Publications

Current Fact Sheets

Rocky Mountain Spotted Fever

• Rocky Mountain spotted fever is a serious, generalized illness that is usually spread by the bite of an infected tick.
• Anyone who is exposed to areas where ticks live or to pets with ticks is at risk for Rocky Mountain spotted fever.
• Rocky Mountain spotted fever is treatable with antibiotics. Without treatment, the disease can be fatal.
• Rocky Mountain spotted fever can be prevented by: 1) avoiding tick bites, 2) removing attached ticks promptly, and 3) getting early diagnosis and treatment.

What is Rocky Mountain spotted fever?

Rocky Mountain spotted fever is a serious, generalized infection that is usually spread to people by the bite of infected ticks. The disease gets its name from the Rocky Mountain area where it was first identified.

What is the infectious agent that causes Rocky Mountain spotted fever?

Rocky Mountain spotted fever is caused by Rickettsia rickettsii, a specialized bacteria. Ticks infected with the organism transmit the disease to humans.

Where is Rocky Mountain spotted fever found?

Rocky Mountain spotted fever is found throughout the United States, except in Maine, Alaska, and Hawaii. Despite the name, few cases are reported from the Rocky Mountain region. Most cases occur in the southeastern United States.

Rocky Mountain spotted fever is spread by the American dog tick, the lone-star tick, and the wood tick, all of which like to live in wooded areas and tall, grassy fields. The disease is most common in the spring and summer when these ticks are active, but it can occur anytime during the year when the weather is warm.

How do people get Rocky Mountain spotted fever?

People get Rocky Mountain spotted fever from the bite of an infected tick or by contamination of the skin with the contents of an attached tick when it is removed from the skin. Rocky Mountain spotted fever is not spread from person to person, except rarely by blood transfusion.

What are the signs and symptoms of Rocky Mountain spotted fever?

People with Rocky Mountain spotted fever get a sudden fever (which can last for 2 or 3 weeks), severe headache, tiredness, deep muscle pain, chills, nausea, and a characteristic rash. The rash might begin on the legs or arms, can include the soles of the feet or palms of the hands, and can spread rapidly to the trunk or the rest of the body.

How soon after exposure do symptoms appear?

Symptoms usually begin 3 to 12 days after a tick bite.

How is Rocky Mountain spotted fever diagnosed?

The disease is diagnosed by special blood tests.

Who is at risk for Rocky Mountain spotted fever?

Anyone who is exposed to tick-infested areas or to tick-infested pets is at risk for Rocky Mountain spotted fever.

What complications can result from Rocky Mountain spotted fever?

Without prompt medical care, kidney failure and shock can lead to death.

What is the treatment for Rocky Mountain spotted fever?

Rocky Mountain spotted fever must be treated with antibiotics. Many persons with the disease need to be hospitalized.

How common is Rocky Mountain spotted fever?

Rocky Mountain spotted fever affects about 800 persons in the United States each year.

Is Rocky Mountain spotted fever a new or emerging infectious disease?

No. However, because of the seriousness of the disease, continued efforts are needed to increase awareness and encourage prevention.

How can Rocky Mountain spotted fever be prevented?

No vaccine is available to protect humans against Rocky Mountain spotted fever. The best way to avoid getting the disease is to avoid areas such as the woods or fields where ticks are found. If this is not possible, you can reduce your risk by taking these precautions:

• Control the tick population on your property. Keep pets tick-free. Mow grass often in yards and outside fences.
• During outside activities in wooded areas and around tall grass, wear long sleeves and long pants tucked into socks.
• Use insecticides to repel or kill ticks. Repellents containing the compound DEET can be used on exposed skin except for the face, but they do not kill ticks and are not 100% effective in discouraging ticks from biting. Products containing permethrin kill ticks, but they cannot be used on the skin -- only on clothing. When using any of these chemicals, follow label directions carefully. Be especially cautious when using them on children.
• After outdoor activities, check yourself for ticks, and have a "buddy" check you, too. Check body areas where ticks are commonly found: behind the knees, between the fingers and toes, under the arms, in and behind the ears, and on the neck, hairline, and top of the head. Check places where clothing presses on skin.
• Remove attached ticks immediately. Removing a tick before it has been attached for more than 4 hours greatly reduces the risk of infection. Use tweezers, and grab as closely to the skin as possible. Do not handle ticks with bare hands. Do not try to remove ticks by squeezing them, coating them with petroleum jelly, or burning them with a match.
• After removing the tick, thoroughly disinfect the bite site, and wash your hands. See or call a doctor if you think that tick parts may remain in your skin. If you get a fever, headache, rash, or nausea within 2 weeks of a possible tick bite or exposure, see a doctor right away.

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have questions about the disease described above, consult a health-care provider.

Return to Infectious Facts Index

Return to DHPE Main Page