Definition

Plague is an infectious disease with an infamous past in 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.

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.

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 http://www.cdc.gov/plague/maps/index.html (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 that 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.

Diagnosis

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

Your bodily fluids will be tested. This can be done with:

• Blood tests
• Cultures of body fluids

Images may be taken of your lungs. This can be done with a chest x-ray.

Treatment

Starting antibiotics early is important. Any delay 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.

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 7 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 the rodent population near your home, since rodents carry fleas.
• 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.

Johns Hopkins’ Office of Critical Event Preparedness and Response (CEPAR) http://www.hopkins-cepar.org

Public Health Agency of Canada http://www.phac-aspc.gc.ca

Plague. Centers for Disease Control and Prevention website. Available at:
http://www.cdc.gov/plague
Updated March 3, 2015. Accessed June 10, 2015.

Plague. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated May 12, 2015. Accessed June 10, 2015.