The Black Death

What causes the Plague?

Black Death plague caused by a bacterium called Yersinia pestis.Fleas become infectedInfected fleas transmit yersinia pestis using rats as hosts, feeding on the rodents' blood . Many rats die during a plague outbreak.Fleas then jump to other animals and humans, carrying the infection with them.

Electron micrograph image

Background to the Black Death

Europe was in a mini ice age by the early 1300’s.Unusual weather - heavy rains -1315 and 1319 Grain crops across Europe were devastated. Widespread starvation occurred across Europe many died or suffered from famine

Origins in ChinaThe Bubonic plague was first noted in China c. 1331. Within 15 years it had spread across Asia to the Black Sea.

The Black Death in Europe

Three Types of Plague

There are Three types of plague: bubonic, pneumonic and septicemic.

Signs and symptoms of plague vary.

Possible to develop more than one type of plague.

Bubonic Plague • Bubonic plague is

most common type of plague in humans,.

• Caused by a bite from an infected flea

• Characterized by an enlarged, infected lymph node called a bubo.

Bubonic plague cont’dSigns and symptoms generally appear within two to six

days after being bitten by a plague-infected flea. Bacteria travel through the 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. Very painful and often people cannot move the affected

part of the body. Bubo usually develops in the groin, but may also appear

in armpit or neck, depending on where the flea bites. More than one bubo can develop, but usually buboes

affect only one area of the body.

Pneumonic Plague

Pneumonic plague is the least common form of plague.Most rapidly fatal. From inhaling infectious droplets coughed into the air by infected a person or animal. 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

Pneumonic Plague

Pneumonic plague progresses rapidly and may cause respiratory failure and shock within two days of infection. Also a complication of bubonic or septicemic plague, if the bacteria spreads to lungs.

Septicemic PlagueSepticemic plague occurs when plague bacteria multiply in your bloodstream.Contracting this form of plague by bacteria entering directly into bloodstream.Also transmitted by a fleabite.Can be a complication of bubonic or pneumonic plague.

Septicemic PlagueSigns and symptoms of septicemic plague include:•Fever and chills•Extreme exhaustion•Abdominal pain, diarrhea and vomiting•Bleeding from mouth, nose or rectum, or under the skin and into other organs•Shock•Blackening and death of tissue (gangrene) in extremities, most commonly fingers, toes and noseThe 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.

Blackening and death of tissue

Effects of Black Death

• 20 million to 30 million deaths in Europe.

• Roughly 1/3 of the population died.• In England, 1.5 million people died out

of 4 million)• The Black Death caused such a

shortage of labour that over the next 100 years many peasants found that they could earn more and their living standards improved.

• With credits to: Jim Nash