DNA reveals: This is where the great death started

In the Chuy Valley, in northern Kyrgyzstan, there are medieval burial sites that archaeologists became interested in as early as the 19th century.

During the years 1338–1339, an unusual number of people died and were buried here, and on the tombstones it can be read that the “plague” was the cause of death.

In an interdisciplinary study that combines modern DNA research, medicine and archeology, researchers have been able to establish that they actually died of the plague. It has also been shown that the bacterium that killed them is derived from the original strain, which is a precursor to the bacterial strains that caused the great death in Europe about eight years later.

– It’s like the plague “Big bang”, if you want to call it that, says Johannes Krause, doctor of genetics and one of the researchers behind the study, in connection with the results being presented during a press conference.

Exact year

The plague still occurs in wild rodents in the area, and the common perception is that the disease-causing bacterium has somehow been transmitted from them to humans.

The place of origin of the infection is at the then Silk Road, a trade route between Europe and China, so the disease may have spread. But the actual spread of infection is believed to have taken place when ships with grain from the Crimean peninsula, present-day Ukraine, called at Italy.

– It also means that the plague, as many researchers strongly suspected, took hold several years earlier in Central Asia before it reached the Mediterranean and Europe, says Fredrik Charpentier Ljungqvist, associate professor of history and natural geography at Stockholm University, who studied the Great Death.

Why it took a full eight years for the infection to spread is still unanswered. At some point in the period from the first deaths in Kyrgyzstan to the onset of the plague pandemic, the original strain was diversified and a number of new bacterial strains emerged, some of which may have been more deadly and contagious. But the fact that there is now a definite year – 1338 – to point out, means that some theories about the spread of infection can be rejected.

– Previously, many researchers have considered that it may have happened a hundred years earlier, and that, for example, the Mongols had a role in the early spread of the infection. Now you can see that this seems to have happened much later, says Fredrik Charpentier Ljungqvist.

Fewer died

Another aspect, where science has recently presented new perspectives, is the estimate of how many people died in the 14th century plague ravages. In the past, science has relegated to as large parts as up to 60 percent of Europe’s population stroking with – that is, up to 50 million people.

But recently published research, to which Fredrik Charpentier Ljungqvist also contributed, wants to write down the death toll to include about 20 percent of Europeans.

According to these results, Eastern Europe and large parts of Central Europe, which at the time were largely sparsely populated, hardly seem to have been affected at all. While Western Europe, which was more densely populated with easily accessible coastal trading posts, was far worse off.

– Diseases, just like covid-19, spread more easily in larger cities and where it is more frequent between people, says Fredrik Charpentier Ljungqvist.

Hepatitis is caused by the bacterium yersinia pestis and causes high fever, headache and swollen lymph nodes near the site of infection. The abscesses can be themselves. The bacterium often reaches the blood, which causes blood poisoning. It can cause tissue death, which is why it is also called black death.

If the bacterium reaches the lungs, the infected person very quickly becomes very ill and without treatment, the mortality rate is close to 100 percent.

The disease is now fully manageable if the infected person receives antibiotics at an early stage.

Historical plague outbreaks

The first documented plague outbreak in history was the so-called Justinian plague (named after the then Byzantine emperor Justinian) which took place in the Mediterranean in the years 541-542. This was followed by recurring outbreaks.

Around the middle of the 14th century, the disease returned with full force to Europe. The first eruption was the Great Death of 1346–1353. It was followed by repeated eruptions in the following centuries. The last outbreak of the plague in England took place 1665–1666, in Sweden 1710–1713, in France 1720–1722 and in Poland and Russia 1770–1772.

Sources: Swedish Public Health Agency, NE, PNAS

Source: DNA reveals: This is where the great death started (postsen.com)