Flu: The Story of the Great Influenza Pandemic of 1918 and the Search for the Virus That Caused It

by Gina Kolata

The 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 plague took off in September of that year, and when it was over, half a million Americans would lie dead. The illness spread to the most remote parts of the globe. Some Eskimo villages were decimated, nearly eliminated from the face of the earth. Twenty percent of Western Samoans perished. And no matter where it struck, the virus went after an unusual group—young adults who generally are spared the ravages of infectious diseases. The death curves were W-shaped, with peaks for the babies and toddlers under age 5, the elderly who were aged 70 to 74, and people aged 20 to 40.

It swept the globe in months, ending when the war did. It went away as mysteriously as it appeared. And when it was over, humanity had been struck by a disease that killed more people in a few months’ time than any other illness in the history of the world.

“Influenza” is an Italian word that, one hypothesis has it, was coined by the disease’s Italian victims in the middle of the eighteenth century. Influenza di freddo means “influence of the cold.”

How many became ill? More than 25 percent of the U.S. population.

How many died worldwide? Estimates range from 20 million to more than 100 million, but the true number can never be known. Many

How lethal was it? It was twenty-five times more deadly than ordinary influenzas. This flu killed 2.5 percent of its victims. Normally, just one-tenth of 1 percent of people who get the flu die. And since a fifth of the world’s population got the flu that year, including 28 percent of Americans, the number of deaths was stunning. So many died, in fact, that the average life span in the United States fell by twelve years in 1918.

No one knows for sure where the 1918 flu came from or how it turned into such a killer strain.

infected people in the spring of 1918, sickening its victims for about three days with chills and fever, but rarely killing them. Then it disappeared, returning in the fall with the power of a juggernaut.

But when it came back, in the second wave, it had become something monstrous, bearing little resemblance to what is ordinarily thought of as the flu.

Yet although much of the world fell ill that spring, there remained large areas that were untouched. Most of Africa and almost all of South America and Canada had no flu epidemic.

The second wave of the 1918 pandemic still was highly contagious. But this time it was a killer. Its path was evident in retrospect,

Few public officials anticipated the disaster and almost no members of the public did. The outbreak, in fact, was preceded by soothing words from medical authorities with a sort of band-played-on bravado.

Within a month after the flu arrived in Philadelphia, nearly 11,000 people died from the disease. On one fateful day, October 10, 1918, 759 Philadelphia flu victims died.

By the first week of October, the flu had spread to every part of the globe except for a few remote islands and Australia.