Men wearing masks during the "Spanish Flu," Alberta, Fall 1918 (National Archives of Canada)

“It was the biggest outbreak of any infection that the world has ever seen either before or since,” says Dr. John Oxford, an expert in the study of viruses.

The signing of the armistice on November 11, 1918, marked both the end of hostilities on the Western Front and the spread of a killer flu that ravaged populations the world over for two years.

Soldiers returning home from the trenches at war's end didn't come back alone. They brought with them a flu virus that at first seemed as benign as the common cold. By the time it had run its course, 50,000 Canadians were dead. Some smaller villages in Quebec and Labrador were almost wiped out. In the United States, 675,000 people died in the epidemic.

“It was like a pressure cooker on the home front,” says John M. Barry, author of The Great Influenza: The Epic Story of the Deadliest Plague in History. “The lid was being kept on during the war, but as soon as the war ended than all those pressures were just released.”

The flu was most deadly for people in the prime of the lives, aged 20 to 40 (an unusual pattern of morbidity for influenza, which typically stalks the elderly and young children). Pregnant women had the highest rates of mortality.

The 1918 strain also struck quickly and inexplicably. Some people went to bed healthy and simply never woke up. “ There are reports of people who went out to work in the morning and were dead before they came home that afternoon,” says Barry. “Some of the more horrific symptoms included bleeding from your nose and mouth, and from your ears and even your eyes. In some cases, the floor would be covered in blood. It was an incredibly gruesome situation.”

At the pandemic’s peak, medical facilities across North America were swamped. Doctors, nurses and other healthcare workers were already overtaxed treating casualties from the war. Many were still working overseas caring for the wounded when the pandemic took hold. No one knows for certain how many became victims of the virus themselves.

Death services, such as mortuaries and cemeteries were also overwhelmed. The bodies of victims lay in homes for days at a time, sometimes more than a week. “It was a horrific circumstance,” says Barry. “In some cases, where they had funerals, they were renting coffins. They would have a service with somebody in the coffin; the body would go to the cemetery without a coffin, and then that same coffin would be reused for another service 15 or 20 minutes later.”

People in closed communities were most vulnerable. For example, the flu spread rapidly through U.S. army camps filled with men who had not deployed overseas. It was reported that 500 prisoners at San Quentin Penitentiary in California were affected.

In some communities, it was a criminal offence to shake hands. Gatherings of more than six people were banned. Schools, theatres and other public buildings were closed. In the U.S., railways demanded passengers have a document certifying they were free of the flu.

“The Red Cross reported that people were starving to death – not from lack of food, but because people were too frightened to go near the sick to bring them food,” says author John M. Barry. “In most cases, you know, the communities began to fall apart.”

Origins of the 1918 virus

The precise origins of the 1918 virus strain remain a subject of debate among experts. Most agree that it took about a year for the 1918 strain to make its way around the world, but it was likely around for a long time prior to that.

“It’s a common misconception that the 1918 flu disappeared very suddenly,” says Dr. Jeffrey Taubenberger, who has studied the 1918 viral genome extensively. “The 1918 virus actually never disappeared; it is still rotating in humans, just in a highly mutated form.”

The virus probably originated in China, as do most flu virus variants. Somehow it found its way to the Western Front in the spring of 1918. The first soldiers infected were British, camped in close quarters in the trenches. It showed up among German forces a few days later and among French troops shortly after that.

The virus quickly tracked along international shipping lanes, from Europe to North America, then to Asia, Africa, Brazil and eventually the South Pacific.

Are we due for a repeat of the 1918 pandemic?

Could 1918 happen again? Scientists around the world are increasingly worried the answer could be yes.

Indian grave of a victim of the flu on Windiandy Flats, Muskeg River, Alberta (National Archives of Canada)

“I think we can and we must envisage a situation where a new pandemic could be worse than 1918,” says Dr. Oxford. “In a day, 20 or 30 million people are moving around the world. Once this new virus begins to break out, it will have opportunities, bigger than anything the 1918 virus could even have dreamt about. That’s why we have to be so careful. That’s why we have to be so guarded.”

Dr. Robert Webster, a world-renowned virologist warns the only the current H5N1 strain hasn’t learned is how to transmit between humans. “If that happens, we are in great trouble in the world. 1918 would seem like a duck walk. This would be much, much more severe.”

Still, this isn’t 1918 and the world is better equipped to deal with a pandemic now than we were than in 1918, says Dr. Frank Plummer, Canada’s leading virus hunter. “ However, a virus that had the lethality of the 1918 pandemic would cause severe social disruption. That’s why the influenza plans have been put in place to try to figure out how we would deal with these things if there were huge numbers of people requiring hospitalization and medical care. And that's why we need to make a vaccine as quickly as we can.”

~ With files from Dan Bjarnason and Robin Rowland

Internet resources about the "Spanish Flu" of 1918:

• The influenza pandemic of 1918
  
• The Spanish Lady and the Newfoundland Regiment, by Dr. W. David Parsons
  
• "The Bitter Flats": The 1918 Influenza Epidemic in Saskatchewan,' by Maureen Lux
  
• A letter from Camp Devens, Massachusetts
  
• “There Wasn’t a Mine Runnin’ a Lump O’ Coal”: A Kentucky Coal Miner Remembers the Influenza Pandemic of 1918–1919
  
• “Please, Let Me Put Him in a Macaroni Box” The Spanish Influenza of 1918 in Philadelphia
  
• “He’ll Come Home in a Box”: The Spanish Influenza of 1918 Comes to Montana
  
• The Spanish Flu in New Zealand

Further reading about the impact of the Spanish Flu during 1918-1919:

• John M. Barry, “The Great Influenza: The Epic Story of the Greatest Plague in History” (2004)
  
• Eileen Pettigrew, “The Silent Enemy: Canada and the Deadly Flu of 1918” (1983)
  
• Lynette Iezzoni, “Influenza 1918: The Worst Epidemic in American History” (1999)
  
• Gina Kolata, “Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus That Caused It” (1999)
  
• Fred R. van Hartesveldt, “The 1918-1919 Pandemic of Influenza: The Urban Impact in the Western World” (1993)
  
• Richard Collier, “The Plague of the Spanish Lady” (1974)
  
• Betty O'Keefe, Ian MacDonald, “Dr. Fred and the Spanish Lady: Fighting the Killer Flu” (2004)
  
• Pete Davies, “Catching Cold: The Hunt For A Killer Virus” (1999)