Pneumonic plague: questions and answers

Plague is a bacterial infection caused by Yersinia pestis. The bacteria live in small mammals such as marmots, ground squirrels and rats, and in their fleas.

Bubonic plague is the most common form. It usually follows a flea bite and causes painful, swollen lymph nodes. Pneumonic plague affects the lungs. It is the most serious form and the only one that can spread from person to person, through respiratory droplets during close contact.

Through bites of infected fleas, through direct contact with infected animal tissue (for example when skinning a marmot), and, for pneumonic plague, by breathing in droplets from an infected person or animal.

Sudden fever, chills, headache, body aches and weakness. Pneumonic plague also causes cough, chest pain, fast breathing and sometimes bloody sputum. Symptoms usually start within a few days of exposure; for pneumonic plague the interval can be as short as one day.

Yes. Common antibiotics are effective when treatment starts early. Untreated pneumonic plague is almost always fatal, so anyone with symptoms after possible exposure should seek medical care immediately.

Health authorities usually trace close contacts, monitor them and may give preventive antibiotics.

Russia has natural plague foci where the bacteria circulate among wild animals, including in the Altai Republic, Tuva, the North Caucasus, the Caspian lowland and Transbaikalia. Human cases are rare.

Public health experts have described the current risk to the public as low. Travellers to known plague areas should avoid contact with rodents and dead animals, use insect repellent and seek care quickly if they develop fever.