How is plague transmitted?
Sep 16, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
Under normal circumstances, plague can be transmitted through various routes, primarily including flea bites, direct contact, droplet transmission, transmission via the digestive tract, and laboratory infections. In addition, people should take personal protective measures in daily life, avoid contact with animals that may carry Yersinia pestis, and regularly clean and disinfect their living environments.
Generally, plague can be transmitted through various routes, mainly including flea bites, direct contact transmission, droplet transmission, gastrointestinal transmission, and laboratory infection transmission. The specific analysis is as follows:
1. Transmission via flea bites
Fleas are important vectors of plague, commonly including Xenopsylla cheopis and Pulex irritans. When fleas bite rodents infected with plague, Yersinia pestis multiplies extensively within the flea. When the flea bites a human, Yersinia pestis enters the human body through the flea's saliva, causing infection. This is a primary route of plague transmission.
2. Direct contact transmission
If humans directly contact the carcasses of animals infected with plague, or their secretions or excretions, Yersinia pestis can invade the human body through wounds in the skin. For example, when handling sick or dead rodents, if the skin is damaged and proper protective measures are not taken, exposure to Yersinia pestis may occur, leading to infection.
3. Droplet transmission
When plague patients are in the stage of pneumonic plague, their respiratory secretions contain large amounts of Yersinia pestis. When patients cough, sneeze, or speak, they may expel droplets containing the bacteria. Healthy individuals who inhale these droplets may become infected as Yersinia pestis enters the respiratory tract. This mode of transmission can easily cause outbreaks in crowded places.
4. Gastrointestinal transmission
If humans consume undercooked meat from animals infected with plague, Yersinia pestis can enter the body through the digestive tract, causing infection. This is because undercooked meat may contain viable Yersinia pestis, which multiplies in the digestive tract and damages the mucous membranes, leading to infection.
5. Laboratory infection transmission
Duing laboratory research on Yersinia pestis, improper handling, such as inadequate protective measures or equipment failure leading to bacterial leakage, may expose staff to Yersinia pestis and result in infection. Although this transmission route is uncommon, it poses a certain risk to laboratory personnel.
In addition, people should pay attention to personal protection in daily life, avoid contact with animals that may carry Yersinia pestis, and regularly clean and disinfect their living environment.
