Lyme Disease:
Lyme Disease On The Rise
Medical Author: William C. Shiel Jr., MD, FACP, FACR
Lyme disease is caused by infection with a bacterium called a spirochete (Borrelia burgdorferi) and is transmitted to humans by infected ticks (Ixodes scapularis and I. Pacificus). Patients with early stage Lyme disease have a characteristic rash (erythema migrans) accompanied by nonspecific symptoms (for example, fever, malaise, fatigue, headache, myalgia, and arthralgia). Lyme disease can usually be treated successfully with standard antibiotics.
The U.S. Centers for Disease Control and Prevention (CDC) released the results of a six-year survey study of Lyme disease from 1992 to 1998. During this period, a total of 88,967 cases of Lyme disease were reported to CDC by 49 states and the District of Columbia, with the number of cases increasing from 9,896 in 1992 to 16,802 in 1998. The researchers concluded that the increase in reported cases is probably a result of both a true increase in incidence within known high-risk areas as well as more complete reporting as a result of enhanced Lyme disease surveillance. They noted that surveillance capabilities and public awareness of Lyme disease have increased during this period.
Researchers also note that Lyme disease remains underreported with an estimated seven to 12 cases for each reported case.
What Is Lyme Disease? What Causes Lyme Disease?
Lyme disease is a bacterial illness caused by a bacterium called a spirochete. In the United States, the actual name of the bacterium is Borrelia burgdorferi. In Europe, another bacterium, Borrelia afzelii, also causes Lyme disease. Certain ticks found on deer harbor the bacterium in their stomachs. Lyme disease is spread by these ticks when they bite the skin, which permits the bacterium to infect the body. Lyme disease is not contagious from an affected person to someone else. Lyme disease can cause abnormalities in the skin, joints, heart, and nervous system.
What Is The History Of Lyme Disease?
Interestingly, the disease only became apparent in 1975 when mothers of a group of children who lived near each other in Lyme, Connecticut, made researchers aware that their children had all been diagnosed with rheumatoid arthritis. This unusual grouping of illness that appeared "rheumatoid" eventually led researchers to the identification of the bacterial cause of the children's condition, what was then called "Lyme disease" in 1982.
Ticks are carriers of the Lyme bacterium in their stomachs. The ticks then are vectors that can transmit the bacterium to humans with a tick bite. The number of cases of the disease in an area depends on the number of ticks present and how often the ticks are infected with the bacteria. In certain areas of New York, where Lyme disease is common, over half of the ticks are infected. Lyme disease has been reported most often in the northeastern United States, but it has been reported in all 50 states, as well as China, Europe, Japan, Australia, and parts of the former Soviet Union. In the United States, it is primarily contracted in the Northeast from the state of Maine to Maryland, in the Midwest in Minnesota and Wisconsin, and in the West in Oregon and Northern California.
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Lyme Disease Information: Lime Disease Foundation
