New HIV diagnosis

An individual receiving a first confirmed HIV-positive test in Ontario. A reactive rapid/point-of-care test result (i.e. suggestive of an HIV-positive result) must be confirmed through laboratory testing to be counted as a new HIV diagnosis. Individuals with previous record of an HIV-positive test in Ontario are excluded to prevent double-counting. However, individuals who test HIV-positive in Ontario through both non-nominal (anonymous or coded) and nominal testing, or who test HIV-positive more than once through non-nominal testing, may be double-counted due to the lack of identifying information to link the these tests in the laboratory database.

Of note, individuals diagnosed with HIV for the first time outside of Ontario, but who subsequently moved to the province and tested again, are included as a new diagnosis. This means that migration can potentially influence trends in new diagnoses in Ontario.