The toll of history’s worst epidemic surpasses all the military deaths in World War I and World War II combined. And it may have begun in the United States.
Haskell County, Kansas, lies in the southwest corner of the state, near Oklahoma and Colorado. In 1918 sod houses were still common, barely distinguishable from the treeless, dry prairie they were dug out of. It had been cattle country—a now bankrupt ranch once handled 30,000 head—but Haskell farmers also raised hogs, which is one possible clue to the origin of the crisis that would terrorize the world that year.
Another clue is that the county sits on a major migratory flyway for 17 bird species, including sand hill cranes and mallards. Scientists today understand that bird influenza viruses, like human influenza viruses, can also infect hogs, and when a bird virus and a human virus infect the same pig cell, their different genes can be shuffled and exchanged like playing cards, resulting in a new, perhaps especially lethal, virus.
We cannot say for certain that that happened in 1918 in Haskell County, but we do know that an influenza outbreak struck in January, an outbreak so severe that, although influenza was not then a “reportable” disease, a local physician named Loring Miner—a large and imposing man, gruff, a player in local politics, who became a doctor before the acceptance of the germ theory of disease but whose intellectual curiosity had kept him abreast of scientific developments—went to the trouble of alerting the U.S. Public Health Service.
The report itself no longer exists, but it stands as the first recorded notice anywhere in the world of unusual influenza activity that year. The local newspaper, the Santa Fe Monitor, confirms that something odd was happening around that time: “Mrs. Eva Van Alstine is sick with pneumonia…Ralph Lindeman is still quite sick…Homer Moody has been reported quite sick…Pete Hesser’s three children have pneumonia …Mrs J.S. Cox is very weak yet…Ralph Mc-Connell has been quite sick this week…Mertin, the young son of Ernest Elliot, is sick with pneumonia,…Most everybody over the country is having lagrippe or pneumonia.”
Several Haskell men who had been exposed to influenza went to Camp Funston, in central Kansas. Days later, on March 4, the first soldier known to have influenza reported ill. The huge Army base was training men for combat in World War I, and within two weeks 1,100 soldiers were admitted to the hospital, with thousands more sick in barracks. Thirty-eight died. Then, infected soldiers likely carried influenza from Funston to other Army camps in the States—24 of 36 large camps had outbreaks—sickening tens of thousands, before carrying the disease overseas. Meanwhile, the disease spread into U.S. civilian communities.
The influenza virus mutates rapidly, changing enough that the human immune system has difficulty recognizing and attacking it even from one season to the next. A pandemic occurs when an entirely new and virulent influenza virus, which the immune system has not previously seen, enters the population and spreads worldwide. Ordinary seasonal influenza viruses normally bind only to cells in the upper respiratory tract—the nose and throat—which is why they transmit easily. The 1918 pandemic virus infected cells in the upper respiratory tract, transmitting easily, but also deep in the lungs, damaging tissue and often leading to viral as well as bacterial pneumonias.
Although some researchers argue that the 1918 pandemic began elsewhere, in France in 1916 or China and Vietnam in 1917, many other studies indicate a U.S. origin. The Australian immunologist and Nobel laureate Macfarlane Burnet, who spent most of his career studying influenza, concluded the evidence was “strongly suggestive” that the disease started in the United States and spread to France with “the arrival of American troops.” Camp Funston had long been considered as the site where the pandemic started until my historical research, published in 2004, pointed to an earlier outbreak in Haskell County.
Wherever it began, the pandemic lasted just 15 months but was the deadliest disease outbreak in human history, killing between 50 million and 100 million people worldwide, according to the most widely cited analysis. An exact global number is unlikely ever to be determined, given the lack of suitable records in much of the world at that time. But it’s clear the pandemic killed more people in a year than AIDS has killed in 40 years, more than the bubonic plague killed in a century.
The impact of the pandemic on the United States is sobering to contemplate: Some 670,000 Americans died.
In 1918, medicine had barely become modern; some scientists still believed “miasma” accounted for influenza’s spread. With medicine’s advances since then, laypeople have become rather complacent about influenza. Today we worry about Ebola or Zika or MERS or other exotic pathogens, not a disease often confused with the common cold. This is a mistake.