Plague
causitive agent: bacterium Yersinia pestis
What is the Plague?
Plague is a deadly infectious disease that is caused by the enterobacteria, Yersinia pestis, named after the French-Swiss bacteriologist Alexandre Yersin. Plague can be spread in the air, by direct contact, or by contaminated undercooked food or materials. There are different types of plague that effect different areas. These are the bubonic plauge in lymph nodes, septicemic plague in blood vessels, pneumonic plague in lungs, etc.
How is the Plague diagnosed?
Health care workers can diagnose plague by doing laboratory tests on sputum, blood, spinal fluid, or infected lymph nodes.
How is the Plague transmitted?
The plague is spread from bites from infected insects or rodents (unlikely). It can also be transmitted through tissues of infected animals. Though rare, plague can also be passed between humans.
Who's most likely to be affected by this disease?
People in poor, unsanitary, overpopulated communities are more likely to be infected with it because of rats and fleas and how quickly it can be passed around. Also, people in Europe or any third world country are more likely to get it because that's where it originally started.
What are the possible complications of the Plague?
Gangrene
Blood clots in the tiny blood vessels of your fingers and toes can disrupt the flow of blood and cause that tissue to die. The portions of your fingers and toes that have died may need to be amputated.
Meningitis
Inflammation of the membranes surrounding your brain and spinal cord.
Death
Most people who receive prompt antibiotic treatment survive plague. Untreated plague has a high fatality rate.
Course of disease
Bubonic plague infects your lymphatic system (immune system), causing inflammation. Untreated, it can move into the blood and cause septicemic plague, or to the lungs, causing pneumonic plague. When the bacteria multiply in the lungs, you have pneumonic plague—the most serious form of the disease. When a person with pneumonic plague coughs, the bacteria from their lungs are expelled into the air. Other people who breathe that air can also develop this highly contagious form of plague, which can lead to an epidemic. When the bacteria multiply in the bloodstream, it is called septicemic plague. When untreated, both bubonic and pneumonic plague can lead to septicemic plague.