Lyme disease was first recognized in the United States in 1975
after an unusual outbreak of arthritis near Lyme, Connecticut.
Since then, reports of Lyme disease have increased dramatically,
and the disease has become an important public health problem
in some areas of the United States.
Diagnosis of Lyme disease should take into account the following
• History of possible exposure to ticks in areas where Lyme
disease is known to occur.
• Signs and symptoms of the illness.
• The results of blood tests used to detect whether the
patient has antibodies to the Lyme disease bacterium
Currently, a two-stage testing process to measure the body’s
production of antibodies to the Lyme disease bacterium is
(1) an enzyme-linked immunosorbent assay (ELISA) or indirect
immunofluorescence assay (IFA), followed by
(2) a Western immunoblot of samples that tested positive or
equivocal by ELISA or IFA.
These tests measure antibodies that the body makes against the
Lyme bacterium. It can take 2-4 weeks after infection for the body
to produce measurable levels of antibodies. Therefore, laboratory
tests for Lyme disease must be interpreted based on the length of
infection. Patients who were recently infected and have erythema
migrans may test negative even though they are infected (false
negative). On the other hand, patients who have been infected
for longer than 4 weeks and have arthritis will almost always 7
test positive. A negative test in a patient with arthritis or long
standing symptoms is strong evidence that Lyme disease is not
the cause of their illness.
Treatment and prognosis
Several antibiotics are effective for treating Lyme disease. These
are usually given by mouth but may be given intravenously in
more severe cases. Patients treated with antibiotics in the early
stages of the infection usually recover rapidly and completely.
Most patients who are treated in later stages of the disease also
respond well to antibiotics. A few patients may have persistent
or recurrent symptoms and may require a second 4-week course
of antibiotic treatment. Longer courses of antibiotics have
not been shown to be beneficial in patients who have been
previously treated and have chronic symptoms. Varying degrees
of permanent damage to joints or the nervous system can
develop in patients with late Lyme disease. Typically these are
patients in whom Lyme disease was unrecognized in the early
stages or for whom the initial treatment was inadequate. Lyme
disease is rarely life-threatening.
Lyme disease and pregnancy
Prevention and early diagnosis of Lyme disease are important
during pregnancy. Rarely, Lyme disease acquired during
pregnancy may lead to infection of the placenta and may
possibly lead to stillbirth. Studies of women infected during
pregnancy have found that there are no negative effects on the
fetus when the mother receives appropriate antibiotic treatment
for her Lyme disease.
There are several approaches to Lyme disease prevention,
including personal protection, tick control, post-exposure
antibiotics, and early diagnosis and treatment.
Personal protection from tick bites
You can decrease the chances of being bitten by a tick with a
Avoid tick-infested areas. This is especially important in May,
June, and July. Many local health departments and park or
extension services have information on the local distribution of
ticks. If you are in tick infested areas, walk in the center of trails
to avoid contact with overgrown grass, brush, and leaf litter at
Use insect repellent.Spray repellent containing a 20%
concentration of DEET on clothes and on exposed skin. You
can also treat clothes (especially pants, socks, and shoes) with
permethrin, which kills ticks on contact or buy clothes that 8
are pre-treated. Permethrin can also be used on tents and some
camping gear. Do not use permethrin directly on skin. Always
follow the manufacturer’s instructions when applying any