Bird Flu Pandemic

According to the more excitable elements of the media, the threat of a bird flu pandemic that could decimate a huge proportion of the human race is mounting by the day, and, worryingly, many of the sober, reserved, scientific journals agree with them.

What, exactly, is a pandemic, and why should bird flu become one?

The word “pandemic” comes from the Greek words pan, meaning all, and demos, meaning people; broadly, it is an outbreak of an infectious disease that spreads worldwide or, at least, affects a very large part of the world. For an outbreak to be classified as a pandemic, it must meet three criteria; the disease must be new to the population, must infect and cause serious illness in humans and must spread easily and sustainably amongst humans.

The H5N1 strain of bird flu meets two of those criteria already – it is new to the human population, and causes serious illness, often leading to death, in humans. All that is lacking for bird flu to become a pandemic is the ability to spread easily amongst humans, and scientists know that H5N1 is both highly adaptable extremely good at combining with other Type A influenza viruses. They believe it is only a matter of time before it combines with another such virus that is already capable of spreading amongst humans, and, when that happens, all the conditions for a bird flu pandemic will be met.

Why would a bird flu pandemic be so dangerous?

So far, only a few people have caught bird flu, mostly, it seems by coming into direct contact with infected birds. However, those people developed severe symptoms, and many of them died as a result. Humans have no natural immunity to bird flu, so if / when H5N1 develops the ability to spread easily amongst humans, many, many more people will become ill and die.

The limited information gathered from those people who have already caught bird flu suggests that it has a longer incubation period than ordinary seasonal influenza. This means that people infected with bird flu would not necessarily become ill for several days, during which time they would be innocently infecting the people around them as they went about their daily business. The first victims would be those living and working in the region where the new virus evolved, but they would quickly pass the infection on to others. It would not be long before an international traveller – perhaps someone whose company had business in the region – became infected and took the virus back home with them. Their fellow passengers on the plane back home would become infected, and would then carry the virus with them as they left the plane to go home, or catch connecting flights, busses, trains etc. Their friends, family and colleagues would all be at risk of catching bird flu and then passing it on.

What is the treatment for bird flu?

There is currently no effective vaccine to protect against bird flu, nor can there be until the final form of the virus that affects humans is known and can be analysed. Even then, it will take many months to produce enough to vaccinate more than a tiny fraction of the world’s population; in all probability, the pandemic will have run its course long before any significant volume of vaccine is available.

Based on the limited evidence available, it seems that some current antiviral drugs, including oseltamivir (Tamiflu) can improve a patient’s chances of surviving H5N1 bird flu, providing it is given within 48 hours of symptoms appearing. However, there is also some evidence to suggest that the virus is already developing resistance to Tamiflu and, in any event, the drug is in critically short supply. Manufacturing capacity for Tamiflu has recently been quadrupled, but even so it would take more than 10 years to produce enough to treat 20% of the world’s population. Worse, the process is both complex and time-consuming, and is difficult to transfer to other manufacturing facilities.

Would the human race survive a bird flu pandemic?

Probably. The human race has survived other large-scale influenza pandemics, including the “Spanish Flu” pandemic of 1918-1919, which is estimated to have killed 25 million people within six months and possibly a total of twice that number throughout its 18 months’ duration. But, while the human race would survive, the odds of any given individual surviving are not encouraging. It is to be hoped that a bird flu pandemic does not break out for some time – or at all.