Plague

Alternative names

Bubonic plague; Pneumonic plague; Septicemic plague

Definition

Plague is an infection caused by the organism Yersinia pestis. It is carried by wild rodents and transmitted to humans.

Causes, incidence, and risk factors

Plague is transmitted among rodents and to humans by flea bite or ingestion of the feces of fleas. It can also be transmitted from human to human when a plague victim develops pneumonia and spreads infected droplets by coughing. An epidemic may be started this way.

Plague is rare in the United States, but areas where the disease is known to occur include parts of California, Utah, Arizona, Nevada, and New Mexico.

There are two types of plague, bubonic and pneumonic. The incubation period is 2 to 10 days but may be as short as a few hours for pneumonic plague.

Risk factors for plague include a recent flea bite; and occupational or environmental exposure to rodents (especially rabbits, squirrels, or prairie dogs; or scratches or bites from infected domestic cats).

Symptoms

BUBONIC PLAGUE

• Sudden onset of high fever
  
• Chills
  
• General discomfort, uneasiness, or ill feeling (malaise)
  
• Muscular pains
  
• Severe headache
  
• Smooth, oval, reddened, painful swellings of swollen lymph glands called buboes in the groin, armpits, neck, or elsewhere in the body. Pain may occur in the area before the swelling; the most common area is in the groin
  
• Seizures
  

PNEUMONIC PLAGUE

• Severe cough
  
• Frothy, bloody sputum
  
• Difficulty breathing
  

SEPTICEMIC PLAGUE

• Fever
  
• Extreme illness
  
• Nausea, vomiting, diarrhea, and abdominal pain
  
• Low blood pressure
  
• Blood clotting problems
  
• Failure of several or all organ systems
  

Signs and tests
These tests may indicate a plague infection: