Rocky Mountain spotted fever is caused by the organism Rickettsia rickettsii. In the United States, this bacterium most often is spread to humans by bites from the American dog tick or the wood tick, depending on the geographic area.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.
Make a gift now to help create new and better solutions for the more than 1.3 million patients who turn to Mayo Clinic each year.