Rocky Mountain Spotted Fever

Fact Sheet about Rocky Mountain Spotted Fever

What is Rocky Mountain Spotted Fever?

Rocky Mountain spotted fever (RMSF) is a disease caused by the bacteria (germ) Rickettsia rickettsii.

Where do cases of RMSF occur?

RMSF is a rare disease in Massachusetts. Between 1995-2017, nine cases were reported. The disease is most often reported from the southeastern part of the state, Cape Cod and Martha’s Vineyard.

How is RMSF spread?

In the Northeast, RMSF is spread by the bite of an infected dog tick, also called the eastern wood tick. The longer a tick remains attached and feeding, the higher the likelihood that it may spread the bacteria. However, unlike for other tick-borne diseases, the germ that causes RMSF often spreads within 24 hours of the tick attaching.

How soon do symptoms of RMSF appear after a tick bite?

Symptoms usually start to appear about 7 days after the bite of an infected tick, but can begin anywhere between 3 and 14 days.

What are the symptoms of RMSF?

Symptoms usually begin with a sudden onset of fever and severe headache, and may also include deep muscle pain, nausea and vomiting, and less frequently stomach pain and cough. Most people develop a rash on their arms and legs about 3 to 5 days after the fever starts. This rash often spreads to the palms, soles, and over the rest of the body.

Is there treatment for RMSF?

RMSF can be treated with antibiotics; however, serious complications including death can occur if the disease is not recognized and treated early.

What can I do to lower my chances of getting RMSF, or any other disease, from ticks?

Prevention begins with you! Take steps to reduce your chances of being bitten by any tick. Ticks are most active during warm weather, generally late spring through fall. However, ticks can be out any time that temperatures are above freezing. Ticks cling to vegetation and are most numerous in brushy, wooded or grassy habitats. When you are outside in an area likely to have ticks (e.g. brushy, wooded or grassy places), follow these simple steps to protect yourself and your loved ones:

  • Use a repellent with DEET (the chemical N-N-diethyl-meta-toluamide) or permethrin according to the instructions given on the product label. DEET products should not be used on infants under two months of age and should be used in concentrations of 30% or less on older children. Permethrin products are intended for use on items such as clothing, shoes, bed nets and camping gear, and should not be applied to skin. Other repellents, such as picaridin, oil of lemon eucalyptus and IR 3535, have also been found to provide protection against ticks. More information on choosing a repellent and how to use repellents safely is included in the MDPH Public Health Fact Sheet on Tick Repellents.
  • Wear long, light-colored pants tucked into your socks or boots, and a long-sleeved shirt. This may be difficult to do when the weather is hot, but it will help keep ticks away from your skin and help you spot a tick on your clothing faster.
  • Stay on cleared trails when walking or hiking, avoiding the edge habitat where ticks are likely to be
  • Talk to your veterinarian about tick control options (tick collars, repellents) for your pets

Did you know?

You don’t have to be a hiker on Cape Cod to worry about ticks. In Massachusetts, you may be bitten in your own backyard. There are lots of things you can do around your own backyard to make it less inviting for ticks! Visit the MDPH Tick-borne Disease Website for suggestions.

After spending time in an area likely to have ticks, check yourself, your children and pets for ticks. Adult dog ticks are about the size of a small watermelon seed. When doing a tick check, remember that ticks like places that are warm and moist. Always check the back of the knees, armpits, groin, scalp, back of the neck and behind the ears. If you find a tick attached to your body, remove it as soon as possible using a fine-point tweezers. Do not squeeze or twist the tick’s body, but grasp it close to your skin and pull straight out with steady pressure.

Know the symptoms of RMSF as described in this fact sheet. If you have been someplace likely to have ticks and you develop symptoms of any disease carried by ticks, see your health care provider right away.

Where can I get more information?

  • For questions about your own health, contact your doctor, nurse, or clinic
  • For questions about diseases spread by ticks, contact the MDPH at (617) 983-6800 or online. You may also contact your local Board of Health (listed in the telephone directory under “Government”)
  • Health effects of pesticides, MDPH, Bureau of Climate and Environmental Health at (617) 624-5757

Spanish and Portuguese translations of this fact sheet are available under additional resources.

Additional Resources

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