What are the transmission routes of plague?
Dec 03, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
Transmission routes of plague generally include flea bite transmission, direct contact transmission, respiratory droplet transmission, gastrointestinal transmission, and laboratory infection transmission. After fleas feed on the blood of infected animals, they can transmit Yersinia pestis to healthy individuals through subsequent bites. This is the primary mode of plague transmission, and the risk of transmission significantly increases in plague-endemic areas when flea density is high.
Transmission routes of plague generally include flea bites, direct contact, respiratory droplets, gastrointestinal transmission, and laboratory infection. The details are as follows:
1. Flea bite transmission: When fleas feed on the blood of infected animals and then bite healthy individuals, they inject *Yersinia pestis* bacteria into the human body. This is the primary mode of plague transmission, especially in plague-endemic areas where high flea density increases transmission risk.
2. Direct contact transmission: Pathogens can enter the body through skin wounds or mucous membranes when handling carcasses or tissues of infected animals or coming into contact with pus or sputum from patients. Hunting and consuming animals such as marmots are common routes of infection.
3. Respiratory droplet transmission: Inhalation of infectious droplets expelled when patients with pneumonic plague cough or sneeze can lead to infection. This mode spreads rapidly and may cause widespread outbreaks among populations, necessitating strict isolation of infected individuals.
4. Gastrointestinal transmission: Consuming undercooked meat from infected animals or drinking contaminated water allows pathogens to enter the body via the digestive tract. This type of transmission commonly occurs among residents in epidemic areas with poor hygiene conditions.
5. Laboratory infection transmission: Infections may occur during plague research or diagnostic procedures due to failure to follow safety protocols, pathogen leakage, or inadequate protective measures. Although rare, such incidents can have severe consequences, highlighting the need for strengthened laboratory management.
To prevent plague, avoid contact with infected animals, refrain from hunting or consuming wild animals, maintain clean living environments, and implement flea and rodent control. Seek prompt medical attention if symptoms such as fever or swollen lymph nodes develop, and individuals in affected areas should cooperate with epidemiological investigations and public health control measures.
