Black Death: Scientists Unravel Mystery of Deadliest Pandemic in History

Scientists have solved the mystery of the Black Death's long reign - they have identified a single gene that allowed it to persist for centuries. The Black Death remains the deadliest pandemic in human history. The devastating pandemic wiped out up to half the population of Europe, Western Asia and Africa, killing tens of millions of people. Now, the mystery of the Black Plague's long reign has finally been solved.

Research has shown that the evolution of a single gene in Yersinia pestis, the bacterium that causes bubonic plague, has allowed it to adapt and survive for so long, writes the Daily Mail.

The study addresses key questions about how pandemics enter human populations, cause mass illness, and develop different levels of virulence. And the findings could help us prevent another pandemic in the future.

"This is one of the first scientific studies to directly examine changes in an ancient pathogen that we still see today, in an attempt to understand what drives the virulence, resistance and/or possible extinction of pandemics," said study co-author Professor Hendrik Poinar.

The new study was conducted by scientists from McMaster University in Canada and the Pasteur Institute in France.

The bacteria that cause the plague evolved and became less deadly over time, allowing them to continue infecting people in three separate pandemics over more than a thousand years. The first pandemic, the Plague of Justinian, broke out in the 500s at the beginning of the Middle Ages and lasted for about 200 years.

According to the Daily Mail, the Black Death began in the mid-1300s and became the deadliest pandemic in human history, killing up to half the population of Europe, Western Asia and Africa, with outbreaks continuing for centuries.

The third bubonic plague pandemic broke out in China in the 1850s and continues to this day, with some cases still reported in parts of sub-Saharan Africa.

"Plague bacteria are of particular importance in human history, so it is important to know how these outbreaks spread," said Javier Pizarro-Cerda, co-author of the study.

The researchers examined samples of Yersinia pestis, the bacteria that causes plague, from each pandemic. In all three cases, the genes of each plague bacterium evolved to become less virulent and less deadly over time, the study found.

Bacteria that cause less severe infections are thought to have increased the duration of pandemics because they have more opportunities to spread among people.

The researchers confirmed this theory by infecting rats with recent plague samples, showing that as virulence decreased, the disease lasted longer.

While antibiotics can now effectively combat the plague, the research could shed light on how other pandemics might develop, the Daily Mail points out.

"This allows us to get a complete picture of how pathogens can adapt to different situations," explains Pizarro-Cerda.

"We finally have a better understanding of what plague is and how we can develop measures to protect ourselves," he added.