Oldest Cases of Plague in Britain Found: DNA Uncovered from 4,000 Years Ago

Researchers at the Francis Crick Institute have identified three 4,000-year-old British cases of Yersinia pestis, the bacterium that causes plague – the oldest evidence of plague in Britain to date, reported in a paper published in Nature Communications.

Working with the University of Oxford, the Levins Local History Group, the Museum of Wales and Mendip have identified two cases of Yersinia pestis in human remains found in a mass grave at Charterhouse Warne in Somerset and one in a circular memorial at Levins in Cumbria.

They took small skeletal samples from 34 individuals across the two sites, and examined the presence of Yersinia pestis in the teeth. This technique is performed in a specialized clean room where the teeth are drilled and the dental pulp, which can trap DNA residues of infectious diseases, is extracted.

They then analyzed DNA and identified three cases of Yersinia pestis in two children estimated to have been between 10 and 12 years old when they died, and one woman who was between the ages of 35 and 45. Radiocarbon dating has been used to establish that the three people likely lived around the same time.

Plague was previously identified in several individuals from Eurasia between 5,000 and 2,500 years before present (BP), a period spanning the Neolithic and Late Bronze Age (termed LNBA), but had not been seen before in Britain at this time. . The wide geographical spread indicates that this strain of plague may have been easily transmitted.

This strain of plague – the LNBA strain – was most likely brought to central and western Europe around 4,800 years ago by humans expanding into Eurasia, and now this research indicates that it has spread to Britain.

Using genome sequencing, the researchers showed that this strain of Yersinia pestis appears very similar to the strain identified in Eurasia at the same time.

All identified individuals lack the yapC and ymt genes, which appear in later strains of plague, the latter known to play an important role in flea transmission of plague. This information previously indicated that this plague strain was not transmitted by fleas, unlike later plague strains such as those that caused the Black Death.

Because pathogen DNA — DNA from bacteria, protozoa, or viruses that cause disease — degrades very quickly in samples that may be patchy or eroded, it is also possible that other individuals at these burial sites may have been infected with the same strain of plague.

The Charterhouse Warren site is rare in that it does not match other funeral sites from the time period – the individuals buried there appear to have died from trauma. Researchers speculate that mass burials were not caused by an outbreak of plague but rather that individuals may have been infected at the time of their death.

Pooja Sawali, Senior Author and Ph.D. A student at Crick said, “Being able to detect ancient pathogens from degraded samples, thousands of years ago, is incredible. These genomes can inform us about the prevalence of pathogens and evolutionary changes in the past, and hopefully help us understand which genes might be Important in the spread of infectious diseases. We see that this strain of Yersinia pestis, including the genome from this study, is losing genes over time, a pattern that has emerged with subsequent epidemics caused by the same pathogen.”

“This research is a new piece of the puzzle in our understanding of the ancient genetic record of pathogens and humans, and how we are involved in evolution,” said Pontus Skoglund, Group Chief of the Ancient Creek Genome Laboratory.

“We understand the massive impact many historical plague outbreaks, such as the Black Plague, have had on human societies and health, but ancient DNA can document infectious diseases of the past. Future research will do more to understand how our genomes responded to such diseases in the past, and the evolutionary arms race.” with the pathogens themselves, which helps us understand the impact of diseases in the present or in the future.”