In 1918, after the end of the First World War, the world faced a new crisis: a health emergency. In March of that year, cases of a new strain of influenza began to be reported in the United States, and by April, the cases were reported in countries all around the globe. This marked the beginning of what became known as the Great Influenza Epidemic, commonly referred to as the Spanish Flu, the deadliest pandemic in history. On this day, October 31st, 1918, the highest death toll from the Spanish Flu was recorded, with a staggering 21,000 deaths.

Origin

The deadly virus responsible for the Great Influenza pandemic was a strain of Influenza A (H1N1), which is now believed to have originated from avian sources. At the time, limited epidemiological data made it impossible to determine the virus’s precise origin. A common misconception is that the outbreak began in Spain, leading to its designation as the “Spanish Flu.” During World War I, many countries censored news reports to maintain morale, but Spain, as a neutral country, openly reported cases of the deadly flu before other nations did. This transparency contributed to the mistaken belief that the virus originated in Spain.

The Spread

Several factors contributed to the rapid and devastating spread of the Spanish Flu. The outbreak coincided with the end of World War I, which exacerbated the situation. Troops and ships were mobilized across the globe, even reaching remote islands. Military camps housed large numbers of soldiers in cramped quarters and poor sanitation, creating ideal conditions for the virus to thrive in many countries. Moreover, the virus was unprecedented, and there were no public health measures in place to contain its spread.

Deadly Consequences

The virus spread widely, affecting nearly one-third of the global population —about 500 million people. The mortality rate was also alarmingly high, with estimates of fatalities reaching up to 100 million worldwide. Studies indicate that approximately 700,000 people died in the United States alone.

The flu virus during the Great Influenza pandemic exhibited an unusual pattern. Typically, the very young and the elderly are considered the most at risk for flu infections. However, in this epidemic, the majority of deaths occurred in individuals aged 20 to 40, which was highly unusual. With no vaccines or medications available to treat infections, the only methods to slow the spread were quarantine, wearing masks, and limiting social gatherings.

A New Era

The widespread devastation and high death toll led to significant advancements in healthcare and medical science. This experience sparked a strong interest in the study of viruses and the development of new vaccines and treatments in the subsequent decades. Additionally, it inspired improvements in public health infrastructure, leading to better systems for managing healthcare crises.