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Lyme disease is an infection caused by a spiral-shaped bacterium Borrelia burgdorferi, that is carried primarily by ticks of the Ixodes species. Standard precautions, such as wearing protective clothing, using a tick repellent and checking for and removing ticks at regular intervals are the best defences against Lyme disease.

People bitten by an infected tick develop this inflammatory disease, which first affects the skin and then may spread to the joints, nervous system, and other body systems. About half of people infected develop a “bull’s eye” rash within 1-2 weeks. 

The rash is usually red and at the location of the tick bite. Other symptoms can include arthritis-like joint pain, fever, headache, muscle aches, fatigue and stiff neck.

Because these symptoms are similar to those of other illnesses, diagnosis of Lyme disease is often delayed. If left untreated, severer symptoms can develop, including painful arthritis, joint swelling, heart problems, and central nervous system problems that can lead to mental disorders. Fortunately, with early detection and treatment, Lyme disease can be cured. There are several oral antibiotics available.

There are a number of tests that can diagnose Lyme disease. One measures the levels of antibodies in the body that have developed against the Borrelia burgdorferi bacterium. This test may appear negative if it is done in the first few weeks after infection. Therefore, if symptoms persist the test should be repeated a few weeks later. After 4-6 weeks, an antibody test is very likely to be positive in true cases. However, because it can be falsely positive in some people who do not actually have Lyme disease, it is recommended that a Western blot test is also performed to confirm the initial screening test. This is more accurate and specific for antibodies to the Borrelia burgdorferi organism. Antibody tests will remain positive for months to years following successful treatment of Lyme disease and cannot be used as a test of cure. As with all pathology testing, it is important that testing for Lyme disease is performed in an accredited laboratory to reduce the risk of incorrect results.

Lyme disease is found in North America, Europe and Asia, particularly in cooler forested areas. In Australia there are no reported cases of locally acquired Lyme disease. In the 1990s, 12,000 ticks were collected from different parts of NSW and were tested for Borrelia bacteria. No evidence of Borrelia infection could be found in any of the ticks collected. Since that time there have been reports of Borrelia-like organisms being found in Australian ticks but these have not yet been confirmed. There are several research groups actively searching in Australian ticks. Some medical practitioners believe that there is a Lyme-like disease present in Australia. However, until an organism is found and characterised it is not possible to develop reliable tests. Most Australian microbiologists believe that many of the test results from non-NATA accredited laboratories in Australia and overseas are unreliable when used in Australian patients who have not travelled overseas. This is discussed in the RCPA Position Statement to be found in the Related pages section.

However, ticks in Australia can transmit other infectious diseases such as those caused by several Rickettsia species. It is generally not necessary to have testing for Lyme disease if there is no history of travel to countries where this disease is commonly found. 

Last Review Date: April 10, 2020

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