Interpretation of Toxoplasma Serologic Testing*
IgG | IgM | Interpretation† |
|---|---|---|
Negative | Negative | No evidence of infection |
Negative | Equivocal | Possibly early infection or false-positive IgM result |
Negative | Positive | Possibly acute infection or false-positive IgM result |
Equivocal | Negative | Chronic indeterminate |
Equivocal | Equivocal | Chronic indeterminate |
Equivocal | Positive | Possibly acute infection |
Positive | Negative | Infection for ≥ 6 months |
Positive | Equivocal | Infection for probably > 1 year or false-positive IgM result |
Positive | Positive | Possibly recent infection in the last 12 months or false-positive IgM result |
* Except in infants less than 12 months | ||
† If results are equivocal or interpretation is uncertain, testing additional samples at a reference laboratory or testing samples taken two weeks or more later may provide useful information. | ||