When people think of the loss of life in a war, they generally think of soldiers sustaining traumatic injuries. However, conditions on the battlefield are anything but healthy, and disease has often inflicted serious casualties on forces that scramble through months of jungle mountains, or scrape through muddy trenches for weeks on end, and sometimes it even occurs in training. Anyone who has been through basic training knows that it can feel a bit like a petri dish, with everyone living in such close quarters in those conditions.

On March 11, 1918, the H1N1 influenza virus was first recognized in a company cook, Private Albert Gitchell — and it wasn’t on the front. It was in Fort Riley, Kansas. He had been sick since March 4, and the virus had already spread throughout the camp, infecting 522 men within a few days. The disease caught on, and spread like wildfire throughout the United States and seriously began to affect the training of troops, thereby affecting the U.S.’s ability to resupply deployed forces with reinforcements.

This wasn’t just a few sniffles and a fever — globally speaking, approximately 10 – 20% of those infected died (these statistics don’t always line up, as documentation was happening during both a world war and arguably the most devastating pandemic in history). In the U.S., approximately 500,000 to 675,000 people died. There were Alaskan villages that did not survive at all. If you believe anything over the most conservative estimates, this disease killed more people than the infamous bubonic plague of medieval times.

The fact that troops were in such close quarters with one another contributed to the global spread, as this was the final year in WWI and the fighting was still incredibly heavy. The flu was hitting troops on all sides of the fighting, and some might even attribute it to some significant German losses that may have turned the tide of the war. But just as it hit the Germans, it hit the Americans, Spanish, British, Japanese, Chinese, the Philippines — even New Zealand was not spared. Over 500 million people were infected worldwide, and 50 to 100 million of those died. Due to how averages work, it dropped the life expectancy in America by 12 years for a time.

It would also become known as the Spanish Flu, since countries tried to censor the spread of the disease in an effort to improve morale during the war. Spain made no such attempts, and so it seemed they were hit harder than most, though this was inaccurate. The “Spanish Flu” was over by the end of the year.

Featured image courtesy of the Associated Press.