infections
Plague and Other Yersinia Infections
Transmission of plague
The bacteria that cause plague usually infect wild rodents, such as rats, mice, squirrels and prairie dogs. The bacteria are spread by the rat flea. When wild rodents die, the fleas may move to rodents that live close to people, then to household pets, especially cats. The rat fleas may then bite people and transmit infection. People may also become infected through a break in their skin if they have direct contact with an infected animal. Rarely, the infection is spread from person to person by inhaling droplets dispersed by coughing or sneezing. The bacteria lodge in the lungs and cause a type of Overview of Pneumonia (pneumonic plague). Spread between people usually happens only when people live with or care for a person with pneumonic plague. Plague bacteria are a potential Biological Weapons . The bacteria can be spread through the air and inhaled. The size of the airborne particle determines where the bacteria lodge in the respiratory tract. Small particles lodge in the lungs, causing pneumonic plague. Larger particles lodge in the throat (pharynx) and cause plague of the throat (pharyngeal plague). 