This time, around a hundred years ago, the world was in the grip of one of the most widespread and virulent pandemics of all time. At a time when the world seems more connected than ever, it's time to talk about the Spanish Flu... THREAD /1 
Where'd it come from? Well, assuredly not Spain, but we'll get to that in a few tweets. Really, we can't be entirely sure. While the first cases were documented in a US Army camp in Kansas, there's compelling arguments it emerged from the east - probably China. /2
The Kansas Army camp, Camp Funston, is widely considered 'Ground Zero' for the 1918 outbreak. During an outbreak beginning in March, 38 men died, with around 1,110 hospitalized. From there, men transferred between camps spread the disease. /3
It was only a matter of time before the disease left the United States, carried aboard troop ships bound for France. It has been speculated that weakened immune systems of fighting men on the Western Front and unhygenic conditions proved to bolster the spread of the virus. /4
Of course, disease doesn't respect uniform, or language, or border, and the virus was soon raging across the European continent, putting people into hospital and alarming officials. /5
The first wave of the virus lasted for a few weeks over the summer, and it picked off those you would expect - the old, the very young, those with compromised immune systems. This was concern enough for many. Worse, however, was to come... /6
Beginning in September, lasting into December, a second wave of the flu hit. This time, those dying weren't the old and the young. Particularly targeted appeared to be young and healthy adults, sickening and dying within a frighteningly short space of time. (Pic: @Wikimedia) /7
Soon the virus had spread across Europe, into India and Africa. Ships brought it to Australia along with their cargo. It spread as far north as the Arctic Circle - but more about that later. /8
Such was virulence of this second outbreak that it's said that people were getting on trams and trains feeling fine and being stretchered off dead. There are harrowing accounts of people suddenly projectile vomiting blood in the throes of the virus. /9
So, what's the deal with that? Research has since identified why so many healthy people were dying - the virus was causing a 'cytokine storm' within. To put it very, simply, the virus was activating a destructive response of the immune system. /10 sciencedaily.com/releases/2014/…
A 'cytokine storm' leads to all sorts of *wonderful* things like necrosis and internal bleeding, in severe cases. Basically, the body is tearing itself apart with its immune response, not the flu virus itself. Bacterial infections swoop in and carry you off. /11
In response, quarantines were enforced in countries across the world. Many public events were cancelled and other services strictly curtailed. A blitz of public health warnings were issued. The rapid response, it is thought, saved millions. /12 nih.gov/news-events/ne…
...and here's why it's called the Spanish Flu. To prevent panic, many nations imposed a blackout on the reporting of the spread of the virus. One nation that *didn't* was Spain, and reports of their king, Alfonso XIII sick with the virus, made many think it originated there. /13
Throughout 1918 - 1919 - a less severe third wave followed the first two - it's estimated that somewhere between 20 and 50 million people died. Truth be told, considering a number of factors, the true toll is probably higher. /14
In the intervening years between 1919 and now, we've come a very long way in terms of what we understand about the Spanish Flu. We understand more about how it may have passed between species, changed over time how we might stop a similar outbreak. /15 sciencedaily.com/releases/2017/…
There's more to say about the virulence of the Spanish Flu, but I'll leave you with this - back in 2006, scientists managed to exhume a sample of the virus from the body of a Canadian victim buried in permafrost. It was given to monkeys. They had to be euthanised hours later. /16
If you'd like to know more about the Spanish Flu, you should read this, because, well, I wrote it a few years back. /17 crikey.com.au/2009/05/14/les…
For something a little more scholarly and in-depth, the @CDCgov is a great place to start. /18 cdc.gov/features/1918-…
I hope you enjoyed that. Well, enjoyed it is as much as someone can, while pondering the death of at least 20 million. Say, are you looking a little pale? /FIN
