Bubonic Plague: A Rare but Still Existent Disease

Upset or having head ache woman lying with hand on forehead and closed eyes.
Svetikd/E+/Getty Images

The headlines were gripping: two people were hospitalized in New York City in November 2002 with bubonic plague. Many people are familiar with bubonic plague as "Black Death," the epidemic that killed millions of Europeans in the Middle Ages. Therefore after the news broke, the New York City health commissioner had to reassure New Yorkers that no plague epidemic was occurring and that the disease would not be spread from person to person.

What Is Bubonic Plague?

Bubonic plague is a potentially fatal bacterial infection called "Yersina pestis." Symptoms of infection include:

  • swollen, tender lymph nodes (called "buboes")
  • high fever
  • chills
  • headache
  • hemorrhages under the skin, causing blackish discoloration of the skin

The infected person may develop serious illnesses, such as pneumonia, blood poisoning (sepsis), or meningitis.

How Is Bubonic Plague Spread?

Bubonic plague is not usually spread from person to person. Small rodents, such as rats, mice, and squirrels, carry the infection. Fleas that live on these animals act as "vectors" and carry the infection from the rodent to humans. People may be exposed to the bacteria through flea bites or from direct contact with an infected animal.

During the "Black Death," many people became sick with pneumonia from Yersinia pestis (called "pneumonic plague") and spread the disease bacteria to each other by coughing and sneezing.

Does Bubonic Plague Still Occur Throughout the World?

According to the World Health Organization, there are 1,000 to 3,000 cases of bubonic plague worldwide each year. There are no known cases in Australia or Europe. Areas where cases occur are in Russia, the Middle East, China, Southwest and Southeast Asia, Madagascar, southern and eastern Africa, the Andes mountains, and Brazil.

The U.S. Centers for Disease Control and Prevention (CDC) reports that there are 10 to 15 cases of bubonic plague in the United States each year. These cases tend to occur in two regions: northern New Mexico, northern Arizona, and southern Colorado; and California, southern Oregon, and far western Nevada.

How Is Bubonic Plague Treated?

Treatment for bubonic plague should begin as soon as the disease is diagnosed. Antibiotics, such as streptomycin or tetracycline, are given to treat the infection while other medications may be used to manage symptoms. 

There is also a vaccination available for people working in or traveling to plague-affected areas of the world.

Can Bubonic Plague Be Prevented?

The "Black Death" of the Middle Ages was due to large numbers of flea-ridden rats infesting homes and workplaces. In most developed countries, cities and towns have successfully controlled their rat populations, but rural and urban areas of developing countries often have problems with rat infestation, and thus are at risk of bubonic plague epidemics. Therefore, reducing the risk of plague outbreaks in these areas would require:

  • Controlling the rat population
  • Watching for plague cases in both rats and humans in the area
  • Using insecticide to reduce the number of fleas
  • Treating pets for fleas

Using these measures, public health workers and residents can help make areas threatened by bubonic plague safe for the people who live and work there.


"Bubonic Plague." Index of Rare Diseases. National Organization for Rare Disorders.

CDC Plague Home Page." Division of Vector-Borne Infectious Diseases. 11 Dec 2007. Centers for Disease Control and Prevention.

Continue Reading