Epidemics in Western Society Since 1600

HIST 234 - Lecture 25 - SARS, Avian Influenza, and Swine Flu: Lessons and Prospects

Chapter 1. New Diseases of the Twenty-First Century [00:00:00]

Professor Frank Snowden: 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

Chapter 2. SARS [00:02:58]

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. And viruses, 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. The pathogen, 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 pneumonia-associated coronavirus. Because of one of its early victims, it was called the Urbani virus. But the name that stuck was SARS, Severe Acute Respiratory Syndrome.

Chapter 3. Symptoms, Epidemiology, and Effects on Society of SARS [00:08:32]

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. The disease, 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.

In addition, 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. Nonetheless, 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.

Chapter 4. Avian Flu [00:26:04]

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.

Chapter 5. Swine Flu [00:29:34]

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.

Chapter 6. Lessons [00:34:38]

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.

Especially important, 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 semester.

[end of transcript]