Dr David Heymann Live
The World Health Day Live Chat
The following is an edited transcript of a live on-line
conversation between students and Dr David Heymann. Dr Heymann is
director of the World Health Organization's division of Emerging
and Other Communicable Diseases Surveillance and Control. He
joined the chat from the headquarters of the WHO in Geneva,
The event was a joint project of the UN CyberSchoolBus and
Turner Educational Services.
- <Moderator1> Welcome to our chat with David Heymann, Director of
the World Health Organization's division of Emerging and Other
Communicable Diseases. Mr Heymann can you give us a little
background information about yourself, the World Health
Organization, and why today is a special day for your
organization. After this we will begin taking questions.
- <David> Infectious diseases are becoming an increasing problem in
today's world because there has been a decrease in resources for
surveillance and control. Here at WHO we have set up a new
programme to respond to the consequences caused by this decrease
in resources. I am the Director of this programme called
Emerging and other Communicable Diseases Surveillance and
- <Moderator1> We'll open the floor for questions now :)
- Q: Dr Heymann, is the small pox virus still around? in a lab?
- <David> Yes, the last stock of smallpox virus or variola virus,
is still stored by two WHO Collaborating Centres.
- Q: Dr Heymann, does storing them present a risk? Why not destroy
them? Who decides on this?
- <David> Storing presents a cost as they are stored under maximum security. As long as the virus still exists, there is a
theoretical risk. A WHO group of experts has recommended that
the viruses be destroyed. The decision of destruction will be
taken by WHO Member States in May 1999 and we hope the
viruses will be destroyed on 30 June 1999.
- Q: What is the advantage of destroying the virus?
- <David> The complete elimination of any risk that the virus
escapes into the world community which is no longer immunized
- Q: Can the virus return naturally?
- <David> Because the smallpox virus had no reservoir outside
humans, the virus cannot return naturally.
- Q: Why not keep the virus for registration purposes? or for
further investigation for possible further cures?
- <David> This has been the argument for not destroying the virus
and which has delayed the initial recommendation that it be
destroyed by December 1993. The virus has been completely
sequenced and different pieces of sequence are available for
scientific study and diagnostic purposes, if needed.
- Q: What is the WHO doing to prevent the spread of diseases like
Ebola and AIDS?
- <David> Regarding Ebola and HIV/AIDS there is no vaccine
available for either of these infections. Fortunately, Ebola can
be prevented from person-to-person spread by strict isolation of
patients and HIV can be prevented by use of condoms and rapidly
treating other sexually transmitted diseases which facilitate the
transmission of HIV. This can be accomplished by intensive
health education and rapid diagnosis and treatment of STDs.
- Q: What is a sequence?
- <Moderator1> This relates to the small pox answer above.
<David> The nucleic acid composition of the genetic material of
- Q: Will we ever be able to control infectious diseases? or will
new ones keep popping up and old ones mutating?
- <David> Micro-organisms will survive man so we will continue to
be exposed to infectious diseases both those we know today and
those which are certain to appear through mutation or by
breaching the gap between animals and man.
- Q: Where is the Ebola virus located?
- <David> We don't know the natural host of the Ebola virus but all
cases have been associated with tropical rain forest in Africa.
Some have been transmitted from chimpanzees to humans. But as
chimpanzees die like humans, we don't believe these are the
natural host of the Ebola virus.
- Q: Dr. Heymann what do you hope to accomplish
with this day?
- <David> Sensitize the world to the need to continue to put
resources into, and high priority on, the surveillance and
control of infectious diseases. We also wish to encourage young
people to take an interest in infectious diseases.
- Q: What is the process of isolating and identifying the host in
this case? of the Ebola?
- <David> WHO is supporting a study in Cote d'Ivoire looking for
possible animal hosts of the virus. So far we know that the
chimpanzee is one host but probably not the one where the virus
hides in nature. So the study is to see how the chimpanzees get
infected by observing their habits and studying the animals
they are in contact with.
- Q: Students ask, "Where are the last two laboratories of the
- <David> Let's keep it clear - it is the virus that is kept. The
two laboratories are in USA and the Russian Federation.
<Moderator1> The US location is the Centers For Disease Control
and Prevention (CDC) in Atlanta, Georgia.
- Q: "How do new viruses get created, naturally?"
- <David> [Lost]... mutate many times. Antibiotic resistance is
another feature which applies to bacteria which mutate to protect
themselves against antibiotics.
<Moderator1> It takes a little time for Mr Heymann's response to
register...he's in a time zone with a 6 hour difference--in
- Q: Is the sequence of the viruses similar to the cloning they did
with the sheep?
- <David> Sequencing is just to study in the laboratory the
composition of the chromosome of a virus, for example. Cloning
is insertion of existing genetic material into a living organism
replacing that organism's genetic material.
- Q: Sent earlier: Does WHO have enough resources to battle
diseases? Are other areas getting higher priority?
- <David> WHO receives its funding from its Member States.
Resources have not been increasing over the past five years
although the work required has dramatically increased. The
challenge will be to maintain sufficient resources in infectious
disease control while meeting the new challenges in the 21st
century which include diseases related to aging and tobacco use.
- Q: 7th grade students requested information about WHO by email
last week. Can you help to get us more information?
- <David> Who did they send their request to? WHO receives an
enormous amount of e-mail requests and sometimes replies are late
or unfortunately overlooked.
<Abou> As you know, we are running some health units on our site.
You can try that. Also, WHO's web site has an enormous amount of
- <Moderator1> Do we have any other questions for Mr. Heymann?
- Q: Is it realistic to think that polio will be eradicated as
- <David> Yes, polio is already eradicated from the Americas, and
there are probably no more than 3000 cases in 1996, which is
about one tenth of what was reported five years ago. Great
efforts are dedicated to countries where polio still exists to
immunize all children. We anticipate that by the year 2000 polio
will be eradicated if the present pace continues.
- Q: Question from 6th grade: Can you, through genetics, cure
- <David> About the cure for cancer: Cancer can not yet be cured
in all cases but many can be prevented by not smoking and by
preventing infectious diseases such as hepatitis B virus.
Genetics in cancer is dealt with by the International Centre for
Cancer Research in Lyon,France which is a WHO centre.
- Q: 6th grades asks, "Are you near to discovering a vaccine for
- <David> There are several vaccines under study for safety in
humans, and to see whether they produce long lasting antibody.
Soon these vaccines will be studied for effectiveness. But it is
likely that these studies will take many years to complete.
- Q: Is the hepatitis A outbreak in the US something that WHO deals
with? Is it something to be seriously concerned about?
- <David> WHO is following the outbreak with our colleagues in the
US. Whenever an epidemic is caused by contaminated food it is a
great concern, especially if that food crosses international
- Q: Is Ebola the number 1 emerging infectious disease? Do you have
a list of diseases that you look out for? Does this only include
- <David> Ebola is only one of many emerging diseases which are of
great concern. Others include hepatitis C which causes liver
disease, E. coli O157 which causes diarrhoea and kidney disease
with death in children. Equally, or more important, are
re-emerging diseases, that is diseases which were once under
control, such as yellow fever, meningitis, and dengue.
- Q: 6th grade students ask about a disease that makes the blood go
out of the pores of the skin?? What is this?
- <Moderator1> Do you have any idea on this Mr Heymann?
<David> Any disease which interrupts the normal clotting of blood
or increases the ability to leak out of blood vessels can cause
those symptoms. There are many viral and bacterial infections
which can cause this.
- <Moderator1> That's the last question.
- <David> Thank you. We have enjoyed chatting with you.
- <Moderator1> Dr Heymann, thanks for taking the time out of your
busy schedule to chat with Students!
We appreciate it :)
Thanks everyone for coming this morning. We appreciate it:)