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Lyme Borreliosis

Lyme Disease

Lyme disease (Lyme borreliosis) is diagnosed using 2 tests conducted in sequence. A first test (Lyme disease serology) screens for all antibodies that may be associated with the presence of the bacteria responsible for the disease. Since several antibodies can produce false positive results in this first step, all positive or inconclusive serological test results must be confirmed by a more specific analysis called immunoblotting. The results of this second test are used to confirm the presence of the disease.

Negative serological test results indicate that Lyme disease is probably not involved. However, a note indicates that samples taken too early (less than 2 weeks after the onset of symptoms) could contain too few antibodies to test positive. If there is strong clinical suspicion, a second serum sample must be collected 7 to 14 days after the first.

Due to the risk of generating false positives, health organizations (Centers for Disease Control, Laboratoire de Santé publique du Québec, etc.) recommend that immunoblotting should not be done when the first-line serological test is negative.

Term of the Week

Hot zone

A hot zone is a section of a facility (sometimes an entire facility or even a city district) where there is a high risk of contamination by patients with an infectious disease. All individuals entering a hot zone must respect appropriate protective measures. By analogy, “cold zone” and “warm zone” are used to refer to areas where there is no infected individual or only individuals suspected of having an infection.