Until the recent COVID-19  pandemic, the 1918 flu epidemic had put every other epidemic of the 20th century to shame.  

It even rivaled the earlier Black Death plague.  Prior to COVID-19,  it was a plague so deadly that it was predicted few or any other disease could possibly kill more people in a single year than heart disease, cancers, strokes, chronic pulmonary disease, AIDS and Alzheimer’s disease combined. The flu epidemic affected the course of history and was a terrifying presence at the end of World War I, killing more Americans in a single year than died in battle in World War I, World War II, the Korean War and the Vietnam War.  

The prediction turned out to be unfortunately true in the United States, now  that COVID-19  has become the deadliest  disease in American history, surpassing the grim statistics of the flu.  

There were an estimated 675,000 American deaths reported for the 1918 flu, which are  based on limited or inconsistent or even speculative reporting. (While it is most commonly referred to as the 1918 influenza, the estimates of death from that pandemic actually cover the last four months of 1918 and the first six months of 1919.)

Global Incidence

Globally, COVID-19  has taken the lives of 4.7 million people, whereas the 1918 flu killed an estimated 20 to 50 million. One-fifth of the world’s population was infected, and 2 to 3% of those infected died. This epidemic differed from all previous ones of its kind and those to come, because for the first time young, healthy adults succumbed.  

By contrast, in past and subsequent influenza epidemics mostly the very young and elderly died. Strangely, despite the devastation from the flu virus, little was known about its structure and genetic sequence.  These properties are essential for understanding what made it so lethal and how to recognize it if it comes again.

The 1918 flu virus was 25 times more deadly than ordinary flu viruses. It infected more than 28% of Americans, dropping the life span by about 12 years. It had been  one of history’s great conundrums, obliterated from the consciousness of historians, who traditionally ignore science and technology but not, for the most part, plagues.

Mortality

The 1918 flu virus’ unique severity puzzled researchers for decades, and prompted a number of questions. For example, why was it so deadly? Where did it originate from? What can be learned from the experience?  

Fortunately, an expert group of researchers took on the task of resolving these long-standing issues. There had been relatively little to go on except for evidence gathered from a small ocean side village in Alaska called Brevig Mission. This small village lost the lives of 72 of its 80 adult inhabitants during the five-day period from Nov. 15-20, 1918. A mass grave site there marked only by small white crosses was created on a hill beside the village and it was frozen in permafrost and left untouched until 1951.

That year, Johan Hultin,  a 25-year-old Swedish microbiologist and PhD student at the University of Iowa, set out on an expedition to Brevig Mission, in hope of finding the 1918 virus and in the process unearth new insights and answers.  Hultin believed that within that preserved burial ground he might find traces of the 1918 virus itself, frozen in time within the tissues of the villagers whose lives it had claimed. He was successful in extracting  lung tissue from a little girl and four additional bodies.  

Despite flying back on a DC-3 propeller driven plane and a number of stops along the way, he managed to refreeze the lung samples using carbon dioxide from a fire extinguisher. Once back to Iowa, Hultin injected the lung tissue into chicken eggs to grow the virus. It did not.  

His next chance came in 1997, when he returned to that same village. This time, after he and four young men dug a hole seven feet deep, they saw the body of a woman almost intact, with lungs that were still preserved.  

He once again extracted lung tissue and placed it into a preservative solution.  Using the tissue Dr. Hultin provided, another research group  became involved.  They published a paper that provided the genetic sequence of a crucial gene, hemagglutinin, which the virus had used to enter cells.  The group subsequently used that tissue to determine the complete sequence of all eight of the virus’s genes.

History

Although suspected influenza epidemics occurred during several decades of the 1700s, Robert Johnson, a physician from Philadelphia, is generally credited with the first description of influenza during the 1793 epidemic.  With his description available and improved health statistics, epidemics were documented in 1833, 1837, 1847, 1889-90 and 1918.

Final Thoughts

Dr. Johan Hultin, the esteemed and persistent scientist, died this January.  He was 97. His groundbreaking  work  (literally)  enables researchers to know what made the 1918 virus so lethal and how to recognize it if it comes again.

Max Sherman is a medical writer and pharmacist retired from the medical device industry.  His new book “Science Snippets” is available from Amazon and other book sellers. It contains a number of previously published columns.  He can be reached by email at  maxsherman339@gmail.com.