R. Rickettsii

• What does R. Rickettsii cause?

  • Rockey Mountain Spotted Fever
  • Most severe and common rickettsial illness
  • Most prevalent in Appalachian Mountains, and Oklahoma
• What transmits this bacteria? 


  • Hard Tick (Dermacentor) - among humans and rodents
• How long are bacteria dormant in ticks and where are they?


  • Several hours in salivary glands
• What does the bacteria do in mammalian hosts?

  • Activated bacteria are released into the mammalian host's circulatory system where they poliferate in the endothelial lining of small blood vessels
• What are the symptoms of Rocky Mountain Spotted Fever?


  • initially develop a rash on the wrists, ankles, soles and palms
  • later spreads to trunk, petechial hemorrhages
• How is Rocky Mountain Spotted Fever diagnosed and prevented?


  • Fab test
  • prevention involves avoiding ticks
• What is the treatment?

  • removal of ticks
  • doxycycline