MMS Physician Focus: February 2010
By Martin Kafina, M.D.
Lyme disease is an increasing threat in Massachusetts, and of
all the infectious diseases that threaten our personal and public
health, it can be one of the most problematic.
The number of confirmed cases in the state is climbing rapidly:
from 1999 through 2008, the incidence of Lyme disease quadrupled,
from just under 1,000 cases to nearly 4,000. The latest statistics
from the Centers for Disease Control indicate that in 2008 the
state ranks second, behind New York, in the actual number of
confirmed and probable cases of Lyme.
Lyme disease is the most commonly reported vectorborne disease
in the United States, according to the CDC. (A vectorborne disease
is one transmitted to humans or other animals by an insect or other
arthropod-type animal. One example: mosquitoes, which transmit West
Nile Virus.) Nationally, the number of confirmed and probable cases
reported in 2008 exceeded 35,000, with more than 90 percent
occurring in just 10 states, concentrated in the northeastern
U.S.
The disease was first outlined in 1977 by epidemiologists at
Yale University, following an investigation of an outbreak of
arthritis among a dozen or so children in Lyme, Connecticut. The
condition is transmitted by ticks, tiny insects some only the size
of a pencil point. These ticks carry what is called a spirochete -
a microbe or bacteria identified as Borrelia burgdorferi - that
infects humans. The microbe is similar to the spirochete that
causes syphilis, and if treated early with antibiotics, the
condition can be cured.
The tick latches on to humans for a blood meal, and as it feeds
itself, the tick regurgitates the spirochete - or germ - into the
human's blood stream infecting the person. If undetected, the tick
may feed itself for 24-48 hours. Removing the tick before that time
period will usually prevent the infection from
occurring.
The signature mark of early infection is a rash, appearing
anytime between 10 to 20 days after the bite as a red circle and
taking the shape of a "bulls-eye" with a fleshy clearing in the
middle. If you see the rash, you've been inoculated with the
spirochete, and you should call your doctor.
When contracted, the disease initially presents flu-like
symptoms, with accompanying fatigue, fever, headache and sore
muscles and joints. But if the disease is missed, misdiagnosed, or
left unattended, the disease can move into secondary and tertiary
stages, and that's when serious problems can occur to joints, the
nervous system, and even the heart.
It's also important not to confuse Lyme disease with other
conditions such as fibromyalgia or Lupus, which can present similar
symptoms. Testing for Lyme disease, with a physical exam and blood
test, can determine if you have the disease. In some instances of
late Lyme disease, there is a condition known as
antibiotic-resistant Lyme disease. This can occur when the immune
system is activated by molecular debris (e.g., dead spirochetal
proteins), and can be treated by a rheumatologist with certain
immunomodulatory medicines.
Lyme disease can be contracted throughout the year, when the
temperature is above freezing and ticks are seeking their blood
meal. But ticks are most active in warm weather and present the
biggest risk then. According to state statistics, the greatest
numbers of cases are reported in July, followed by June and August.
Prevalence is also high in May, September, and October. For those
who spend a lot of time outdoors or live in tick-infested areas -
areas with woods, overgrown grass, or lots of bushes -- vigilance
is the key.
The most important thing to remember: Early detection is
critically important, because if caught early, Lyme disease is
curable with a regimen of antibiotics, thus preventing those
serious health problems.
No vaccine to prevent the disease currently exists, so the best
prevention is protection - wearing long-sleeve shirts and pants,
using a repellent with DEET according to instructions, and - most
important -- performing a "tick check" on yourself after being in
tick-infested areas. And animal lovers should know that animals can
also get Lyme disease, so if you have pets or share space with
animals, check them as well. For more information on Lyme disease,
visit the state Department of Public Health at www.mass.gov/dph or the CDC at
www.cdc.gov.
Martin Kafina, M.D., is a rheumatologist at Emerson Hospital in
Concord and an instructor at Harvard Medical School. Physician
Focus is a public service of the Massachusetts Medical Society.
Readers should use their own judgment when seeking medical care and
consult with their physician for treatment. Send comments to PhysicianFocus@mms.org
