Rickettsia rickettsii

Categorization
Cell Wall: Gram Negative Shape: Rod
Life Cyle: Obligate Intracellular Parasite
Transmission
  • Rocky Mountain Spotted Fever (RMSF) is transmitted to humans and other mammals by Dog and Wood Ticks. Although the name of RMSF appears to indicate a particular geographic distribution, the disease is observed throughout North America.
Clinical Consequences
  • RMSF initially appears as a non-specific viral illness with fever and headache being dominant symptoms. Over a few days, a skin rash appears on the extremities and spreads to the trunk. The characteristic distribution of rash on the palms and soles of the hands and feet described in some texts is seen only late in the disease. The skin rash consists of hemorrhagic macules as well as petechiae caused by inflammation, occlusive thrombosis, and micro-hemorrhages from capillaries due to R. rickettsii infection of endothelial cells.
Treatment
  • Doxycycline or chloramphenicol