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Rocky Mountain Spotted Fever
(tick-borne typhus fever)
What is Rocky Mountain spotted fever?
Rocky mountain spotted fever (RMSF) is a disease caused by a rickettsial
organism transmitted to humans by the bite of an infected American dog
tick, Dermacentor variabilis, and frequently by other tick species. Fewer
than 50 cases are reported annually in New York State.
Who gets RMSF?
In the eastern United States, children are infected most frequently,
while in the western United States, disease incidence is highest among
adult males. Disease incidence is directly related to the exposure to
tick-infested habitats or to infested pets. Most of the cases in New York
State have occurred on Long Island.
How is RMSF spread?
RMSF is spread by the bite of an infected tick (the American dog tick,
the lone-star tick or the wood tick), or by contamination of the skin
with tick blood or feces. Person to person spread of RMSF does not occur.
What are the symptoms of RMSF?
RMSF is characterized by a sudden onset of moderate to high fever (which
can last for two or three weeks), severe headache, fatigue, deep muscle
pain, chills and rash. The rash begins on the legs or arms, may include
the soles of the feet or palms of the hands and may spread rapidly to
the trunk or rest of the body.
How soon do symptoms appear?
Symptoms usually appear within two weeks of the bite of an infected
tick.
Does past infection with RMSF make a person immune?
One attack probably provides permanent immunity.
What is the treatment for RMSF?
Certain antibiotics such as tetracycline or chloramphenicol may be effective
in treating the disease.
What can be done to prevent the spread of RMSF?
Frequent checking of clothing and skin when in infested areas is extremely
useful in reducing potential incidence of disease. Tick repellents applied
to legs and clothing may be helpful to prevent tick attachment. Due to
the nature of American dog ticks, local populations may be effectively
controlled with applications of pesticides to vegetation along trails;
mowing grass frequently in yard and outside fences also helps to reduce
tick populations.
How should a tick be removed?
To remove an attached tick, grasp with tweezers or forceps as close
as possible to attachment (skin) site, and pull upward and out with a
firm and steady pressure. If tweezers are not available, use fingers shielded
with tissue paper or rubber gloves. Do not handle with bare hands. Be
careful not to squeeze, crush or puncture the body of the tick which may
contain infectious fluids. After removing the tick, thoroughly disinfect
the bite site and wash hands. See or call a physician if there is concern
about incomplete tick removal. It is important that a tick be removed
as soon as it is discovered. Check after every two to three hours of outdoor
activity for ticks attached to clothing or skin. If removal occurs within
three hours after attachment, the risk of tick-borne infection is reduced.
Source: NY State Department of Health
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