1. Bubonic Plague:
- Bubonic plague was the most common form and was transmitted primarily through the bites of infected fleas. The bacterium entered the body through a flea bite and traveled to the lymph nodes, causing swelling and inflammation. These swollen lymph nodes, known as buboes, were typically found in the groin, armpits, or neck.
- Symptoms included fever, chills, headaches, muscle aches, weakness, and the formation of buboes. The buboes would often become painful, suppurate, and rupture.
- If left untreated, bubonic plague could progress to septicemic or pneumonic plague, both of which were often fatal.
2. Pneumonic Plague:
- Pneumonic plague was a more severe and contagious form of the disease. It was transmitted through the inhalation of infected droplets expelled by an infected person.
- Symptoms included fever, chills, cough, shortness of breath, chest pain, and difficulty breathing. The cough could produce blood-tinged sputum.
- Pneumonic plague spread rapidly and was highly fatal, with a mortality rate close to 100% if left untreated.
3. Septicemic Plague:
- Septicemic plague was the least common form of the disease and was characterized by the presence of bacteria in the bloodstream. It could develop from either bubonic or pneumonic plague.
- Symptoms included high fever, chills, skin discoloration (often turning black, hence the name "Black Death"), bleeding, and organ failure.
- Septicemic plague affected multiple organ systems and had an extremely high mortality rate.