By Bruce Fleury, Ph.D. for The Great Courses
Authorities think that the 1918 Spanish Flu spread out of America and mutated into a killer during its time in Europe. By late summer, this mutant or hybrid strain was poised and ready to re-enter the United States. Re-entry may have occurred August 12, 1918, from passengers on the Norwegian ship, the Bergensfjord. The liner entered New York harbor with 200 people sick; four of them had been buried at sea. All of the passengers who were sick and those who had been exposed went down the gang plank and scattered into the New York City population.

Note from the editor:
This is the second article in a series of three that covers the flu of 1918. In his 24-lecture series, “Mysteries of the Microscopic World,” Dr. Bruce Fleury covers the world of bacteria, viruses, fungi, and other organisms, collectively known as microbes.
In Lecture 12 of the series, (the second of three lectures on the deadliest epidemic of all time), he speaks about the mutated form of the 1918 flu as it reached American shores and killed an estimated 675,000 people out of a population of 105 million.
Even though when this course was produced we were still years away from the first reported cases of COVID-19, it gives context to our current climate to look back on this stage of our world history and witness how it affected the entire world. Below, you can read his lecture in its entirety, and watch the full video.
Infected Passengers Aboard the Bergensfjord
Ms. Olsen, a passenger on the Bergensfjord, was one of the first to die in America in that second wave of the flu. Over half a million Americans followed her into the grave. This scene was repeated over and over again, as the flu that America had sent overseas returned with a vengeance. In June of 1918, the City of Exeter arrived from Liverpool and docked in Philadelphia with 28 people ill. The victims from the City of Exeter were rushed into strict quarantine and the city was spared for a little while.
The Somali, arriving from India with 89 sick crewmen, put ashore at Grosse Isle in Canada. All of these port cities, all of the cities with large military installations turned out to be most vulnerable. Boston was an early target. One story is that a group of 106 sailors in Boston called in sick at the Commonwealth Pier; 26 of them died and the flu spread rapidly from there.
The Terror at Camp Devens and Beyond
Camp Devens in Boston was especially hard hit. Col. Victor Vaughan, former AMA president, was among those who were sent by the army to Camp Devens to investigate the outbreak. Vaughan saw:
“Hundreds of stalwart young men in the uniform of their country coming into the wards of the hospital in groups of 10 or more. They are placed on the cots until every bed is full, yet others crowd in. Their faces soon wear a bluish cast; a distressing cough brings up the bloodstained sputum. In the morning the dead bodies are stacked about the morgue like cord wood.”
One of the first cases at Devens was a young soldier from the Forty-Second Infantry. He ached so badly that he screamed whenever anyone touched him. He was misdiagnosed with meningitis, along with several others. In a single day at Camp Devens, 1,543 soldiers reported sick. Needless to say, the medical staff was soon overwhelmed. Then the doctors and nurses started to sicken and die. One doctor at Devens described it:
“One can stand it to see one, two or 20 men die, but to see these poor devils dropping like flies. … It takes special trains to carry away the dead. For several days there were no coffins and the bodies piled up something fierce. … It beats any sight they ever had in France after a battle.”
From sailors and soldiers in coastal cities, the flu spread inland following the rivers and railroads. It ravaged the Great Lakes Naval Training Station near Chicago. One of the nurses recalls wrapping still-living men in winding sheets and putting death tags on their toes because it saved time and they were utterly exhausted. In her nightmares, she wondered “what it would be like to be that boy who was at the bottom of the cord wood in the morgue.”
This is a transcript from the video series Mysteries of the Microscopic World. Watch it now, Wondrium.
Camp Grant, near Rockford, Illinois, was jammed with over 40,000 troops. Col. Charles Hagadorn, who was the commander of Camp Grant, decided to ignore the army regulations against overcrowding. The camp medical staff objected, but they were overruled. On September 21, the first soldier who reported sick was from an infantry training group that included officers from Camp Devens. Within a week, he was joined by 4,102 soldiers; 1,810 soldiers reported sick in a single day.
On that same day that the first soldier died of flu at Camp Grant, Col. Hagadorn ordered a crowded troop train to leave Camp Grant for Camp Hancock, near Augusta, Georgia. He ignored demands for a quarantine of the camp. Hundreds of men were packed into each car, and the flu spread very rapidly onboard that overcrowded train. Two thousand of the 3,100 soldiers on that train got the flu, with a death rate estimated at over 10 percent. When the death toll at Camp Hancock passed 450 men, Col. Hagadorn instructed his staff to clear the building, shut himself in his office, and shot himself.
The Harrowing Search for Answers
One of the reasons the flu was so terrifying at that time is that no one had any real idea of what had caused it. Researchers followed several bacterial dead ends. In the wake of the 1889–1890 flu pandemic, Dr. Richard Pfeiffer had isolated a new species of bacterium which he called Bacterium influenzae, also known as Pfeiffer’s bacillus.
Learn how ecological disturbances, both natural and human-made, can benefit harmful microbes.
It’s now known as Haemophilus influenzae, and it was thought by many, including the Public Health Service, to be the causative agent. This one comes a little bit too close to home for me because I nearly lost my only child to Haemophilus influenzae when he was six months old. Baby’s first Christmas was a rather anti-climactic event.
When you ask a doctor about the odds of fatality for any disease and they can’t look you in the eye, you should be very, very concerned. We discovered, to our horror, that this is a major killer, especially of children. It’s a very dangerous disease, but not, as it turned out, the cause of the 1918 Flu. The bacterium could easily kill hosts in the lab, but the symptoms weren’t quite identical to those of influenza.
Nevertheless, Dr. Pfeiffer insisted that he had found the culprit, and his sterling reputation and his high standing in the scientific community managed to convince many of his colleagues that he was correct. But despite improved culture techniques, the bacterium was not always present in flu victims and was usually found together with several other pathogens.
By 1919, the bacterial hypothesis had been rejected and researchers were concluding that whatever the cause, it must be viral. That was a controversial conclusion because it was based entirely on negative evidence—the gradual elimination of all the alternative hypotheses.
Remember that viruses back in 1918 were still a big mystery. The first influenza virus wasn’t isolated and observed until 1934. The first flu vaccinations didn’t come along until 1944. So, was the whole thing a fiendish German plot? Maybe German spies had mined Boston Harbor with “influenza-sprouting germs.” Maybe it was started by Germans put ashore from U-boats, setting germs loose in theaters and other public places. There was no cure—even secondary bacterial infections like bacterial pneumonia were untreatable (sulfa drugs and antibiotics had not yet been invented).
Medical treatment consisted mostly in comforting, and, whenever possible, isolating the patient—in other words, basic nursing. Treatments included: bleeding, saline or glucose injections, enemas, alcohol, camphor oil, heroin, morphine, mustard plasters, castor oil, sulfur smoke, lard mixed with camphor and chloroform, or—my favorite—lard mixed with turpentine. That will cure you or kill you.
Public health responses included: fumigating trains, buses, passengers, and luggage; urging people to wear gauze masks; campaigns against spitting and sneezing; warnings about public gatherings; and a general prescription of rest, fresh air, and reporting cases to the authorities. Folk cures abounded; they included: stuffing salt up children’s noses, magic charms, wearing goose grease poultices, hanging little bags of garlic or onions around your neck (something my mom made me do when I was a very little boy), and gargling with disinfectants. Snake oil salesmen were everywhere.
By mid-October the full, tragic potential of the epidemic had been realized. Many American cities and towns were hard hit with unprecedented mortality rates. Families were devastated and all public life ground to a halt. William Sardo, of Washington, D.C., said:
“People were afraid to kiss one another, to eat with one another; they were afraid to have anything that made contact because that’s how you got the flu. … You were constantly afraid, you were afraid because you saw so much death around you. … It wiped out entire families from the time that the day began in the morning to bedtime at night. … There was an aura of constant fear.”
One Ottawa newspaper writes: “Street cars rattled down Banks Street with windows open and plenty of room inside. Schools, vaudeville theaters, movie palaces [were] dark; pool halls and bowling alleys deserted.”
Outbreak in Philadelphia
Philadelphia was typical of most big cities ravaged by the flu. The Philadelphia Navy Yard was booming; the Hog Island shipyard, the world’s largest shipyard with over 35,000 workers, had just opened that year. Munitions factories, Midvale Steel, Baldwin locomotive—the city, like many American cities at the time, was bursting at the seams.
The war industries added 300,000 people to the city’s population of 1.7 million, and housing was nearly nonexistent. Boy Scouts patrolled the city to locate shelter for new arrivals. Boarding houses and apartments were jammed to capacity, with workers on separate shifts often sharing a single bed. Overcrowding, inadequate social services, and squalid living conditions among the poor—all of these made Philadelphia a powder keg for the flu.
City government was so bad at that time, and so corrupt, that Lincoln Steffens called it “the worst-governed city in America.” Its machine-appointed health director, Dr. Wilmer Krusen, was honest but inexperienced, over-cautious, and in the end, completely ineffective. Despite frequent warnings, despite mounting military cases, he made no plans for an epidemic, he made no stockpiles of medicine or equipment, and he didn’t even draw up a list of first-responders (doctors and nurses to contact in an emergency).
The news of the epidemic raging in Boston arrived in Philadelphia too late to put the city on alert. And besides, the AMA Journal had announced in September that the flu was nothing special, and had “already practically disappeared from the allied troops.”
On September 28, 1918, life in Philly was great. The biggest local news story was the ongoing coal miner strike and the upcoming parade. The Liberty Loan Parade, designed to sell war bonds, was to be the biggest parade in the city’s history. Flu had already arrived in the city, hitting the Navy Yard in mid-September. The day before the parade, over 200 flu cases were reported, 123 of them civilian.
Navy personnel tried to stop the parade, but with no success—morale trumped public health. Dr. Krusen continued to insist that there was no danger of an epidemic; it was only, as he called it, “old-fashioned influenza or grippe.” That enormous crowd of several hundred thousand were packed together for hours as that two-mile long parade flowed by. Airplanes flew overhead and anti-aircraft guns fired live shells rigged to explode at a low altitude.
I had to miss Mardi Gras parades this year to record these lectures, but I managed to squeeze in a few parades before I left. As I was standing on St. Charles Avenue watching muses flow down the street, watching float after float after float, I couldn’t think about all the people with their hands in the air saying, “Throw me something, Mister!” All I could think about was the Liberty Loan Parade, and looked around to see who was coughing and sneezing.
The flu incubation period is typically 24 to 48 hours. Within a day or two of the parade, several hundred people fell ill. The hospitals began to fill and lines of desperate people formed, waiting to get in, offering nurses bribes of $100 or more to be admitted. Crosby said:
“Visiting nurses often walked into scenes resembling those of the plague years of the 14th century. One nurse found a husband dead in the same room where his wife lay with newly born twins. It had been 24 hours since the death and the births, and the wife had eaten no food but an apple which happened to lie within reach.”
Twelve emergency hospitals would eventually open to receive the growing number of the sick and dying. Like most big cities, Philadelphia had a severe shortage of doctors and nurses; 850 of them were away on war duty. In Philadelphia’s General Hospital, 54 nurses ended up as patients (that’s 43 pecent of the entire nursing staff), and 10 of them died. The call went out for retired doctors, even medical students. All five Philadelphia medical schools closed and sent their third- and fourth-year students to help.
On October 3, Dr. Krusen finally ordered all schools, churches, and theaters to close, and banned all public gatherings. Most grocers were closed and few stores of any kind were open. The closing of the schools and the churches, in particular, further isolated citizens from one another and contributed to a growing climate of fear. An editorial in the Philadelphia Inquirer asked:
“Since crowds gather in congested eating places and press into elevators and hang to the straps of illy-ventilated street cars, it is a little difficult to understand what is to be gained by shutting up well-ventilated churches and theatres. The authorities seem to be going daft. What are they trying to do—scare everybody to death?”
Shutting down bars and taverns created some unusual problems because now you could only get whiskey at the drugstore and only with a prescription. Drugstores became crowded with long lines of people buying whiskey. A few unscrupulous pharmacies pushed the price of whiskey as high as $52 a gallon—a princely sum in 1918.
So many people took the ferry to nearby Camden because the bars there were still open that the City of Camden shut down all of its taverns to stem the tide of new customers who were bearing the flu. In retrospect, the closings were probably unnecessary. For cities like Philadelphia that shuttered public places, the case rate and the death rate were no better than the statistics for cities that left the bars open.
Philadelphia Takes a Turn for the Worse
As the true horror of the flu took hold, Philadelphia became a city of the dead. Isaac Starr, a University of Pennsylvania student, wrote that “the life of the city had almost stopped.” Absentee rates ran from 20 to 40 percent for those businesses and factories that still remained open. The local press and public health officials continued to lie to the public about the epidemic, insisting that the worst was over. They created a prevailing attitude of public mistrust of government at every level. In early October, Dr. Krusen insisted, “These deaths mark the high water mark in the fatalities, and it is fair to assume that from this time until the epidemic is crushed the death rate will constantly be lowered.” The next day, 428 people died, and the body count kept going higher and higher.
Citizens took to hanging crepe paper on their doors to show that someone had died. White paper meant that a child or young adult had died; black meant that the victim was middle-aged; grey was used to mark the death of the elderly. In the suburb of West Manayunk, a mob of weeping housewives actually blocked the car of a local doctor making a house call, and would not let him leave until he had treated every child in the neighborhood—all 57 of them.
So many phone workers were out sick that calls were limited to emergencies only. Bell Telephone took out ads in the local papers to announce that no calls would be accepted “other than absolutely necessary calls compelled by the epidemic or by war necessity.” One such ad stated:
“Telephone Service Faces a Crisis—The situation is one which the public must meet squarely—800 operators—27% of our force—are now absent due to the influenza. It is every person’s duty to the community to cut out every call that is not absolutely necessary that the essential needs of the government, doctors, and nurses may be cared for.”
Crosby tells us that Dr. Krusen empowered the phone company to cut service to any customers that made unnecessary calls; about 1,000 people were disconnected for violating that rule.
As the casualties continued to mount, orphans and starving children became a problem—there was no one left alive to feed them. As the epidemic peaked during the week of October 16, 4,597 people died—759 of them in a single day (October 10).
With a severe shortage of undertakers and gravediggers, the bodies piled up rapidly. Prisoners, seminary students, and clergymen were pressed into service. To bury its poorest citizens, the city finally resorted to trench graves dug by steam shovels in Potter’s Field. Some undertakers took to profiteering, raising rates up to 600 percent. Some cemetery workers and gravediggers demanded an extra fee of $15 or more and even insisted after being bribed that the customers dig their families’ graves themselves.
Citizens were left with wooden boxes and instructed to leave their dead on the front porch. In some cases, the bodies were simply tossed in a heap on wagons, reminiscent of the plague years in medieval Europe. Many people were forced to live with the dead—often for several days—closing them off in a separate room if they had the luxury, or just wrapping them in a sheet and leaving them in a corner.
Citizens became increasingly isolated, huddled behind closed doors. Ambulances were supplemented with private cars, police cars, anything with wheels. Taxi drivers were pressed into service, and to their infinite credit, not a single taxi driver in Philadelphia refused to carry the sick and dying to the hospital.
Every social agency in the city, public and private, chipped in to help as best they could, without regard to race, creed, or color. Idled teachers volunteered in droves, along with nuns, priests, Boy Scouts, firemen, policemen, and hundreds and hundreds of private citizens. Archbishop Dennis Dougherty sent 1,000 Sisters of Saint Joseph out into the community to help care for the sick.
A Respite of Sorts
By October 18, the worst was over and emergency hospitals began to close. On Sunday the 27th, churches were reopened; schools started the next day. On the 30th, the bars and the theaters reopened, followed by a noticeable spike in arrests for drunk and disorderly conduct.
As many as 500,000 citizens had been infected, and at least 12,897 had died. Those numbers are very conservative, as thousands of cases went unreported in the chaos that had descended upon the city. All across America, in the aftermath of the flu, the fate of the survivors became a major problem. Many families were impoverished, with one or more bread winners sick or dead. The flu left behind a world filled with widows and orphans—21,000 orphans from the flu in New York City alone.
Deaths of 15- to 34-year-olds rose to 20 times the normal rate in a flu epidemic, so it wasn’t just the very young or the very old who died, this time. More elderly people survived than usual, we think because they might have been exposed to a similar virus earlier in their lives. That initial attack may have been so mild it wasn’t noticed, but it left them with at least partial immunity to the new, related virus.
Influenza is a little unusual in that new strains are fiercely competitive with one another. This is an interesting example of competitive exclusion. One competitor is so successful that it drives the other into local extinction. The flu triggers the body’s immune response against any and all strains of the flu that that person has ever come in contact with. So, an existing strain that tries to re-infect someone will find the door already closed, and will rapidly die out as a result; only one subtype of flu can exist in the human population at one time.
As time goes on, fewer and fewer people are creating antibodies for other forms of the flu, so a fresh strain now has an open playing field. Competing strains usually coexist for a brief period, a few months perhaps. The only way to trace the path of the flu is by serological archaeology—what a fascinating field—taking blood samples from various age groups and examining the antibodies to see what strains each age group had been exposed to, and trying to link those up with recorded instances of epidemics or pandemics.
The third and final wave followed in late 1918 and into early 1919. The flu, at this point, seems to have gradually mutated into a weaker strain, because the third wave was short and sharp but relatively mild compared to that killer second wave. The final toll was grim. Estimates of Americans who died run up to 675,000, and that’s out of a population of 105 million. Britain lost 228,000 to the flu. The best global estimate out of 1.8 billion is 50 to 100 million dead, and that comes from Nobel laureate and flu expert Dr. Macfarlane Burnet.
Native populations of people were especially hard-hit. Many isolated populations do not have regular contact with common viruses, and that leaves them highly vulnerable in pandemics because they have no immunity whatsoever. American Samoa, on the other hand, survived without a single victim because of its early and very effective quarantine.
Australia had the lowest global death rate, also thanks to an early quarantine. At the very end, a troopship with 90 sick soldiers did finally sneak into port, but by then the virus had weakened. In Chiapas, Mexico, 10 percent of the population died. In the Fiji Islands, 14 percent of the population died in 16 days. In Nome, Alaska, out of 300 Inuits, 176 died. Many Inuit villages were completely wiped out, with some villages sustaining 85 percent casualties or more.
Over 20 million people are now thought to have died in India alone. One Delhi hospital treated 13,190 flu patients, only to watch over 7,000 of them die. An estimated one-third of the entire population of Labrador died, in Okak, Labrador: 266 citizens, only 59 survivors. Hebron: One hundred fifty Inuits dead out of 220. In many rural and isolated areas, packs of wild dogs became a serious problem.
Starving dogs often broke into dwellings to feast on the dead, or on those too sick to fight back. The Rev. Andrew Asboe shot over 100 dogs before he was rescued. The virus killed an estimated 7 percent of the entire population of Russia and Iran. These kinds of epidemics are sometimes called “virgin soil” epidemics. Everyone on Earth at one time was probably exposed to that virus.
Those who survived the infection formed an immune reaction. In the end, the virus had no place left to go; it couldn’t maintain itself in the human population. Fortunately for the flu virus, it doesn’t need humanity to sustain itself. Birds are its primary host, and as long as bird populations are healthy, the flu will always find a home.
At the height of the second wave, Victor Vaughan nearly lost hope. He wrote, “If the epidemic continues its mathematical rate of acceleration, civilization could easily disappear from the face of the Earth within a matter of a few more weeks.” But by late November of 1918, the crest of influenza deaths had passed.
It was the worst epidemic in the history of mankind. Many great cities like Philadelphia ground to a halt for several weeks during the pandemic; and as the City of Brotherly Love reminds us, these disasters bring out both the best and the worst in humanity.