THE WORD “INFLUENZA” comes from the Italian word for “occult” and was first used in the Middle Ages.
Back then, just like today, the flu appeared to come out of nowhere every winter, incapacitating or killing large numbers of people, only to vanish come springtime. Today, seasonal flu is estimated to kill around half a million worldwide every year.
But the flu, in many important respects, remains mysterious. Determining how many deaths it really causes, or even who has it, isn’t easy. It’s also one of the most adaptable of viruses, constantly evolving to outwit our attempts to fight it (this is why you need a new flu vaccine every year).
What’s a pandemic?
Then every so often an unusual bug springs up, infecting way more of us than normal season flu variants do. It’s these rogue viruses that cause pandemics (a pandemic is defined by the WHO as “the worldwide spread of a new disease” and an influenza pandemic “occurs when a new influenza virus emerges and spreads around the world, and most people do not have immunity”.)
The worst flu pandemic in recorded history was the “Spanish flu” of 1918–19. It emerged at the tail end of World War I and had devastating effects. A third of the world’s population was infected, with at least 40 million (maybe as many as 100 million people) dying.
To put that figure into perspective, it’s more people than were killed in World Wars I and II combined.
Spanish flu was caused by the H1N1 influenza virus. As expected from the name it originated in Madrid. The first report of it was reassuring:
A strange form of disease of epidemic character has appeared in Madrid. The epidemic is of a mild nature; no deaths having been reported.
The local festival, Fiesta de San Isidro was occurring during the outbreak and the virus soon began to spread. People began to simply collapse on the street. It was reported as having a low mortality rate however. This initial outbreak occurred in May 1918 and died down during the summer months.
It returned with a vengeance, however, in the autumn and spread to other areas of Europe. It may have mutated because, now the mortality rate was much, much higher.
Spanish flu in Ireland
The outbreak of Spanish flu here in Ireland was probably brought back to by returning soldiers but the epidemic was further spread by the intense political activism and mobility movement of people, around the General Election of 1918.
Just think though how much worse that would be today in our hyper connected and mobile world. There were 23,000 Irish deaths – that number is higher than deaths in the War of Independence and the Civil War put together.
Influenza mortality is typically high among the elderly and very young, but a global peculiarity of the 1918–19 pandemic was its targeting of normally healthy young adults. In 1918, 22.7% of all deaths from influenza in Ireland were of people aged between 25 and 35.
The theory is that their strong immune systems over-reacted to the flu strain. Post-mortems revealed severe haemorrhages in lungs unlike anything we’d ever seen before.
It’s only a matter of time before we’re hit by another flu pandemic
Most experts agree that it’s only a matter of time before we’re hit by another devastating flu pandemic. In fact we’re overdue a pandemic. Our main lines of defense are pharmaceutical—vaccines and antiviral drugs to try and halt the spread of flu and prevent people from dying from it.
But there simply won’t be enough to go around. Not even enough for 10% of the population. But what would happen if a bad pandemic strikes?
Imagine thousands of people are dying from a mystery virus. The hospitals are full, the health service at a standstill and casualties left by the hundreds on the streets. Our GDP is slashed. Everyone is paranoid. We won’t know who will get sick next and kissing your wife could kill you.
Dr Tim Hinchey is a Dublin based GP. He blogs at Common Sense Medicine and you can follow him on Twitter here.
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