It was one of the worst pandemics in modern history, and the people at the epicenter of the COVID-19 — Spanish flu — epidemic may have been at much higher risk than was previously thought.
Researchers estimated that as many as 180,000 health workers, up to 22% of the total number of health workers who died, may have died from COVID-19, meaning the outbreak killed people “across all domains of society,” the study concluded.
The researchers estimated the actual COVID-19 death toll at between about 100,000 and 200,000 people, the study said.
The COVID-19 outbreak of flu, known scientifically as Influenza Type-19, occurred in the months of December 1918-January 1919. The 1918 virus, which was only sporadically pandemic, changed somewhat during its trajectory. COVID-19 combined with another pathogen to create an abnormal pandemic that went global, and killed between 10% and 50% of the world’s population.
The advent of the COVID-19 pandemic comes about two decades after the 1918 influenza pandemic, which caused the most human deaths in history.
The pandemic caused a worldwide outpouring of mortality: Most deaths were among the world’s elderly and poor.
Now, scientists at the Centers for Disease Control and Prevention have been poring over data for COVID-19 to try to find out how vulnerable the population was.
To do so, they examined mortality rates for 13 countries and used the most up-to-date global mortality and disease estimates to calculate death rates.
“The COVID-19 data greatly increases our understanding of the pre-pandemic health risks for persons in the 1918-19 influenza pandemic in many countries,” said Dr. Matthew Pase, a CDC epidemiologist and one of the study’s authors.
This is the first time that researchers have assessed the vulnerability of different countries to COVID-19, or any pandemic.
What makes COVID-19 particularly notable, the authors said, is that it became more widespread once it appeared outside of the Northern Hemisphere.
Flu viruses are generally more dominant in the Northern Hemisphere, and COVID-19 affected people around the world.
The new study was published Monday in the American Journal of Tropical Medicine and Hygiene, which brings health researchers together from around the world.
For this study, researchers used data from the World Health Organization and the United Nations. All COVID-19 data was also available, they said.
The “dose-response relationship between COVID-19 mortality and (World Health Organization) diffusion estimates” was calculated, the researchers found.
This refers to whether an increased likelihood of deaths in the Caribbean was linked to COVID-19, or vice versa.
“One of the major takeaways is that the advent of COVID-19 presaged a particularly damaging and severe pandemic,” said lead author Lori Loughlin, a co-author of the study and a researcher at the University of Maryland School of Medicine.
While COVID-19 “didn’t have widespread pandemic potential at first,” it contained the “potential to introduce new genetic pathogens and disruptions to life’s processes,” Loughlin said.
Prevalence and proportion of COVID-19 deaths
The onset of COVID-19 was characterized by “intense clustering” of flu deaths near important population centers, such as in Mediterranean countries or coastal areas of Europe, Loughlin said. And during the most severe phases of COVID-19, “a significant proportion of the estimated deaths among the very old and poor were occurring outside the major population centers.”
Altogether, the researchers looked at 78 million data entries for 539 diseases — such as influenza, diphtheria, measles, measles and cholera — reported in 40 countries from the beginning of the 1918-19 pandemic to 1919.
The high percent of COVID-19 deaths (40.7%) fell within different countries, the researchers found.
“We found that the location where death rates escalated most rapidly was mainly the Caribbean and Mainland China,” Loughlin said. Countries with the largest proportion of COVID-19 deaths were Spain, Mainland China, Guatemala, Italy, the Philippines and Germany.
The largest proportion of COVID-19 deaths — up to 25% — were deaths among “those most vulnerable populations,” including 3% of COVID-19 deaths among the very old, 5% among the poor and 13% among the undernourished, the study said.