Pneumonic plague

Pneumonic plague

is one of the three main forms of plague, all characterized by the bacterium Yersinia pestis. It is rare and virulent bubonic plague. The difference between the versions of the plague is the site of infection. Pneumonic plague is an infection of the lung (s), bubonic plague is an infection of the lymph nodes or bubo, and septicemic plague is an infection in the blood.

Typically, pneumonic form is secondary to the spread of infection to a first bubonic. Primary pneumonic plague results from inhalation of infectious droplets and can be transmitted from human to human without involvement of fleas or animals. N. pneumonic plague has a very high mortality rate.