How Did Lyme Disease Become Known?
Lyme disease was first recognized in 1975 after researchers
investigated why unusually large numbers of children were being diagnosed with juvenile rheumatoid arthritis in Lyme, Connecticut, and two neighboring towns.
The researchers discovered that most of the affected children
lived and played near wooded areas where ticks live.
They also found that the children’s first symptoms
typically started in the summer months, the height of the
tick season.
Several of the patients interviewed reported having a skin rash just before developing their arthritis.
Many also recalled being bitten by a tick at the rash site.
Further investigations discovered that tiny deer ticks
infected with a spiral-shaped bacterium or spirochete
(which was later named Borrelia burgdorferi) were
responsible for the outbreak of arthritis in Lyme.
In Europe, a skin rash similar to that of Lyme disease
had been described in medical literature dating back
to the turn of the 20th century.
Lyme disease may have spread from Europe to the U.S. in the early
1900s, but health experts only recently recognized it
as a distinct illness.
Ticks Transmit Lyme
Ticks that most often transmit Lyme disease in the U.S. (these ticks look very similar)
Ixodes scapularis (most common in the
Northeast/Midwest but also found in the South/Southeast)
Ixodes pacificus (found on the west coast)
Ticks & Hosts Which Cause Lyme Disease
Role of Deer & Rodents
Small rodents and deer play an important role in a
deer tick’s life cycle.
deer ticks lay eggs that turn into
larvae that feed on mice and other small mammals
larvae then develop into immature
ticks called nymphs
nymphs then feed on small mammals
and humans
adult deer ticks usually feed on deer
during the adult part of their life cycles
Both nymphs and adult ticks can transmit Lyme disease causing
bacteria.
On-The-Rise
The recent increase of the deer population in the Northeast and of housing developments in areas where deer ticks are commonly found probably contributed to its increased spread.
The number of reported cases of Lyme disease as well as
the number of geographic areas in which it is found have
increased. Lyme disease has been reported in nearly all
states in the United States, although more than 95% of all reported cases are concentrated in:
Northeast / Mid-Atlantic states
Wisconsin
Minnesota
No. Calif
Lyme disease is also found in large areas of Asia and Europe.
Symptoms of Lyme Disease
Lyme Disease Screening Quiz
Lyme Disease: Test Your Knowledge
Erythema Migrans
Usually, the first symptom of Lyme disease is a red rash
known as erythema migrans (EM).
The telltale rash starts
as a small red spot at the site of the tick bite.
The spot expands over a period of days or weeks, forming a circular or oval-shaped rash.
Sometimes the rash resembles a bull’s eye, appearing as a red ring surrounding a clear area with a red center.
The rash, which can range in size from
that of a dime to the width of your back, appears within a
few weeks of a tick bite and usually at the site of the bite.
As infection spreads, rashes can appear at different sites
on the body. Erythema migrans is often accompanied by flu-like symptoms such as:
fever
headache
stiff neck
body aches
fatigue
Although these symptoms may resemble those of common viral infections, Lyme disease symptoms tend to persist or may come and go.
Arthritis
After several months of B. burgdorferi infection, slightly more
than half of people not treated with antibiotics develop recurrent attacks of painful and swollen joints that last a few days to a few months.
The arthritis can shift from one joint to another.
The knee is most commonly affected.
About 10 to 20% of untreated people will go on to develop chronic
arthritis.
Neurologic Symptoms
Lyme disease also can affect your nervous system,
causing symptoms such as:
stiff neck and severe headache (meningitis)
temporary paralysis of facial muscles (Bell’s palsy)
numbness, pain, or weakness in the limbs
poor muscle movement
More subtle changes also have been associated with Lyme disease such as:
memory loss
difficulty concentrating
change in mood or sleep habits
Nervous system problems usually develop weeks, months, or even years following an untreated infection. These symptoms often last for weeks or months and may return.
Heart Problems
Fewer than 10% of people with Lyme disease
develop heart problems, such as irregular heartbeat,
which can start with dizziness or shortness of breath.
These symptoms rarely last more than a few days
or weeks. Such heart problems generally show up
several weeks after infection.
Other Symptoms
Less commonly, untreated people may develop other
problems weeks, months, or even years after infection.
Lyme disease can also result in:
eye inflammation
hepatitis (liver disease)
severe fatigue
Although none of these problems is likely to appear without other Lyme disease symptoms being present.
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