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Press Briefing Transcripts

CDC Briefing on Public Health Investigation of Human Cases of Swine Influenza

April 24, 2009, 2:30 p.m. EST

Glen Nowak:  This is Glen Nowak. I’m a chief of media relations here at the Center for Disease Control Prevention, and we’re here to give an update on human swine food investigation and cases.  With us today is Dr. Richard Besser.  Dr. Besser is the acting director at the Centers for Disease Control and Prevention, and I will turn the microphone over to Dr. Besser.

Richard Besser:  Thanks very much, Glen I want to welcome you to today’s update on the human swine flu situation.  As with yesterday, our goal today is to provide an update on what we know as well as some of the important initial public health actions we’re taking with respect to the recently identified cases of human infection with swine influenza. 

Before I talk about the cases and specific actions, I want to recognize some initial guiding concepts.  First I want to recognize that people are concerned about this situation.  We hear from the public and from others about their concern, and we are worried, as well.  Our concern has grown since yesterday in light of what we’ve learned since then. 

I want to acknowledge the importance of uncertainty.  At the early stages of an outbreak, there’s much uncertainty, and probably more than everyone would like.  Our guidelines and advice our likely to be interim and fluid, subject to change as we learn more.  We’re moving quickly to learn as much as possible and working with many local, state and international partners to do so.
I want to recognize that while we’re moving fast, it’s very likely that this will be more of a marathon than a sprint.  I want to acknowledge change.  Our recommendations, advice, approaches will likely change as we learn more about the virus and we learn more about its transmission.

I want to acknowledge that we’re likely to see local approaches to controlling the spread of this virus, and that’s important; that can be beneficial; that can teach us things that we want to use in other parts of the country and that other people in other places may find useful.  Because things are changing, because flu viruses are unpredictable and because there will be local adaptation, it’s likely that any given moment there will be confusing – or may be confusing or conflicting information available.  We are very committed to minimizing and that where we find that, clearing up any of that misconception.

So on to today’s update.  The United States Government is working with the World Health Organization and other international partners to assure early detection and warning and to respond as rapidly as possible to this threat in order to lessen its potential health and socioeconomic impact.  We’re committed to sharing any new information with our international partners and with the public as it becomes available.  We do not know whether this swine flu virus or some other influenza virus will lead to the next pandemic; however, scientists around the world continue to monitor the virus and take its threat seriously.  The Government of the United States strongly supports the International Health Regulation, which establish a framework for effective international cooperation in monitoring, reporting, and responding to public health emergencies of international concern.

To on today’s update of confirmed cases.  Yesterday we reported we had confirmed a total of seven cases in the United States.  Today, we’ve confirmed one additional case in California, bringing the total number of U.S. confirmed cases to eight.  The most recently confirmed case involved a child in the San Diego area, who has recovered.  Today, Mexico’s Minister of Health confirmed that they have cases of swine influenza in people and that they believe some of the people who were infected died from swine influenza. 

While we are now working with health officials in Mexico, we’re very early on in those efforts.  We’ve only tested a very limited number of samples from Mexico, and we do not have enough information to fully assess the health threat posed by this swine flu virus.  We’ve tested 14 samples from Mexico, and seven of those tested positive.  We also only had eight confirmed cases in the United States, which makes it hard to draw conclusions about the full spectrum of the clinical picture.  We need more comprehensive laboratory analyses and a better understanding of what’s really going on with respect to the number of people who experience influenza-like illness in Mexico.  We still do not have enough information to give us any sense of the extent of spread of this virus, and the illness spectrum is not currently known.

I want to go over some of the CDC and other public health agency actions that have been taken.  We’re working very closely with state and local officials in California, Texas as well as with health officials in Mexico, Canada and the World Health Organization.  CDC has sent teams to California and will be sending a team to Texas to assist state and local health officials in identifying people who are potentially infected, contacting people who lived with or were in extended close contact with confirmed cases and helping on laboratory work.  CDC expects to send people to Mexico to assist in the public health efforts there.

In terms of our travel recommendations, at this time there are no recommendations for U.S. travelers to change, restrict or alter their travel plans to Texas, California or Mexico.  CDC will be issuing today an outbreak notice for American travelers to Central Mexico and Mexico City.  A CDC outbreak notice is designed to inform travelers of an increased health risk due to an outbreak in a limited geographic area.  Outbreak notices also are reminders about standard or enhanced recommendations for the region.  In this case, we’re reminding travelers about our standard recommendation.  Based on the currently available information, CDC is not recommending any additional precautions for travelers to California, Texas or Mexico.  Our standard recommendations, however, do remain in place.  Cover your cough or your sneeze, wash your hands frequently and see your doctor if you have fever, cough, sore throat, body aches, headache, chills and fatigue, and we do want people to realize that some people have reported diarrhea and vomiting associated with the swine flu.

Some other specific CDC actions include posting of another MMWR health dispatch.  That will be up later this afternoon.  This puts forth our latest recommendations, and as we’ve noted before, these include that clinicians should consider swine flu in the differential diagnosis of patients with febrile respiratory illness who live in San Diego in and Imperial County in California and Guadalupe County in Texas or have traveled to these areas or been in contact with ill persons from these areas on the seven days before their illness onset. 

CDC requests that state public health laboratories and all influenza A specimens that cannot be subtyped to the CDC Influenza Division surveillance and diagnostics branch laboratory.  And as a precautionary step, the CDC is working to develop vaccine seed strains specific to these recent swine influenza viruses in humans.  This is also something we often initiate when we encounter a new influenza virus that has the potential to cause significant human illness. 
We’ve created a web page with information and updates.  We encourage the public and the media to visit this web site for information.  It’s  But you can get it from our main web site; there’s a link there.  We also have a CDC information line that’s set up, and that’s 1-800-CDC-INFO.

I’d now like to open it up to questions.  We’ll begin with some questions in the room, and then we’ll move on to some from the – from the phone bridge.

Operator:  Our first question.

Reporter:  (INAUDIBLE) here in Atlanta you talked a little bit about today you’re growing more concerned.  Tell us a little bit about why more concerned today.

Richard Besser:  Well, what we’ve learned from yesterday when we spoke with you and today is that the cluster of cases that we’re seeing in Mexico is being attributed to the swine flu virus.  What we are seeing here in the United States so far are eight cases of swine flu, primarily mild disease.  All have recovered.  Only one of the eight has been hospitalized.  It’s really critically important we learn more about what’s going on in Mexico because reports from Mexico are raising concerns about much more severe disease, and in that – in Mexico individuals who have died.  We do know or have heard from the health officials in Mexico that there are other influenza viruses that are circulating there.  They are other viruses – respiratory viruses circulating, and so sorting out what is caused potentially by the swine flu virus, what is caused by other or what could be caused by co-infection, those are important public health questions.

Laurie Daniel:  Hi.  Laurie Daniel, NBC News.  Can you reconfirm is there a travel domestic restrictions that there is Mexico restrictions?

Richard Besser:  We don’t have restrictions for travel domestically or to Mexico.  What we’ve posted is something that we do all the time, and that’s an outbreak notice so that individuals who may be traveling to that area will be aware that there is an outbreak of respiratory infection and can decide for themselves whether to travel, and if they travel what precautions to take.
Let me go to the phone for a question, then we’ll go back and forth.  We’ll take the next question from the phone bridge, please.

Operator:  The question is from Helen Branswell.  Your line is open.

Helen Branswell:  Hi, Dr. Besser.  Thanks so much for doing this.  I’m wondering if you can tell me, the samples that you’ve tested from Mexico that tested positive, has any at least preliminary sequencing of the virus isolates been done?  Can you say anything about how closely related they are to the isolates you have from the California cases, and also I’m wondering if you are talking to vaccine manufacturers about potentially ceasing production of seasonal flu vaccine for next fall and starting up production of a swine flu vaccine?

Richard Besser:  Thanks, Helen.  As I said, the analyses of the – of the virus are preliminary.  We’ve been looking at one part of the virus, and what we’re seeing in that part of the virus is similarity.  But the more detailed analysis of the whole genome has not taken place.

In terms of the scale up for vaccine, what we have done is created a seed (Editor’s Note: this is a correction) stock for this virus which is something we do whenever we see a new novel strain of influenza that can cause disease, and then as part of that we would need to explore with the manufacturers what it would take to be able to scale up vaccine production.  At this point we have not made any decisions regarding the need for manufacturing of vaccine, but we thought it was prudent to develop that seed stock.

Helen Branswell  Can I ask a follow-up question?

Richard Besser:  Sure.

Helen Branswell:  What pandemic threat level are we actually at today?

Richard Besser:  So far there has not been any change in the pandemic threat level.  The World Health Organization will be looking at the situation that’s occurring in Mexico and will be convening – most likely convening their group of experts to address that situation.  As Dr. Schuchat talked about yesterday, there are really three things we want to look for when we’re thinking about whether a virus is causing a new pandemic.  One is: Is it new?  In order to cause a pandemic, you need a virus to which the majority of the population does not have protection or immunity.  Does it cause severe disease?  There are probably new viruses that appear all the time that don’t cause severe disease, but with an influenza virus, one of the factors we look at is the severity of disease.  And then the third factor is whether it’s easily transmissible and sustainable in a population.  So those are the three factors that WHO would be considering when they look at the threat level.  In the room.  We’ll go back to the phone bridge, please.

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

David Brown:  Yes, thanks.  Acknowledging that the investigation is still under way, can you give us some sense of what you have heard about the number of cases and the number of deaths in Mexico, because it’s been – there’s been some reports of 60 deaths, hundreds of cases, and it would be nice to know what sort of order of magnitude we’re talking about.

Richard Besser:  Yes, you know I think that that’s a really important question, and we look forward to understanding more about the numbers from Mexico.  I’d refer you to the Mexican Government for that as well as the World Health Organization, which will be starting to report on cases reported to them.  We’re not in a position here to report on the number of cases and severity going on in Mexico.  We are offering support to the Mexican Government in terms of epidemiologists and laboratory scientists to help with their investigation.

David Brown:  OK, can I ask a follow-up?  There’s also been a report that their – the attack rate and severity is greater in sort of young adults, you know the kind of 19, 18 picture, young adults, teenagers rather than children and the elderly.  Have you heard that also?

Richard Besser:  Yes, I think that exploring the epidemiology, understanding who is getting sick in Mexico is critically important, and it’s premature to comment on that, but with a pandemic one of the things that you frequently see is infection in younger adults, a population that usually doesn’t get as severe disease from a seasonal flu outbreak.  In the room?  Yes.

John Cater (ph):  John Cater from WXIA 11 Alive news out of Atlanta.  Just wondering is there a common thread that the patients in the cases that you’ve seen in the United States and Texas and California that each one of these people had?

Richard Besser:  That’s a great question, and that’s what we’re looking for.  So far we’ve not been able to identify that.  We’ve not been able to identify a common exposure or a common behavior that they’ve had, and when you’re doing an outbreak investigation, that’s what you’re looking for because that can give you a window into how can you potentially control – how is the virus spread and how can you potentially control the spread.  The number of cases we’ve identified in the United States, eight, is not very many, and so we are doing intensive looking to see are there cases out there that have gone undiagnosed, looking both in the clinic setting as well as in hospitals.  Are there patients in hospitals with pneumonia where a diagnosis wasn’t made who may, in fact, have this infection.  So far we haven’t identified any.  Phone line?

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

Rob Stein:  Yes, hi.  Thanks very much for taking this.  I just was hoping you could elaborate a little bit more on the analysis of the strains you’ve gotten from Mexico.  You said you analyzed 14, and 7 tested positive for the swine flu, and you see it looks like there’s a match.  So are all seven of those who tested positive, did they match the strains in the United States?

Richard Besser:  Yes, all seven isolates were matched based on the genetic component we analyzed. It matched the strains that we've seen here in the United States. 

Rob Stein:  Great, thanks very much.  And so do you have any sense of why there is such a difference in illness that it’s causing?  Mild illness in this country and apparently severe illness in Mexico?

Richard Besser:  That's one of the analysis that both the laboratory will be working on and see are there any factors related to virulence related to various disease that differ between the strains.  As well as something that we'll be looking at as part of the epidemiologic investigation to see are there other factors that would give us an answer as to why they're seeing more severe disease in Mexico. In the room?  We'll go back to the phone bridge.

Operator:  The next is from Betsy McKay, Wall Street Journal, your line is open.

Betsy McKay:  Hi, Dr. Besser.  Thank you.  Just to follow-up on the previous question about the seven strains do you know who those seven strains are from?  In other words are any of these I mean of these seven samples are any of them from people who died in Mexico?  That's the first question.   And secondly do you have any information on what links the U.S. cases may have to Mexico or were they Mexican-Americans, have they traveled or been in contact with family who traveled to and from Mexico? 

Richard Besser:  Thanks, Betsy, the first question was…?

Betsy McKay:  The seven samples…

Richard Besser:  Yes…

Betsy McKay:  Are any of them connected – are any of them from people who died?

Richard Besser:  We have not received detailed case information on the seven patients.  We do understand that they were taken from individuals with severe disease.  But we're looking to get more detailed information about that in terms of their ages and the clinical course.  In terms of your second question, yes…

Betsy McKay:  (INAUDIBLE).

Richard Besser:  We’re in the process of working on those case investigations.  My understanding is that one of the cases in San Diego had traveled to Mexico.  Having lived in San Diego myself traveling to Mexico is a very common behavior and so, you know, it's hard to put any risk on that from what we know so far. 
Question in the room?  Back to the phone bridge. 

Operator:  The next is from Daniel DeNoon, WebMD.  Your line is open. 

Daniel DeNoon:  Thanks very much, Dr. Besser so we hope this is going to be limited in Mexico and nothing is going to happen but can you walk me through what the scenario might be that would trigger a higher level of concern? 
In other words what might we see happen that would get CDC to move on?  And can you tell me if we did move on to a higher level of preparedness what that would look like and how we would proceed exactly?

Richard Besser:  There has been extensive planning across the federal government, across federal, state and local governments within the private sector, in schools.  Our communities have been planning for pandemic influenza for many, many years. 

We don’t know that this strain will develop into a pandemic strain.  But the level of planning that has taken place in this country in unprecedented.  And I think will allow us to respond in ways that we would not have been able to respond had this occurred 10 years ago. 

At this point we don’t know what actions will need to be taken.  There is a lot of work that's been going on around community control of a pandemic virus and what needs to take place.  The types of activities that need to take place depend on the severity of the virus.  And, you know, I’d refer you to our Web site on pandemic flu planning to see the detailed guidance around those types of steps. 

Again, though in terms of this situation and this swine flu we are not at the point and WHO is not at the point of declaring a pandemic.  We are at the point of trying to learn more about this virus and understand the transmission and how to control it. 

Another question from the phone bridge? 

Operator:  Richard Knox, National Public Radio your line is open. 

Richard Knox:  It seems as though from what has been reported that it's likely – more likely than not that the conditions may be met to raise the level of pandemic alert to level four; novel virus, severe disease and fairly efficient or widespread human-to-human transmission.  When do you think you'll have enough information and WHO is likely to have enough information to make that determination?  And I have a follow-up too if I may. 

Richard Besser: You know, we are working very closely with the World Health Organization.  We've been in direct contact with the Director General, Dr. Chan and the Deputy Director of PAHO having discussions around those questions as well as general control questions for this particular virus.  And they convene an expert panel to look at the conditions to determine whether or not we should elevate the status. 

When we look at what actions we take though we look at actions on the ground.  And so what you're seeing is a lot of activity around San Diego, a lot of activity in one part of Texas, a lot of activity in certain parts of Mexico.  And that's because that’s where we're seeing disease occurring.  What we expect to be seeing is that people start thinking about their own preparedness. 

What would they do if there were a pandemic?  What would they do if there were a new disease in their community?  It's all about general preparedness and I'd refer you to our Web site to get ideas as to what people could do as part of general preparedness. 

There has been a lot of business planning going on around if there were a pandemic what would businesses do?  School planning around what would they do.  This is the time for people to be thinking about that.  And, again, it's not because we have information that this will develop into a pandemic strain but it's a time where there is a teachable moment and people can take some action around preparedness. 

Richard Knox:  So, you're not prepared now to say how long it's likely to be before we know whether those conditions will be satisfied or not? 

Richard Besser:  No, but, you know, my initial comments that we're moving quickly.  That we are being very aggressive in our approach.  We are taking this very seriously.  That applies not just to our activities here at the Centers for Disease Control and Prevention but that goes for the thinking at the World Health Organization. 
So, I expect that each day we're going to be evaluating the situation and making decisions. 

Reporter:  If you went to Mexico would you do exactly the same thing that you would do in Mexico as you’re doing here on the ground or would you, you know, be following Mexican officials or…?

Richard Besser:  In terms of assistance?  CDC has a long history of providing assistance on outbreak investigations domestically and globally.  And so the same sort of things that we are assisting folks in California and Texas, the things that they're doing on the ground, trying to identify who was sick, looking to see who was in contact and whether those individuals get sick. 
That gives you an idea as to whether the virus can spread, collecting samples and trying to understand the disease transmission, is there – what did the spectrum of disease look like?  Those are very important things to help us determine whether the conditions for a pandemic will be met. 

Reporter:  Other countries like Mexico are usually happy to have you guys come. 

Richard Besser:  The CDC has personnel all around the globe and our interactions with Mexico are very strong in this area. 

Report:  And should people outside of Texas and California, how concerned should they really be about them?

Richard Besser:  Well, you know, I think that it's very important that people are paying attention to what's going on.  The situation has been developing quickly.  As I said at the beginning, this is something we are worried about and we are treating very seriously. 

I think that’s important that people are paying attention to what's going on.  At this point, all we have found in terms of cases is in those two areas in Texas and in California but it is worth people thinking about this. 
On the phone?

Operator:  The next is from Maggie Fox of Reuters.  Your line is open. 

Maggie Fox:  Dr. Besser, you say you got strong interactions with Mexico but are CDC personnel in Mexico and has Mexico officially asked for CDC help?  And can I ask you if anyone is talking about trying to contain this virus. 

Richard Besser:  We are, we have not sent a team to Mexico yet.  We're still in discussions with Mexico but we anticipate that we will have folks there very soon.  In terms of the issue of containment, you know, there are things that we see that suggest containment is not very likely and that we're seeing cases in Texas and we're seeing cases in San Diego without any connection between them which makes us think that there has been transmission from person to person through several cycles. 

You know, the idea of containment with a new infection we think about when it's limited to a focused, a well defined geographic area and that’s not something that we have seen here. 

Reporter:  OK.  When you talk about spreading from person to person through several cycles, tell me what you mean by that. 

Richard Besser:  Yes.  Thinking there – if you have an individual who's sick and you have another individual who's sick and you can find no connection between them.  So it hasn’t gone from one individual to another family member to another person that family member had contact with.  That would in a sense a two step move.  Here we're not seeing any linkages at all between the cases in Texas and those in California.  But again it's really early in the investigation.  As more information comes to light, we could see connections that haven't shown up so far. 

Reporter:  Is the Canada Mexico connection, why does Canada evaluate Mexico viruses?

Richard Besser:  You know, many countries provide support to other countries through bilateral relations.  And just as we provide support and other countries provide support to us.  So there is a relationship between Canada and Mexico that lead to that taking place.  On the phone?

Operator:  The next is from Mike Stobbe, Associated Press.  Your line is open. 

Mike Stobbe:  Hi, doctor.  Thanks for taking the question.  So, 14 samples from Mexico, seven positive.  I'm going to add a follow-up to this but can we say in a simple statement that it’s the same virus in Mexico as in California and Texas?

Richard Besser:  I think that you would be safe in saying that.  From everything we know to date, the virus appears to be the same.  You know, again, my earlier comments that information is changing and as we find more information, we'll share that with you.  So far, the genetic elements we've looked at are the same. 

Mike Stobbe:  OK.  As a follow-up, what were the other seven that came back?  What did they turn out to be?  Also you mentioned one person from San Diego had been to Mexico.  Which person was that?  The 10 -year-old boy? 

Richard Besser:  The other samples came up negative and so we can't really say anything about those specimens.  And I'm sorry your second question?

Mike Stobbe:  One person had been to Mexico, somebody from San Diego.  Which individual was that?  Was it the 10-year-old boy or the father or was it the teenage daughter or –

Richard Besser:  I'm going to need to refer to the folks in San Diego on that.

Mike Stobbe:  OK.  Thank you. 

Richard Besser:  Yes.

Reporter:  One more question on air travel, maybe in a little bit different kind of context.  My understanding is that some of the local authorities in a press conference in Texas suggested that folks who may be suffering flu like symptoms perhaps ought to consider staying off of airplanes, tight spaces, circulated air.  Is that something that you all would recommend?

Richard Besser:  Well, that’s the general recommendation.  You know, it’s a good idea, if you're sick and you have the flu, you should stay home whether you're planning to go on a plane for travel or you're planning to go to work. 
We know that influenza, seasonal flu, is spread person to person.  And staying home allows you to rest and recover but it also allows you to not spread your infection to your coworker or the person sitting next to you on a plane. 
So that’s a general recommendation that we have but if you're sick with fever and aches and flu like symptoms, you shouldn’t be getting on a plane.  On the phone?

Operator:  The next is from Mike Lees, San Diego Union Tribune.  Your line is open. 

Mike Lees:  Thank you and thank you for taking the call.  I'm looking for a couple of things here.  One is some details on the newest case in San Diego, the age, city of residence, whether the patient was hospitalized, and I believe you said the person has recovered.  And then secondly, I'm looking at what the geographic area is that you're asking doctors to test specimens from patients with flu like symptoms?

Richard Besser:  Yes.  The newest case in San Diego, I'll need to refer you to the health department there.  I don't have those specific details.  I know that the child recovered and I believe was not hospitalized. 

In terms of the areas that we're looking at, in terms of doctors doing testing, we're looking at patients in the areas where we've seen cases so far, which is in San Diego County and Imperial County and Guadalupe County in Texas. 
But it's important that clinicians have a high index of suspicion.  As I said at the beginning, we're just starting to learn here about this virus and about transmission and so having a high index of suspicion is a good idea.

Travel histories are useful.  If you have a patient who has traveled to Mexico to a part of that country that’s been affected, it's really important that you do the proper testing. 

Glen Nowak: Other questions in the room?

Richard Besser: I have time for two more questions.  One in the room and one on the phone.  OK, two from the phone. 

Operator:  The next is from Jeffrey Wise, Dallas Morning News.  Your line is open. 

Jeffrey Wise, Dallas Morning News:  Yes.  A clarification and then a question.  The clarification, the cases in Mexico, do we know if any of those people had contact with swine? And then the question is Dallas is one of many cities where there is a lot of travel between Mexico, Mexico City in particular, and Dallas.  Is there anything that local officials should be doing thinking about DFW Airport or at the bus station or other places where people do a lot of travel?

Richard Besser:  At this point we don't know about swine contact with cases in Mexico.  We really don't have detailed information on those cases and their exposures.  That’s one of the important reasons to do a detailed investigation.

In terms of travel screening and at airports or bus stations, there are approximately 400 million crossings at the border between United States and Mexico a year.  I think that the best approach is to really encourage people who are sick not to travel.  So if you have the flu you shouldn’t be getting on the bus or getting on the airplane and traveling. 

Thank you very much.  I appreciate your questions and we will be providing regular updates. 




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