Rocky Mountain spotted fever (RMSF) is a bacterial infection caused by the bacterium Rickettsia rickettsii. Despite its name, Rocky Mountain spotted fever is not limited to the Rocky Mountain region and can occur in various parts of North, Central, and South America. The bacterium is primarily transmitted to humans through the bite of infected ticks, especially the American dog tick (Dermacentor variabilis), Rocky Mountain wood tick (Dermacentor andersoni), and brown dog tick (Rhipicephalus sanguineus). These ticks become infected when they feed on small mammals, such as rodents or dogs, that carry the bacteria. Symptoms of Rocky Mountain spotted fever typically appear within 2 to 14 days after a tick bite and may include: High fever Severe headache Muscle aches Chills Fatigue Nausea and vomiting Rash (may start on the wrists and ankles and spread to other parts of the body) If left untreated, Rocky Mountain spotted fever can be a serious and potentially fatal illness. It is importa...