Sunday, August 2, 2009

Swine flu: batten down the hatches – and wait

Sunday, August 02, 2009 By Tom McGurk
In 1918,as the catastrophe that was World War I was coming to an end, it seemed hardily imaginable that an even greater disaster, which would kill even more people, could begin.

It did, and it was the great 1918 flu pandemic, commonly referred to as the ‘Spanish flu’ which, by the time it ended, had killed somewhere between 50 and 100 million people. That figure was equivalent to a third of the then European population - and the accuracy gap in the final death toll is a measure of the paucity of communications in that age.

Exactly like the current threatened swine flu, it too was a virus strain of the subtype H1N1, although the historical and epidemiological data are inadequate to identify the geographic origin of the virus. Astonishingly, most of its victims were young, healthy people, in contrast to the usual flu casualties of the very young and the very old or infirm.
The 1918 pandemic lasted for over two years - from March 1918 until June 1920 - spreading to places as remote as the Arctic and small islands in the Pacific. An estimated one third of the world’s population became infected and it is now believed that 10 to 20 per cent of those infected died, meaning that 3 per cent to 6 per cent of the world’s population perished.

That pandemic was described subsequently as ‘‘the greatest medical holocaust in history’’. It may even have killed more people than the Black Death.

Significantly - in a contrast to the population mobility of our times - in 1918 the huge movement of troops as the war ended may have hastened its spreading. Some historians even argued that the carnage the flu inflicted on the German side in 1918 may have had a significant effect in causing their eventual surrender.

Also significant is the fact that the Spanish flu pandemic swept in two waves across those years with presumably - after it mutated - the second wave becoming even more deadly and virulent than the first. In the end, the final death toll for Britain and Ireland came to 250,000 people.

The disease killed between 2 per cent and 20 per cent of those infected, as opposed to the more usual flu epidemic mortality rate of 0.1 per cent.

One theory as to why it often killed the young as opposed to the old is that older people enjoyed partial protection through exposure to the previous Russian flu pandemic of 1889.

Now, it seems, familiar historical ghosts are beginning to reappear. Our current threatened human swine flu pandemic (as defined by the World Health Organisation) is already under way, particularly in Australia and the United States. So far, there is no evidence to suggest that we are headed into a 1918 scenario, but how are we to know? The blunt truth is that we don’t.

The scientific reality - as opposed to all the speculation - is that all researchers can do is follow the patterns, intensity and global behaviour of the swine flu. This has been ongoing since earlier in the year and some significant patterns have emerged that require careful attention.

In general, swine flu symptoms have mostly been mild and the virus seems to respond to anti-viral drugs such as Tamiflu.

However, even to date, it has sprung some surprises. Unlike the common flu, swine flu seems to affect younger people more. Hopefully, this is not a signal that we are facing into a 1918 scenario.

Since the new flu threat emerged early this year, there has been an intense race against time in research labs across the globe to create a vaccine.

Apparently, one potential antidote underwent field trials last week in the US but, as yet, there is no vaccine as such. This is important to remember because vaccination is intended as an important weapon should the pandemic change in character.

Without alarming people, it is important to remember that we are also in another race - to have a vaccine ready and tested before the traditional autumn flu season in Europe.

Careful observation of its behaviour is critical to dealing with any flu pandemic. So what happens in the US is vitally important because the pandemic there is some two months ahead of its emergence in Europe.

The accepted theory is that what happens there will happen to us two months later. But that need not be the case either, as conceivably the flu could suddenly mutate here in Europe differently to elsewhere.

The bottom line is that we do not know where human swine flu will end up, or what its ultimate potential is. It could well continue in its current mildly-infecting state with a consequent and proportional increase when the traditional flu season arrives later in the year. Or it could suddenly become something else.

The bottom-line defence in Ireland is to vaccinate everyone in the country twice - presuming an effective vaccine is developed. Given the current state of our health service, can one imagine the logistics of that scenario? Equally, are we storing sufficient anti-viral drugs?

But there is simply no way of knowing if this bottom-line defence will be adequate to the challenge we face, because we don’t know the size of the challenge.

Of great concern is our modern transport system where hundreds of thousands of people cross the globe in hours. It wasn’t like that in 1918.Consequently, during modern pandemics, health officials pay attention when the virus reaches places with social upheaval, looking for deadlier strains of the virus.

We can only batten down the hatches and wait for the autumn flu season. As yet, human swine flu has given us only limited messages as to its intensity, but significant signals as to its dimensions. The current Frankensteinlike theory doing the rounds on the internet is that somehow recent DNA experimental investigations of preserved corpses from 1918 has unleashed the epidemiological ghosts. And in Britain the corpse of an aristocrat who died of Spanish flu in 1919 is being exhumed to see if it can provide any clues in relation to swine flu.

There’s some thoughts to keep you awake.

No comments: