One hundred years on from the Spanish Flu, we are facing another major pandemic

The World Health Organisation has put scientists and health workers around the world on alert for a new and potentially deadly pathogen, which it has named as Disease X

During the epidemic soldiers with a mild strain stayed where they were, while the severely ill were sent on crowded trains to crowded field hospitals, spreading the deadlier virus (Alamy)

Should you meet someone who, unfortunately, has developed a fever, become short of breath, whose face appears to be tinged with blue and is subject to vomiting and severe nose bleeds, you could wonder if the Spanish Flu has returned, one hundred years after it first appeared in 1917/18, near the end of the First World War. For according to Dr Jonathan Quick, we are due another visit from this terrifying disease which is said to have infected 500 million people around the world. Dr Quick is chair of the Global Health Council.

Dr Quick doesn’t mince his words: “The big one is coming: a global virus pandemic that could kill 33 million victims in its first 200 days. Within the ensuing two years, more than 300 million people could perish worldwide. At the extreme, with disrupted supply of food and medicines and without enough survivors to run computer or energy systems, the global economy would collapse. Starvation and looting could lay waste to parts of the world”. And what is this “big one”. It is indeed the Spanish flu again. Dr Quick says that the most likely culprit will be a new and unprecedentedly deadly mutation of the influenza virus. The conditions are right. “It could happen tomorrow”.

Dr Quick explains that somewhere “out there”, a flu virus is boiling up in the bloodstream of a bird, bat, monkey or pig, preparing to jump to a human being. When that combination from birds and beasts finds its way into a person, the resulting new human strain can kill us more easily because it is unknown to us and our bodies have zero immunity to it.

The scientist also argues that we have inadvertently developed a powerful way of helping influenza to kill us, 100 years on. This is our addiction to cheap chicken and pork — and the factory farm industry that supplies it. Factory farms present one of the greatest potentials for catastrophic disease because they pack animals together by the million in conditions that can be fetid incubators of disease.

The consequences of the over-crowding of troops during what was to be the final year of the First World War are indeed part of the explanations for the outbreak of Spanish flu one hundred years ago. While there is no unanimity about the location of the first examples, one influential inquiry pinpoints a major troop staging and hospital camp in Étaples, France, as being the origin of the 1918 flu pandemic.

It also was home to a live piggery; and poultry were regularly brought in from surrounding villages. A British team led by virologist John Oxford of St Bartholomew's Hospital has argued that a significant precursor virus, harboured in birds, mutated so it could migrate to pigs that were kept near the front line. In other words, it was a perfect setting for the way viruses can leap between birds and beasts and human beings.

Spanish flu begins to spread when an infected person sneezes or coughs. It is a simple as that. No doubt there was a lot of sneezing in the First World War armies. Moreover, these soldiers are likely to have been suffering from malnourishment, given the absence of proper cooking in the trenches, from the stress of combat, naturally enough, and from the chemical attacks that were first developed as a weapon of war at this time.

However, there were some oddities about the outbreak. For instance, the pandemic mostly killed young adults. The American statistics are astonishing. In 1918–1919, 99 per cent of pandemic influenza deaths in the US occurred in people under 65, and nearly half in young adults aged 20 to 40 years old with particularly high death rates in pregnant women. This is in sharp contrast to what one would expect – that the main sufferers would be the very young or the very old.

Another strange aspect of the outbreak was that it seemed to be at its worst in the summer and the autumn rather than in winter, its usual season. I can relate to this because, no doubt like many people, I have occasionally suffered from a cold in high summer, and when it has occurred it has generally been a bad one.

But the big questions are why the death toll was so massive and why were so many countries affected? The figures are astonishing. In India, as many as 17 million people died, about 5 per cent of the population. In Iran, the impact was enormous and according to an estimate, between 900,000 and 2.4 million of the total population died. Then, in descending order came the United States with 500,000 to 675,000 deaths. Brazil lost 300,000 as well as its President, Rodrigues Alves.

Then come France and Britain. In France the score was 400,000 deaths, and in Britain as many as 250,000 died. Given that the two countries have broadly similar populations, could Britain’s lower figure be attributed to the protection afforded by the English Channel and by the related fact that none of the fighting that took place during the First World War, mainly trench warfare with its consequences for the spread of disease, actually took place on British soil?

Consider, too, the arithmetic of the pandemic. About a third of the population of the world was infected. Of these cases an estimated 10 per cent to 20 per cent died. In turn this implies that some 3 per cent to 6 per cent of the entire global population died. These are incredible figures, even if historians calculate that the medieval Black Death was even worse. Current estimates say 50–100 million people worldwide lost their lives from Spanish Flu.

It seems that a third oddity might explain the sheer size of the pandemic. There is something called a cytokine storm which turns your own immune system “against you”, so a healthy immune system might actually "hurt" more than it "helps". It was then postulated that the strong immune reactions of young adults ravaged the body, whereas the weaker immune systems of children and middle-aged adults resulted in fewer deaths among those groups.

A second wave of the pandemic began to develop in August 1918. It began in France, Sierra Leone and the United States. More seriously still, the virus had mutated to a much deadlier form. As a result, the thirteen weeks between September and December 1918 proved to be the costliest in lives.

We are still not done with the oddities. For this peak has been explained in almost Darwinian terms. In civilian life, natural selection favours a mild strain. For the mildly ill continue with their lives, preferentially spreading the mild strain while those who get very ill stay home. But this pattern was reversed in the trenches. Soldiers with a mild strain stayed where they were, while the severely ill were sent on crowded trains to crowded field hospitals, spreading the deadlier virus.

The final oddity is how the pandemic suddenly eased quite dramatically. We have the figures for Philadelphia in the United States. Some 4,597 people died in the week ending 16 October 1918, but by 11 November, influenza had almost disappeared from the city. It looks as if the virus may have mutated extremely rapidly to a less lethal strain. This is, apparently, a common occurrence with influenza viruses

Now there comes another forecast of a new deadly disease, which supports the dire warnings by Dr Jonathan Quick quoted above. The World Health Organisation (WHO) has put scientists and health workers around the world on alert for a new and potentially deadly pathogen, which is has named as Disease X. A pathogen is an infectious agent such as a virus or bacterium.

The WHO states that “‘Disease X’ represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease. History tells us that it is likely the next big outbreak will be something we have not seen before.” John-Arne Rottingen, a scientific advisor to the WHO commented that it might seem strange to be adding an “X” but the point is to make sure that we prepare and plan flexibly in terms of vaccines and diagnostic tests. Mr Rottingen’s chief fear is that Disease X could be sparked by a disease that jumps from animals to humans – just as the Spanish Flu of a hundred years ago seems to have done.

So what conclusions should we draw? We should consider pandemics as natural disasters like hurricanes or forest fires. We cannot prevent their occurrence. Instead we must consider how best to meet the consequences, among them sudden increase in the demand for nurses, doctors and medical specialists along with hospital facilities. If our public services can rehearse for a terror attack, as they do, they can also act out the best responses to a pandemic.