In the spring of 1918, a disease began to spread across the planet – a deadly virus that infected a third of the world’s population and claimed the lives of more than 50 million people. In this article, we explore the history of the devastating impact and far-reaching legacy of the Spanish flu pandemic, or Spanish flu.

spanish flu

On September 28, 1918, a Spanish newspaper gave its readers a short educational program on influenza. “The agent responsible for this infection is the Pfeiffer bacillus, which is extremely small and only visible under a microscope.”

The explanation was timely because the world was in the grip of the worst flu pandemic in history. But the note turned out to be wrong: the Spanish flu was caused by a virus. Unfortunately, not only one Spanish newspaper misidentified the causative agent. The idea that influenza was caused by a bacillus or bacterium was adopted by the most eminent scientists of the time, who were completely helpless in the face of the calamity.

History of the Spanish flu epidemic

The H1N1 influenza virus was one of the deadliest disasters in history. Between the first recorded case in March 1918 and the last in March 1920, 50 million people died, although some experts suggest that the total could have been twice that. The “Spanish flu” killed more people than World War I, perhaps even more than World War II, and even more than both wars combined.

Spanish flu epidemic

The pandemic struck at a critical stage in the evolution of the understanding of infectious diseases. Back in the 19th century, epidemics were considered natural disasters, a concept that dates back to the Middle Ages. Bacteria were first discovered in the 17th century, but they were not originally associated with human disease. In the late 1850s, the French biologist Louis Pasteur established the link between microorganisms and disease, and a couple of decades later, the German microbiologist Robert Koch advanced modern concepts of infectious disease. The “germ theory” spread everywhere, gradually replacing more fatalistic ideas.

You can read about the most dangerous diseases in history in a separate article on LifeGlobe.

Where did the Spanish flu come from?

It is also impossible to pinpoint exactly where the Spanish flu originated. Although the most common explanation is the trenches of the First World War, where poor sanitation and disease were extremely common. The filthy, rat-infested conditions undoubtedly affected the soldiers’ immune systems, making them more vulnerable to disease.

history of the spanish flu

The first cases are believed to have been recorded in United States military forts before spreading at an alarming rate to Europe. But still, the pandemic was called the “Spanish flu, or Spanish flu.”

Military censorship exaggerated the impact of the virus in Spain. While the UK, France, Germany and the US censored and restricted reports of the epidemic, newspapers in Spain (a neutral country) were free to report all the horrifying details of the pandemic. Thus, the name “Spanish flu” spread throughout the world.

By the 20th century, the application of germ theory, combined with improvements in hygiene and sanitation, greatly increased the fight against the so-called “mass” diseases that afflict human communities. This was especially true of the great cities that grew up in the wake of the Industrial Revolution. During the 19th century, the urban population was greatly reduced due to diseases such as cholera, typhus and tuberculosis, so the cities needed a steady influx of healthy peasants from the countryside.

By 1918, faith in science was high, and some scientists began to overestimate their strength and knowledge. This prompted the Irish playwright George Bernard Shaw to write The Doctor’s Dilemma, in which he warned physicians against pride. But it took the outbreak of another massive disease – the Spanish flu – to convey to them how little they know.
patients with Spanish flu in the hospital
When scientists talked about “germs” in the early 20th century, they usually meant bacteria. The virus was a new concept. The first virus, discovered in 1892, infected tobacco plants and was discovered indirectly by its ability to transmit the disease. Unlike many bacteria, it was too small to be seen through an optical microscope. Without seeing viruses, scientists discussed their nature: organism or toxin, liquid or particle, dead or alive? They were shrouded in mystery, and no one suspected that they could be the cause of the flu.

During a previous flu pandemic—the so-called “Russian” flu that began in 1889—a Koch student named Richard Pfeiffer claimed to have identified the bacterium that caused the flu. As it became known, the Pfeiffer bacillus exists and causes the disease, but does not cause the flu. During the 1918 pandemic, pathologists who grew bacterial colonies from the lung tissue of influenza victims found Pfeiffer’s bacilli in some, but not all, of their cultures. This question puzzled them.

Vaccines developed against Pfeiffer’s bacilli seemed to benefit some patients. In fact, these vaccines were effective against secondary bacterial infections that caused pneumonia – in many cases the leading cause of death – but scientists didn’t know about it at the time. They realize their mistake too late.

Why is it called the “Spanish flu”?

The Russian flu got its name because it originated in Bukhara in Uzbekistan (at that time part of the Russian Empire). The pandemic that struck nearly 30 years later will always be referred to as the “Spanish flu” even though it didn’t start in Spain. This flu swept the world in three waves, which in the northern hemisphere corresponded to a mild wave in the spring of 1918, a deadly wave the following autumn, and outbreaks in the early months of 1919, which were intermediate in virulence. The first cases were officially reported in March 1918 at Camp Funston, a military base in Kansas. Within six weeks the disease had reached the trenches of the western front in France, but it was not until May that influenza broke out in Spain.

flu epidemic

Unlike the US and France, Spain was neutral in the war, so it did not censor its press. Therefore, the first Spanish cases were published in the newspapers, and since King Alfonso XIII, the Prime Minister and several cabinet members were among these early cases, the country’s plight was very visible. People all over the world believed that this disease spread from Madrid. This is a delusion encouraged by propagandists in those warring countries who knew they had contracted it before Spain. In the interest of maintaining the morale of their own population, they were happy to shift the blame to Spain. The name “Spanish flu” is firmly rooted in everyday life.

Could the flu kill thousands again?

Paul Morland: “Even the Spanish flu pandemic was not enough to stop population growth.”
It is clear that the Spaniards understood the injustice of this slander: they knew that they were not responsible, and they suspected the French of carrying the flu across the border.

But although the Spaniard was not born in Spain, this country has suffered greatly from the disease. In the early 20th century, influenza was seen as a democratic disease—no one was immune from it—but even in the thick of a pandemic, it was noted that the disease was spreading unevenly. It “preferred” certain age groups: the very young and the old, but also the average cohort in their 20s and 40s. The flu favored men over men, with the exception of pregnant women, who are at especially high risk.

Spanish flu death chart

These age and gender patterns recurred throughout the world, but virulence also varied from place to place. People in parts of Asia are 30 times more likely to die from the flu than people in parts of Europe. Overall, Asia and Africa had the highest death rates, while Europe, North America and Australia had the lowest.

But there were also big differences across the continents. In sub-Saharan Africa, death rates are two or even three times higher than in the northern desert, and Spain has one of the highest death rates in Europe – twice as many as in Britain, three times as many. than in Denmark.

The inconsistencies didn’t stop there. In general, cities were worse affected than rural areas, but some cities were worse affected than others, and even within cities there were differences. For example, newly arrived immigrants tended to die more often than more established groups. At the same time, in the countryside, one village could be destroyed, while another, outwardly similar in every respect, received a small dose.

Who was most at risk?

The flu seemed to infect with an element of chance. Adults in their prime died en masse, children were left orphans, elderly parents could not fend for themselves. People could not explain this lottery, and this caused deep anxiety. Trying to describe this feeling, a French doctor from the city of Lyon wrote that it was not at all like the “pain in the intestines” that he experienced while working at the front. It was “a more diffuse anxiety, a feeling of indescribable horror that seized the inhabitants of the city.”

It was only later, when epidemiologists focused on numbers, that models began to emerge and the first elements of an explanation were put forward. Some of the volatility can be explained by wealth inequality. Poor nutrition, living conditions and limited access to health care have weakened immunity, making the poor, immigrants and ethnic minorities more susceptible to infection. As French historian Patrick Silberman said, “The virus may have behaved democratically, but the society it attacked was hardly egalitarian.”

Any other underlying illness made a person more susceptible to Spanish flu, while prior exposure to the flu itself modulated the severity of the illness. Remote communities without much historical experience of the disease were hard hit, as were cities that were bypassed by the first wave of the pandemic because they were not immunologically “prepared” for the second. For example, Rio de Janeiro—the capital of Brazil at the time—received only one flu wave in October 1918 and had a death rate two or three times higher than American cities in the north that received both sources and autumnal waves. And Bristol Bay in Alaska was protected until early 1919, but when the virus finally got there it reduced the Bay Eskimo population by 40%.

Public health campaigns made a difference, despite the fact that medical professionals did not understand the cause of the disease. Since time immemorial, whenever an infection is a threat, people have practiced “social distancing” — knowing instinctively that getting rid of infected people increases the chance of staying healthy. In 1918, social distancing took the form of quarantine zones, isolation wards, and bans on mass gatherings. Where they have been properly implemented, these measures have slowed the spread. Australia avoided the autumn wave entirely by imposing effective quarantines on its ports. You can read more about the quarantine history in a separate LifeGlobe article.

Exceptions prove the rule. In 1918, Persia was a failed state after years of being used as a pawn in the “Great Game” – the struggle between the British and Russians for control of the vast territory between the Arabian and Caspian seas. Her government was weak and nearly bankrupt, and lacked a consistent sanitary infrastructure, so when influenza broke out in the northeastern holy city of Mashhad in August 1918, no social distancing measures were in place.

Spanish flu virus under a microscope

Within two weeks, every house in Mashhad was infected – two-thirds of the city’s population fell ill this fall. With no travel restrictions, the flu spread with pilgrims, soldiers, and merchants to much of the country. By the time Persia got rid of the flu, it had lost up to 22% of its population.

When Charles Darwin laid out his theory of evolution by natural selection in On the Origin of Species (1859), he did not expect his ideas to be applied to human societies, but the “science” of eugenics was born. Eugenicists believed that humanity was made up of different “races” that struggled to survive, and by 1918 their thinking had become mainstream in industrialized societies. Some eugenicists have noted that the poorer sections of society suffer disproportionately from the flu, which they attribute to constitutional inferiority. They also incorporated germ theory into their worldview: if the poor and working classes were more prone to infection, the eugenicists reasoned, they had only themselves to blame, because Pasteur taught that infection could be prevented.

See also – the most dangerous bacteria on Earth.

Indian tension

The dire consequences of such thinking are nowhere better illustrated than in India. The British colonizers of the land had long held the view that India was inherently unhygienic and therefore invested little in the health care of the indigenous peoples. Up to 18 million Indians have died in the pandemic, the largest loss in absolute numbers of any country in the world.

Britain’s lack of response to the spread of influenza caused resentment in the independence movement. Tensions came to a head with the passage of the Rowlatt Act in early 1919, which expanded martial law in the country. This sparked peaceful protests, and on 13 April British troops opened fire on an unarmed crowd in Amritsar, killing hundreds of Indians. This stimulated the independence movement.

The Spanish flu sparked uprisings elsewhere. In the autumn of 1918, a wave of labor strikes and anti-imperialist protests took place around the world. Discontent smoldered even before the Russian revolutions of 1917, but the flu fanned the flames, exacerbating an already dire situation of inequality. Even well-organized Switzerland narrowly escaped civil war in November 1918 after left-wing factions blamed the government for the large number of influenza deaths in the army.

virus researcher

Consequences of the Spanish flu epidemic

There were still places in the world where people had never heard of either Darwin’s theory or germs, and the populace turned to more proven explanations. For example, in rural areas of China, many people still believed that disease was sent by demons and dragons. They paraded figures of dragon kings through the streets in the hope of appeasing angry spirits. One missionary doctor said he went door to door in Shanxi province in early 1919 and found scissors in doorways, apparently to ward off demons.

Even in the modernized west, people hesitated. Death often seemed unreasonable. Many still remembered the more mystical, pre-Darwinian era, and four years of war had destroyed the psychological defenses. Seeing how poorly prepared their men of science were, many people came to the conclusion that the pandemic was an act of god—divine retribution for their sins and unbelief.

In Zamora, the same Spanish city whose newspaper claimed with such certainty that the Pfeiffer bacillus was the causative agent, the bishop defied the health authorities’ ban on mass gatherings and ordered people in churches to appease the “legitimate wrath of God.” Subsequently, this city recorded one of the highest flu death rates in Spain. This is a fact that the locals were aware of, although they did not object to their bishop. Instead, they awarded him a medal in recognition of his heroic efforts to end their suffering.

The 1918 pandemic hit a world that was completely unprepared for it, dealing a severe blow to scientific hubris and destabilizing social and political orders for decades to come.