History and COVID-19, Part I: Lessons from 1918

  • CSA Committee on the History of Anesthesia
| Apr 06, 2020

With instant access to the ever-worsening news of the COVID-19 crisis, unsettling emotions—fear, anxiety, anger, and grief—can overtake us.  For many of us anesthesiologists, work is now far more stressful, with heightened PPE requirements in the face of limited supply, direct or indirect exposure to COVID-19 patients, and the constant fear of contracting or spreading the virus.  As tensions run high and survival instincts kick in, conflicts with colleagues can also occur.  For others of us, the cancellation of elective surgeries may cause significant financial burdens. 

Even with our advanced medical capabilities, we Americans were still unprepared for this.  While scientists had long warned of a global outbreak due to mutations of an influenza virus, no one expected this “once-in-a-century pathogen”1 to be a coronavirus.

Without a vaccine for this highly transmissible disease, and with limited resources to treat the critically ill, this is a public health crisis of epic dimensions.  During this bewildering time, many have looked to the past for answers, lessons, and some point of reference.  

The 1918 Flu: A Brief History

As COVID-19 began to approach pandemic status, comparisons to the 1918 “Spanish” Flu began to appear.  In modern times, the number of new infectious outbreaks has increased due to globalization, urbanization, and the commercialization of livestock.  Ebola (2014-16), MERS-CoV (2012-present), the H1N1 swine flu (2009-10), and SARS-CoV (2002-3) come to mind.  Even so, the 1918 H1N1 influenza pandemic, occurring a little over a century ago, was still the deadliest to date. 

It is estimated that the 1918 influenza, due to an antigenically novel subtype, infected one-third of the world’s population, killing at least 50 million people globally, and 675,000 in the U.S.  It appeared in three waves over the course of a 12-month period.  These numbers vastly surpassed the death toll of World War I, which was being waged at the same time.  American life expectancy plummeted from 51 years in 1917 to 39 years in 1918.   

The first recorded outbreak, which went largely unnoticed by the public, was in March 1918 at a U.S. Army camp in Kansas.  Young American soldiers then carried the virus over to the unsanitary and cramped trenches of Europe.  By the summer, all of Europe had been affected. 

In August 1918, a more virulent second wave appeared almost simultaneously in France, Sierra Leone, and the U.S.  By late October, this stronger strain had spread to the entire world.  And just as societies began to relax restrictions and emerge from this deadly second wave, the virus roared back with a third wave in early 1919.  

2020 vs. 1918

Numerous comparisons have been made between the 1918 Flu and COVID-19 today.  Due to their novel antigenicity, mortality rates for both have been significantly higher than that of seasonal influenza.  But while COVID-19 disproportionally kills the elderly, the 1918 Flu had a “W-shaped” curve, taking the lives of many in their 20s to 40s.  Soldiers huddling together during the war, and cytokine storms caused by hyperactive young immune systems, may have contributed to this trend.

Given the shorter incubation period of the 1918 Flu (a median of 1-2 days), there was some hope that the longer incubation time of COVID-19 (a median of 5-6 days) would allow for more effective contact tracing.  However, this effect may be counteracted by the much longer duration of symptoms, as well as the higher risk of asymptomatic transmission, associated with COVID-19. 

Of course, medicine was far from modernized in 1918.  While the germ theory of disease was well-established, social conditions were still less sanitary.  Scientists falsely believed Haemophilus influenzae to be the culprit until 1933, when the first H1N1 virus was discovered.   Identification the virus would pave the way for the development of vaccines.  In 1918, antimicrobials did not exist, nor did basic monitors that we take for granted today.  Supplemental oxygen therapy was just beginning to be explored.  Endotracheal intubation, positive-pressure ventilation, and intensive care units were all unimagined concepts.

In spite of all of the improvements in sanitation, medical technology, and public communication today, the transmissibility of COVID-19, due to various factors, is considered to be higher than that of the 1918 influenza.  (The median R0 in 1918 was ~1.8; the median R0 of COVID-19 is ~2.8.  The R0, or reproduction number of an infection, describes the number of new cases generated by a single case.)  Without a vaccine, and with limited critical care resources, we still find ourselves in a similar position as our predecessors over a century ago—dependent on public health measures to stem the tide. 

Lessons from the “Spanish” Flu

Given our similar dependence in 2020 as in 1918 on quarantines, contact tracing, and physical distancing to “flatten the curve,” what lessons can we learn from the 1918 influenza?

Historian John M. Barry, author of the increasingly popular book The Great Influenza, has repeatedly stated that the number one lesson is for political leaders and public health officials to “tell the truth.” 

During the 1918 Flu, President Woodrow Wilson never spoke publicly about the disease, fearing that this would expose weakness and dampen public morale during World War I.  The 1918 influenza was misnamed the “Spanish” flu precisely because Spain, a neutral party during the war, had a free media that openly covered the outbreak. 

Mortality was around 50% lower in American cities where leaders were honest about the disease and instituted social restrictions and public closures early on.  St. Louis, San Francisco, San Diego, Milwaukee, Kansas City, and New York City are known to have responded quickly and effectively in 1918.  These cities’ leaders chose to accept the huge economic costs of societal restrictions, risking their own political futures, in order to protect the health of their communities.     

In the U.S., Philadelphia was the hardest hit.  Poor decisions on the part of the city’s health commissioner were blamed for the death of 12,000 Philadelphians by the end of the pandemic.  The first virulent case was noted on September 17, 1918, but schools, businesses, and public gatherings were kept open until October 3.  In addition, a Liberty Loan parade to promote the sale of war bonds was allowed to proceed on September 28.  200,000 people attended. 

In addition to timing, the duration of public health interventions also mattered.  St. Louis, which enacted closures just two days after its first case, was a model of early intervention.  However, the city experienced a pronounced second wave of infections when it lifted restrictions less than two months after the outbreak began. 

A final fact to ponder from the 1918 Flu is the stark difference in mortality between richer and poorer countries.  While around 2% of infected people in developed nations died, Russia and Iran lost 7% of their population, and Fiji 14%.  This inequality is still a pressing concern today.  If faced with massive outbreaks, countries that lack access to basic sanitation tools, let alone critical care resources, face the prospect of alarming mortality and socioeconomic collapse. 

Please stay tuned for “History and COVID-19, Part II: An Anesthesia Perspective.”


1. Gates B. Responding to Covid-19: A once-in-a-century pandemic? NEJM. 2020 Feb 28. doi: 10.1056/NEJMp2003762. Accessed March 28, 2020. 

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