🦠microbiology review

Plague

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

A plague is a serious infectious disease caused by the bacterium Yersinia pestis, often resulting in high mortality rates. It primarily affects the lymphatic and circulatory systems.

5 Must Know Facts For Your Next Test

  1. The three main forms of plague are bubonic, septicemic, and pneumonic.
  2. Plague is typically transmitted through the bite of an infected flea or direct contact with contaminated fluids or tissues.
  3. Yersinia pestis can evade the immune system by inhibiting phagocytosis and inducing apoptosis in macrophages.
  4. Symptoms of bubonic plague include swollen and painful lymph nodes (buboes), fever, chills, and weakness.
  5. Effective treatment for plague includes prompt administration of antibiotics such as streptomycin or gentamicin.

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