BACTERIA

Rickettsia prowazekii Rickettsia prowazekii infections

Rickettsia prowazekii appearance

  • small Gram-negative short rods or coccobacilli
  • nonmotile
  • obligate intracellular parasite

Infections caused by Rickettsia prowazekii

Rickettsia prowazekii is the etiologic agent of epidemic typhus, transmitted in the feces of lice. Epidemic typhus is a form of typhus so named because the disease often causes epidemics following wars and natural disasters. Typhus was also common in prisons (and in crowded conditions where lice spread easily), where it was known as Gaol fever or Jail fever.

Symptoms include severe headache, a sustained high fever, cough, rash, severe muscle pain, chills, falling blood pressure, stupor, sensitivity to light and delirium. A rash begins on the chest about five days after the fever appears, and spreads to the trunk and extremities.

Epidemic typhus is found most frequently during times of war and deprivation. In the periods between outbreaks, when human to human transmission occurs less often, the flying squirrel serves as a zoonotic reservoir for the Rickettsia prowazekii bacterium. The mortality rate is 10% to 60%, but is vastly lower (close to zero) if intracellular antibiotics such as tetracycline are used before 8 days (Wikipedia).

R. prowazekii can establish a latent infection, which can reactivate after years or decades (referred to as Brill-Zinsser disease).

Rickettsia prowazekii treatment

Tetracyclines
  • tetracycline
  • doxycycline

Alternative:
  • chloramphenicol

Rickettsia prowazekii vaccination

  • Infection can also be prevented by vaccination.Vaccine developed by Herald R. Cox in 1938 was widely available and used extensively by 1943.

Links:

Wikipedia


Rickettsia prowazekii morphology Rickettsia prowazekii cell morphology Rickettsia prowazekii Gram-stain