Rocky Mountain spotted fever (RMSF) is a bacterial infection caused by bites from infected American dog ticks. Symptoms include fever and headache and generally begin 2 to 14 days after the tick bite. RMSF can be successfully treated with antibiotics, but the infection can be severe or even fatal if not treated early. Most RMSF cases are reported in the central and southeastern regions of the United States. RMSF is not frequently reported in West Virginia residents (0 to 10 cases per year).