Rocky Mountain spotted fever
American dog tick (a common vector of Rocky Mountain spotted fever)
Source: Centers for Disease Control
What is Rocky Mountain spotted fever and what are the symptoms?
Rocky Mountain spotted fever (RMSF) is the most severe tick-borne illness in the United States. Initial symptoms may include fever, nausea, vomiting, muscle pain, lack of appetite and severe headache. Later signs and symptoms include rash, abdominal pain, joint pain, and diarrhea. RMSF can be a severe illness and the majority of patients require hospitalization. About 3 to 5 percent of cases reported in recent years in the United States have been fatal.
Patients infected with RMSF usually visit a physician in their first week of illness, following an incubation period of about 5-10 days after a tick bite. Although this disease was reported most frequently in the Rocky Mountain area early after its discovery, relatively few cases are reported from this area today.
How do people get RMSF?
RMSF is transmitted by the bite of an infected tick. The American dog tick and Rocky Mountain wood tick are the primary vectors of RMSF bacteria in the United States.
How is RMSF diagnosed?
A diagnosis of RMSF is based on a combination of clinical signs and symptoms and specialized confirmatory laboratory tests.
How is RMSF treated?
RMSF is best treated by using a tetracycline antibiotic, usually doxycycline. Patients are treated for at least 3 days after the fever subsides and until there is evidence of clinical improvement. The standard duration of treatment is 5 to 10 days.
How can RMSF be prevented?
Limiting exposure to ticks reduces the likelihood of RMSF infection. In persons exposed to tick-infested habitats, prompt careful inspection and removal of crawling or attached ticks is an important method of preventing disease. It may take several hours of attachment before organisms are transmitted from the tick to the host.
It is unreasonable to assume that a person can completely eliminate activities that may result in tick exposure. Therefore, prevention measures should be aimed at personal protection:
- Wear light-colored clothing to allow you to see ticks that are crawling on your clothing.
- Tuck your pants legs into your socks so that ticks cannot crawl up the inside of your pants legs.
- Apply repellants to discourage tick attachment. Repellents containing permethrin can be sprayed on boots and clothing, and will last for several days. Repellents containing DEET (n, n-diethyl-m-toluamide) can be applied to the skin, but will last only a few hours before reapplication is necessary. Use DEET with caution on children. Application of large amounts of DEET on children has been associated with adverse reactions.
- Conduct a body check upon return from potentially tick-infested areas by searching your entire body for ticks. Use a hand-held or full-length mirror to view all parts of your body. Remove any tick you find on your body.
- Parents should check their children for ticks, especially in the hair, when returning from potentially tick-infested areas. Additionally, ticks may be carried into the household on clothing and pets. Both should be examined carefully.
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More information about RMSF can be found by visiting the Centers for Disease Control