Analysis of several teeth from Vikings around 1,400 years old suggests they were infected with smallpox. According to the researchers, these great navigators may even have contributed to the spread of the disease across Europe.
Smallpox was characterized by the eruption of hundreds of pustules on the body. It is one of the worst diseases suffered by mankind. Eradicated since 1980, it will still have been responsible for the death of more than 300 million victims in the 20th century alone. Caused by the variola virus , whose reservoir is strictly human, it was transmitted directly by droplets from coughs and sneezes.
The history of human smallpox is still very hazy. Genomic studies suggest that the virus began to evolve independently around 3,400 years ago. However, until now we only had proof of its presence from the 17th century, hence the importance of this new study published in the journal Science .
Traces of this condition have indeed been isolated on the corpses of 11 Vikings evolving around 1,400 years ago . These bodies come from several countries:Denmark, Norway, Russia, United Kingdom and the island of Oland (Sweden).
These new strains have little to do with their descendants. “They have a very different pattern of active and inactive genes compared to the modern virus “, says Dr Barbara Mühlemann, from the University of Cambridge. “There are multiple ways viruses can diverge and mutate into milder or more dangerous strains. This is a significant insight into the stages followed by the variola virus during its evolution “.
The genetic structure of these ancient strains is different from that of the smallpox virus eradicated in the 20th century. Nevertheless, they did indeed exist 1400 years ago. “We now know Vikings had smallpox “, emphasizes Eske Willerslev, co-author of the study.
According to the researcher, the way of life of the ancient great navigators could even have contributed to spreading this disease across Europe. It obviously draws a parallel with the Covid-19 pandemic which has already killed more than 600,000 people worldwide.
“People traveling around the world quickly spread Covid-19. It is therefore likely that the Vikings themselves spread smallpox “, he explains. "The difference is that at that time they traveled by boat rather than by plane “.
However, it remains difficult to say whether this disease was at the time as deadly as it was in the 20th century. The individuals studied in this work did indeed die with enough smallpox in their blood that we could detect it 1,400 years later. However, nothing says today that this virus is the cause of their death.
