The deadly flu pandemic had its mild beginnings a century ago. It started like any common flu, in the spring of 1918, affecting American soldiers in the army camp of Fort Riley, Kansas. Many recovered and death rates were low.

Nonetheless, as the season waned, and as soldiers (mobilised for World War I) marched to Europe – the virus gained potent strength. And by May that year, it had swept relentlessly across America, Europe and Asia – tearing apart families and wrecking businesses.

Almost mercilessly, the lethal virus infected 500 million worldwide and killed 30 – 50 million young adults aged between 20 – 40 years, recording a death toll higher than any disease outbreaks in history. The sudden onset signalled an alarming propensity for pneumonic complications, leading to allegedly eight million deaths in Spain, and King Alfonso XIII was reported to have been gravely infected by the virus. This unprecedented invasion led to it being dubbed the “Spanish flu”.

The mystery virulence stirred a pandemic age shift, sparing the two extremes of the demographic spread – the very young, below five, and the very old, above 65 years old.

A healthy person could succumb to the disease within an hour or two. Fever could scale as high as 105 degrees Fahrenheit (approximately 40.6 degrees Celsius), and those infected said they felt as though they had been hit with a club.

Victims died within hours or days of their infection, with their skin turning blue and lungs suffocating with fluid. In just one year, the average life expectancy in America plunged by a dozen years.

Flu came like a tornado with little warning

Women wearing surgical masks in Brisbane, 1919. Photo credit: John Oxley Library, State Library of Queensland/National Museum Australia
Women wearing surgical masks in Brisbane, 1919. Photo credit: John Oxley Library, State Library of Queensland/National Museum Australia

Faced with an extraordinary violent pandemic, the world was on high alert. People walked around with masks and streetcar conductors turned away passengers without masks.

Yet, there was little or no immunity, and the spread was swift and depressing. Bodies piled up and businesses closed.

The symptoms deviated from the typical that it was initially misdiagnosed as dengue, cholera or typhoid.

A letter from a physician at one US Army camp to a colleague read, “These men start with what appears to be an ordinary attack of LaGrippe or Influenza, and when brought to the hospital, they very rapidly develop the most vicious type of pneumonia that has ever been seen … It is only a matter of a few hours then until death comes… It is horrible. One can stand it to see one, two or twenty men die, but to see these poor devils dropping like flies…”

There were no effective flu treatments and most doctors had initially mistakenly attributed the cause to bacteria instead of a deadly virus. It was only in the 1940s that scientists came up with working flu vaccines for the world.

In their investigations, scientists chanced upon one hint which pointed to an Italian immigrant to the US, Adolfo Sartini, 29, who died from the flu while in the military. Uncovering his story shed light to hypotheses about the immune systems of young adults in 1918.

Recent analyses revealed that deaths in 1918 were highest among individuals born around 1889, like Adolfo. Flu viruses fall into groups that are related evolutionarily. The virus that circulated when Adolfo was a baby was likely in what is called “Group 2”, whereas the 1918 virus was in “Group 1”. Adolfo would be unlikely to have had the immunity to this “Group 1” virus.

Preparing for an impending pandemic

The factors surrounding the 1918 flu remain unclear despite modern-day scientists’ attempts to sequence the DNA of the 1918 virus from frozen lung samples of victims.

Meanwhile, scientists have come forward with plausible explanations for the high mortality rate. Some researchers attribute it to the unusually aggressive nature of the specific variant of the virus. One group found that transfection in animals caused a rapid progressive respiratory failure and death through a cytokine storm (overreaction of the body's immune system). The postulation was that the strong immune reactions of young adults ravaged the body, whereas the weaker immunity of children and middle-aged adults saved them from the deadly strain.

More recent findings, mainly based on original medical reports from the pandemic, found that the viral infection itself was not more aggressive than any previous influenza, but that less than conducive factors like malnourishment, overcrowded medical camps and hospitals, and poor hygiene could have exacerbated the bacterial superinfection.

A hundred years on, and there is no assurance that history does not repeat itself. Today, armed with more effective vaccines and stronger antivirals, are we in any way better prepared – or safeguarded – from the next wave? While revisiting the past and predicting trends, the question invariably remains: When will this pandemic return? MIMS

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