• Posted October 10, 2023

Contrary to Popular Belief, 1918 Flu Did Not Target the Healthy Young

It has long been believed that the 1918 flu pandemic disproportionately affected healthy young adults, but a study of human remains tells a different story.

Together, Canadian and American researchers found that preexisting medical conditions like asthma and lower income increased the likelihood of death, just as in other pandemics, including COVID-19.

"Our circumstances -- social, cultural and immunological -- are all intertwined and have always shaped the life and death of people, even in the distant past,"said lead study author Amanda Wissler, an assistant professor of anthropology at McMaster University in Hamilton, Ontario.

"We saw this during COVID-19, where our social backgrounds and our cultural backgrounds influenced who was more likely to die, and who was likely to survive,"she said in a university news release.

The 1918 influenza pandemic killed an estimated 50 million people worldwide.

Many people fell ill quickly, which led physicians at the time to believe the healthy were as likely to die as those who were sick or frail, according to researchers.

To test the accuracy of that perception, researchers studied lesions on the bones of 369 people who died between 1910 and 1938 and reviewed their age of death.

Remains came from the skeletal collection at the Cleveland Museum of Natural History.

The research team divided the sample into those who died before and during the pandemic.

Specifically, the scientists looked for lesions on the shinbones of the pandemic victims, knowing that the skeletal structure can change because of poor health.

"By comparing who had lesions, and whether these lesions were active or healing at the time of death, we get a picture of what we call frailty, or who is more likely to die. Our study shows that people with these active lesions are the most frail,"said Sharon DeWitte, a biological anthropologist at the University Colorado Boulder and a study co-author.

The authors found that those most likely to die of the 1918 flu had exhibited signs of previous environmental, social and nutritional stress.

Asthma and congestive heart failure are common risk factors that also raise the odds of death from influenza.

Racism and institutional discrimination can amplify these effects as it did during the COVID-19 pandemic, the authors said. They noted that during the Black Death in London, people who had suffered environmental, nutritional and disease stressors were more likely to die from the plague than their healthier peers.

"The results of our work counter the narrative and the anecdotal accounts of the time,"Wissler said. "This paints a very complicated picture of life and death during the 1918 pandemic."

The findings were published Oct. 9 in the journal PNAS.

More information

The U.S. National Archives has more on the influenza pandemic of 1918.

SOURCE: McMaster University, news release, Oct. 9, 2023