Education Corner

Pneumonic plague is a type of plague and a serious infectious disease caused by the bacterium Yersinia pestis. If not treated promptly, it can be fatal. Pneumonic plague is particularly dangerous because it can spread from person to person.

What is plague?

Plague mainly occurs in three forms: pneumonic plague, bubonic plague and septicaemic plague.

• Pneumonic plague: The bacteria infect the lungs. It is the most severe form and can spread from person to person through respiratory droplets from an infected patient.

• Bubonic plague: The most common form. Bacteria enter the body through a flea bite, causing painful swelling of the lymph nodes.

• Septicaemic plague: The bacteria enter the bloodstream and spread to other organs, potentially causing serious complications.

The main routes of transmission are exposure to respiratory droplets from a person with pneumonic plague, bites from infected fleas carried by infected animals—especially rodents such as rats—and direct contact of broken skin with the body fluids or tissues of infected animals.

Common symptoms

The incubation period for pneumonic plague is generally 1 to 4 days, while the other two forms are generally 1 to 7 days.

What to do if you suspect infection?

If you have recently travelled to an area where plague is endemic, had contact with rats or wild rodents, or been bitten by fleas, and you develop sudden fever, swollen lymph nodes, coughing up blood or difficulty breathing, seek medical attention immediately. Tell the doctor about your travel history, contact with animals and any possible flea bites.

• Do not take antibiotics on your own or delay seeking medical care.

• If you have a cough, are coughing up blood or have difficulty breathing, wear a mask as much as possible and avoid close contact with others.

• Healthcare professionals will arrange testing, isolation and treatment according to the clinical situation. Patients with pneumonic plague are highly infectious, so strict precautions are required.

How is plague treated?

Patients with plague must be isolated and receive appropriate antibiotic treatment as early as possible.

Early treatment is crucial. Pneumonic plague is usually fatal if not treated promptly, while untreated bubonic plague has a fatality rate of approximately 30% to 60%. If you develop possible symptoms, seek medical care as soon as possible and do not wait for symptoms to resolve on their own.

Can plague be prevented by vaccination?

There is currently no widely available preventive vaccine for plague. In addition to preventing flea bites and avoiding contact with wild rodents, everyday preventive measures are especially important.

For pneumonic plague in particular, prevention focuses on personal hygiene, wearing masks and avoiding close contact with infected patients. Pneumonic plague can spread through respiratory droplets within 2 metres, so avoid close contact with people who have respiratory symptoms such as fever, coughing or coughing up blood.

• Wear a mask correctly: Wear a medical mask properly in crowded or poorly ventilated places, or in high-risk and potentially affected areas, to reduce the risk of inhaling respiratory droplets and spreading infection.

• Wash hands frequently: Wash hands thoroughly with soap and water, especially after coughing or sneezing, touching public facilities or animals, and handling rubbish.

• Avoid touching your eyes, ears, nose and mouth: Before thoroughly washing your hands, avoid touching your eyes, ears, nose and mouth to reduce the risk of bacteria entering the body through mucous membranes.

• Maintain household cleanliness: Clean your home regularly, dispose of rubbish and store food properly, and keep the environment dry and hygienic to reduce the chance of rats and fleas breeding.

• Prevent flea bites: When travelling to areas where plague is endemic or to outdoor areas, wear long-sleeved clothing and long trousers, and apply insect repellent containing DEET to exposed skin and clothing.

• Avoid contact with rats and wild animals: Do not touch, handle or eat wild animals or their carcasses. If you find an animal carcass, notify the local health or relevant authority for proper handling.

Pneumonic plague progresses rapidly. Early treatment with appropriate antibiotics can greatly reduce the risk of death. People who have had close contact with a pneumonic plague patient should also follow medical advice for medical observation or preventive treatment. If you have any symptoms that suggest possible plague infection, seek medical attention as early as possible. Do not self-medicate or delay treatment.