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Spotted Fever Group Rickettsia (Rocky Mountain Spotted Fever & Pacific Coast Tick Fever)

Spotted fever group Rickettsia are a group of bacteria that can cause disease in humans, specifically Rocky Mountain spotted fever (RMSF) and Pacific Coast tick fever (PCTF). The bacteria that cause RMSF and PCTF are transmitted by the bite of an infected tick. Symptoms of these diseases usually include a fever and rash ("spots").

In California, the American dog tick (Dermacentor variabilis), the Pacific Coast tick (Dermacentor occidentalis), and the brown dog tick (Rhipicephalus sanguineus) can transmit the bacteria that cause RMSF to people and dogs. PCTF is transmitted by the bite of an infected Pacific Coast tick (Dermacentor occidentalis).

These ticks must be attached to the skin for at least 4 to 6 hours before they can infect a person. The best way to prevent diseases like RMSF and PCTF that come from ticks is to protect yourself from tick bites: use tick repellent when going outside in areas where ticks are common, and check yourself and pets often for ticks while outside and after you return indoors. 

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