PerspectivePlague Was Around for Millennia Before Epidemics Took Hold – and the Way People Lived Might Be What Protected Them
One of civilization’s most prolific killers shadowed humans for thousands of years without their knowledge. Sonja Eliason and Bridget Alex write that the bacteria Yersinia pestis, which causes the plague, is thought to be responsible for up to 200 million deaths across human history — more than twice the casualties of World War II. People were contracting and dying from plague at least 3,000 years, but plague epidemics are more recent phenomena. The reason? Human lifestyles that encouraged the spread of the disease.
One of civilization’s most prolific killers shadowed humans for thousands of years without their knowledge.
Sonja Eliason and Bridget Alex write in The Conversation that the bacteria Yersinia pestis, which causes the plague, is thought to be responsible for up to 200 million deaths across human history — more than twice the casualties of World War II.
The write:
Scientists long assumed that the deadly disease began infecting humans just before the earliest epidemic, the Justinianic Plague.
But recent paleogenetics research reveals that plague has been with us for millennia longer: Ancient DNA (aDNA) from the bacteria was recovered from human skeletons as old as 4,900 years. This means people were contracting and dying from plague at least 3,000 years before there’s any archaeological or historical evidence for an epidemic.
Why didn’t these earlier infections lead to devastating outbreaks like the Black Death? It seems the answer is part biological — genetic mutations to the bacteria itself — and part cultural — changes to human lifestyles that encouraged the spread of the disease.
They add:
The harsh reality is that it’s exceedingly difficult, if not impossible, to control a pathogen, its possible mutations or its next outbreak. But understanding how human behaviors affect the spread and virulence of a disease can inform preparations for the future.
As a society, we can take organized measures to reduce the spread of infection, whether by limiting over-congestion, controlling food waste, or restricting access to contaminated areas. Human behaviors are just as critical to our disease susceptibility as are the characteristics of the pathogen itself.
