much household transmission is taking place.  We're doing studies looking at health care setting transmissions, we're doing community surveys to see how much background disease is there.  This will be very helpful to help put into perspective the numbers.  You may see a state that is only reporting a small number of cases but if a community survey is showing that there's really broad based influenza-like illness, that would be very helpful to know how is this progressing, where are we in the state of the outbreak?  The health care worker investigation work as I mentioned before, there's some of that is taking place here in the United States.  And some of that taking place in Mexico.  And the goal here is to make sure we are providing the best guidance possible for health care workers.  Some of the these studies are very difficult to undertake in that we know that seasonal flu virus is still circulating in the community.  And H1N1 virus circulating in the community.  So for a given health care worker, attributing the source of the infection can be tough.  It may be that it's acquired in the health care setting, it may have been actually that the infection was acquired in the community, but these studies are still important and can giveus a sense of what is taking place.  Okay. 

So in closing, a few things I wanted to mention.  From the beginning I've been trying to stress this is a marathon, not a sprint.  And you know, across the country, this is what we're seeing.  We expect this to continue to progress.  We expect it to progress around the world.  We expect additional countries to be affected.  It's very important that we continue to pay attention and study this and learn from this and provide the best guidance we can based on available science at that time. 

In the future, we will likely change our approach to these media briefings.  And dial that back to a cycle that fits that kind of marathon pattern.  Right now, while we're seeing new information still coming up on a regular basis, we'll continue this.  We want to make sure that we're meeting your needs in terms of information.  But as we dial back, I don't want that to be taken as a sign that this outbreak isn't continuing.  And that the ongoing efforts aren't still warranted.  It's very important are that we keep our focus on that.  World Health Organization, has this at a level 5.  And as I've explained before, they are looking in countries that have not had sustained transmission yet to see if that's starting to occur.  We expect that once that occurs, we would revisit the issue of level.  And then as we go forward, I want to remind people of the issue of shared responsibility.  There are things that public health is doing, there are things that community groups are doing and there's so much that needs to be done on the individual level, the importance of hand washing and use of alcohol hand gel, the importance of covering your cough, the real importance of staying home when you're sick and keeping your children home when they're sick from school.  And then, the importance of planning.  And planning for now, but also planning for the future.  Because as we've been saying, we don't know what the fall will bring.  What's been seen with some previous outbreaks is that the virus goes away, because flu season ends during the winter, these viruses transmit much better than during other parts of the year.  The virus could go away and come back.  There are all kinds of information sources on what you can do to plan.  I would refer you to a website called, that has great information for individual, it has information for businesses, community groups, things that you need to be thinking about because as we as a government are thinking about the fall, as we've talked about vaccines and whether that's something that's going to be done, the response to a potential pandemic is not just about vaccines, it's been all of the things we've been talking about over the past two weeks.  During this period of time, between now and the fall is critically important to individual preparedness, the community preparedness and how the impact of this could be on our communities should this virus come back in a severe form.  We'll be following it very closely in the southern hemisphere that will give us clues to what we might see in the fall and efforts people take now are empowering, they can give people some control in the event this does come back and can ensure that should this come back in a severe form, we've done all that we could to reduce the impact on the health of our population and people around the world.  So with that, I'll stop and take your questions.

Operator: Thank you, ready to begin the question and answer session.  If you would like to ask a question, please press star one.  Again, press star one to ask a question.  One moment for our first question.

Ceci Connolly: Ceci Connolly from "The Washington Post." I wanted to ask you about the 1976 experience and in what specific ways that is beginning to inform your thinking about actions in the fall.  It may affect how you approach the decision around vaccination, I'm guessing it may affect how you handle public messaging.  What are you already studying and thinking about there? 

Richard Besser: Yeah, thanks.  In 1976, the country was faced with decisions around whether to develop and administer a vaccine for a new flu strain.  We may as a nation be faced with similar decisions.  It's important that these decisions be informed by science.  But it's also important for us to understand where science takes you and what's left beyond that.  And this administration has taken a very proactive stance in terms of public engagement.  And that's something CDC as an agency has found extremely valuable.  Engaging the public around some of these decisions.  Things that we'll be looking at will include what would take place in the southern hemisphere.  Are we seeing severe disease, are we seeing a virus that's competing very well with seasonal flu strains that are circulating down there.  That will give some of the scientific information that goes into this.  We'll be looking at the virus to see has it mutated into something more severe?  Has it picked up any of the factors that we know have been associated with severe disease in the past.  Has it developed any resistance?  What is happening in terms of the age distribution of who is getting sick.Those -- that will be very important scientific information.  At the same time, we're working on the development process in terms of vaccine to see -- to move us forward in terms of developing a safe and effective vaccine.  But in the end, the decision will need be to be made and we're all reviewing the process that took place in 1976, trying to understand lessons learned.  And we'll be getting a lot of input from people around the country, around that decision. 

Richard Besser: Next question from the phone.

Operator: We have a question from Helen Branswell from the Canadian Press.  You may ask your question.

Helen Branswell: Hi, thanks very much.  Hi, Dr. Besser, I was hoping you could give us a sense of whether your sense is that there's a lot of ongoing transmission or if it's starting to peter out with the sort of rise in temperatures.  You know, you mention the fact that some of this would be backlogged testing in the labs.  There had been an anticipation this would start to peter out towards the summer.  Are we actually seeing that?  Or are you seeing continuing evidence this thing is still spreading?

Richard Besser: Thanks.  As we look at the data so far, we are not seeing any sign of this petering out.  And we would not expect that we would at this point.  We are still in the upswing of what we call the epidemic curve.  We fought the cases over time and we're on the upswing.  When we look at the data from Mexico, there's still significant ongoing transmission there, but they're seeing similar phenomena to what we're seeing here but that's a different picture we're seeing in other parts of the country.  This would be very early for us to see any kind of leveling off here.  We expect to see far more cases and that's part of why we're going to be moving away from case counts.  It doesn't become as useful as being able to talk about widespread activity in a given place, limited activity.  You know, isolated activity, the kinds of terms that we've used in seasonal flu.  Hopefully we'll be aided by warmer weather and periods of time when flu viruses don't transmit as easily.  But at this point, we see ongoing transmission, we expect that to continue.  That's why people need to continue to wash their hands or use alcohol based gels.  Cover their coughs, stay home when they're sick, keep their children home when they're sick.  Next question from the phone.

Operator: Thank you.  Our next question comes from Sharon Otterman with "The New York Times," your line is open.  Sharon Otterman with "The New York Times," your line is open.  Please check your mute feature.  We'll go ahead to the next one.  That's John Cohen with "Science" Magazine. you may ask your question.

John Cohen: Hi, thanks for taking my call.  The MMWR coming out today says and I'll quote from it, the percentage patients requiring hospitalization appears to be higher than would be expected during a typical influenza season.  Can you clarify whether that's because of the testing issue that you mentioned later or whether that's accurate as is?

Richard Besser: It appears to us that that is a testing phenomenon.  And you know, that was summarized I think yesterday, we had a visit from the mayor of New York who said you want 200 more cases let me know and we'll test 200 more people.  What you're going to see and what we're already seeing at some of the state level is that they are change are their testing policy.  Because it uses resources, laboratory resources, personnel resources and if it's not going to affect the care of the individual or the public health decision, once you have widespread activity, that individual testing loses a lot of that value.  So we're seeing some shifting around in that percent as we see more testing of the less acute cases but we're not seeing this as more severe than what has been seen with recent seasonal flu outbreaks.  Next question from the phone.

Operator: Thank you.  Our next question comes from Mike Stobbe with the Associated Press.  You may ask your question.

Mike Stobbe: Hi.  Thanks for taking the call.  Two questions, the first one, doctor, earlier, there had been a lot of questions about what's going on in Mexico versus the United States and why does it seem more severe there and an explanation was they were further along, probably more cases going on, so it was hard to compare.  Now we've got about roughly equal numbers of confirmed cases in both countries.  949 versus 896, but we've got two deaths in the U.S. and I've seen 29 and I've seen 42 in the number of deaths in Mexico.  Can we compare those numbers and do we have a better understanding right now of why does it does seem a little more severe in Mexico?

Richard Besser:Thanks, Mike.  I don't think we can compare that.  Because the outbreaks occurred sooner in Mexico.  One of the things you see in flu outbreaks is that mortality, death is a lag indicator.  You can have an outbreak and people who are sick in the hospital who are lingering for quite a while and death occurs late and so I wouldn't feel comfortable saying that we have a great handle on that number.  I expect that as we see more cases in more places, as we see more severe cases that we will see more deaths in this country.  And so I wouldn't put much on that.  One of the things we're able to look at and will be looking at over time is treatment practices in the two countries and presentation practices.  You know, we don't have good data on it yet but the general sense in Mexico is that people tend to wait longer to come to the hospital.  And that may have an impact in terms of treatment and treatment outcomes.  So right now, I cannot say that there is a true difference between what's taking place in Mexico and what we're seeing here.  Next question from the phone?

Operator: Next question comes from Craig Schneider with Atlanta journal Constitution.  You may ask your question.

Craig Schneider: Hello.  I'm sorry if somebody asked this before, but did want to get a general sense of what the CDC's guidelines or as to who should be tested now.  I know the states are making own policies but is the CDC saying anything in general as to who should be tested now?

Richard Besser: The use of testing will vary by location.  And that's appropriate.  I understand that New York state is backing off on some of their testing because they have a fair amount of disease in that state.  And so where you are in terms of the outbreak in --

Craig Schneider: Let's say Georgia.

Richard Besser: What you want to do is early on, especially before you've had any documented cases, you want to do more widespread testing.  You want to do testing of cases across the continuum, you want to make sure that you, that you're definitely testing severely ill people wherever, if someone is in the hospital and it's acutely ill with respiratory illness, you want to test them for this virus.  Where you're going to start to see the differences is in the milder cases.  And I think also you want to make sure that in individuals where the diagnosis would impact on your treatment, individuals who may have certain underlying chronic disease where is it could impact on other treatment they received, you want to make sure that doctors are involved in those decisions.  Individuals who are sick should be contacted from their doctors around those decisions.  But the differences you see from state to state, most frequently relate to where they are in the outbreak.  We've been saying the number of states each day that have cases and today we're reporting that there are confirmed cases in 43 states.  Well, the seven states that don't have confirmed cases, I would expect they're going to be doing much broader use of testing than the states that already have confirmation.  Two more questions from the phone. 
Operator: Our next question comes from Erin Sykes with NBC News Channel, you may ask your question.

Erin Sykes: Hi, there's so much.  I would like to get your opinion on swine flu parties and what perspective can you provide on this?  It seems to go against the advice that you've been providing to Americans about how to protect themselves from the flu but there's till this I idea that exposing yourself to the illness may about way to protect yourself from the virus in the fall.

Richard Besser: I've been hearing a little bit about this and I appreciate the question.  I think that having swine flu H1N1 parties is a big mistake.  This is the new emerging infection.  And we're learning more each day.  But you know, how an individual person will be impacted by the infection is not something we know.  And I think that it is -- you know it is a big mistake, it's that putting individuals and children at risk.  And CDC does not recommend that people follow that course.  One last question from the phone.

Operator: Our next question comes from Kate Traynor with the American Journal.  You may ask your question.

Kate Traynor: That's the American Journal of Health System Pharmacy.  Thanks for taking my question.  CDC late last night updated its interim guidance on anti-viral use in H1N1 infected people and it looks like you're pretty much telling clinicians to handle this as if it were seasonal flu a whereas before people thought to have H1N1 but weren't necessarily very sick were supposed to be getting anti-virals.  Can you tell me a little bit about how that has evolved? 

Richard Besser: As we learn more each day, we're going to be revising our various guidance documents.  You will see as I've said from day one, you will see some inconsistencies between various guidance documents as we transition.  One of the first documents that we revised is the school closure guidance.  We've just revised the clinical treatment guidance and clinical treatment guidance now is much more in line with what we do with seasonal flu, the reason for that is that we have additional information in terms of severity.  And our feeling in terms of severity is that this strain is currently acting much more like the seasonal flu strain and that is allowing us to adapt that.  Our other guidance documents are also going to review and will be updated as well when we find documents that are based on a level of severity that we no longer think is occurring in our communities.

Reporter: Okay.  Thank you. 

Richard Besser: So we appreciate when people bring some of these inconsistencies to our attention.  We are reviewing them and we're working very hard to make sure that there's -- that what is said in one guidance document in terms of severity, in terms of approach is consistent with what is in other documents.  Thank you very much for your time. Thank you.




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