What is plague?
Plague is a disease caused by the bacteria, Yersinia pestis and is carried by fleas that feed on infected rodents. Plague is rare in the United States and occurs most often in the Southwest during summer months.
What is the mortality rate of plague?
About 14% (1 in 7) of all plague cases in the United States are fatal. Reportedly, about 50-60% of bubonic plague patients who fail to receive any antibiotic treatment die. Untreated septicemic or pneumonic plague is almost always fatal.
What are the symptoms?
The typical symptoms of the most common form of human plague is a swollen and very tender lymph gland, called a "bubo" (hence the term "bubonic plague"). Buboes can appear in the groin, armpit or neck region and may be accompanied by fever, chills, headache, or extreme exhaustion. When bubonic plague is left untreated, the plague bacteria can invade the bloodstream and spread rapidly throughout the body causing a severe and often fatal condition called septicemic plague. Infection of the lungs with the plague bacterium causes pneumonic plague, a less common but much more dangerous form of the disease, characterized by high fever, cough, bloody sputum and difficulty in breathing.
How is plague spread?
Usually by bites from fleas that are infected with the plague bacterium although smaller numbers of cases occur following direct contact with infectious body fluids or inhalation of infectious respiratory droplets.
Who gets plague?
Anyone can get plague. However, people in occupations such as laboratory, geology or biology may have more contact with infected rodents and fleas and therefore are at greatest risk. Any person who is exposed to the bites of infected fleas, handling infected animals or exposed to persons or animals with plague pneumonia and a cough are at risk for acquiring plague.
What is the incubation period for plague?
A person usually becomes ill with bubonic plague 2 to 6 days after being infected. The incubation period for pneumonic plague cases acquired by inhalation is usually about 2 days.
How is it diagnosed?
Diagnosis of plague is made by laboratory tests that look for the bacteria in specimens such as blood and spinal fluid.
How is plague treated?
According to treatment experts, a patient diagnosed with suspected plague should be hospitalized and medically isolated. Laboratory tests should be done, including blood cultures for plague bacteria and microscopic examination of lymph gland, blood, and sputum samples. Antibiotic treatment should begin as soon as possible after laboratory specimens are taken.
How can you prevent plague?
To avoid becoming infected with plague, follow these important guidelines:
Avoid unnecessary contact with animals such as mice, rats, prairie dogs and squirrels, and use protective gloves if handling is necessary.
Prevent rodent access to food and shelter by ensuring appropriate storage and disposal of food, garbage, and refuse.
Use an appropriate insect (flea) repellent while camping in rural areas where plague is common, and report dead or sick animals to park rangers or public health authorities.
Provide flea treatments for your pets, especially in areas where plague is present.
Wear gloves when handling animal carcasses.
Where can I get more information?
This fact sheet is for information only and is not intended for self-diagnosis or as a substitute for consultation. If you have any questions about the disease described above or think that you may have an infection, consult with your healthcare provider.