Rocky Mountain spotted fever was originally called “black measles” because of the appearance of the rash.
Rocky Mountain spotted fever was first discovered in the Snake River Valley of Idaho in 1896. It was frequently fatal and many people in the region got sick. By 1900, it had been found in Washington, Arizona, and New Mexico.
Today it is found throughout the United States, Canada, Mexico, and South America.
Rocky Mountain spotted fever is caused by a bacterium that is spread to people through tick bites. Symptoms of the disease include fever, headache, and muscle pain, followed by the appearance of a rash. The disease is hard to diagnose in its early stages and can be fatal.
The bacterium that causes Rocky Mountain spotted fever has a complex life cycle that involves ticks and mammals. People are considered accidental hosts and are not involved in the natural transmission cycle of the bacteria.
Howard T. Rickets was the first to identify the bacteria that causes Rocky Mountain spotted fever. The genus of bacteria, Rickettsia, is named after him. Dr. Rickets died of typhus in Mexico in 1910, soon after he finished his work on Rocky Mountain spotted fever. Typhus is caused by a bacteria that is closely related to the one that causes Rocky Mountain spotted fever—it is from the genus Rickettsia as well.