Smallpox-Infected Viking Skeleton Pushes Deadly Virus Age Back 1,000 Years

By Katy Pallister
23 JUL 2020, 19:00

Killing around 300 million people in the 20th century alone, smallpox – the disease caused by the variola virus – is one of the deadliest diseases in history and the first to be officially eradicated. But it is now clear that humans have been plagued with smallpox for much longer than previously evidenced.

In the teeth of Viking skeletons unearthed from sites across Northern Europe, scientists have extracted new strains of smallpox that are poles apart from their modern descendants.

“The ancient strains of smallpox have a very different pattern of active and inactive genes compared to the modern virus,” Dr Barbara Mühlemann, of the University of Cambridge, said in a statement. “There are multiple ways viruses may diverge and mutate into milder or more dangerous strains. This is a significant insight into the steps the variola virus took in the course of its evolution.”

Smallpox is a disease spread from person to person via infectious droplets. The earliest genetic evidence of the disease found prior to this study dates back to the mid-1600s, but Mühlemann and her colleagues discovered extinct smallpox strains in 11 individuals located in Viking-era burial sites in Denmark, Norway, Sweden, Russia, and the UK, dated to nearly 1,400 years ago. In fact, the Viking way of life may have also helped to spread this disease.

More:
https://www.iflscience.com/health-and-medicine/smallpoxinfected-viking-skeleton-pushes-deadly-virus-age-back-1000-years/