Rocky Mountain Spotted Fever Slideshow Pictures Strep or Sore Throat Slideshow Pictures Infectious Mononucleosis Slideshow Pictures

Medical Author:

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP

Mary D. Nettleman, MD, MS, MACP is the Chair of the Department of Medicine at Michigan State University. She is a graduate of Vanderbilt Medical School, and completed her residency in Internal Medicine and a fellowship in Infectious Diseases at Indiana University.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Rocky Mountain spotted fever (RMSF) facts

• Rocky Mountain spotted fever is caused by the bacterium Rickettsia rickettsii.



• The bacterium is spread to humans through the bite of infected ticks, and so the disease is most common in months where ticks are active, such as summer.



• Despite the name, the disease is not limited to the Rocky Mountains but rather occurs throughout most of the U.S.



• Symptoms of headache, fever, and fatigue begin about a week after exposure. A few days later, a rash develops. The rash may be so mild that it is hard to see or so dramatic that it progresses to gangrene. Other possible symptoms include confusion, abdominal pain, and vomiting.



• Most cases require hospitalization, and severe cases require intensive care.



• The disease is diagnosed by finding high titers of antibodies in the blood or by seeing the organism under a microscope in specially stained skin biopsies.



• The treatment of choice is the antibiotic doxycycline (Vibramycin, Oracea, Adoxa, Atridox). Prompt treatment improves survival and reduces complications.



• Most people with RMSF recover completely over a few weeks. In severe cases, patients may have brain damage or other neurological problems that persist after treatment.



• The risk of RMSF can be reduced by reducing exposure to ticks. This includes avoiding areas that have large concentrations of ticks, using insect repellents and wearing protective clothing.



• Because the risk of infection increases with the duration of tick attachment, people should check themselves for ticks when they return from an outing.

What is Rocky Mountain spotted fever?

Rocky Mountain spotted fever is a bacterial infection that is transmitted to humans through the bite of a tick. Statistics show that rates of disease have been rising steadily over the past decade. Although most people recover completely, fatalities occur in approximately 0.5%-5% of cases.

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; NN=not reported. SOURCE: CDC.