What is plague?


Plague is an infectious disease caused by a bacteria called Yersinia pestis. This bacteria is found all over the world, including the U.S. The disease affects rodents, humans, and other animals.

How is plague spread?

Plague typically is spread through the bite of an infected flea. People can also become infected by handling the body of an infected animal. Inhaling respiratory droplets from an infected cat or human can spread pneumonic plague.

Plague is spread when fleas feed on infected rodents, and then feed on humans.

What are the types of plague?

  1. Bubonic: transmitted through the bite of an infected flea
  2. Septicemic: transmitted through the bite of an infected flea or from handling a sick animal
  3. Pneumonic: the most serious plague, spread through respiratory droplets from person to person

What are the symptoms of plague?

People usually experience symptoms of plague between 1 to 6 days after infection occurs. If left untreated, bubonic plague can develop into septicemic plague or pneumonic plague.

  • Bubonic: Fever, headache, chills, weakness, and/or swollen or painful lymph nodes
  • Septicemic: Fever, chills, extreme weakness, abdominal pain, shock, bleeding into the skin or organs, black skin or tissues that may die
  • Pneumonic: Fever, headache, weakness, rapidly developing pneumonia with shortness of breath, chest pain, cough, and bloody or watery mucous, may cause respiratory failure or shock

Who is at risk for plague?

People who live in areas where rodents are common are more likely to get plague.   Typically those who live in rural and semi-rural areas are at higher risk.

Is plague contagious?

Pneumonic plague can spread from person-to-person by breathing in an infected person’s respiratory droplets. However, this is rare.

How is plague diagnosed?

A healthcare worker will give you an evaluation to determine if plague is possible. If so, samples of a patient’s blood, sputum, or lymph node aspirate will be sent to a lab to confirm plague diagnoses.

How is plague treated?

There is no vaccine currently available for plague, but it can be successfully treated with antibiotics. Patients with plague will need to be hospitalized, and occasionally, medically isolated. Laboratory blood, sputum, and lymph node aspirate tests should be done for examination. Antibiotics should be given immediately, preferably within the first 24 hours that symptoms occur.

When is plague most common?

Plague is most common from late spring to early fall in the U.S.

Where is plague most common in the U.S.?

Plague is most common in semi-rural areas of the U.S. It is mostly found in southwestern states.

How common is plague in the U.S.?

An average of 7 cases are reported in the U.S. each year (between 1-17/year) in all ages, although half of cases occur in people aged 12-45. Between 1,000 and 2,000 are reported world-wide each year, although the number is likely higher.

What is the death rate of plague?

Although plague can be treated by antibiotics, it can still be fatal. Pre-antibiotics, the death rate in the U.S. was around 61%, but it has since fallen to around 11%. Between 8-10% of people will die from plague worldwide, although it is higher in some countries.

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