23 April 2003
CDC Provides Support to Canada Against SARS
(Experts deployed to Toronto to help contain disease) (8200)
The U.S. Centers for Disease Control and Prevention (CDC) sent a team
of medical experts to Toronto, Canada, on April 22, responding to a
request from the Canadian health agency to provide assistance in the
face of an outbreak of severe acute respiratory syndrome (SARS).
CDC Director Dr. Julie Gerberding said in an April 22 press briefing
that "the Canadian health officials are doing an absolutely
outstanding job" in dealing with the SARS outbreak, which has so far
remained confined to the Toronto area. According to the World Health
Organization (WHO) official survey of the disease, 140 cases are
reported in Canada as of April 23, the largest number in any country
outside of Asia.
SARS transmission has spread the disease to more people in Canada than
in the United States. Gerberding said CDC officials will be "focusing
on protection in the health care setting and looking at the kinds of
isolation and safety precautions that would be most useful there."
The partnership between CDC and the Canadian agency, Health Canada,
reflects a broader collaborative effort among health experts in many
countries working to respond to this outbreak. Gerberding said U.S.
scientists are working with others abroad to understand this emerging
disease. "These projects are really trying to answer some of the
really important questions that will help us understand where is this
going to go and why is it unfolding the way it's unfolding," she said.
Gerberding said the medical researchers are stumped on the questions
of why some patients are apparently more infectious than others, why
the illness remains mild in many patients and escalates into serious
pneumonia in others, and what it will take to truly recover from SARS.
On April 22, CDC issued an alert to Americans planning travel to
Toronto, advising that travelers avoid medical care settings and
hospitals where the disease has occurred.
In another development, WHO issued a press release April 23
recommending that all but essential travel to Toronto be postponed,
the same level of caution it recommends for those considering travel
to locations where SARS outbreaks are most severe -- Hong Kong and
Guangdong Province of China. WHO on April 23 also extended the same
precautionary travel advice to Beijing and Shanxi Province.
WHO information about SARS is available at
http://www.who.int/csr/don/en/
CDC posts information about SARS at http://www.cdc.gov/ncidod/sars/
Following is an excerpted version of the CDC briefing April 22:
(begin excerpt)
U.S. Centers for Disease Control and Prevention
CDC Telebriefing Transcript
April 22, 2003
Update on Severe Acute Respiratory Syndrome (SARS)
DR. GERBERDING: [In progress] 109 case of SARS internationally that
meet the probable case definition, plus 39 cases in the US that meet
the probable case definition. WHO is also reporting a total of 229
deaths and a case fatality rate of 5.9 percent. Looking at SARS from
the international perspective we remain sobered by the ongoing
transmission in Hong Kong, China, and probably Singapore. We also see
countries where there has been at least some successful containment
and looks like progress is being made in a number of fronts in that
regard. Here in the United States we are continuing to cast a very
broad net in terms of decisions about isolation. So although we have
distinguished between probable and suspected cases in our reporting
format, we are continuing to recommend the same standard of isolation
for both suspect and probable case to be sure that we get everybody
properly isolated as early as possible in the course of their illness
and do everything we can to prevent transmission to others.
And let me just review for you what the domestic priorities are for us
at this point in time. First and foremost, case detection remains an
extremely important componential of this. So we are continuing to
alert inbound travelers to the United States from the areas of the
world were ongoing transmission is still occurring and that includes
travelers incoming from mainland China, from Hong Kong, from Taiwan,
from Vietnam, from Singapore, and from Toronto, Canada. Specifically
with respect to Toronto, we are working with the Health Canada
officials to provide an alert to travelers coming into the country who
have been in the Toronto area. This alert is being distributed at
Toronto international airport and over the next week we anticipate
beginning the process of providing this alert to people traveling by
land across the major highways connecting US and Toronto, and are also
be looking at if and when we need to be doing that for train
passengers as well. This is the mechanism to simply alert people to
the fact that that is a community where SARS is being transmitted and
that if an individual becomes ill within ten days of their last point
of contact they should contact their medical provider. So that's one
very important component of identifying at the earliest possible
moment people who might be coming down with SARS.
And next very important component of our containment here in the
United States is initiating the appropriate isolation of SARS patients
as soon as they are suspected and we are specifically advising
travelers or others who know they have been in contact with SARS
patients to not just show up in the doctor's office, but to call ahead
and alert the health care delivery system so that the infection
control precautions can be ready for them when they arrive, and that
health care workers will not be unprotected at the point of first
contact in the medical care environment. This is working well. Already
we are been hearing reports about medical care facilities that have
put up large signs in the emergency room and immediately access
patients with a travel history and institute the isolation steps prior
to obtaining the full medical history so that they can be sure that
the health care providers are afforded the best possible protections
and that the individual patient is given the best possible timely care
in the medical environment.
Another very important component of our containment here is to make
sure that household contacts or other face-to-face contacts with
patients with SARS are in an active-monitoring program during the ten
day period of time after their last exposure where they might possibly
come down with the illness, and so we have asked health departments
across the country to develop methods for actively monitoring exposed
persons. We're not asking exposed persons to do quarantine, but we are
asking that they participate in some kind of a regular evaluation so
that if they develop any of the early symptoms of SARS they will
contact a health care provider and then go through that process of
coming in and getting seen.
The earliest signs of SARS include not only fever, but in addition
other evidence of respiratory illness, including dry cough, headache,
fatigue, muscle aches and so on and so forth, that those could be the
earliest signs. And someone who's traveled to one of the affected
areas, that would be an indication for further assessment or at least
a call to a clinician.
We are also interested in getting some input from our expert advisory
committees about whether there are any circumstances where additional
quarantine measures or additional precautions need to be taken. For
example, if a health care worker has unprotected exposure to a SARS
patient, for example, while inserting a ventilator tube for mechanical
ventilation, which would be a procedure that could involve direct
face-to-face contact with infected body fluids, there may be
additional steps for those health care workers to take during the
period of potential incubation to be absolutely sure that they don't
acquire the infection or don't have a risk of passing it on to others.
So we have already provided some advice for managing potentially
exposed health care personnel, but we are going to be asking for input
today and this week to see whether or not there are additional steps
that should be taken to ensure that we're doing everything we can to
limit any spread of this illness here in the states.
But also, I'd like to say that we talked a little bit about this
epidemic. We still have no capacity to predict where it's going or how
large it's ultimately going to be. I think the good news is that we do
see effective containment in some areas and some measures do seem to
be very successful. I think we're also very sobered by the ongoing
transmission in parts of the world, including Hong Kong, where very,
very appropriate public health steps have been taken, and yet the
epidemic is continuing to evolve there. So it's too soon to predict
where it's going to go.
We must remain vigilant here. The last thing that we can do at this
point in time is relax and say, well, thank goodness we don't have
very many probable cases in the United States, and therefore, maybe
we're not ever going to have any subsequent spread so that we don't
need to be doing the things that we're doing now. This is exactly the
time where we need to continue to do what we're doing and learn our
lessons from what we are observing in the other countries who are
working on this problem.
And I would say, just not entirely parenthetically, that the Canadian
health officials are doing an absolutely outstanding job in Canada.
Today a team of experts from CDC have gone, at the invitation of
Health Canada, to provide additional technical support for the efforts
under way in Toronto, and these individuals will be specifically
focusing on protection in the health care setting and looking at the
kinds of isolation and safety precautions that would be most useful
there.
We have also a large number of evaluations and assessments going on at
CDC in conjunction with our state and local health partners across the
United States, as well as in conjunction with the WHO teams in the
various countries that are affected, and these projects are really
trying to answer some of the really important questions that will help
us understand where is this going to go and why is it unfolding the
way it's unfolding.
Some of those questions include why are some patients apparently more
infectious or more capable of serving as source of infection to others
than most patients are? How long does a person remain infectious after
they acquire the illness? What are the factors that determine who gets
very sick and develops a full-blown pneumonia, and who has the
relatively mild form of the illness? What's the long-term follow up of
patients who have recovered from SARS? Do they fully recover? What is
their health status on an ongoing basis? And I think also importantly,
what are the things that we as a public health agency can do to be
effective at communicating common sense and prudent recommendations
from a public health perspective without causing unnecessary fear and
panic or over reaction in the public? And what can we be doing to
address the stigma and the bias that's still ongoing in some of the
affected communities?
So we are working very hard to get these questions answered. At the
same time we're working with the private sector and our partners in
the federal government to continue to test antiviral compounds and to
initiate additional strategies for identifying a test protocol for the
infection. A lot of progress has been made very quickly, but there
still is a great deal to learn and a great deal to do, and
unfortunately, we're not out of the woods yet, so we will be
continuing to provide you updates on an ongoing basis as we move
forward.
Let me take some questions now from the reporters on the floor.
AT&T OPERATOR: And ladies and gentlemen, again, if you do wish to ask
a question, you would depress the 1 on your touchtone phone. Thank
you.
QUESTION: [In progress] -- Hong Kong and in Toronto. First, Health
Canada is saying today that they've been given results of a study
conducted by CDC that indicates that the SARS virus survives on
surfaces for up to 24 hours, and I'm wondering if you could address
that study and tell us more about those results?
And secondarily, both Toronto Public Health and the Hong Kong
Department of Health have said that they're seeing very high rates of
diarrhea in their patients, 24 percent in Toronto and over 60 percent
in the [inaudible] Gardens outbreak in Hong Kong. I'm wondering
whether you are contemplating making any changes in your case
definition or addressing that particular clinical--that [inaudible].
DR. GERBERDING: Right, thank you. Before I answer your question, I
just wanted to alert the people who are trying to call in on the phone
that we understand there's been some delay in reporters being able to
access through the phone system, so we'll take that into consideration
and do our best to make sure that they get a chance to queue in for
Q&As.
With respect to your question about the longevity of coronavirus on
surfaces, we've known for a long time that coronaviruses can survive
on external surfaces for several hours, and I'll ask Dr. Hughes to
amplify the data on that particular point from the NCID perspective.
While he's preparing to do that, I'll take your other question which
relates to diarrhea.
We have known that diarrhea could be a symptom of this illness from
the very first cases that were presented. I think the initial report
said something like a 10 percent prevalence of diarrhea in the early
reports. Coronaviruses in many animal and bird species actually
primarily cause gastrointestinal infection and diarrhea, so it's not
surprising to see that in here.
The problem is, like some of the other symptoms, diarrhea is a very
nonspecific finding, and I'm not aware that we've seen it as the only
presentation, so it's part of the constellation of the fever and the
respiratory illness. A variable proportion of patients have also had
diarrhea, and I think that is worth noting and something that we'll be
looking at in our case-controlled studies, to see whether that
correlates with any clues about how it's being spread or what the risk
factors for severe disease are. But for right now, it's not in and of
itself an important component or an indication for changing the case
definition.
Let me introduce Dr. Jim Hughes, the Director of National Center for
Infectious Disease, who will provide some more perspective on the
first question.
DR. HUGHES: Yes, thank you. The question relating to environmental
survival of coronaviruses. There's been limited studies done over the
years looking at other coronaviruses that cause colds in humans, and
reports have indicated that one of those viruses has been able to
survive on a surface for up to 3 hours and the other one for up to an
hour. That was one study.
There's work now in WHO collaborating laboratories, and some of them
looking at persistence of this(?) agent. We haven't done that yet here
ourselves, but in one of the other WHO labs that work has been done
that suggested perhaps a longer period of survival in the environment,
but I understand that study is actually being repeated at the moment.
So I would say stay tuned. We don't have definitive data yet, but it
is an important question that needs to be addressed.
DR. GERBERDING: There's a question there.
QUESTION: Thank you, Dr. Gerberding. I'm John Sherrick with WXIH,
Channel 11 in Atlanta.
Regarding your information about the notices that are going out to
travelers at the airport in Toronto, what consideration have you had
about giving notices to people who were traveling to some of the
affected areas? For example, people here at Hartsfield Airport who
might be going to Toronto or Singapore or Hong Kong.
DR. GERBERDING: There is a difference between the message that's for
the outbound passengers as opposed to the message for the inbound
passengers. The yellow alert card that looks like this is the standard
format that we're using for arriving passengers, and this is the
message that says you've been someplace where SARS is a problem, and
if you get sick, see your clinician, and likewise there's a message to
clinicians here.
In addition to that, CDC and the State Department routinely issue
various kinds of advice to outbound travelers. One kind of advice is
called a health alert, and that's just simply a heads-up. There's a
health problem in the area where you may be traveling. You need to be
aware of it. Perhaps there are some special things that you need to do
to protect yourself if you're going there.
And we have issued a health alert to travelers to Toronto, Canada. And
that health alert basically says, no reason to stay home, but if
you're going there, be aware that SARS is present in some settings in
the community and you may wish to avoid the hospital environment or
the health care environment, for example, because that's one of the
places where there has been transmission. So it is not advice to not
travel, but it's simply information and some practical measures that
people can do to protect themselves.
A different level of advice to outbound passengers is a travel
advisory, and we also have travel advisories for SARS. These are now
in effect for China, including mainland China as well as the Hong Kong
Special Administrative Region, Hanoi, and Singapore. And these
outbound advisories right now are saying, please avoid non-essential
travel to these areas because there is ongoing transmission in the
community that is not linked back to the initial cases.
We can't exactly predict where the cases are present or where the
hazard might be, and therefore it's in your best interest to not go
there if you don't need to.
Let me take a telephone question, please.
MODERATOR: We do have a question from the line of Helen Branswell [sp]
with the Canadian Press. Please go ahead.
QUESTION: Thank you very much for taking my call. You sent a team of
people to Toronto today, I guess. A couple of weeks ago, the Ontario
health authorities were saying that they were asking, had made a
request a couple of times to have assistance from the CDC and that
that hadn't been acquiesced to. I'm wondering what's the difference
now.
I'm also curious about the Coronavirus. We heard this morning from the
head of the National Microbiology Laboratory in Winnipeg that they're
only finding evidence of Coronavirus in about 40 percent of specimens
from people who have probable and suspect SARS, and they're finding it
in some people who don't have any signs of the disease. So I'm curious
if you could give us an idea of what kind of figures you're finding in
your labs and why you seem to really believe that the Coronavirus is
the causative agent.
DR. GERBERDING: To answer your first question, which is the timing of
the arrival of the CDC teams in Toronto. First of all, very early on
Health Canada, from a national perspective, assigned a Canadian to the
operations center at CDC and we in turn subsequently assigned a CDC
employee to work in the operations in Canada, so that we would have a
communications exchange and be able to share information rapidly.
In addition, there was, at various levels, some requests from Toronto
for CDC technical assistance. But our system of exchanging scientists
works through the federal government in Canada, and so Health Canada
made the request to have additional technical assistance, and we are
certainly willing to do what we can in any way that we can to assist.
So it's a difference between working through the province and working
through the national system, and our responsibility at CDC is to work
through the federal health officials in Canada.
With respect to the second question about the association of
Coronavirus and the condition known as SARS, there are several reasons
why not all patients have evidence of Coronavirus. First and foremost
is probably because they don't have SARS and they don't have
Coronavirus infection; they have some other respiratory illness that's
caused by something else.
Another explanation is that although we have tests that can identify
it when it's present, we don't know how sensitive they are. If they
are not very sensitive, there may be patients who really have
infection but the test is negative because it just doesn't have the
sensitivity to pick it up.
Another reason is the timing of the specimens. We know, for example,
even with influenza, which is an illness that we have very good tests
for, if we don't do certain tests early in the course of influenza,
the tests are too negative. They're just simply done too late.
So there are many reasons. And of course we want to get answers to
those questions. One test that will probably help us out in the long
run is the antibody test, because in general antibody tests are a good
marker of actual infection with an agent. But these tests don't tell
us that information until several weeks after the infection is already
present. So it's going to take us awhile to get all those samples and
put all of the different test results together with the clinical
conditions of the patient and come up with a more precise
understanding of the utility of the test, but also the spectrum of
illnesses that present with the SARS syndrome, which may or may not
actually be caused by this virus.
Let me take another telephone question, and then I'll come back to
reporters on the floor.
MODERATOR: We have a question from the line of Kelly Patrick with the
Toronto Globe and Mail. Please go ahead.
QUESTION: Would you tell me a little bit more about your plans to
issue advisories at the land crossings as opposed to just the Toronto
National Airport. If you could tell me where you intend to issue the
handouts and when you intend to start doing it?
DR. GERBERDING: Yes, the question about the health alert for travelers
coming to the United States from Ontario and Toronto. The airport has
been doing this for some time, (Editor's Note: Distribution of health
alert cards at U.S. airports receiving direct flights from Toronto is
expected to begin by the end of the week.) and we will be initiating
at land crossings a form of alerting that will utilize the same card
and the same information. There are two very large bridges between
Ontario and the U.S. I think those are in Detroit and Buffalo. And
there are two smaller major thoroughfares where the majority of
traffic back and forth moves. And so those will be--those four
intersections between the two countries will be the primary place for
distributing these health alerts. At least that's the plan right now.
It's going to take a little while to get these organized and printed
and moved and translated and get the mechanisms up in place to
distribute them. But if all goes as we plan, we should be able to
initiate that later this week.
I'll take a question here.
QUESTION: Thank you, Dr. Gerberding. [Inaudible] from the Wall Street
Journal. I was wondering if you could update us on the question of
treatment, just to give us a little more detail about what treatment
options are being considered as an anti-viral, what, if anything,
seems promising. Along with that question, there seem to be some
reports from Hong Kong that the treatment of ribavirin and steroids
may be harming some patients more than it's helping them. I just
wondered if you could tell us anything you know about that.
DR. GERBERDING: Right now, we don't have any scientific evidence to
suggest that any form of specific treatment for SARS is effective.
There were initial reports, primarily from Asia, that seemed to
indicate patients might do better if they received ribavirin and
steroids, but in retrospect that was very anecdotal information and
probably not supportable by the broader experience that they've been
having there recently. And ribavirin is a drug that does have some
serious side effects, including hemolytic anemia and other
complications. We also know from the early results of the viral
testing studies that there doesn't seem to be any activity of
ribavirin in the methods that are being tested right now against this
particular Coronavirus.
So, so far we don't have any leads on an antiviral compound, but the
Department of Defense laboratory and NIH are working in partnership
with us to look at as many compounds as we can very quickly. So if we
get any clinically promising compounds, we will of course work hard to
get them into a clinical trial or an investigational drug protocol so
that we can check them out. This is not going to happen fast.
I think there was a question here also.
I have two questions. First of all, could you hold up the yellow card
again so we can get a shot of that.
DR. GERBERDING: I can even give you one.
QUESTION: Okay, great. The next--
DR. GERBERDING: The yellow card looks like this. It comes in several
languages and the cards that are in print right now have expanded from
the various Asian languages that are on here to include Spanish and
French as well, so that we're trying to get them out in as many
different formats as possible.
QUESTION: Great. The other question I had was on Friday we learned
that Emory University doctors had developed a blood test for SARS.
Have you had a chance to look at that? Would you be using it, or is
there another test that can be used to help identify patients?
DR. GERBERDING: Let me talk about testing generically because there is
a lot of interest in getting good testing protocols available for the
patient. We published, along with the Canadians, the sequence of the
virus on the Internet, and once the sequence is known, just about
anybody with a biotechnical capacity can create the reagents necessary
to do one kind of test that's just called a PCR base test or a test
that relies on finding little pieces of the virus genetic material and
reproducing them in high volume so that you can easily detect it in
your test system. And so my understanding is that's the basis of the
Emory test. So the technology to create a test like this is pretty
much recipe in many biomedical laboratories.
The problem is knowing whether the test you're using is accurate or
not, and the only way you can really determine that is by using your
test on a wide variety of clinical specimens including people that
you're very confident have the infection, as well as people that
you're very confident don't have the infection, and that takes time,
but it also takes access to a whole panel of specimens.
CDC is working on this here in collaboration with the WHO partner
laboratories, and we are sharing specimens and working very fast to
try to understand the accuracy of the variety of tests that are out
there so far, and I'm sure we will be able to have a good test
available in the future. But now we're still in--let's check these
tests out and try to interpret their accuracy before we use them to
make decisions for individual patients, and then ultimately the FDA
has to be involved. We need to get an exemption to use an experimental
test just like we get approval to use an experimental drug, and those
protocols are under way.
Let me take a telephone question, please.
AT&T OPERATOR: Thank you. And from the line of Christian Redd with the
New York News. Please go ahead.
QUESTION: Good afternoon. How are you doing?
DR. GERBERDING: Good.
QUESTION: I wondered if--I have a couple of questions but they're all
related so it should be pretty easy to answer. When was the first
reported death in Canada, and is the CDCP doing anything different
with regard to professional sports teams that are traveling to either
Toronto or Canada? Are the warnings that these teams getting or the
information they're getting any different from what you just described
as far as the alerts to make them aware of what's going on there?
And then lastly, are the alerts that you're talking about--since I
can't see what you're holding up--are they available on the CDCP
website under this menu of "to the traveler" and it says "during your
recent travel to SARS affected areas including Toronto," et cetera? Is
the same as what you're talking about when you're holding up these
cards?
DR. GERBERDING: Yes. All of the CDC materials are available on our
website, including the alerting cards as well as the health alerts for
the outbound passengers and the health advisory for the outbound
passengers. So basically all of our material is available.
With respect to the date of onset and the date of death of the initial
patients in Canada, I don't have that information here, but you can
get that from our press office or better yet from the Canadian
officials.
QUESTION: From Health Canada or someone?
DR. GERBERDING: Yes.
QUESTION: Okay.
DR. GERBERDING: But with respect to the question about advice sports
teams and so forth, from a CDC perspective, we have generic advice to
travelers generically. We don't have customized information for any
particular class of travelers at this time, and there's no reason to
think that sports teams, per se, would be at any different risk than
others traveling to Toronto for whatever reason. So it's a generic,
just a heads-up kind of advice at this point, and we would advise them
not to visit the hospital or spend time visiting people who are in the
hospital if they had that on their personal agenda.
I'll take another telephone question.
QUESTION: Sorry. Were there any recommendations against playing in
Toronto or--
DR. GERBERDING: No, there are no advisories against participating in
sporting events in Canada at this time.
QUESTION: Great.
DR. GERBERDING: Let me take another question from the phone.
AT&T OPERATOR: Thank you. And we do have a question from the line of
Rob Stein with the Washington Post. Please go ahead.
QUESTION: Hi, Dr. Gerberding. Thanks for doing this.
DR. GERBERDING: I think we lost the question. Can we try again to get
Rob back on the phone?
QUESTION: Hello?
DR. GERBERDING: Rob?
QUESTION: Yeah. Hi. Can you hear me now?
DR. GERBERDING: Yes, we can hear you.
QUESTION: Great, thanks very much. I'm one of the people who didn't
get in early on the conference call, so I was wondering if you
wouldn't mind just sort of recapping what it is you might have
announced at the beginning?
DR. GERBERDING: Yeah. I'll just give a very quick recap. We provided
the information on the updated numbers of cases in the WHO and the
CDC, and we can refer you to the website to recapture those, but
basically we're talking about 3,909 global cases, plus 39 probable
U.S. cases at this point in time. Also discussed the importance of
maintaining vigilance here domestically, not to be lulled into any
kind of false sense of security because we haven't seen large-scale
community transmission here. We don't know the reason that we've been
lucky so far, but we're not taking any chances and we just need to
continuously work hard to isolate cases when they initially present,
and to protect our health care workers from any exposures in the
health care environment. And also we plan to continue to seek input
and advice from our infection control experts to see if there are
additional things that we need to do to protect health care workers or
expand our monitoring of exposed people during the period of
intubation for the illness.
Is there a question?
AT&T OPERATOR: Yes, ma'am, we do have a question. From the line of
John [inaudible] with the Washington Facts. Please go ahead.
QUESTION: Yes. Thank you, Dr. Gerberding. I also got in late here. I'm
hoping that you might be able to speak a little bit about what if any
evidence there's been of a zoonotic connection with SARS. We've heard
mixed reports.
DR. GERBERDING: We are very intrigued by the possibility of a zoonotic
source for the SARS coronavirus. That's a speculation at this point in
time based only on the fact that we know coronaviruses do infect a
wide variety of animals and poultry, and that people in many parts of
the world, including Asia, have contact with some of the animals that
are sources of coronavirus in some of the poultry, so that it would be
a biologically plausible possibility, but we absolutely have no data
at this time to support it.
Unfortunately, sequencing the virus that we have has not yet pointed
us into a direction of similarity with known animal or bird viruses to
give us any hints about where to look. So this is part of the work
that needs to go on in Guangdong Province and others areas where the
very early cases occurred, to see whether or not by evaluating animals
or birds in those regions or learning more about the first patients,
we would be able to get some hints about any possible link between
birds, animals and people that could have been one way this got
started.
But I would stress that's only a speculation at this point in time and
there are many other possibilities for how the strain of coronavirus
we're dealing with right now may have emerged or evolved in people.
I think we had a question over here.
QUESTION: Elisa Gail, NBC Nightly News.
It's kind of a three-pronged question. It's all related. Should the
U.S./Canadian border towns have any reason to be more worried about
SARS coming up there than any other area of the country? And if so,
should they be taking more precautions than other towns, and what
should those precautions be? And then lastly, what is the CDC doing to
monitor these towns?
DR. GERBERDING: There is no evidence at all right now that border
communities are at any particular risk of SARS. Let me just stress
again that the situation in Toronto is one where all of the known
cases of SARS can be linked to the initial cluster of individuals who
were infected from their travels to Asia. And so we can explain all
the cases there by following the epidemiology of this person was
exposed to that person, and then that person was exposed to this
person. So we're not seeing evidence of unexplained cases of SARS
anywhere in that community. It's very different from the situation in
Hong Kong.
And right now there is no suggestion that people living in the borders
or traveling through the border communities are at any greater risk,
so we're not implementing any special monitoring in those regions
other than what our local and state health officials are already
doing, which is to support this whole enterprise around alerting early
detection, casting a broad net, isolating presumptively until more
information is available if someone is suspected of the disease, and
then working that from that point.
Let me take a telephone question, please.
AT&T OPERATOR: We do have a follow-up question from the line of Rob
Stein with the Washington Post. Please go ahead.
QUESTION: Yeah. Hi, Dr. Gerberding. I have a question about the
genetic analysis of the sequence of the virus. I was wondering if you
had seen any evidence of any mutations occurring yet?
DR. GERBERDING: I think it's important to first of all acknowledge
that we have sequenced an isolate here, and we'll be able to sequence
more isolates as we go forward. The isolate sequenced in the United
States was not exactly the same from the same patient as the isolate
sequence in Canada. Amazingly, these isolates were very close in their
genetic composition, suggesting that there's high conservation as the
viruses move from at least those early stages of transmission. In
other words, they are very, very similar. They differ in just a small
number of base pairs, and in fact, that could just be by small
mistakes in the laboratory or just very small changes in the virus
which is typical for an RNA virus.
So the sequence data is really not at this point allowing us to
interpret anything about why some people are getting sicker than
others, or is the virus evolving enough over time to account for
differences in the clinical presentation or the epidemiology of
spread. We need to sequence more viruses, and that will be a longer
term aspect of our overall investigation.
Let me take another question from the phone. I apologize to the phone
callers who were not able to get into the call, and if you contact our
press office, we'll do everything we can to make the transcript and
our introductory remarks available to you as quickly as we can.
If there's another phone question, I'll be happy to take it at this
time.. . .
MODERATOR: We have a question from the line of Miriam Falco of CNN.
Please go ahead.
QUESTION: Hi, Dr. Gerberding. I have a couple of questions. One, can
you tell us how many of the 39 probable cases in the U.S. are
close-contact? And also, can you tell me how often are folks being
taken off planes as suspected SARS cases, like we had a few weeks ago
when we had the plane in San Jose, even though it turned out nobody
had SARS on that plane? Is that a frequent thing, and we're not
hearing about it? Or is it very rare that people are flying into this
country and before they even get to the gate folks think that they
might be sick and they're being put aside?
DR. GERBERDING: With respect to your first question, how many of the
probable SARS patients are travelers and how many were infected
through exposure once they've arrived, 37 out of the 39 probable
patients were patients who had recently traveled to an affected area.
One of them is a health care worker, and one of them is a close
contact of a suspected SARS patient. I'll ask Dr. Cetron here, who is
in charge of our quarantine operations for SARS, to answer the
question about the frequency with which we're actually boarding planes
or ships and assessing the presence of SARS among passengers.
DR. CETRON: Thank you. I would characterize it as a relatively rare
event considering the number of flights that public health officials
have been meeting arriving from affected areas, which is over 2000
flights in the month that we've been at this. And in probably less
than a dozen instances have those encounters happened on flights that
you saw in the air. And the other thing is, we should point out that
more and more of the airports in the SARS-affected areas are
implementing WHO-recommendations to do pre-boarding screening using
questionnaires and questions, and this helps keep sick people off
airplanes and helps that process as well. Whereas a combination of
those two measures in place, I think we're seeing that much less
frequently.
DR. GERBERDING: We have a question from a reporter here in the room.
QUESTION: Can you elaborate on the places of social containment and
what that means, what the definition is? And also I was wondering
about, can you elaborate on the fatality rate? Is that a little higher
than what was previously announced?
DR. GERBERDING: With respect to containment, we're very careful not to
label any particular area as "contained," meaning that it's over and
no one needs to be concerned anymore. But there are places, such as
Taiwan, where there were some patients with SARS evaluated and
diagnosed that were not seeing change of transmission on an ongoing
basis and we're certainly not seeing new cases popping up in the
community.
There are some parts of the world where we haven't heard about new
cases, but you need to be confident that not only is the health care
delivery system able to alert us and notify us when they have a
suspected case, but also that we don't miss community cases,
especially in areas where people don't have the same kind of access to
more contemporary health care facilities.
So containment at this point in time is a relative term. It really
means the absence of known ongoing transmission in the community. And
you'd like to be optimistic about those areas, but time will tell
whether or not the problem is truly abated in those regions.
With respect to the mortality rate, I mentioned earlier that the
postulated mortality rate right now is 5.9 percent. Thankfully, we
have had no deaths in the U.S. up to this point in time. You may see
the mortality rate go up as we go forward, but it is in part because
the definition of SARS will become more precise as we begin to utilize
laboratory tests or as some of the people initially included in the
definition are ultimately found through virus testing or other kinds
of antibody testing to have something else. So the denominators
shrink, and the number of deaths may stay the same, so obviously the
number will get larger.
Other reasons for that may include that individuals that were not
initially known or thought to have SARS right now being captured and
included in the [inaudible] observation in China. So there are lots of
aspects of the numerator and denominator in calculating the death
rate, and there are lots of different ways to present that
information. WHO is choosing a very simple method for accounting for
the deaths, and will be, obviously, interested in, again, what are the
factors that determine who has severe illness and what are the risk
factors that seem to be associated with the people who die or have the
worst outcomes.
But if you see the death rate going up, it's not necessarily because
SARS per se is getting worse. There are other epidemiologic factors
that are complicating that as well.
QUESTION: Dr. Gerberding, thanks a lot. This is John Linn from
[inaudible]. I have two questions. Many Chinese people have tried to
seek help from traditional Chinese medicine. And do you have some
comment on the effectiveness of these, all kinds of treatments from
traditional Chinese medicine? And the second question is some people
in Beijing have tried to use vinegar for disinfection purpose. Do you
have comment on the effectiveness of that?
DR. GERBERDING: Thank you. You know, I trained in an environment where
many of my patients used traditional medicines, and I have a very
healthy respect for the value that those alternative approaches can
have. And I don't think we had formally discussed at CDC whether or
not some of these compounds could or should be included in the
antiviral compound testing that we're doing, but I think it's
something we definitely need to look into, and I thank you for
bringing it up.
Right now I don't have information from any source that tells us one
way or another whether any of these approaches have scientific value,
but Dr. Hughes and I will certainly suggest that.
With respect to vinegar as a disinfectant, that would really not be a
recommended disinfectant. It's an acidic compound, as you know, and
there are many things that wouldn't survive well in it, but a lot of
things do. And I think soap and water is a very good disinfectant for
most purposes, and if you need to have a specific antibacterial
compound, there are other products that would be much more reliable
including alcohol.
Let me just take one phone call question, please.
AT&T OPERATOR: And ladies and gentlemen, we now have a question from
the line of John Lauerman at Bloomberg News. Please go ahead.
QUESTION: Hi. Thanks for taking my question. I also wanted to touch on
the issue of masks. We see a lot of people wearing masks. I know that
the N95 masks have a very good record, but what about other masks? Do
you think the masks--is there any suggestion or evidence that the
masks in use may be helping to slow down the spread of the virus? Do
we have any knowledge about that?
DR. GERBERDING: It's very important to understand the two main kinds
of masks that are relevant in this particular illness. The surgical
masks, those simple, inexpensive square masks that you can buy almost
anywhere and tie behind your head like you see in ER, those masks are
useful in containing the droplets that you might disseminate if you
talk, cough or sneeze. So they're very good at filtering out large,
relatively large particles of moist materials from your respiratory
system, and that's the reason why we recommend that those masks be
used for patients with SARS because it contains their secretions and
prevents them from being disseminated in the environment.
The N95 respirator that you're talking about is a much more efficient
mask. And by that I mean it filters out particles that are much
smaller than the kinds of droplets that are the source of infection.
These masks protect the breather from very small dried-out particles
that are airborne, and so their filtration is much more effective. And
the designation N95 is the standard of certification from the National
Institute of Occupational Safety and Health. That means basically they
are capable of filtering out at least 95 percent of particles of a
particular diameter under pretty stringent testing conditions, meaning
they're very good masks.
But there are also N99 masks and N100 masks that are even more
efficient than N95. So we know from the research that's been done in
the health care environment and at NIOSH that N95 masks are an
appropriate level for protection against airborne infections.
The only problem with them is they don't work well if they're not
exactly fit to your face, because if you're breathing through them and
air is leaking in around the sides, you might as well not have a mask
on at all. And so one of the caveats about using an N95 mask is that
you really need to know that it's properly fit and that's something
that a trained professional really is in the best position to help you
with.
We don't recommend N95 masks for the general public. We don't
recommend N95 masks for patients. We are recommending surgical masks
for patients if they're well enough to wear one, and we're using those
N95 masks in the health care environment in hospitals where we've got
sick patients most likely to be aerosolizing relatively high
concentrations of infectious material.
I'll just take my last question here from the reporter on the floor.
QUESTION: Thank you very much, Dr. Gerberding. You said a moment ago,
in discussing the mortality rates, that we may say the mortality rates
calculations go up as the definition of SARS becomes more precise.
Following up on that, can you say at this point when you expect
laboratory confirmation to become a part of the case definition of
SARS? Can you forecast how long it will be or how short a time it will
be before the tests are out there widely enough to use that?
DR. GERBERDING: Getting laboratory confirmation of a case of SARS
depends on us having very high confidence that we understand the
accuracy of the test. And we are right now circulating some draft
suggestions about what a laboratory confirmed case definition would
look like. We need to get input from our partners in the public health
laboratories, and some of the epidemiologist at the state and local
level as well as the FDA just to make sure that everyone agrees that
this is the appropriate strategy. And it's just a little premature to
use it that way, but we're pushing for that on the fastest possible
track because we think that would add an additional element of
accuracy to our understanding of the epidemic as well as the care and
treatment of individual patients.
Let me thank you for your input and your attention. And again, for the
callers on the phone, we regret that it was difficult to dial in
today, and we'll do everything we can to get the transcript available
to you as quickly as possible, and as we learn more, we'll tell you
more.
Thank you.
(end excerpt)
(Distributed by the Office of International Information Programs, U.S.
Department of State. Web site: http://usinfo.state.gov)
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