Definition

Plague is a bacterial infection that can be deadly. The disease occurs naturally after a bite by an infected flea or from handling or eating an infected animal. Governments have studied the bacteria's use as a germ-warfare weapon. As a weapon, it would be released in the air. There are several types of plague, depending on where the exposure and symptoms occur:

  • Pneumonic (in the lungs)—from breathing in droplets or as a progression of another type
  • Bubonic plague (in the lymph nodes)—occurring after a rodent-flea bite
  • Septicemic plague (a body system-wide infection)—occurring after a rodent-flea bite
  • Pharyngeal plague (in the throat and nearby lymph nodes)—due to ingesting infected tissue or inhaling large droplets

Causes

Yersinia pestis causes the infection. It is spread by droplets in the air. People can catch pneumonic plague from face-to-face contact with someone who has the disease. Bubonic and septicemic plague, without respiratory complications, are not spread from person-to-person.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Risk factors for plague include:

  • Exposure to the bacteria
  • Biological terrorism
  • Contact with rodents
  • Rodents in the environment

Symptoms

Symptoms depend on the type of plague. They occur in naturally-acquired cases within two to eight days. Plague can progress within a few days and cause sepsis , meningitis, or death. Experts expect the first symptoms after a biological attack would appear within a couple of days. People would be expected to die soon after the first symptoms occurred.

Bacterial Meningitis

Bacterial Meningitis
© 2009 Nucleus Medical Art, Inc.

Symptoms of pneumonic plague include:

  • Fever
  • Chills
  • Weakness
  • Headache
  • Cough, with bloody or watery secretions
  • Difficulty breathing
  • Chest pain
  • Possible nausea, vomiting, and diarrhea

Symptoms of bubonic plague:

  • Fever
  • Chills
  • Weakness
  • Headache
  • Swollen, tender lymph nodes
  • Skin may appear red and tight over affected lymph nodes
  • Raised bumps or sores at site of flea bite
  • Restlessness
  • Lack of energy
  • Possible agitation, confusion
  • Possible nausea, vomiting, and diarrhea

Symptom of pharyngeal plague:

  • Swollen lymph nodes

Symptoms of septicemic plague and progression of other forms:

  • Bleeding under the skin
  • Black fingers, toes, or nose
  • Abnormal clotting
  • Difficulty breathing
  • Shock
  • Organ failure
  • Death

Diagnosis

The doctor will ask about your symptoms, medical history, and possible source of exposure, and perform a physical exam. Other cases in the area may alert healthcare workers of the possibility of a bioterrorism attack.

Test may include:

  • Chest x-ray
  • 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

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 patient with lung symptoms will be placed in isolation to protect others. Caregivers and visitors should wear a mask, gloves, goggles, and a gown. Lymph nodes may require draining. Cases are reported to public health officials.

Medications

Any of the following antibiotics may be used:

Supportive Care for Septicemic Plague

Health professionals will monitor the patient for changes in status and take appropriate action. Maintaining adequate heart function, blood pressure, and oxygen supply are of prime importance.

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 patient should wear masks.

Antibiotics may be ordered in the event of a terrorism exposure. People may be placed on the drugs after developing a cough. There would be no warning systems to alert authorities that plague bacteria had been released. The success of an attack would depend on the bacteria's quality and strain, the way it was produced, and weather conditions at the time of release. A vaccine does not exist for pneumonic plague.

Measures to prevent naturally-occurring plague include:

  • Do not touch dead rodents or sick cats.
  • Use insecticides around the house.
  • Eliminate rat habitats near the house.
  • Do not allow dogs or cats to roam in areas where plague is common.