Interpretation

Negative: No IgM or IgG antibodies to Toxoplasma gondii detected. False-negative results may occur in immunocompromised patients or if testing was performed within 1 to 2 weeks of initial exposure and repeat testing may be helpful. A single negative result should not be used to rule out toxoplasmosis, and repeat testing is recommended for patients at high risk for infection.

Borderline: Repeat testing on a new sample collected in 2 to 3 weeks is recommended to assess for seroconversion. Further confirmatory testing may be necessary at a Toxoplasma reference laboratory in borderline results persist following repeat testing.

Positive: Toxoplasma gondii IgM antibodies detected. Specimens with positive results should be confirmed by a laboratory with expertise in the diagnosis of toxoplasmosis. T gondii IgG antibodies detected, indicating recent or past infection. A significant change in T gondii IgG levels suggests recent infection. For confirmation of toxoplasmosis, the US Food and Drug Administration issued a Public Health Advisory (07/25/1997) that recommends sera found to be positive for T gondii IgM antibodies should be sent to a Toxoplasma reference laboratory.