2007, Volume 100 Number 1

North America has recently seen flares of measles, mumps, SARS, and XDR-TB (extensively drug-resistant tuberculosis). The latter caused the Atlanta-based Centre for Disease Control to order a man into isolation. The last time the CDC issued such an order was 1963, for smallpox.

The federal department of Health Canada started pandemic planning in 1976, following the Swine 'flu (influenza A) outbreak which resulted in 24% of the US population being vaccinated. The Public Health Agency of Canada released its updated national pandemic influenza plan this winter: it runs 609 pages. Still unresolved is the question of using anti-virals to prevent 'flu in essential workers. This measure is known as prophylaxis — it keeps people from getting sick, but it doesn't cure the disease. The national stockpile is now considered adequate and there may not be a need of priority lists. The anti-virals would be used before a vaccine, which must be specifically calibrated to the virus — which could then shift to resist the anti-virals. Provincially, Newfoundland and Labrador's 2006 budget added $800,000 to the anti-viral cache.

How else does a government prepare for a pandemic? The Newfoundland Quarterly talked to two officials involved with pandemic planning, Dr. Catherine Donovan, an Associate Professor of Public Health, Division of Community Health and Humanities, and Dr. David Allison, Medical Officer of Health with Eastern Health and Clinic Associate Professor with MUN/HSC Division of Community Health, about how health and government officials prepare for the worst case scenario.

#1 Determine that it is a pandemic, not an epidemic or outbreak.

"An epidemic is essentially a level of disease above what would normally be expected, and exactly what number constitutes an epidemic depends on the disease," said Dr. Donovan. "So if you have no disease present, even having one or two cases might be a concern. For example, (with) measles, in this province we might say we had an outbreak with five or ten cases. Something like 'flu (of) which you could have hundreds of cases, you'd have to have a lot more before it constituted an epidemic."

And how do you tell an epidemic from a pandemic? "A pandemic is essentially a world-wide epidemic," said Dr. Donovan. "An epidemic is usually focused in a specific geographic area in a particular time frame. A pandemic is one that is affecting the entire world. We don't have too many of those. Usually it's a disease that's relatively easy to spread that can turn into a pandemic, and obviously influenza is the classic example."

"Look at mortality," said Dr. David Allison. "And at who's ill and who's not ill. With the annual influenza, you anticipate the elderly and the very young are going to have the most severe disease. With a pandemic, that is likely to be different; we anticipate people of all ages becoming ill. When you look at the 1918 experience, it seems that younger people were more severely impacted than older individuals. You see elevated mortality in a population you don't expect."

#2 Determine where the alarm signals are coming from.

"If we're talking locally, it would probably be the physician's office," said Dr. Donovan. "That's where things would happen. Locally, the physician's office is where it would normally show up; if we were looking for a severe disease it might be the emergency room. Those would be the two areas where we would start to see cases. There is an ongoing surveillance program for respiratory illness, but it is enhanced for influenza, and we use sentinel sites like long term care homes, schools (looking at absenteeism), and emergency rooms looking at flu-like illness. So we're constantly monitoring what's happening. But the physician's office is probably where it's going to start. Ultimately if you're looking at a pandemic there are a whole lot of steps in the alert process that would be triggered. If we're looking globally, Asia is the place where we usually see flu coming from."

"With the worldwide perspective on surveillance what we'll first see, probably in Asia, is the emergence of a strain of influenza that affects the population differently," said Dr. Allison, "and we will have four to six months before it arrives on out doorstep. The front line could start here if the right mutation happened to occur, but it is more likely, with the tremendous mixing of human and bird and animal viruses in Asia where people are much closer together, much closer together with animals — that is the pot where the changes to the virus are brewing."

#3 Take the appropriate steps.

What kind of directives can federal and provincial health officials take? Technically, all flights can be grounded. "The power exists," said Dr. Donovan. "It's in the public health legislation. But it's highly unlikely. There's going to be a point where the epidemic is so pervasive there's not going to be much point. There may be added surveillance initially, there may be isolation and quarantine initially, and that primarily will delay the spread. It's not likely to stop the spread. The nature of the virus is that it spreads through the air. The initial isolation and quarantine would be so that you can prepare, and after a certain point those are not going to be effective tools."

"People do travel very rapidly," said Dr. Allison. "We had that experience here during the SARS scare. We didn't have any cases here, but we certainly had people suddenly arriving back in St. John's having just left Asia where they were teaching. It is entirely possible for something to arrive very quickly at our doorstep, but in terms of the natural progression of an epidemic, when people are infecting more and more people on a day-to-day basis, it would probably take a number of months."

Also during SARS, health care workers were extremely stressed when they needed to isolate themselves from their own families. What if they had chosen to stay home? "Can you force people to work?" asked Dr. Allison. "I don't know if you can. I don't think health care workers would necessarily avoid working. That's part of why they're health care workers. But there are a lot of legal conundrums, legal and ethical challenges."

#4 Have a good plan.

"Ideally what we've done is anticipated and vaccinated as many people as we can," said Dr. Donovan. "The first line of defense is immunization. Once we recognize that there is something going on, there is an alert put out to physicians, to emergency rooms, to other regions. That alert is to say keep an eye open, we've got some influenza, do some testing so we can identify the type that we have. And then the advice (is) if you're sick, stay home, (and follow) basic hygiene, wash your hands.

"In normal flu the impact tends to appear more significant for the elderly, those who have chronic diseases or those who are very young," said Dr. Donovan. "It may not be that it is worse for the well, average adult, it's just that with so many more affected, they have such a profound impact on how society runs. If you have health care workers, if you have municipal workers that are affected, we're going to notice that. There is certainly a strain on the system when there is a flu outbreak now, (but) the young and the healthy are not so much affected, they tend to be more resistant to the disease. But in a pandemic it's often a variant that hasn't been seen and therefore no one has any significant resistance to it."

"First of all you collectively look at our past experiences dealing with outbreaks, large and small," said Dr. Allison. "We draw on the experiences where we worked with small numbers of staff in difficult situations, like a strike situation, and that forms the basis of our understanding of how to respond.

"One of the challenges with a pandemic is really knowing how severe or to what extent the impact is going to be felt. When we talk about influenza, every year we have influenza that occurs, basically, naturally, the annual influenza epidemic. And there's usually some kind of change in the virus that occurs annually, and that's reflected in the vaccine that's available. So when we turn that into trying to think about a pandemic, you're really dealing with the same kinds of dynamics in terms of an illness, except that the illness is possibly much more severe than we've experienced previously."

#5 Learn from experience.

"Epidemiologists study (the Spanish Influenza)," said Dr. Donovan. "But it's a very different story (today). Health care is much more sophisticated, surveillance is much more sophisticated, there's negatives and positives in that, the speed of travel means it is going to be transmitted much more quickly, but we have the capacity to be better prepared than people were in 1918.

"And there's been a lot of lessons learned from SARS, there's been a lot of activity both provincially and federally to enhance our surveillance systems and our information systems, and ensure than they communicate better with each other.

"The SARS experience certainly comes into our thinking," said Dr. Allison. "It isn't particularly representative of influenza, but there's a good example of a severe disease that afflicts a relatively small number of people and has a tremendous impact on others around them. (We) had to put into place quarantine measures and contact tracing, to try to get a handle on the disease and understand it. But ultimately that was a disease that only transmitted well in very certain circumstances and by and large it was transmitting poorly. It didn't affect that many people directly, and rapidly came under control.

"Pandemic influenza is going to be very much different than that, because it will affect a large number of people."

#6 Accept that it is coming.

"We know it's happened in the past; what we don't know is when it's going to happen again," said Dr. Allison. "It was there in 1918, in 1957 (Asian Influenza), in 1968 (Hong Kong Flu). Any time there's a major change in the influenza virus there's a pandemic, and it depends on the nature of the change in the virus how severe that pandemic is. The change in 1918 was comparatively greater than the change in 1957 or 1968. Those two pandemics didn't have the same impact as 1918. 1918 also had tremendously different social circumstances, they didn't have anti-biotics available to them."

"Everybody thinks it's inevitable," said Dr. Donovan. "It tends to be cyclical. It's happened so often that it would be very unlikely that it wouldn't again."

#7 But don't panic.

"For some perspective on the pandemic planning process, we've known for many years that something ought to happen," said Dr. Allison. "In 1976 there was the Swine flu outbreak in the US, which triggered Canada to put together a plan. That didn't really go anywhere until 1997, when the Avian influenza first emerged in Hong Kong. Our present cycle of planning was initiated then, we dusted off the old plans, looked at them, and we've been building ever since, assembling more and more information on how to respond.

"If you were to say, 'Well, whose job is it?', there's two or three. But who's involved in planning? Many people. It's not just having the plan on the shelf, which it takes one person to write up. The planning process means everyone in the health care system from the front line up needs to understand what their role is. I can't say we've got there yet. But we are gaining an appreciation for the complexity of it."

"SARS was a very small thing," said Dr. Donovan. "It scared a lot of people but there was very little consequence worldwide — from a health perspective, clearly there were economic consequences. But SARS was an unknown, it was a complete unknown. We had no idea what kind of an organism was at play, we had no idea really how it was transmitted.

"There are things you are not going to be able to anticipate. There is a huge investment in planning for a pandemic. You can only prepare to a certain extent. But I think we know flu. And we know what the potential consequences are. There are many knowns about flu. We can be better prepared for flu."