Scientists to resurrect 'Black Death' bacteria in lab

The Black Death has long captured the imagination of historians and storytellers since it ravaged Europe in the middle of the 14th century. Historians long believed that the estimates of mortality for the Black Death which ranged as high as one-third to one-half the population of Europe were once badly exaggerated. However, modern medical research has revealed those estimates were probably too low.

LOS ANGELES, CA (Catholic Online) - At no point in history has such a virulent disease wiped out so many people. The impact of the disease was so great, that the population of Europe took 300 years to recover. A few very fortunate communities were spared entirely between 1347 and 1351. Except for those isolated pockets, lucky communities were those that lost only a third of their population. In the Russian city of Smolensk, only three people were said to have survived.

In the wake of the disease, peasants and the serfs were so few in number that a major multi-year famine followed the plague. Not because of the weather, which was admittedly quite poor -- the Earth's temperature was cooling at that time. But because there were so few people to work the land. The people were able to revolt and petition their lords for more rights. Needing to spare the lives of their workers, feudal lords had no choice but to relent. The collapse of the feudal system began in earnest following the plague.

The Black Death itself was caused by a bacteria known as Yesinia Pestis. The bacteria made its home in fleas found throughout Central Asia who in turn infested small mammals such as rats. Rats carrying infected fleas presumably arrived in Sicily and Italy in 1347. After the rats disembarked merchant ships, likely from the Black Sea, they made their way into the cities and the fleas found new human hosts on which to feed.

Biting humans, the fleas transferred the bacteria to the bloodstream where it rapidly spread. Victims first complained of flu-like symptoms, quickly followed by the swelling of lymph nodes. These lymph nodes swelled anywhere from the size of a walnut to an apple. Swollen with blood, pus, and bacteria, these were the "buboes" which gave the bubonic plague its name. Bleeding beneath the skin led to widespread bruising, which gave the disease it's more popular name of, "the Black Death."  The period between the original bite and death was typically less than a week. Worse, during the last stages of the disease, bacteria would settle in the victim's lungs. As the victim coughed violently, droplets of saliva and blood were often inhaled by caregivers. Victims who inhaled these bacteria were typically dead within 24 hours.

Eventually, by 1354 the disease had "burned" itself out. During the time, many people believed the end of the world was nigh. Others argued that the Black Death was caused by Jews who organized and conspired to kill Christians. Observers often noted that Jewish communities tended to be spared the worst of the plague while Christian communities suffered the full force. Widespread persecution of Jewish communities typically occurred following the plague.

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Deciphering why the plague was so deadly has been an important question that modern researchers want to answer. Sanitation figures prominently. For example, Jewish communities tended to be much cleaner than others which meant their homes were less infested with rats, fleas, and lice, all which carried and transmitted the disease.

The shocking poverty, poor nutrition, and squalor all served to exacerbate the impact of the disease. But in addition to those factors, scientists believe the genetic makeup of the bacteria is also largely responsible for its virulence. Researchers in England recovered DNA from the teeth of four plague victims in London. Using that DNA, they were able to break down its genome. The bacterium's genome is made of a single chromosome and is approximately 4.6 million DNA units long. When compared to modern living samples of the bacteria, they found that the disease has hardly changed over the course of nearly 700 years.

Researchers intend to study the DNA units in great detail. They already suspect that the nature of those units, particularly their sequence, has much to do with why the disease was so contagious and deadly.

Scientists plan to re-create the original disease using their carefully recovered DNA samples. The research will have to be conducted in a special laboratory that prevents risk of outside contamination. However, researchers point out that even if the disease were to escape the lab, which is extraordinarily unlikely, it could easily be treated today using antibiotics, something they didn't have in the 14th century.

They also point out one other significant protective factor -- sanitation.

The research is expected to take several years but should help scientists and historians to unravel the final mysteries of the long-storied Black death.

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