Friday, May 10, 2013

The Plague of Justinian

In 541 AD, eight centuries before the Black Death, a deadly infectious disease hit the Byzantine Empire, reaching Constantinople in 542 and North Africa, Italy, Spain, and the French-German border by winter 543. The so called “Plague of Justinian”, named after the contemporaneous emperor, led to mass mortality in Europe similar to that of the Black Death. It persisted in the territory of the Roman Empire until the middle of the 8th century and likely contributed to its decline, shaping the end of antiquity.

Based on historic records it had been assumed this Justinian plague was similar to the bubonic plague that struck Europe eight centuries later. However, some discrepancies between historical accounts and the progression of infections with the bacterium that causes the plague (Yersinia pestis) caused considerable debate among scientists about whether it is the same disease or a completely different infection. This was further complicated by the fact that the origin of the disease was unknown, although it is thought to have arrived from Egypt through trade ships.

A new study now confirmed unambiguously that Yersinia pestis was indeed the causing agend of this first pandemic. The researchers used ancient DNA analyses on samples obtained from an early medieval cemetery in Achheim in Bavaria, Germany. By using both quantitative Real-Time PCR and a conventional PCR approach they amplified and sequenced a 70 bp portion and a 133 bp fragment of the Yersinia pestis-specific plasminogen activator gene (pla). This gene, which is specific to Yersinia pestis, has been used in previous studies to test samples from plague skeletons dating to the time of the Black Death. The group was also able track down the origins of this plague. As for the second and third pandemic, the original sources of the bacillus were in Asia.

The question remains if at Justinian times only one strain or several were introduced to Europe. The latter was the case for the Black Death in the 14th century. 

Amazing what a couple of bones are able to tell us more than 1400 years after they were buried.

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