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Rocky Mountain Spotted fever
What is Rocky Mountain spotted fever?
Rocky Mountain spotted fever (RMSF) is the most severe tick-borne rickettsial illness in the United States. This disease is caused by infection with the bacterial organism Rickettsia rickettsii.
How do people get Rocky Mountain spotted fever?
The organism that causes Rocky Mountain spotted fever is transmitted by the bite of an infected tick. The American dog tick (Dermacentor variabilis) and Rocky Mountain wood tick (Dermacentor andersoni) are the primary athropods (vectors) which transmit Rocky Mountain spotted fever bacteria in the United States. Rocky Mountain wood tick is found in the Rocky Mountain states and in southwestern Canada. Adult ticks feed primarily on large mammals. Larvae and nymphs feed on small rodents.
What are the symptoms of Rocky Mountain spotted fever?
Patients infected with R. rickettsii usually visit a physician in their first week of illness, following an incubation period of about 5-10 days after a tick bite. The early clinical presentation of Rocky Mountain spotted fever is often nonspecific and may resemble many other infectious and non-infectious diseases.
Initial symptoms of Rocky Mountain spotted fever may include: fever, nausea, vomiting, muscle pain, lack of appetite, and severe headache. Later signs and symptoms of Rocky Mountain spotted fever include: rash, abdominal pain, joint pain, and diarrhea.
Three important components of the clinical presentation are fever, rash, and a previous tick bite, although one or more of these components may not be present when the patient is first seen for medical care. Rocky Mountain spotted fever can be a severe illness, and the majority of patients are hospitalized.
In the United States, where do most cases of Rocky Mountain spotted fever occur?
Rocky Mountain spotted fever is a seasonal disease and occurs throughout the United States during the months of April through September. Over half of the cases occur in the south-Atlantic region of the United States (Delaware, Maryland, Washington D.C., Virginia, West Virginia, North Carolina, South Carolina, Georgia, and Florida). The highest incidence rates have been found in North Carolina and Oklahoma. Although this disease was first discovered and recognized in the Rocky Mountain area, relatively few cases are reported from that area today.
How is Rocky Mountain spotted fever diagnosed?
A diagnosis of Rocky Mountain spotted fever is based on a combination of clinical signs and symptoms and specialized confirmatory laboratory tests. Other common laboratory findings suggestive of Rocky Mountain spotted fever include thrombocytopenia (decreased platelets), hyponatremia (low blood sodium), and elevated liver enzyme levels.
How is Rocky Mountain spotted fever treated?
Rocky Mountain spotted fever 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. Standard duration of treatment is 5 to 10 days.
Can a person get Rocky Mountain spotted fever more than once?
Infection with R. rickettsii is thought to provide long lasting immunity against re-infection. However, prior illness with Rocky Mountain spotted fever should not deter persons from practicing good tick-preventive measures or visiting a physician if signs and symptoms consistent with Rocky Mountain spotted fever occur, especially following a tick bite, as other diseases may also be transmitted by ticks.
To Remove Attached Ticks:
1.
Grasp the tick as close to the skin surface as possible
Use fine-tipped tweezers or notched tick extractor, and protect your fingers with a tissue, paper towel, or latex gloves (see figure). Persons should avoid removing ticks with bare hands.
2. Grasp the tick as close to the skin surface as possible and pull upward with steady, even pressure. Do not twist or jerk the tick; this may cause the mouthparts to break off and remain in the skin. (If this happens, remove mouthparts with tweezers. Consult your health care provider if illness occurs.)
3. After removing the tick, thoroughly disinfect the bite site and wash your hands with soap and water.
4.
Pull upward with steady, even pressure
Do not squeeze, crush, or puncture the body of the tick because its fluids may contain infectious organisms. Skin accidentally exposed to tick fluids can be disinfected with iodine scrub, rubbing alcohol, or water containing detergents.
5. Save the tick for identification in case you become ill. This may help your doctor make an accurate diagnosis. Place the tick in a sealable plastic bag and put it in your freezer. Write the date of the bite on a piece of paper with a pencil and place it in the bag.
Do folklore remedies work?
No. Folklore remedies, such as the use of petroleum jelly or hot matches, do little to encourage a tick to detach from skin. In fact, they may make matters worse by irritating the tick and stimulating it to release additional saliva or regurgitate gut contents, increasing the chances of transmitting the pathogen. These methods of tick removal should be avoided.
