Rickettsial illnesses are caused by bacterial infections transmitted by ticks, fleas, or mites. The word "rickettsial" refers to diseases caused by different species of Rickettsia bacteria. Synonyms for this word include typhus, spotted fever, and ehrlichiosis. These diseases can cause many symptoms, including fever, headache, muscle pain, and rash. Some rickettsial infections can be severe and may even be fatal if left untreated. Prevention is key, and people can reduce their risk of contracting these illnesses by avoiding tick and flea bites, using insect repellent, and wearing protective clothing.