From io9:
An international team of researchers has discovered that two of the deadliest pandemics in history, the Plague of Justinian and the Black Plague, were caused by strains of the same plague. They warn that mutated — or even bioengineered — versions of the bacteria could lead to future outbreaks.
Above: Pieter Bruegel's The Triumph of Death (c. 1562)
The culprit is Yersinia pestis,
a bacterium that can infect humans and other animals. Scientists now
suspect that separate and independent emergences of this bacterium have
been responsible for some of history's worst pandemics. And it may not
be done yet.
Blight
During
the sixth century AD, this bacterium caused the Plague of Justinian,
killing between 30 and 50 million people — virtually half of the world's
population at the time. It spread across Asia, North Africa, Arabia,
and Europe before mysteriously petering out.
But it would eventually return. Some 800 years later it re-emerged as the Black Death, a blight that killed 50 million Europeans over a four year period from 1347 to 1351 — an astounding figure, to be sure. It's a death rate that averages out to 34,245 mortalities per day.Just as disturbing, a strain of Yersinia pestis appeared in the late 1800s, spreading from Hong Kong to across the globe. Today, thousands of cases of plague are still reported to the World Health Organization each year. But with proper treatment (i.e. antibiotics), prognosis is considerably better than it was in the past....MUCH MORE including a link to "Yersinia pestis and the Plague of Justinian 541—543 AD: a genomic analysis." at The Lancet.
