The pneumonic plague, less common though more contagious than bubonic, is contracted by having someone with any form of the plague breathe on you. Literally. One contracts the pneumonic plague by inhaling airborne droplets coughed up by other carriers of the black death.
Sputum is a mixture of saliva and mucus excreted by the respiratory system to prevent itself drying out from the near constant exposure to open air that it endures. A victim of the pneumonic plague will cough up slimy, blood-tinged sputum. After a few days, the increasingly bloody sputum will flow freely.
The symptoms take from 1-7 days from contraction, as does death. Mortality rate untreated is about 95%, and about 10% if treated with modern medicine.
