Prof: I wanted to begin
with just a housekeeping item, which is that next Monday we’ll
have the last class, if you want to call it that,
but it will be completely different in that it will be a
review session. I’ll elaborate on what format
that might take. But essentially I’ll be–there
won’t be anything that I’m planning to lecture about.
On the contrary,
it will be your opportunity to raise questions or make comments
on any aspects of the material that you wish to discuss more.
The format will be that
there’ll be a microphone, and you’ll come up and use it
and ask questions, and then we’ll discuss anything
that you wish. It will really be–I’ll be in
your hands, and that will be a class that
would be helpful if you came with things that you wanted to
discuss or things that you think that we should go into more.
So, that will be what we’ll do
on Monday. For today, instead,
we’re going to talk about three,
in fact, new diseases, that demonstrated once more
that the post-World War II idea, the complacent assumption,
that modern medical science and public health had the tools to
protect society and to eradicate diseases one by one,
when that illusion, fostered by the example of
smallpox, and nearly by the near
eradication of polio, was once again punctured,
as it had been earlier by the emergence of HIV/AIDS.
Most of all it showed that our
society is still vulnerable, particularly to respiratory
infections in the industrial world,
transmitted by air or droplets. They’re true diseases of
globalization and modernity, that thrive on high population
density and modern means of high-speed communication.
I want to end our semester by
talking about SARS, avian flu and swine flu,
and some of the lessons we’ve learned from those experiences.
I would regard them as the
first new diseases of the twenty-first century,
and also as our great dress rehearsals for something much
more serious, that may or may not come later.
Once again, I don’t want to
make a prediction. So let’s begin with SARS,
the first great dress rehearsal of the twentieth century.
As you know or remember,
it began in November 2002 with an index case from someone from
the Guangdong Province in Southern China,
a severe and unusual pneumonia. What took place then in China
was not something that was extraordinary,
as our press tried to persuade us.
Rather, it was something that’s
happened many times, the emergence of a new pathogen
previously unknown. Only in the sixties and
seventies was there a boundless optimism about the capacity of
modern medicine to prevent that from happening again.
Once again we were reminded
that the natural world isn’t static but in a state of
constant Darwinian evolution, with the consequence that there
are always and inevitably new and emerging diseases.
as you know, are especially capable of
sudden, rapid mutation. Well, the media did us a
disservice at the outset of SARS with sensationalizing headlines
attempting to stir up fear; examples being,
“Is This the Big One?,” “Killer
Bug,” and the like. The Chinese authorities,
in their response to SARS, practiced a conspiracy of
silence at the outset, producing no reports or
statistics, and censoring the press.
I’m hoping that this will
remind you– what happened in China–that
also concealment isn’t something we haven’t encountered before,
and it will remind you of other examples of public health by
concealment. Now, why, we might speculate,
did the Chinese decide to conceal this outbreak?
First, we could say,
would be the fear of economic repercussions.
The world economy at the time
was already stagnant, and there were fears of the
implications for vulnerable sectors: travel,
tourism, investment. There was a matter of national
pride. The World Health Organization
had already produced a report ranking world healthcare
systems, and China had ranked one
hundred and forty-fourth, just below Bangladesh.
So, a medical emergency could
cast a new and harsh light on Chinese public health.
It’s also probably true that
authoritarian political systems have people who man the
apparatus, whose career depends on producing good news.
We might also point to what we
might call an authoritarian paternalism;
the idea of sparing the population anxiety and avoiding
giving rise to challenges to the state and its priorities.
In any case,
and whatever the reasons, China placed the health of its
own citizens at risk by failing to enable them to make informed
decisions about their own health.
And it took the risk also of
allowing the new disease to threaten the international
community, delaying the process of patient
detective work that’s required to unravel the secrets of this
new infection. Finally, on the ninth of
February, the Chinese Ministry of Health
notified the World Health Organization of some three
hundred and five cases in six municipalities in Southern
China. This too was a serious
underestimate, and it was followed by weeks of
tardy release of dubious statistics that were meant still
to be reassuring. So, for weeks the World Health
Organization wasn’t allowed to send teams of researchers to
investigate the disturbing events in China.
which is this one, was unknown at the time of the
outbreak; was now known to be a
previously unencountered coronavirus.
Its structure was–a schematic
picture of it would be that. Its early names–what to call
it? It was called human
Because of one of its early
victims, it was called the Urbani virus.
But the name that stuck was
SARS, Severe Acute Respiratory Syndrome.
Let’s follow our usual
procedure and look at the symptoms and the epidemiology,
and some of the effects on society of the SARS outbreak.
In terms of symptoms,
the disease was first identified and defined by
Dr. Carlo Urbani, a forty-six-year-old infectious
disease expert for the WHO, who was working at Hanoi,
and was one of the early physicians to encounter the
disease. He contracted it and died soon
after. The symptoms were an incubation
period of about a week– five to ten days or
so–followed by a sudden onset of fever–
about a hundred degrees, a hundred and one-general
malaise, headache, muscle pain,
dizziness, sore throat. Three to seven days later the
majority of cases improved spontaneously,
with no lasting ill effect. But a minority of cases
worsened at that very point, with lower respiratory
involvement, and this led to a hacking,
non-productive cough, terrible shortness of breath
and chest pain. It’s worth remembering that the
disease at this stage was thoroughly unpleasant.
A Toronto nurse,
suffering from SARS, was interviewed by phone from
her hospital room, and she said that the cough she
was experiencing was so violent that she turned blue,
and it caused her to fall to her knees.
In a minority of cases there
was a progress to very severe respiratory distress,
requiring oxygen and mechanical support.
X-rays revealed what was called
atypical pneumonia, which was a somewhat confusing
term because it had been used, until that time,
for a different condition. On the seventh of May 2003,
the World Health Organization suggested that SARS had a case
fatality rate of about fifteen percent or so.
There was no known specific
treatment, and patients were given
broad-spectrum antibiotics and antivirals,
but they weren’t very effective, and treatment was
really symptomatic and supportive.
What about transmission?
The dominant mode for
transmitting SARS was clearly face-to-face contact,
droplets from coughing or sneezing,
and the droplets that were inhaled were the contaminated
objects– that is, fomites–and a person
touching them and then bringing the hand to the mouth could
ingest the virus. This mode of transmission was
encouraging for public health because it meant that the
disease required prolonged contact at close range,
and was much less contagious than say the Spanish influenza,
smallpox or pneumonic plague. And the dominant pattern of the
epidemic was for SARS to spread in tight clusters of people,
closely gathered around a patient: healthcare personnel,
their family members, hospital visitors,
guests on the same floor of a hotel,
or residents of the same wing of an urban tenement dwelling.
And the disease,
like airborne viral infections in general,
seems to be an equal opportunity affliction that can
pass to all classes of society, the young, the old,
the healthy and those with preexisting conditions.
But there also was some
evidence, although it mostly remained confined to the
hospital environment, at least outside of China,
it could spread to communities. There were speculations during
the outbreak of people who were called super-spreaders–
sort of viral Typhoid Marys, was the image–
who were unusually virulent and who shed viruses inhaled at a
greater distance; perhaps through the
air-conditioning system of a hotel, or the circulating air of
an airplane. There was speculation that
sometimes it could spread through the fecal-oral route,
or through asymptomatic carriers.
In any case,
the disease spread from Southern China and Guangdong
Dong Province to its next epicenter, which was Hong Kong;
which was particularly important because of population
density and mass air travel, Hong Kong being one of the
great hubs of the international air travel network.
It’s important noting too that
Hong Kong had intense, constant links with neighboring
southern China. In sheer size it had some 6
million people and was known as one of the most densely crowded
cities on earth, and possessed the busiest
airport in Asia. The first outbreak was at the
Metropole Hotel in Hong Kong, and then very rapidly
thereafter the Prince of Wales Hospital.
at the initial cases, wasn’t really recognized and no
special precautionary measures were taken,
though the hospital and the hotel soon became world famous
as the first foci of infection outside of Guangdong Dong
Province. The people afflicted early on
were doctors, nurses, orderlies,
attendants, hospital visitors and a couple of guests at the
hotel. So, Hong Kong became the second
world epicenter, and the disease spread from
there, using air travel as its means.
It went to three places
particularly. First was to Hanoi in Vietnam,
then to Singapore, and then on to this continent,
to Toronto. It struck Toronto through a
seventy-eight-year-old immigrant from Hong Kong who’d been
staying at the Metropole Hotel, before returning to Toronto.
She was hospitalized and died
in the Scarborough Hospital in Toronto.
There was soon a joke about
SARS; that is to say,
“Are you worried about terrorists?”
“No, we’re worried about
Canadians.” In any case,
what were the public health measures that were adopted?
The first thing to note is
that–I’ve said this was a great dress-rehearsal,
and it was a transformative event;
although we’re going to see that all of these three
pandemics that we discuss this morning were relatively limited
in terms of their impact, they are really important for
our consideration because they mark a real change in public
health. One of the factors was that
SARS led to an unprecedented coordination of international
public health responses. What happened was really
extraordinary, as Julie Gerberding,
the director of the CDC, pointed out,
saying that this was “a monumental international
transformation.” What happened on the twelfth of
March, the World Health Organization issued a global
alert; by the fifteenth,
a travel advisory; and thereafter some eleven
laboratories in nineteen countries were linked
electronically, as they shared all information
in real time, hunting for the pathogen.
They began genetic sequencing,
and began work attempting to find a vaccine and a reliable
diagnostic test. The result was success in world
record time. On April 16^(th),
the World Health Organization Laboratory Network announced
that it had identified the pathogen responsible for SARS.
By the twenty-sixth of March,
there was the beginning of electronic grand rounds,
in which the internet was used to bring together eighty
clinicians from thirteen countries,
to share information on the care and maintenance of SARS
patients. Those were novel features.
there were some traditional measures that were taken,
that constitute in part a review of things that you’re
already well familiar with. A team of World Health
Organization epidemiologists began investigating the epidemic
in Southern China and its outward spread.
Some airports began to
quarantine people who arrived. They took their temperatures,
examined them for symptoms, and gave them advisory cards
with information on what to do if they fell ill.
Hospitals set up isolation
wards, with a capacity to contain air,
and with barrier protection for hospital personnel:
double gowns, facemasks, goggles,
gloves, hand disinfection, changes of shoes.
In affected areas,
there was the rigorous tracking of all contacts of known cases.
There was quarantine,
in some places, even house arrests,
with video cameras, unannounced police visits,
sanctions, fines, and all the rest.
And you might like to know that
the Toronto Star also recommended reading material for
those in quarantine, and it looked a little bit like
something that might be a reading list for our course.
That is, the most popular book
for the SARS patients, you’ll all be glad to know,
was Daniel Defoe, Journal of a Plague
Year. And they also read Camus and
Boccaccio, in their quarantine in Toronto.
There was public information in
the media and on the web, enabling citizens to make
rational public health choices. There was compulsory masking,
the closing of schools, cancellation of sports events
and other large gatherings of people.
All of those were measures that
were fairly traditional. So, what’s striking is a kind
of contrast. On the one hand,
the high-tech end, working out the biology and
epidemiology of SARS, with extraordinary rapid,
efficient and high-tech interventions.
On the other hand,
public health measures and treatment were rather
old-fashioned, low-tech and traditional.
But the public health measures
were effective. By mid-May there were signs
that the outbreaks were retreating and being
successfully contained in healthcare settings.
By June 18^(th),
as the global epidemic reached its hundredth day,
the number of cases was down to a handful.
On the fifth of July,
the World Health Organization announced that SARS had been
controlled worldwide. The total, by the end,
was something like 8,000 cases and a few hundred deaths.
the passage of this marked a transformation,
as I said, in international public health
interconnectedness. It also left behind it
important effects on communities.
Hong Kong was described as a
ghost town. Its shops, restaurants,
theaters, churches, public health transport were
all deserted and many closed. Communion wasn’t administered
in churches, and daily life was transformed for those in
quarantine, and for healthcare personnel.
A joke circulated in Hong Kong
that if you wanted space to yourself, all you had to do was
sneeze and you’d immediately be left alone.
There was economic impact,
the collapse of tourism and the retail industry.
One estimate was that some ten
billion dollars were lost in Asia because of the impact of
SARS, with knock-on effects on
unemployment and fragile economic growth.
Toronto, this epicenter in
North America, was less severely affected.
But there were things there too
that remind us of parts of our course, that you now know very
well. There were reports in the city
that it was being seized by a SARS panic, a stigmatization of
victims and scapegoating. A nurse, who had been
hospitalized and later interviewed in the press,
reported that a crowd had gathered outside her home and
stoned it. There was, in the Canadian
press, a series of reports on what was called SARS racism,
particularly in Chinatown, and children of Asian origin
were bullied in school, and Asian Canadians were
shunned in public. Toronto also spawned reports of
a general fear. Polls show that sixty percent
of Canadians were worried or very worried about contracting
SARS. And even places not touched by
the disease experienced some ripple shock effects.
Los Angeles and San Francisco
had–people reported that surgical masks had been sold
out. ERs and primary care physicians
were overwhelmed with people with coughs and the common cold.
Chinese restaurants and
Chinatowns in the United Sates, in various cities,
were deserted, and Health Canada reported an
outbreak of what it termed “SARS racism against the
Asian community.” So, the experience of SARS was
the first dress rehearsal of the twenty-first century for
emerging diseases. And I think it showed that the
world community was still vulnerable, especially to
airborne diseases. SARS tested the preparedness of
public health and the preparedness of political
authorities. On the positive side,
it revealed and stimulated an extraordinary technical and
scientific capacity, in interlocking laboratories
that identified the pathogen, and in the ground rounds in
cyberspace. But I would argue that there
wasn’t really room for complacency.
The world was lucky and dodged
a bullet with SARS, for a variety of fortuitous
circumstances. The disease spread by droplets
isn’t really very readily transmissible.
The chronology was fortunate.
The disease began to spread
globally in the spring; which, as you know,
is normally the beginning of the end of the flu season.
And there was serendipity.
The disease spread to Hong
Kong, Singapore and Toronto, and those are all places of
highly developed healthcare systems and resources making
containment possible. One wonders what the result
might have been had the earlier travelers,
who spread SARS, gone to different destinations
in resource-poor Third World cities.
So, that was the first dress
rehearsal. The second followed fairly
quickly after, and this was avian influenza,
H5N1, which was a new or emerging epizootic.
It was first isolated in 1996,
but began as a disease of waterfowl in Southeast Asia in
mid-2003. Early cases were mostly
undetected and unreported. There then followed three small
waves of this influenza outbreak,
beginning in December 2003/January 2004 in Korea,
Vietnam, Japan, Cambodia, Indonesia,
first among susceptible birds. It spread rapidly and affected
their internal organs with a mortality rate of nearly a
hundred percent. And this was one of the great
global epizootics, with tens of millions of wild
birds perishing. Then H5N1 demonstrated that it
was capable of transmission to human beings who came into
contact with infected poultry: butchers,
people who raised live poultry or live in close contact with
them. This is–that’s the masking
from SARS, but I wanted to show you someone at risk during the
epidemic of avian flu. Then there were human cases
that began a second detected wave in June and July 2004 that
ended in November 2004, and a third wave beginning in
December of 2004, again in Southeast Asia.
Once again, if we look at–I
wanted to show you a few cases of humor generated by the avian
flu. Here we see a person saying
that they’re safe at last, but in fact they weren’t
really. Then there’s this one,
which might take you a second to see what’s happened to our
friend Donald Duck. I think it’s worth knowing that
epidemic diseases sometimes also generate a human response.
And then there’s this one,
that I was particularly fond of,
which is your flock of geese and of poultry,
with one sneezing in the back, and someone in the front
saying, “Very funny.”
In any case,
the spread was by migratory birds in flight,
but also by the great trade routes of the poultry industry,
the trade in chickens, in feathers,
in chicken parts for use as feed, chicken excrement for use
as fertilizer. Once again, the world was
fortunate in that avian flu didn’t spread readily among
human beings. We then experienced our third
rehearsal for the twenty-first century, and this was swine flu,
that all of you know, H1N1.
It first appeared in Mexico in
March/April of 2009, as far as is known,
then swept the globe and isn’t in fact–
hasn’t entirely ebbed, as we meet this morning.
Thus far, however,
apart from the early phase of the disease in Mexico,
where it was fairly–it was fairly serious in Mexico–
it’s been elsewhere a widespread, relatively mild
disease, that’s infected millions and
millions of people, but with a strictly limited
mortality; a mortality less even than
seasonal influenza. But we need to remember that we
don’t know the end of this story yet.
Viruses for influenza are
highly unstable and capable of mutating, and so it could
achieve still a greater virulence.
And we know from previous
outbreaks of influenza that it could return in future waves.
Often a pattern of influenza
outbreaks has been to have a series of waves.
We don’t know what will happen
with the swine flu. This was the first epidemic
disease, however–and this was a major
transformation in public health–
to appear after the entry into force of the new international
health regulations of 2005 that were signed by one hundred and
ninety four nations, including all members of the
World Health Organization. Those regulations were intended
to provide rapid international response to public health
threats. And in particular the old
regulations had declared that there needed to be reporting
only for diseases that were already known.
It seemed to assume a static
world, without the emergence of new diseases.
The new regulations took that
into account and called for compulsory reporting of disease
events; of known diseases but also new
ones, new public health threats. The new regulations then
required reporting. They standardized and improved
international surveillance, and they allowed World Health
Organization intervention through regularized procedures.
And they played,
the new regulations, an important role in the
unfolding pandemic. Indeed, the coordination of the
international response to swine flu,
at every level, was one of the most encouraging
lessons of this particular pandemic,
along with the speed with which a vaccine was developed and
distributed, along with antiviral
medications. But once again,
there was no real place for complacency.
It was true–and this was a
worrying sign–that the disease took the world public health
community by surprise. The ruling dogma in matters of
influenza was that the next threat would emerge in the Far
East, and it was there that surveillance was concentrated.
But this was a pandemic that
surprised everyone by breaking out first of all in Mexico,
and it did so at a time that no one was expecting,
in the spring rather than in the early fall or winter,
as influenza normally does. The crisis also exposed a lack
of capacity in the public health system, limited surge capacity
in terms of hospital beds or caregivers.
There was an ongoing public
distrust of vaccination as something dangerous.
It also showed the capacity of
airborne respiratory disease to emerge without warning,
and to spread rapidly across the globe,
before vaccines could be developed to contain them.
And as in the case of SARS and
avian flu, so too H1H1 showed that the
world community was fortunate, because this turned out really
to be a dress rehearsal in that the pathogen had a very limited
virulence. So, as a society,
how prepared were we? Once a pandemic strain
appeared, it took quite a bit of time.
I think we should say that
neither doomsday pessimism nor complacency are rational.
The threat is real.
But pessimism is also
unrealistic, and there are many steps that could be taken to
contain the threat. The SARS lesson showed us that
virologists can now be instantly linked via the web around the
globe, and that clinicians can
exchange information on patient care in the same manner.
SARS was epoch-making in this
organized response, and this process was
strengthened through avian flu and swine flu.
as I’ve said, was the entry into force of the
new set of international health regulations,
and individual communities and countries now put into place
advance planning, after SARS, with procedures
before the next emergency. Globalization,
in other words, was not only a health risk,
but also a resource. And you can see the difference
right here on our campus. SARS, I would argue,
caught Yale unprepared, and the result was confusion,
fear and delay. By the time of the swine flu
outbreak, however, the lesson had been
learned, and it was very impressive to
note that this time around there was a coherent strategy;
that everyone was kept informed throughout the course of events.
And perhaps the only worrying
aspect was something that wasn’t our community’s fault but a
sobering global issue. It was worth remembering that
last fall, at the height of the swine
outbreak, vaccines arrived just as the
disease was moving on from the State of Connecticut.
In any case,
in the absence of an effective therapy or prophylactic,
for patients supportive care and nursing are crucial
considerations, and one could argue that
perhaps for-profit medicine has squeezed the surge capacity out
of our system, and radically reduced the ratio
of nurses to patients. There was also a crucially
important factor, which was the race to develop a
vaccine. And here, to cultivate the
virus–in the case, for example,
of SARS–massive numbers of– or avian flu–what was
discovered was the need for massive numbers of hen eggs.
And, so, the poultry industry
should perhaps have been declared of crucial importance,
because the hens themselves were needed for the vaccine,
but would perish in crippling numbers in the event of the
avian flu going further. Communities also learned that
they could plan their response in advance;
that they could take measures to educate about
coughing/sneezing etiquette, hand sanitizing,
the danger of fomites, the utility of masking,
and the utility of avoiding assemblies of people and,
as far as possible, to isolate themselves during
the outbreak, and the importance of
information to prevent the spread of panic.
So, I would argue that these
three dress-rehearsals, for the twenty-first century,
had major– although all three were in
terms of their impact as diseases,
they were very limited. The world was fortunate in that
respect. They revealed important
vulnerabilities, but they also provoked a new
organization of response through laboratories;
a new coordination of the public health community;
new awareness of the need rapidly to distribute antivirals
and vaccines; and they taught the necessity
of preparation in advance for the next outbreak.
I would say that the world
moved on enormously as a result of SARS, of avian flu and swine
flu. But I would argue that emerging
diseases are an inherent part of the human condition,
nothing totally to be thought of as unexpected or strange.
And if I were to make just one
prediction, I would expect that there would
be more, and that the systems set in
place and improved by SARS, avian flu and swine flu will be
tested again in our new century. And with that I’ll stop.
And we’ll gather again on
Monday for a review session of everything that we’ve covered in
our course. So, the review should include
everything from the beginning, down through the very end.
It’s not meant to be limited
just to the first half, but to the whole of the