Information for Healthcare Professionals
Spotted fever group (SFG) Rickettsia are a group of intracellular bacterial pathogens transmitted to humans primarily through ticks. SFG rickettsioses of concern in California include Rocky Mountain spotted fever (RMSF) and Pacific Coast tick fever (PCTF). In California, 1–3 confirmed cases of RMSF and 0–3 confirmed cases of PCTF are reported each year. The fatality potential of RMSF makes it critical to recognize and report suspected cases of these diseases.
Healthcare providers are required to report cases of SFG rickettsiosis to the local health department within one week (seven calendar days) of identification.
Many diagnostic tests for spotted fevers, especially tests based on the detection of antibodies, will frequently appear negative in the first 7–10 days of illness and cannot be relied upon for initiation of antibiotic therapy (doxycycline).
Information from patients such as recent tick bites, exposure to tick habitats, contact with dogs, similar illnesses in family members or pets, or history of recent travel to areas of high incidence can be helpful in making the diagnosis. Tick bites are often painless, and many people with rickettsioses do not remember being bitten by a tick.