Pandemic Flu

Basic Facts On Pandemics And Avian Flu
You hear dire warnings on the news nearly every day about the threat of pandemic illness. There are reports from across the globe about new appearances of the Avian – or Bird – Flu. But if you’re like many people, these threats may seem remote, even far-fetched. Just how likely is it that we’ll really be affected? How bad would it be? What does it mean for me, my family and my business? Here are answers to some of the most commonly asked questions:

What is a pandemic?
A pandemic is a disease outbreak that affects the entire world, or a significant enough geographic area that it is considered to be an essentially worldwide phenomenon. Right now, incidents of Avian Flu are concentrated primarily in Southeast Asia, although there have been occasional appearances in other parts of the world. Should the disease evolve into a form that is more readily spread, we would expect that it would rapidly appear in many parts of the globe in a short period of time, making it a true pandemic.

Is it really likely that we’ll experience a flu pandemic?
Yes, it is. While it’s impossible to say with certainty that Avian Flu will be the next global influenza event, we can say with a good degree of confidence that at some point in the relatively near future there will be a widespread outbreak of one form or another. The World Health Organization has noted that flu pandemics tend to happen once every 10 to 50 years, and we experienced three of them in the 20th century. The most well-known of these occurred in 1918 and was responsible for an estimated 40 million deaths. An additional two million people died in the outbreak of 1957, and one million died in the pandemic of 1968.

How quickly does pandemic flu spread?
Because each variant of the flu has slightly different characteristics that determine how transmissible it is, it’s impossible to say with certainty exactly how quickly it spreads. Moreover, because the flu would likely affect large segments of the population, we could expect to see a significant disruption in ordinary travel patterns. This could, in turn, influence how rapidly the disease is transmitted. Nonetheless, the WHO estimates that a typical pandemic flu would circle the globe in three months.

Why would we see such widespread infection?
Because the specific strain of flu would be new to those who encounter it, very few would have any form of natural immunity. This makes it likely that a significant number of people will be infected. If transmission follows historical patterns, members of the medical community can expect to be among the first victims, after which the disease will work its way rapidly through the entire population.

What exactly is the flu?
The flu, or influenza, is a virus that attacks the upper respiratory tract, producing fever, headaches, body pains, coughing and a sore throat. It is distinguished from the common cold because flu symptoms typically appear quickly and powerfully while colds occur more slowly and are typically more tolerable. The flu can be, and often is, genuinely debilitating, requiring bed rest. If you feel generally under the weather but well enough to continue with your typical routine, you are more likely than not suffering from a cold.

Each year, according to WHO estimates, between 5% and 15% of the population suffer from the flu, and of these, somewhere between a quarter and a half million people die. Most victims of the flu are the elderly or people who are otherwise too frail to mount an effective immune response.

Why don’t we develop an immunity to the flu?
Actually, we do. The problem is that we only develop immunities for strains that we have been exposed to, and since the flu virus readily mutates, each time we’re exposed to a new variation, we’re susceptible to infection.

This is why we need to produce a new flu vaccine each year. Scientists do their best to look at emerging strains of the virus and identify which version is likely to be virulent enough to spread across populations. They craft their vaccines to attack these particular strains. However, nature can be unpredictable, and it has happened that the virus used to create the vaccine is not the same as the one that ultimately emerged. While these vaccines do generally confer a degree of protection, they’re usually not nearly as effective as versions created for the proper strain.

Why don’t we make a vaccine for the Bird Flu?
Because we don’t yet know exactly what form the flu will take. When scientists develop a vaccine, they’re producing a substance to fight a known quantity – they’ve seen the disease as it emerges and are responding to the specific characteristics of that virus. However, the Bird Flu as it exists right now is not in the form that scientists expect it will take if – or when – it evolves into a more dangerous strain.

In addition, because most flu bugs are not virulent enough to cause a pandemic, manufacturers typically have the time to produce a sufficient quantity of vaccine to protect large portions of the population. That is not necessarily going to be the case with the Bird Flu. If the pandemic emerges as expected, it will transmit rapidly – so rapidly, in fact, that there may be little time for pharmaceutical manufacturers to produce sufficient quantities of vaccine.

If the Bird Flu is out there now, how come we’re not all getting sick?
Because the flu that we’re seeing has not taken on a form that is easily transmitted from person to person. There are three general requirements that need to be met for a virus to become a pandemic: 1) It needs to be a new subtype that humans have not been exposed to in the past, 2) it must produce illness in humans and 3) it must be readily transmitted from person to person. The Avian Flu virus meets the first two criteria but, fortunately for now, not the third.

However, there is a good chance that this will change. Flu viruses can mutate in two ways. In some cases, they evolve as they move from person to person, changing into a form that is more potent and easily transmitted. In other cases, they actually swap genetic material with other forms of the flu, combining characteristics. Should, for example, a poultry worker with a more common form of the disease also contract the Avian Flu, it’s possible that the two viruses could interact in his or her body to produce a new strain altogether. If this strain has the transmissive characteristics of the first virus – that is, if it’s easily spread through casual contact – but the potency of a virus that we have no natural immunity to, the result could be a pandemic.

The current strain of the Avian Flu – it’s known as H5N1 among scientists – is not the strain that would infect large populations. Despite the fact that millions of chickens and other poultry have been exposed to the virus, very few people have contracted the disease, and indication that it is difficult to catch in its present form. And while there have been very rare cases of human-to-human transmission, those have occurred only when there has been close personal contact. For H5N1 to become a pandemic, it will need to evolve – and as long as the virus continues to circulate among livestock, that evolution is a very real possibility.

How many people could die as a result of a flu pandemic?
It’s impossible to tell with any degree of confidence, but the WHO reports that some models suggest that anywhere from 2 to 7.4 million people may die. That’s as many as 30 times more deaths than occur from the flu in a typical year. As staggering as that number may seem, keep in mind that a far greater number will become significantly ill, many requiring hospitalization, so the ultimate toll the disease takes on worldwide medical and economic resources may be truly devastating.

How will we know that a pandemic is occurring?
It will be impossible to miss. The first signs will likely be clusters of illness, particularly among family members and medical workers. As the disease spreads beyond these groups, it will be identified as a new flu strain. Cases will begin to appear in the dozens, and they’ll occur in a geographically widening area. Then, instead of dozens of cases, hundreds will be reported each day. The disease may begin to appear in distant regions as infected travelers carry the germ with them. By this time, there will be no mistaking what is happening.

Once it’s spreading, can anything be done to stop it?
This may be the most important question of all, since it is a virtual certainty that at some point in the near future, some new form of flu will threaten to become a pandemic. Some studies have suggested that, if certain conditions are met, it may be possible to contain an outbreak. Those conditions include the rapid identification of the new disease, immediate delivery of a sufficient quantity of antiviral medicine to the area, treatment of everyone with the potential for exposure and the imposition of travel restrictions. All of this needs to happen within a matter of weeks – a daunting task that could be complicated by everything from weather to political conditions. It’s far from certain that all of this could be accomplished, and even then, because infected people are often contagious before they show any symptoms of the disease, by the time an outbreak is recognized for what it is, the germ may have spread too far to be stopped. Nonetheless, considering the threat that such a disease poses, we may have no other options.

What can I do to reduce my exposure?
The practice of good personal hygiene may be the most effective thing you can do to minimize the likelihood that you will contract the flu. This means washing your hands frequently with soap and warm water, covering your mouth when you cough and sneeze, and avoiding contact with surfaces that are likely to have been in contact with other people (particularly in restrooms and kitchens). In the event of an outbreak, many people will likely choose to wear face masks, although there is no clear evidence that this reduces transmission rates among the general population. However, there is also no evidence that it is in any way detrimental to do so.

Source: World Health Organization. For more information, visit them online at www.who.int, and read their handbook on influenza pandemics (PDF)