Pneumonic plague is the least common form of plague. Pneumonic plague is the most contagious form because it can spread from person to person in airborne droplets.

  1. With pneumonic plague, the first signs of illness are fever, headache, weakness, and rapidly developing pneumonia with shortness of breath, chest pain, cough, and sometimes bloody or watery sputum.
  2. The pneumonia progresses for 2 to 4 days and may cause respiratory failure and shock. Without early treatment, patients may die.