However, controlling populations of small animals helps reduce the number of ticks. Insecticides are also helpful. Rocky Mountain spotted fever can cause serious illness or death. Therefore, when a doctor suspects Rocky Mountain spotted fever, an antibiotic is given immediately, before laboratory test results become available. Antibiotic therapy has significantly reduced the death rate from about 20 to 7 percent.
Death usually occurs when treatment is delayed.
Severely ill patients with Rocky Mountain spotted fever often have inadequate blood circulation, which can lead to kidney failure, anemia, tissue swelling, and coma. They also may have considerable leakage from infected blood vessels. For this reason, if intravenous fluids are needed, they are given cautiously to avoid increasing fluid accumulation in the lungs or brain, particularly during the later stages of illness. A rash appears on the 4th to 6th day. Untreated, the infection may be fatal, especially in those over age 50 years.