Covid-19 overtakes 1918 Spanish flu as deadliest disease in American history

The Covid-19 pandemic has become the deadliest disease event in American history, with a death toll surpassing that of the 1918 Spanish flu.

The Spanish flu was previously the disease event that caused the biggest loss of life in the United States; the Centers for Disease Control and Prevention estimate that 675,000 Americans died during the 1918 pandemic, in waves of illness that stretched out over roughly two years in this country.

According to STAT’s Covid-19 Tracker, Covid deaths stand at more than 675,400.

“In terms of raw numbers of deaths, that’s a high number,” said Howard Markel, director of the Center for the History of Medicine at the University of Michigan School of Public Health. “And it’s higher still than it should have been, frankly.”

U.S. deaths make up roughly 14% of the nearly 4.7 million fatalities that have been reported worldwide in this pandemic to date, even though the country’s population comprises only about 4.2% of the global population.

“In the U.S., we are among the worst affected in our class of countries — rich countries with an aging population. But other countries in Europe did poorly as well,” said Cécile Viboud, an infectious diseases epidemiologist who has done a lot of research into deaths from the 1918 flu.

Whether the Covid pandemic will qualify as the deadliest event in U.S. history is perhaps a question for Civil War historians. The long-accepted toll of the War Between the States was 620,000, which this pandemic has already surpassed. But in 2011, David Hacker, a historian at Binghamton University in New York State, published an article in the journal Civil War History arguing the true number of deaths in the Civil War was more likely around 750,000.

The heavy toll the pandemic has taken in the U.S. is due to the country’s inadequate response early on, said Markel. David Morens, a medical historian at the National Institutes of Allergy and Infectious Diseases, agreed.

“I think it’s generally known around the world that America didn’t do a very good job in the early stages of controlling the pandemic,” said Morens, who has also written extensively on the 1918 flu pandemic.

Comparing events that happened more than a century apart has its perils. For instance, the population of the United States in 1918 was a third of what it is now. So as a percentage of the national population, the Spanish flu deaths still has the lead on Covid-19.

Likewise, the mean age of the people who died in 1918 was 28, whereas with Covid, deaths are occurring mainly in the elderly, said Viboud, who works at the National Institutes of Health’s Fogerty International Center. In terms of cumulative years of life lost, the Spanish flu’s impact thus remains greater.

But modern medicine is far more advanced than what was available in 1918. Now people whose lungs are under attack from Covid can be put on ventilators or extracorporeal membrane oxygenation — ECMO — machines, which pump oxygen into blood when a person’s heart and lungs are no longer up to the job. These were not options in 1918.

And for months now, the country has had vaccines that are highly effective at lowering the risk of dying from Covid. Still the fatalities pile up, though at a slower rate than earlier in the pandemic.

“We have no idea what would have been the impact of Covid-19 without interventions,” Viboud acknowledged.

The deaths will continue to climb for some time still, Morens noted.

“Remember, we’re still counting,” he said. “In 1918, the pandemic became not so deadly within two years. We have no idea — I don’t and I don’t trust anybody who says they do — where this Covid-19 will go.”

The global Covid death figure is without doubt an underestimate, but then again, the American tally likely is as well.

“The true deaths from Covid-19 in the United States are probably higher than the actual numbers. But how much higher is a matter of speculation,” Morens said.

There is some work that suggests what a truer figure might be, Viboud said, pointing to a research paper published in the journal eLife in June.

The study, by Ariel Karlinsky, an economist and statistician at Hebrew University in Jerusalem, and Dmitry Kobak, of the Institute for Ophthalmic Research at the University of Tübingen in Germany, actually attempted to estimate a more accurate picture of Covid deaths in 103 countries. Their calculations were based on looking at what is known as excess mortality, the differences between the number of deaths reported since the start of the pandemic and the annual average mortality figures for the years 2015 through 2019 in each of the countries studied.

Some countries have actually had fewer deaths — negative excess mortality — during the pandemic. One such country is New Zealand, which has managed in the main to keep Covid from spreading by using stringent border controls. New Zealand reported 1,900 fewer deaths than normal during the pandemic, the Karlinsky and Kobak paper reported, attributing the lower number of deaths to the fact that viruses like influenza haven’t circulated to normal degrees during the pandemic.

Their work estimated that the true Covid death toll in the United States is probably 10% higher than the declared number of lives lost to the disease in the country. That would place the Covid deaths in America in the ballpark of 741,000.

In rivaling the Spanish flu, the Covid-19 pandemic has given medical historians a new lesson to teach, said Markel, who wrote about that fact last month in The Atlantic.

“The truth is we have no historical precedent for the moment we’re in now,” he wrote. “We need to stop thinking back to 1918 as a guide for how to act in the present and to start thinking forward from 2021 as a guide to how to act in the future.”

In his interview with STAT, Markel recalled that during a briefing he gave to former President Barack Obama about the 1918 pandemic — he was president during the 2009 H1N1 pandemic — Obama noted that 1918 was a long time ago. That’s the problem with disease outbreaks that are 100-year events; they are so rare that the lessons one can take from them may seem out of date when they are next needed.

“We finally now have a modern pandemic,” said Markel. “In modern times with modern vaccines and so on. So to me, this is the one I’m going to be teaching my medical students and public health students.”

This story has been updated.