🦠microbiology review

Rickettsia prowazekii

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

Definition

Rickettsia prowazekii is a gram-negative, obligate intracellular bacterium that causes epidemic typhus. It primarily infects endothelial cells lining blood vessels, leading to severe vascular inflammation.

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5 Must Know Facts For Your Next Test

  1. Rickettsia prowazekii is transmitted to humans through the bite of an infected body louse (Pediculus humanus corporis).
  2. The bacterium is known for causing epidemic typhus, which can be fatal if untreated.
  3. It has a genome that is highly reduced and dependent on the host cell for many functions.
  4. Symptoms of infection include high fever, rash, and severe headache.
  5. Rickettsia prowazekii can remain dormant in the body and reactivate later to cause Brill-Zinsser disease.

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