A flu that brought nations to a standstill

Jennifer A. Summers
King’s College London, United Kingdom


Seattle police during Spanish Influenza epidemic
Policemen in Seattle, US, wearing masks made by the Red Cross,
during the influenza pandemic, December 1918. National Archives at College Park,
College Park, Maryland, United States.

The year was 1918 and after four grisly years of the First World War, the longed-for peace was within the grasp of the Allied powers. But little did they know, that a threat far greater than any war experienced by humans loomed over their existence.

An influenza virus, minute in size, was slowly making its presence felt. Fuelled by the unprecedented movement of troops worldwide, it spread to almost every corner of the globe.

The symptoms of this influenza were particularly gruesome. The typical clinical features, such as fever, chills, and malaise, were often accompanied by explosive nose and ear bleeds, delirium, and a propensity for lethal secondary pneumonic complications. Cyanosis occurred during the final stage, as lungs filled with blood and pus, the circulation of oxygen was restricted, slowly turning the skin of victims black. Victims essentially drowned in their own blood in as little as 24 hours.

Wartime censorship held a firm grip on influenza reports at the time, as military authorities speculated that the gas-soaked trenches and horrific conditions of the Western Front were somehow responsible. Civilians were therefore left in the dark about the approaching pandemic. Indeed, its common name ‘Spanish Flu’ is a reference to neutral Spain being the first country in the world to report its existence officially to its citizens.

The Spanish Flu disrupted the normal flow of life: towns and cities stopped functioning; desperate authorities enforced quarantine by gunpoint and imposed drastic restrictions on public gatherings. Police patrolled streets to ensure public safety in anticipation of mass panic. In the most extreme example, the US territory of American Samoa was successfully quarantined and had no influenza deaths, whereas its neighbor, Western Samoa, was decimated and 25% of its population succumbed to the raging pandemic.

The 21st century saw the first full genome sequence reconstruction of the 1918 H1N1 influenza strain in 2005. It took Dr Taubenberger and his team at the Armed Forces Institute of Pathology in Maryland, US, nine years to do this, using preserved lung tissue samples and excavated samples of corpses.1 They found that the 1918 H1N1 strain was novel to humans. This may partially explain its particular deadliness; the populace probably lacked acquired immunity, which is conveyed from past exposures to similar viral strains.

This plague represents one of the worst pandemics of any kind in recorded human history, claiming the lives of an estimated 50-100 million worldwide. This human disaster was much greater than the seventeen million deaths caused directly by the First World War., Even today, however, much remains unknown about this influenza virus, and we are left with an obvious question: could it happen again?

In short, yes.

Influenza pandemics generally occur several times in a century. The pandemics of 1957 and 1968 claimed just over two million lives, and the most recent ‘Swine Flu’ pandemic of 2009 resulted in an estimated 14,000 deaths globally. The Swine Flu had its genetic origin from the 1918 H1N1 virus; however, fortunately, it had both a lower virulence and transmissibility compared to its 1918 predecessor.

Nonetheless, the epidemiological similarities between the pandemics of 1918 and 2009 are worrisome. Perhaps even more concerning was the rapid spread of the 2009 Swine Flu despite supposedly well thought-out quarantine and disease control plans developed over the last ninety years.

In 2009 it took the Swine flu only a few weeks before over thirty countries reported sustained transmission. By comparison, the Spanish Flu, with the absence of modern air travel and in a pre-antiviral and antibiotic era, took much longer. Its more insidious two-year spread makes the quarantine defences of some nations appear very impressive. Iceland, for example, managed partial sequestration of one third of its island population in 1918.

A prominent feature of the Spanish Flu was the disproportionately high mortality experienced amongst fit young adults between the ages of 20-40 years. A similar effect was observed in 2009, the Swine Flu being deadliest amongst people under the age of 65. The reasons for this phenomenon remain unclear, although some researchers have hypothesized that the young adults immune systems overreacted to the influenza infection, experiencing what is referred to as a cytokine storm.

The World Bank estimates a future pandemic could cost approximately $1.5US trillion globally and have a projected worldwide fatality of upwards of 1%.2 This equates to about seventy million deaths. Therefore continued international research is needed to enlighten understanding of influenza pandemics and help reduce these grim projected statistics.

As the Spanish Flu represents one of the worst pandemics ever experienced by humans in recorded history, it could be regarded as an example of a worse case scenario from which to guide future pandemic planning. And it is imperative to do so, for as Webster reminds us: “unfortunately until the basis of influenza virulence is understood, the human population will be defenceless against similar outbreaks in the future.”3

Influenza could once again bring nations to a standstill.



1 Taubenberger JK, Reid A, Lourens RM, Wang R, Jin G, Fanning T. Characterization of the 1918 influenza virus polymerase genes. Nature. 2005; 437 (7060).
2 Burns A, van der Mensbrugghe D, Timmer H. Evaluating the economic consequences of avian influenza. Global Development Finance. World Bank. 2006.
3 Webster RG. A Molecular Whodunnit. Science. 2001; 293 (5536).



JENNIFER A SUMMERS, BSc, PgDipPH, PhD, was born in Wellington, New Zealand. She has degrees in psychology, statistics and public health, and has a PhD in historical epidemiology from Otago University, where she studied the 1918-19 Influenza Pandemic in Military Populations of the First World War. She is currently a Post-Doctoral Research Fellow in Medical Statistics at King’s College London, United Kingdom.