Dead men tell no tales, but their bones sure do. Even more than 100 years later.
And now a pair of researchers — one from the University of Colorado Boulder and another from McMaster University in Canada — are using those skeletal stories to question a conventional wisdom about the 1918 flu pandemic.
In a new peer-reviewed study published this week in the journal PNAS, the researchers take on the notion that the 1918 flu was unusually dangerous to the young and healthy. This is a common theme in stories about the pandemic, that it viciously struck down robust people in the prime of life. And this threat of an indiscriminately lethal pathogen has informed pandemic planning ever since.
But when the researchers, CU anthropology professor Sharon DeWitte and McMaster anthropology professor Amanda Wissler, studied the bones of people who died in the 1918 pandemic, they found that people exposed to stresses like poor nutrition, pre-existing illness or physical hardship were more likely to die from the pandemic flu than those whose bones showed fewer signs of stress. The most frail, based on an analysis of bone lesions, were 2.7 times more likely to die from the flu.
“Honestly, it shouldn’t be surprising because of what we see routinely from various causes of death,” DeWitte said in an interview with The Colorado Sun.
DeWitte is a well-known expert in a field called bioarchaeology — that is, the study of human life in the past through the examination of people’s skeletons. Much of her work has focused on the Black Death and skeletons exhumed from medieval London cemeteries. In that pandemic, too, she found evidence that society’s most frail and vulnerable were disproportionately affected.
The work inspired Wissler to work with DeWitte on a study on deaths in the 1918 pandemic and whether this notion of a plague that cut down healthy young people was true.
To answer the question, the researchers looked to the Hamann-Todd Human Osteological Collection, a collection of more than 3,000 human skeletons kept in the basement of the Cleveland Museum of Natural History, each with detailed notes on age and cause of death. The on-site work fell to Wissler, who spent hours in the basement looking for evidence of bone lesions in 369 skeletons that fit their study parameters. (While the research coincidentally took place during the height of the COVID pandemic, it had been thought up well before that virus began circulating.)
DeWitte said they were looking specifically for what are called periosteal lesions on people’s shin bones. The lesions can be caused by physical trauma, but also by illness, some nutritional deficiencies and other causes. In bioarchaeology, DeWitte said, such lesions are “often viewed as a nonspecific stress indicator.”
Their findings — which the anthropologists caution are ultimately limited by their small sample size — suggest the 1918 pandemic actually worked like a lot of other pandemics, including COVID-19: It was most devastating to the most medically and socially vulnerable. Even though the 1918 pandemic was unusual in having a higher death rate among young adults than typically seen in flu outbreaks, the disparities in who was dying remained. It largely wasn’t people who were otherwise healthy.
“The results contradict prior assumptions about selective mortality during the 1918 influenza pandemic,” the two anthropologists wrote in their study.
DeWitte said she hopes this knowledge will help public health leaders better prepare for future pandemics. If a narrative were to persist that there are some pandemics that kill indiscriminately, she said, “it sort of fosters complacency about doing anything to prevent horrible outcomes.”
Her research, she said, shows there are things that can be done, namely working to improve public health for society’s most vulnerable and better targeting resources to those groups when a pandemic does hit.
But, as historic and more recent events have shown, those aren’t policies that are adopted easily.
“The COVID-19 pandemic really highlighted for me how the work that I do has relevance to people today,” DeWitte said. “But it’s also depressing because we have these recent pandemics that people are experiencing firsthand and we’re not learning the lessons of the past.”