Tests for HIV infection

The diseases caused by HIV-1 and HIV-2 are similar although there is some evidence that type 2 is less severe. HIV-2 is very rare in Canada.

A new subtype of HIV-1 has been identified as subtype 0. Antibodies to subtype 0 may not be detectable by ELISA; provincial laboratories are modifying their testing kits to identify this subtype. Specific questions about the incidence of this subtype should be directed to provincial public health authorities.

HIV tests are inexpensive. The detection of HIV antibodies by ELISA (also called EIA) is the most sensitive and commonly used test. However, all positive test results must be verified by a second independent assay, usually the Western blot or immunoblot.

Interpretation of test results (GIF, 24K)

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