The pneumonic plague can be transmitted directly from person to person. This airborne version of the plague occurs when the temperature drops suddenly, and the virus invades the victim's lungs. After a two to three day incubation period 95 - 100 percent afflicted are killed.
Similar to bubonic plague, septicaemic plague is carried by fleas, which enters the blood stream directly and kills within a day. This type of plague is always fatal, but is very rare.
There are peculiar environmental conditions that determine the presence and virulence of plague epidemics. First, there are factors of insect and rodent ecology. It is carried on a flea, Y. pestis that enters the digestive system of a human. This flea routinely lives on rats, then moving to other host populations such as dogs, horses, and ultimately humans.
This traveling among host populations ensures that the plague will reoccur among humans every generation.
In this new peace traders traveled across Europe and into Russia, Iberia, and Palestine. Middle East tradesman functioned as intermediaries between China and India, and the Byzantine Empire. The Empire acted as a gate into Western Europe. Indeed, prior to the coming of the Mongol Empire, a vast system of trade through multiple partners developed. A good, leaving China, would travel through Middle Eastern middle-men, through the Byzantine Empire, and into Europe -- by sea, or land.
With the establishment of a host population, the plague was ready to spread. Established in the late 12th century by Genghis Kahn, and still powerful in the 14th century, the Mongol Empire was crucial because it served as a link between less mobile Eurasian societies in China, India, the Middle East, and Europe. This military success secured the overland trade routes, which were patrolled by Mongol horsemen. This encouraged extended communication between all major civilizations of the time. With the travelers, of course, were the rats and fleas carrying the Black Death.
There were three arteries of trade
that spread the Black Death; all ended in Italy. The first was an
overland path through northern China and across central Asia to the trading
ports on the Black Sea's northern coast. This route was traveled
primarily by caravans, protected and enforced by the Mongol Peace. The
second path was primarily by sea, and was intricately tied to the lucrative
spice trade of South Asia. Ships sailed west across the Indian Ocean,
into the Persian Gulf, whereby goods were then transported by caravan across
the northern Arabian peninsula to the Eastern Mediterranean Coast.
The third route was also primarily by sea and originated in South Asia.
Goods were carried across the Indian Ocean, around the Southern Arabian
Peninsula, past Yemen, and into the Red Sea. There, they were taken
overland to Gaza, or the ports of the Nile Delta.
The principle ports receiving these goods in Europe were the important Italian ports of Pisa and Genoa. Genoa was hit in late 1347, and Pisa in 1348. There was a thirty to forty percent loss of population in both cities -- unheard of at the time. Reactions to the plague ranged form severe drinking, reveling, and spending money, to abandoning children, leaving husbands and wives, and forsaking infected victims. Spreading upon the existing trade routes, supported by the old Roman Empire infrastructure, the Black Death carried on as people tried to live their everyday lives.
Moving on these internal routes, the Plague hit Paris in 1348, confusing all medical doctors at the Sorbonne. This deficiency in medical treatment prompted a new generation of medical practitioners to treat victims with new methods and new attitudes. Gone were the blood lettings, vomiting, and medieval medical practices, replaced by innovative surgery, hospital care, and sanitation reform. Confusing the job of these new doctors were religious practices of the day. Communal mourning rights promoted the spread of a disease most effectively combated by quarantine. Puzzled, communities and doctors continually suffered the plague, despite their efforts.
Crossing the channel, the plague struck England in Augurs of 1348. The geography of England provides a useful case study of plague development. England, being ninety percent rural did not experience the devastating casualties associated with plague infection, although their port towns did suffer similar percentage losses in population. This stark contrast is due to the living quarters within cities. Close-quatered, tightly packed housing complexes, lining streets filled with waste and garbage, only served to multiply the infection rates among the populations of the city. Therefore, England with its rural villages of no more than 1,000 people, was spared the death associated with garbage, overcrowding, and poor sanitation.
Running through Flanders and the Benelux countries, the plague moved into Germany. Germany too was spared the plague's devastating horrors. Among down the Rhine Valley from France, and over the Alps from Italy, the plague invaded Germany. Germany fought back like no other country before it. In Alsace-Lorraine and Bohemia, mortality was only about ten percent -- the lowest death toll of any major cities in the Western World. German cities, like Nuremberg, were fortunate do to their noteworthy system of public health. The streets were paved and regularly cleaned, trash and garbage could not be dumped in the streets, pigs were not allowed to roam in the city, and personal cleanliness was held in high regard. Obviously these unusual methods fought the poor sanitation and overcrowding responsible for so many Black Death associated deaths.
Ironically, the scourge of the Black Death ended where it began; in the central plains of Asia. Coming to Europe from the south central plains, it ended up however, in the northern plains. Russia avoided the plague because its trade routes entering the northern reaches came from the East, not West. Thus, as the Plague moved on trade routes through the mountains and plains of Hungary and Bohemia, it entered Russia sometime around 1351.
Fittingly, the plague ended where it began, but not before it killed twenty-five to fifty percent of Europe's population from 1347 to 1351, accelerating political, economic, social, and cultural changes. Truly though, the plague did not end here. Returning to Europe every twenty to thirty years for the next three centuries, the plague still hauntingly strikes us today. The outbreaks in 1918 and others, show the durability of this disease, a disease spread by environment, geography and human interaction.
Composed by Brendon S. Clark and Charles J. Dittrich