Written by:Fact check:

Overview

What Is Plague?

Plague is an infection caused by the bacterium Yersinia pestis. It can occur in bubonic, pneumonic, or septicemic forms, depending on which parts of the body are affected. People usually become infected through fleas, infected animals, or respiratory droplets in certain situations. Historical references to the Black Death usually describe widespread medieval plague outbreaks, but plague still occurs in some areas today.

Symptoms

Plague Symptoms

Symptoms of plague can begin suddenly after exposure, and the pattern varies by form. Because the infection can worsen quickly, suspected plague requires urgent medical assessment rather than self-diagnosis.

Bubonic Symptoms

  • Sudden fever
  • Painful, swollen lymph nodes (buboes)
  • Chills
  • Headache
  • Muscle aches
  • Weakness

Pneumonic Symptoms

  • Cough
  • Shortness of breath
  • Chest pain
  • Bloody or watery sputum
  • Fever

Septicemic Symptoms

  • Fever
  • Chills
  • Extreme weakness
  • Abdominal pain
  • Bleeding under the skin
  • Blackened or dying tissue in the fingers, toes, or other areas

SEEK PROMPT CARE

Rapid evaluation matters

Fever or rapidly worsening illness after possible flea, rodent, wildlife, animal-tissue, or respiratory exposure should not be self-diagnosed. Contact a healthcare professional urgently and mention the possible exposure.

How It Spreads

How Plague Spreads

Yersinia pestis circulates mainly among wild rodents and other animals. People can develop plague after being bitten by an infected flea, handling an infected animal or its tissues, or inhaling respiratory droplets from someone or an animal with pneumonic plague.

ANIMAL AND FLEA EXPOSURE

Infected fleas can transmit the bacterium after feeding on rodents or other animals. Contact with infected rodents, cats, wildlife, or animal tissues can also lead to bubonic or septicemic disease.

RESPIRATORY EXPOSURE

Pneumonic plague can spread through close contact with respiratory droplets from an infected person or animal. This route is different from the usual flea-borne spread of bubonic plague.

Risk Factors

Plague Risk Factors

  • Living in or traveling to an area where plague occurs
  • Contact with wild rodents or other potentially infected animals
  • Exposure to infected fleas
  • Handling tissues or carcasses from infected animals
  • Working in veterinary care
  • Working with wildlife or wild-animal habitats
  • Close contact with a person or animal with pneumonic plague
  • Delayed medical treatment after symptoms begin
  • Having an underlying health condition that may make severe infection more likely

Factors associated with more serious illness

Plague can become more severe when treatment is delayed. Overall health and certain underlying conditions may also affect how well the body handles the infection, so people with possible exposure should seek medical advice promptly.

Complications

Plague Complications

  • Sepsis can develop when the infection triggers a dangerous whole-body response.
  • Respiratory failure can occur with severe pneumonic plague.
  • Tissue damage or gangrene can affect the fingers, toes, or other body areas.
  • Meningitis can occur when the infection involves the tissues around the brain and spinal cord.
  • Shock can cause dangerously low blood pressure and poor blood flow to organs.
  • Death can occur, especially when treatment is delayed or disease is severe.

MEDICAL URGENCY

Plague can worsen quickly

Prompt antibiotic treatment greatly affects outcomes. Suspected pneumonic plague also raises concerns for close contacts, who may need urgent evaluation, monitoring, or preventive antibiotics.

Diagnosis

How Plague Is Diagnosed

Clinicians consider the type and timing of symptoms, recent travel or residence, flea or animal contact, and possible contact with pneumonic plague. They combine this information with laboratory testing to determine whether Yersinia pestis is present.

  • A sample from a swollen lymph node may be tested for Yersinia pestis.
  • Blood may be tested for evidence of the infection.
  • Sputum may be tested when pneumonic plague is suspected.
  • A sample from other affected tissue or body fluid may be examined when clinically appropriate.

Treatment & Management

Plague Treatment and Management

  • Severe illness may require hospital care and supportive treatment.
  • Wounds or damaged tissue may need cleaning, dressing, or other tissue management.
  • People with pneumonic plague may need respiratory precautions and appropriate infection-control measures.
  • Healthcare teams monitor for sepsis, shock, respiratory failure, and organ failure.
  • Public-health teams may identify and monitor close contacts.
  • Preventive antibiotics may be offered to close contacts when indicated.
  • Patients may receive advice about isolation, animal contact, and flea exposure control.

Public-health teams may identify and monitor close contacts, provide preventive antibiotics when indicated, and advise on isolation and control of animal or flea exposure. Follow the medical and public-health instructions provided during evaluation and treatment.

Prevention

Plague Prevention

  • Avoid contact with sick or dead wildlife.
  • Use appropriate flea control products for pets under veterinary guidance.
  • Wear gloves when handling animals or animal tissues.
  • Reduce rodent habitat near homes by removing food sources, brush, and clutter.
  • Seek medical care promptly after a concerning flea, rodent, wildlife, or animal-tissue exposure.
  • Follow public-health advice after possible close respiratory exposure.

Outlook and Prognosis

Plague Outlook and Prognosis

Plague is serious but treatable when antibiotics are started promptly. Prognosis depends on the form of disease, its severity, how quickly treatment begins, and the person’s overall health. Untreated disease can deteriorate rapidly.

  • Bubonic plague often responds well to prompt treatment, but it can progress to more severe forms if untreated.
  • Septicemic plague can worsen rapidly and requires urgent treatment and monitoring for shock, sepsis, and tissue damage.
  • Pneumonic plague can cause severe breathing problems and may spread through close respiratory contact, so urgent treatment and follow-up are important.
  • People recovering from severe illness may need follow-up to monitor organ function, tissue damage, or other complications.

When Should You See a Doctor

When Should You See a Doctor for Possible Plague?

GET MEDICAL HELP

Do not wait if plague is possible

Seek urgent medical care for sudden fever or compatible symptoms after exposure to fleas, rodents, wildlife, animal tissues, an affected area, or someone with possible pneumonic plague. Tell the healthcare team about the exposure and when it occurred.

  • Trouble breathing requires emergency evaluation.
  • Confusion can be a sign of severe illness.
  • Collapse requires immediate emergency care.
  • Rapidly worsening illness should not be monitored at home.
  • Severe weakness may indicate a serious infection.
  • Signs of shock, such as fainting, cold skin, or extreme dizziness, require emergency services.

If pneumonic plague is possible, call ahead before arriving so healthcare staff can prepare respiratory precautions. For severe symptoms or an immediate emergency, contact local emergency services.

Branches

1 topic

Symptoms

1 topic