The Black Death

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The Black Death
Warning Some images in this PowerPoint are
graphic.
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Europe Before the Black Death

• By the early 1300s Europe was experiencing a
  mini ice age. Unusually heavy rains between 1315
  and 1319 destroyed grain crops across Europe.
  Many Europeans died or were weakened by famine
  (widespread starvation).

Oceanic Conveyor Belt
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What is it?

• Yersinia pestis is the bacterium that causes the
  Black Death plague. Infected fleas transmit
  yersinia pestis primarily among rodents. When a
  plague outbreak among rodents kills many of them,
  infected fleas that were feeding on the rodents'
  blood jump to other animals and humans, carrying
  the infection with them.

Electron micrograph image
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Origins

• Bubonic plague was first seen in China c. 1331
  and in 15 years had spread across Asia to the
  Black Sea.

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The Black Death in Europe
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Types of Plague

• Three types of plague occur bubonic, septicemic
  and pneumonic. Signs and symptoms of plague vary
  depending on the type and on how you contract it.
  It's possible to develop more than one type of
  plague.

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Bubonic plague

• This is the most common type of plague in humans,
  accounting for the majority of naturally
  occurring cases. Bubonic plague is caused by a
  bite from an infected flea and characterized by
  an enlarged, infected lymph node called a bubo.
• Signs and symptoms of bubonic plague generally
  appear within two to six days after a
  plague-infected flea bites you. After you're
  bitten, the bacteria travel through your
  lymphatic system, infecting the first lymph node
  they reach. The resulting bubo is usually 1 to 10
  centimeters in diameter, swollen, painful and
  warm to the touch. It can cause so much pain that
  you can't move the affected part of your body.
  The bubo usually develops in your groin, but may
  also appear in your armpit or neck, depending on
  where the flea bit you. More than one bubo can
  develop, but typically buboes affect only one
  area of your body.

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The following images are graphic
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Septicemic Plague

• Septicemic plague occurs when plague bacteria
  multiply in your bloodstream. You can contract
  this form of plague when bacteria transmitted by
  a fleabite enter directly into your bloodstream,
  or as a complication of bubonic or pneumonic
  plague.

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Septicemic Plague

• Signs and symptoms of septicemic plague include
• Fever and chills
• Extreme exhaustion
• Abdominal pain, diarrhea and vomiting
• Bleeding from your mouth, nose or rectum, or
  under your skin and into other organs
  
• Shock
• Blackening and death of tissue (gangrene) in your
  extremities, most commonly your fingers, toes and
  nose
  
• The gangrene associated with septicemic plague
  inspired the nickname Black Death for the
  14th-century pandemic. Without treatment, death
  can occur within one to three days.

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The following images are graphic
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Pneumonic Plague

• Pneumonic plague is the least common form of
  plague but the most rapidly fatal. Pneumonic
  plague can occur when you inhale infectious
  droplets coughed into the air by a person or
  animal with pneumonic plague. Early signs and
  symptoms, which generally occur within one day to
  four days of inhaling contaminated droplets,
  include
• Sudden onset of fever and chills
• Headache
• Extreme fatigue
• Signs of pneumonia, including chest pain,
  difficulty breathing and a cough with bloody
  sputum
  

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Pneumonic Plague

• You can also develop pneumonic plague as a
  complication of bubonic or septicemic plague, if
  the bacteria spread to your lungs.
  
• Pneumonic plague progresses rapidly and may cause
  respiratory failure and shock within two days of
  infection.

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Effects

• During the years of the Black Death, plague
  caused 20 million to 30 million deaths in Europe.
  Roughly 1/3 of the population died.