Rocky Mountain Spotted Fever

Medical Author:
Medical Editor:

Rocky Mountain spotted fever facts

  • Close to 2,000 cases of Rocky Mountain spotted fever (RMSF) are reported in the United States each year.
  • RMSF is a potentially serious tick-borne disease that can cause fatalities, and it is the most common cause of fatal tick-borne diseases in the United States.
  • The incident of RMSF has increased from less than two cases per million people in the year 2000, to over six cases per million people in 2010.
  • Although RMSF cases have been reported throughout the United States, the highest incidence of cases in 2010 were in Arkansas, Delaware, Missouri, North Carolina, Oklahoma, and Tennessee.
  • RMSF is treatable with antibiotics, but it can have serious long-term effects and lead to death if not treated quickly and properly.

What is Rocky Mountain spotted fever?

Rocky Mountain spotted fever (RMSF) is a tick-borne disease caused by the bacterium Rickettsia rickettsii. This illness, which is found in North, Central, and South America, is transmitted via the bite of an infected tick. The illness affects the lining of blood vessels (causing a condition termed vasculitis), causing the blood vessels to leak, which ultimately can cause damage to nearly all internal organs.

Where do most cases of RMSF occur in the U.S.?

Cases of RMSF have been reported from most areas of the country, and the disease is not restricted to the Rocky Mountain region. In fact, Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee account for over 60% of reported cases. In 2008, there were approximately 2,500 cases reported in the U.S., which is more than twice as many cases as were reported annually in the 1990s.

Reported incidence of RMSF per million people in 2008
Reported incidence of RMSF per million people in 2008; NN=not reported. SOURCE: CDC.
Medically Reviewed by a Doctor on 5/15/2014

Patient Comments

Viewers share their comments

Rocky Mountain Spotted Fever - Symptoms and Signs Question: What symptoms and signs did you experience with Rocky Mountain spotted fever?
Rocky Mountain Spotted Fever - Prognosis Question: Please describe your experience with Rocky Mountain spotted fever.
Rocky Mountain Spotted Fever - Prevention Question: If you live in a region with ticks or previous outbreaks of RMSF, how do you try to prevent it?
Rocky Mountain Spotted Fever - Location Question: Please share your experience with RMSF, including the region in which you contracted it.