Plague

Plague is an infectious disease with an infamous past that has affected human history. Because of its contagious nature, plague is a weapon of bioterrorism. Although it is not as common as it once was, outbreaks of plague do occur today. Types of plague include: Plague is treated with isolation and antibiotics.

  • Causes

    Plague is caused by specific bacteria.

    Bubonic and septicemic plagues are spread by bites from infected fleas. Transmission can also occur when a person comes in contact with infected tissue or bodily fluids from another person or animal.

    Pneumonic plague is spread by droplets in the air when an infected person coughs or sneezes. The disease is transmitted to another person when the droplets are inhaled. Transmission by droplets is the only way pneumonic plague spreads among people.

    Pneumonic Plague Transmission
    Droplets from an infected person are inhaled into the lungs.
    Copyright © Nucleus Medical Media, Inc.

  • Definition

    Plague is an infectious disease with an infamous past that has affected human history. Because of its contagious nature, plague is a weapon of bioterrorism. Although it is not as common as it once was, outbreaks of plague do occur today.

    Types of plague include:

    • Pneumonic—in the lungs, from breathing in droplets or as a progression of another type
    • Bubonic—in the lymph nodes, occurring after a flea bite
    • Septicemic—a body system-wide infection, occurring after a flea bite

    Plague is treated with isolation and antibiotics.

  • Diagnosis

    The doctor will ask about your symptoms and medical history. A physical exam will be done. Your doctor may ask about the possible source of exposure.

    Test may include:

    • Blood tests to look for indications of an infection
    • Blood test to detect antibodies to plague bacteria
    • Examining body fluids using special techniques
    • Culture of body fluids to check for bacteria
    • Chest x-ray
      to look for signs of infection in the lungs

  • Prevention

    Antibiotics may prevent infection following close contact with someone who has the disease. The drugs should be taken daily while in contact, and for seven days after the last exposure. In addition, the caregiver and person with plague should wear masks.

    In the event of a terrorism exposure, antibiotics may be given to people in the affected areas who have a fever or cough. A vaccine does not exist for pneumonic plague.

    Measures to prevent naturally occurring plague include:

    • Reduce or control rodent population near your home
    • Wear gloves when handling or skinning animals to protect contact with your skin
    • Use insect repellent containing DEET when you are outside
    • Keep fleas off your pets by using flea control products
    • Keep dogs and cats from sleeping in your bed if they roam in endemic areas

  • Risk Factors

    Factors that may increase your chance of getting plague include:

    • Exposure to the bacteria
    • Contact with fleas or infected rodents
    • Living in the Southwest United States


    You can get more information about the distribution of plague from the
    Centers for Disease Control and Prevention
    (CDC).

  • Symptoms

    Pneumonic plague may cause:

    • Fever
    • Weakness
    • Headache
    • Cough
    • Bloody or watery mucous
    • Difficulty breathing
    • Chest pain

    Bubonic plague may cause:

    • Fever
    • Chills
    • Weakness
    • Headache
    • Swollen, tender lymph nodes
    • Skin may appear red and tight over affected lymph nodes

    Septicemic plague may cause:

    • Bleeding under the skin
    • Black fingers, toes, or nose
    • Fever
    • Chills
    • Weakness


    Complications of plague include
    shock, organ failure, and death.

  • Treatment

    Starting antibiotics early is essential. Any delay greatly increases the risk of death. The drugs are injected in a muscle or given through a vein. Later in treatment, some drugs can be given by mouth. A person with lung symptoms will be placed in isolation to protect others. Caregivers and visitors should wear a mask, gloves, goggles, and a gown. Cases are reported to public health officials.