Rocky Mountain Spotted Fever

  • Medical Author:
    Jerry R. Balentine, DO, FACEP

    Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

  • Medical Editor: Steven Doerr, MD
    Steven Doerr, MD

    Steven Doerr, MD

    Steven Doerr, MD, is a U.S. board-certified Emergency Medicine Physician. Dr. Doerr received his undergraduate degree in Spanish from the University of Colorado at Boulder. He graduated with his Medical Degree from the University Of Colorado Health Sciences Center in Denver, Colorado in 1998 and completed his residency training in Emergency Medicine from Denver Health Medical Center in Denver, Colorado in 2002, where he also served as Chief Resident.

Rocky Mountain Spotted Fever Slideshow

See pictures of the ticks that transmit Rocky Mountain spotted fever (RMSF). Plus, get tips on how to prevent RMSF.

Quick GuideRocky Mountain Spotted Fever: See Photos of the Rash

Rocky Mountain Spotted Fever: See Photos of the Rash

Rocky Mountain spotted fever facts

  • RMSF is a potentially serious tick-borne disease, and it is the most common cause of fatal tick-borne diseases in the United States.
  • The incidence of RMSF has increased from less than two cases per million people in the year 2000 (approximately 500 cases) to over six cases per million people in 2010 (approximately 2,000 cases).
  • 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 can potentially 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. It is the most common cause of fatal tick-borne diseases in the United States. The fatality rate is less than 1%.

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

Cases of RMSF have been reported in many areas of the country, and the disease is not restricted to the Rocky Mountain region, as its name may imply. In fact, Arkansas, Missouri, North Carolina, Oklahoma, and Tennessee account for over 60% of reported cases. In 2010, there were approximately 2,000 cases reported in the U.S., which is more than twice as many cases 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 10/28/2016

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