Bubonic plague is an infection spread mostly to humans by infected fleas that travel on rodents. Called the Black Death, it killed millions of Europeans during the Middle Ages. Prevention doesn’t include a vaccine, but does involve reducing your exposure to mice, rats, squirrels and other animals that may be infected.
Plague is an infectious disease caused by a specific type of bacterium called Yersinia pestis. Y. pestis can affect humans and animals and is spread mainly by fleas. Bubonic plague is one type of plague. It gets its name from the swollen lymph nodes (buboes) caused by the disease. The nodes in the armpit, groin and neck can become as large as eggs and can ooze pus.
The other types of plague are:
Yes. Bubonic plague deaths exceeded 25 million people during the fourteenth century. This was about two-thirds of the population in Europe at the time. Rats traveled on ships and brought fleas and plague with them. Because most people who got the plague died, and many often had blackened tissue due to gangrene, bubonic plague was called the Black Death. A cure for bubonic plague wasn’t available.
There have been other episodes of bubonic plague in world history apart from the Black Death years (1346-1353). Bubonic plague still occurs throughout the world and in the U.S., with cases in Africa, Asia, South America and the western areas of North America. About seven cases of plague happen in the U.S. every year on average. Half of the U.S. cases involve people aged 12 to 45 years.
In the U.S., most plague cases in people happen in two areas: Northern New Mexico, northern Arizona and southern Colorado, and another area involving California, southern Oregon and western Nevada.
Bubonic plague symptoms include:
Symptoms of septicemic plague may include blackened tissue from gangrene, often involving the fingers or toes, or unusual bleeding. People with pneumonic plague may have additional trouble breathing and may cough up blood. Sometimes there are symptoms like nausea or vomiting.
Bubonic plague is a type of infection caused by the Yersinia pestis (Y. pestis) bacterium which is spread mostly by fleas on rodents and other animals. Humans who are bitten by the fleas then can come down with plague. It’s an example of a disease that can spread between animals and people (a zoonotic disease).
It can be noted that cats in particular are vulnerable to plague and can be infected by eating sick rodents. These cats can pass droplets infected with plague to their owners or to the veterinarians that treat them.
Person-to-person spread is unlikely, except in rare cases of someone who has pneumonic plague (infected lungs) spreading plague through droplets sprayed into the air. In other rare cases, people have been infected with pneumonic plague by their dogs or cats.
To diagnose bubonic plague, your healthcare provider will order blood or tissue sample tests. The samples will be sent to the lab for testing to see if Y. pestis is present.
The bubonic plague can be treated and cured with antibiotics. If you are diagnosed with bubonic plague, you’ll be hospitalized and given antibiotics. In some cases, you may be put into an isolation unit.
Antibiotics that treat bubonic plague include:
Bubonic plague can be fatal if it’s not treated. It can create infection throughout the body (septicemic plague) and / or infect your lungs (pneumonic plague.) Without treatment, septicemic plague and pneumonic plague are both fatal.
You can take the following steps to prevent bubonic plague:
In the U.S., there is currently no bubonic plague vaccine. In other locations, a vaccine is available only to people who have a high exposure to the plague because of their jobs.
If you’ve had bubonic plague and been treated for it, your outlook is very good. Symptoms usually develop two to six days after exposure. The best recovery happens if you are treated within 24 hours of developing symptoms. You’ll probably feel better after one to two weeks. However, untreated bubonic plague can be fatal.
If you develop symptoms of plague, such as high fever, pain and swollen lymph nodes, you should contact your healthcare provider. This is especially true if you have been exposed to flea bites. This is also true in the rare case that you have been exposed to someone who has bubonic plague.
A note from Cleveland Clinic
Bubonic plague may seem like a part of the past, but it still exists today in the world and in rural areas of the U.S. The best way to prevent getting plague is to avoid the fleas that live on rodents such as rats, mice and squirrels. The fleas can also live on chipmunks and rabbits. Take care to protect your pets and yourself from fleas and the possible infections they can carry. Make sure to contact your healthcare provider if you develop high fever, chills and especially symptoms like swollen and painful lymph nodes.
Last reviewed by a Cleveland Clinic medical professional on 06/17/2021.
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