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Indiana State Department of Health

Epidemiology Resource Center Home > Surveillance and Investigation > Diseases and Conditions Resource Page > Rocky Mountain Spotted Fever Rocky Mountain Spotted Fever

About... Rocky Mountain Spotted Fever

What is Rocky Mountain spotted fever (RMSF) ?

Rocky Mountain spotted fever is the name given to a disease caused by the bacteria, Rickettsia rickettsii, that can infect both animals and people. Named because it was first recognized as occurring in the Rocky Mountain states, however, most cases occur in the East especially the Southeast. Cases occur each summer in Indiana

How is RMSF Spread?

RMSF is spread in Indiana by the bite of the dog tick, Demacentor variablis. Ticks acquire their infection from small wild living rodents. The tick injects the bacteria into either the animal or human host as it is engorging on blood. Pictures of the dog tick can be viewed at: www.ent.iastate.edu/imagegal/tick/dvar/

What are the symptoms of RMSF?

Patients with RMSF first show symptoms 5-10 days after a tick bite. Early symptoms are not specific for RMSF but may include:

  • Fever,
  • Sever headache,
  • Nausea vomiting, and lack of appetite
  • Muscle pain, joint pain
  • Rash

How do I know if I have RMSF?

You cannot tell without seeing your doctor. Your physician will complete a thorough history, review of your signs and symptoms, physical examination, and laboratory testing to confirm whether or not you have RMSF.

How is RMSF treated?

RMSF can be treated with appropriate antibiotics, usually a tetracycline or doxycycline, but others may be used depending on the patient’s age or other health status.

How RMSF can be prevented?

Preventing tick bites is the only way to prevent this disease. Preventing tick bites can be accomplished by:

  • Staying out of area where ticks are likely to occur. Keeping high grass, weeds and brush from yards to remove places that serve as harborages for ticks.
  • If you do enter area where ticks are likely to be present:
    • Wear long pants and long sleeved light-colored clothing to easily see ticks on clothing and prevent access to skin.
    • Tuck pant legs into sock to prevent ticks from reaching skin of legs or crawling up inside of pant legs.
    • Use repellents containing DEET may be applied to the skin or clothing will discourage ticks from attaching to the body for several hours before needing to be replaced. Products containing permethrin can be sprayed on your shoes and clothing and will be effective for several days. Carefully follow label directions when using any repellent.

After leaving a tick infested area do a full body tick check and remove any ticks found with either tweezers, paper tissue, or while wearing gloves. Ticks should be removed by grasping them close to the skin and pulling upward with a steady, even pressure. For additional instructions on tick removals go to: www.cdc.gov/ncidod/dvrd/rmsf/Prevention.htm.


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