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The VDRL test detects the presence of syphilis. The test is indicated for individuals with symptoms or risk of exposure to syphilis or other STDs. Syphilis is a mandatory reporting disease. The VDRL test detects a constituent associated with the presence of the bacteria that causes syphilis (Treponema pallidum). In an undiagnosed individual, a positive VDRL test must be confirmed at the Laboratoire de santé publique du Québec (LSPQ) by a technique that detects the bacterium itself. Syphilis can be detected approximately ten days after infection. The window (period during which detection is possible) ends twelve weeks after exposure.

A negative VDRL test result indicates the absence of syphilis or the presence of syphilis in a dormant stage. If suspected, the test should be repeated three months after the presumed contact. A positive VDRL test confirmed by the LSPQ indicates the presence of syphilis, which will need to be staged based on the clinical presentation (primary or secondary infectious, latent, etc.). If a positive VDRL test is not confirmed by the LSPQ, there is no infection unless it is in the incubation period. A new test is indicated two to four weeks after the first.

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.