Rocky Mountain Spotted Fever (RMSF) and Spotted Fever group (SFG) Rickettsia are diseases caused by Rickettsia bacteria that are transmitted to people through the bite of an infected tick. RMSF, caused by Rickettsia rickettsii is the most severe and most frequently reported rickettsial illness in the United States (U.S). Contrary to its name, RMSF is rare in the western U.S.; most cases occur in the Midwest and southeastern U.S. Only one or two cases of RMSF are reported each year in California. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment it can be fatal.
SFG Rickettsia can cause a fever, headache and a small open wound about ¼ inch in size that turns into a dark scab (called an eschar). A SFG Rickettsia called 364D has been recently identified from a small number of people in northern California and has been found in the Pacific Coast tick in eight counties, in both northern and southern California.
- ACDC: A Manual of Departmental Rules, Regulations and Control Procedures (B73)
- Spotted Rickettsioses Disease Case Report (CDPH 8575)
- LAC Reported Cases of Selected Diseases 2006-2011
- LAC Reported Cases of Selected Diseases 2003-2008
- CDC: Rocky Mountain Spotted Fever
- CDC: Other Tick-borne Spotted Fever Rickettsial Infections
- CA DPH Fact Sheet: Spotted Fever Group Rickettsia and Rocky Mountain Spotted Fever
- CA DPH: Spotted Fever Group Rickettsia and Rocky Mountain Spotted Fever
- CID: Rickettsia 364D: A Newly Recognized Cause of Eschar-Associated Illness in California