Primary route of entry: Inhalation

General signs and symptoms: High fever, chills, headache, coughing up of blood (hemoptysis), and toxemia, progressing rapidly to difficulty in breathing (dyspnea), and bluish discoloration of the skin and mucous membranes (cyanosis).

There is another form of the disease called “bubonic plague”. While it is caused by the same organism, it is not transmissible through human contact. Pneumonic plague is transmissible through human contact.