Unlocking SARS
What is “Severe Acute Respiratory
Syndrome” and why should I be
aware of it?
SARS background
 SARS first appeared in China in February
of this year.
 On about March 15th, 2003, the World
Health Organization issued a “Worldwide
Disease Alert”
 This “Alert” is unprecedented in my life
time. I have never seen a “worldwide
disease alert.”
SARS background
 SARS has spread in China to at least 5 of its
10 provinces
 SARS has spread to Hong Kong, Singapore,
Thailand, Korea, Vietnam and was spread to
Canada, the US, Europe, and is now
showing up in Brazil, Pakistan, and is now
infecting people in about 20 different
nations.
SARS background
 The mortality rate – the proportion of
people that die when infected – is about 4%
 To put this in perspective, the great Spanish
Flu Epidemic of 1918 had a mortality rate
of 2.5%
 In the Spanish Flu Epidemic of 1918
between 20 and 40 million people died
worldwide.
SARS background
 There is a reason why there is a “Worldwide
Disease Alert”
 There are currently (April 16, 2003) about
3,500 people that have been infected
worldwide and about 180 people have died.
 This does not seem to be a big problem at
all to us at this time; most people are
unconcerned.
SARS epidemiology
 Mathematical models of SARS growth in
the population suggests that in a very short
time, some 3 or 4 months, there could be
many 10s, if not 100s, of thousands of
people infected if the disease continues to
infect people as it has for the last month.
 It is not unreasonable to expect between 5k
to 6k worldwide infected by the end of
April, 2003.
SARS epidemiology
 So far, of the approximate 200 people
infected in the US, no one has died from
SARS. But…
 In Hong Kong, SARS is now killing young
persons, e.g., 25 to 50 years old who were
apparently healthy before they were
infected.
 There is no cure for SARS at this point.
SARS epidemiology
 SARS is caused by a coronavirus
 Members of the coronavirus family that are
relatives of SARS include bovine
coronavirus, murine hepatitis virus, avian
bronchitis virus, porcine diarrhea virus.
 SARS is not any of these and is a brandnew virus.
 There is no vaccine for SARS
SARS epidemiology
 The viruses related to SARS suggest that it
will be very difficult, in not impossible, to
create a vaccine for the disease.
 Viruses related to SARS show that they are
capable of reinfecting an animal that has
previously survived an infection – there
does not seem to be development of natural
immunity to the virus.
SARS Epidemiology
 Currently nations are employing quarantine
procedures to isolate the sick from the notsick.
 There are many reports that medical staff
treating patients with SARS become
infected themselves. Several hundred
medical staff are infected with SARS in
Hong Kong.
SARS epidemiology
 Quarantine procedures have been instituted
in Toronto, Canada to deter disease spread
including the closing of 2 different hospitals
and several health clinics.
 Singapore closed its schools to all K-12
students for 15 days and, just yesterday,
opened them again with concern that they
may need to close them again.
SARS epidemiology
 In the US, California, New York,
Washington, Florida, and, Illinois have the
highest number of SARS-infected persons.
There are more than 30 now in California.
 SARS is, as I said, a coronavirus. It is very
similar to the viruses that typically cause the
common cold – but this is far more
challenging.
SARS epidemiology
 There are no vaccines for colds despite
years of interest; there are no preventatives
for colds; there are only palliative
treatments for colds.
 For SARS, some Chinese hospitals have
used ribavirin and steroids to help people
get through the disease.
SARS epidemiology
 Let’s assume 100 people are infected by
SARS
– 80 of those hundred will survive the infection
just fine and have only a really-bad cold
– 20 of those infected will go on to have really
serious breathing problems and may require
hospitalization and ventilator treatment
– 4 of those 20 will die
– The 20 will be in the hospital for > 10 days
SARS Epidemiology
 What are the symptoms?
– A fever of 100.5 degrees
– A persistent dry cough
– Malaise and body aches
– Serious shortness of breath
 SARS is, as you probably know, highly
contagious (but it is not as contagious as a
flu (orthomyxovirus) virus)
SARS epidemiology
 The SARS coronavirus can survive outside
the body on a dry surface for at least 3 to 4
hours.
 The main vectors of infection appear to be
water-droplets sprayed out when an infected
person sneezes or if the fomite falls on
surfaces that people touch.
 It can be spread by any body fluid contact
SARS epidemiology
 It is likely that the SARS coronavirus can
be airborne but not quite so infective as an
influenza virus (which is also airborne
transmission).
 There are many researchers working on
ways to stop the disease right now including
both the World Health Organization and the
Centers for Disease Control in Atlanta,
Georgia.
SARS epidemiology
 Will these scientists be successful in
stopping this disease?
 It is hard to say… so far, the disease
appears to be spreading in an exponential
fashion… the numbers infected are really
going up quickly.
 Quarantine procedures have slowed the
epidemic but have not stopped its growth
SARS epidemiology
 Regular reports from infected nations are
published on number of infected persons in
each nation on a daily basis by the World
Health Organization.
 Daily reports on the number of infected in
the US are published by the CDC in Atlanta
and both are available daily on the web.
SARS epidemiology
 Is this an epidemic?
– You are witnessing the beginning of an
epidemic; an “outbreak” of a new disease
– Numbers are growing; no cure, no very
effective treatments; no vaccines
– Luckily, the US has had no deaths yet;
Americans have died but were in China
– Canada has had 13-15 deaths
– We are in the very early stages of an epidemic
SARS epidemiology
 Will SARS become a pandemic?
– A pandemic is a global epidemic
– It is highly likely that it will become a global
pandemic
– There are reports of SARS outbreak in Africa,
Bangladesh, and other places in the 3rd world
– These countries do not have the sophisticated
health care system that exists in the US and,
once established, it will spread quickly
SARS epidemiology
 What was the virus again?
SARS virus under electronmicroscope
SARS virus
 What is the DNA code
for the SARS virus?
 About 27,000
nucleotides long
 Adenine,
Cytosine,Guanine, and
Thymine
 CDC sequenced the
virus on 4/14/03
SARS virus
 You can view the
sequence of DNA of
the virus at:
 http://www.cdc.gov/nc
idod/sars/pdf/nucleose
q.pdf
 And the phylogeny is
here:
http://www.cdc.gov/nc
idod/sars/pdf/proteina
nalysis.pdf
SARS virus
 You can learn to do
“multiple sequences
alignments” on this or
any other virus and
learn what viruses
SARS is related to if
you like.
Where will SARS go?
 SARS cases will continue growing for the
next months
 IF quarantine procedures work and IF
nations act responsibly to prevent disease
THEN it may be ok and we’ll only see some
10k to 30k cases worldwide and only a few
thousand deaths.
Where will SARS go?
 IF quarantine is not successful and IF
nations and peoples do not act responsibly,
we may have a 1918-Spanish-Flu-like
pandemic in the world. It is too early to
know what will happen but it is soon
enough to alert YOU to this possibility.
 You can protect yourself
How you can protect yourself
 You should wash your hands frequently.
 You should avoid going to areas that are
SARS zones.
 You should avoid being around anyone that
is infected with SARS.
 You should eat right, sleep right, and have
generally good health and exercise.
 Don’t worry – just yet…
How you can protect yourself
 Get yourself educated about SARS, its
spread, the number of infected persons
worldwide, what nations are infected, and
follow the medical literature.
 Current literature on SARS is available
here:
http://www.ncbi.nlm.nih.gov/entrez/query.fc
gi?db=PubMed
What if SARS shows up here?
 The college administration has been alerted
to the fact that SARS is an emerging disease
and is contagious.
 The CDC has issued policy statements for
schools and universities to employ should
SARS infect anyone at a school/university
 There is currently only a very-tiny risk to
you personally… next to ZERO
What if SARS shows up here?
 Should the next 4 months show the rapid
growth of numbers infected as are predicted
by a mathematical model, SARS will show
up sooner or later.
 Remember that 80% of those infected
recover completely and are just fine.
 Only 4% of those infected die.
 Time will tell… in the next 6 months.
What might happen?
 It is hard to say… either:
– SARS will become a major pandemic rivaling
the Spanish-flu epidemic of 1918 in magnitude,
or,
– SARS will be a nuisance like mumps and
measles used to be where some died, or,
– SARS will mutate into a mild form and will be
just another cold virus…
– NO ONE knows right now.
Why am I interested in this?
 I’ve written a couple of books on viruses
and have taught myself virology as a hobby.
 I’m able to do multiple sequence alignments
and BLASTS and other virus-hunter
procedures
 As a psychologist and statistician, there’s
growing interest in the virology of mental
illness and epidemiology in the field.
Questions about SARS or
viruses?
 If you have any questions about SARS, the
virus, its epidemiology, its mortality, its
construction, relatives, its transmission, or
DNA code, I’ve read everything I can get
my hands on about SARS for the last
month.
Questions about SARS or
viruses?
 The mathematical model for April SARS
growth is here:
 http://www.bhc.edu/eastcampus/leeb/aids/i
mages/SARSexpApril2003.pdf
Thank you for listening.