Media are abuzz with reports of the outbreak of a deadly influenza in Mexico, called swine flu, because it seems to have originated in swines. At this moment, about 150 people in Mexico have died of this disease. Just for some perspective: some weeks ago, media were abuzz with the drug war in Mexico, with many thousands of deaths.
The number of infected persons in the USA seems to be still below hundred, but so far, nobody has died.
One strange thing is that mortality is high in Mexico, but not in the USA, although the virus seems to be the same. This is rather easy to explain: the health care system in the USA is much better than that of Mexico (actually, the US system is excellent, contrary to many sensationalist claims; it’s just way too expensive). If flu patients are well cared for (monitoring and maintaining electrolyte balance, administering stabilizing drugs, etc.), their chances for survival rise considerably.
There are currently three suspected cases in Germany; people who just have returned from Mexico and show symptoms of flu. They are tested for the specific virus, but so far the cases are not confirmed.
However, the media is hyping this topic as if the next killer pandemic were in the making and we all are going to die. Of course, bad news are good news for the media, and especially in this case. A panicked populace means many readers for newspapers, watchers for TV stations, etc. Furthermore, as fear of pandemics comes up every other year or so, they can recycle a lot of material from the last time, e. g., material on the Spanish flu. And they can produce interviews with medical experts, which are cheap to do (for newspapers just a phone call, for a TV station a camera team sent for a short ride). In short, the media have a field day, and like to keep the fear of a killer pandemic alive.
The last real killer pandemic was the Spanish flu in 1918/19, which killed 25 or even 50 million people. It was a flu of type H1N1; the current swine flu outbreak in Mexico is also of type H1N1, but the viruses are different.
For many years now, experts have claimed a flu pandemic like the Spanish flu should occur every thirty years or so, and the next one is long overdue, so it could happen any moment.
The WHO especially likes to peddle this theory.
The WHO is a large bureaucratic organization with surprisingly little real power. But if there is one thing that bureaucrats crave, it’s power. And worldwide epidemics are just the right tool, so the WHO jumps onto any bird flu/SARS/swine flu bandwagon that comes along. Therefore their constant warnings of the next pandemic.
Well, it won’t happen. The Spanish flu wouldn’t have been possible without World War I.
The Spanish flu better should be called the Great War flu (prior to WWII, WWI was known as the Great War), as only this war created the conditions that led to the pandemic. It is not mere luck that such a pandemic hasn’t occurred since; and it will not occur in future, until some very specific circumstances are met.
The Great War flu occurred in three waves: spring 1918, autumn 1918, and spring 1919. The first wave had a low lethality, the second was the real killer, the third had again a lower lethality.
When studying infectious diseases, it is important to look at evolutionary aspects. The main goal of an infectious agent is to spread and multiply – of course, a glob of protein like a virus has no goal, but the evolutionary reality is merciless: if it does not spread, it will die out and vanish; in that case we wouldn’t recognise it. If it survives and thrives, it can become very visible, and then we can describe it as if it were following a strategy. So bear with me as I describe viruses as thinking beasts.
Any infectious disease doesn’t really want to kill its host. A living host is much more useful, as it can pass around the infection. Any disease that kills its host so quickly that it cannot be passed around simply dies out. When a disease kills its host, this is due to one of two reasons: it starts a process in the host which aids the spreading of the disease, but has the side-effect that it kills the host (e. g., cholera, which spreads with the diarrhea into the water supply, but kills the host due to the loss of water and electrolytes†; or rabies, which spreads through bites, but messes with the nervous system so thoroughly that the host dies). The other reason is maladaption: due to crossing a species boundary, or due to a random mutation, the lethality is too high to keep the disease running; it either dies out (cf. sporadic break-outs of ebola), or through evolutionary adaption (i. e., more mutation), it reduces its lethality.
For a virus to have a high lethality and still keep spreading, specific conditions must be met: a large number of potential hosts must be forced together into confined space and for some time. If those hosts have a weakened immune system, so much the better.
And now we have the reason why the Great War flu became such a lethal pandemic: trench warfare on the western front. New recruits were coming in (some may have brought the original, rather harmless virus, from Haskell County, Kansas), conditions were simply dreadful, all people were cramped together, soldiers were kept there in the trenches, people were malnourished, many were wounded. People were eating anything they could, even Speckled Jim. So there could have been crossings of species barriers, or random mutations (if there are many infected hosts instead of only a few, more mutations occur). Whatever it was, the virus could adapt to the situation that a huge number of potential hosts were cramped together over some time. It never needed to reduce lethality; even with very high lethality it could easily keep on spreading. Soldiers which were relieved of their duty in the trenches carried the virus home. Other soldiers were transported to stations in the colonies. This is the reason why the virus spread worldwide. But the reason why it was so deadly is simply that it was bred this way due to the trench warfare.
One fact that puzzled many medics is that many of the victims were otherwise healthy people, of the ages 20 to 40, who normally would be resilient to diseases. Let’s see: who would be in trenches during a war? Otherwise healthy men of the ages 20 to 40. I might just see a pattern here.
So, if we want to prevent a pandemic like the Great War flu from happening again, we should avoid the conditions that bred that specific disease, i. e., large scale trench warfare over extended time periods. But we do this already, even if for other reasons.
And this is the reason why a pandemic like that of 1918/19 hasn’t happened again: the conditions for breeding it weren’t there. And for this reason there will be no such pandemic in the future (although extremely overcrowded third-world countries are a breeding place; but when a deadly disease breaks out, people flee the disaster area, and evolutionary pressure on the disease is to reduce its lethality).
This does not mean that we shouldn’t monitor infectious diseases carefully around the world, au contraire; we should do it thoroughly. But it does mean that there is no reason to panic; the world is not going to end. And it does mean that we should be wary of the media. It has no interest in describing matters of the world calmly and rationally.
Oh, and by the way: about one million people will die this year of malaria. As did last year. And the year before. And the year before …
† Nobody needs to die of cholera. When I read news that in Zimbabwe thousands died of cholera, I was gripped by rage – all those deaths would have been preventable. You just need to provide the sufferers with uncontaminated drinking water and electrolytes in the form of oral rehydration solution. If you run low on stocks, the WHO will happily provide you with some.