Toxoplasma gondii: serologic analyses

Description of tests

The NRC will choose to perform one or more of the following tests :

• IgG and IgM antibodies using one or two different techniques
• IgG avidity determination
• Determination of IgG against different parasite antigens using immunoblot

Purpose of the tests

Interpreting the serological profile as a function of gestational age. To advise on the possibility of a recent infection in pregnancy.

Criteria for performing this test  

• The reference centre only confirms serological analyses in pregnant patients and neonates. Application forms must be completed in full.
• The reference centre will perform the test(s) it deems necessary. As a rule, IgG and IgM are determined first and, depending on the results of this initial screening, additional tests deemed necessary for interpretation of the serological profile may be performed. To diagnose toxoplasmosis in newborns, the NRC may compare the IgG profile with maternal antibodies via immunoblot. In this case, send one serum from the child and one from the mother.

Instructions for samples and transport 

At least 1 ml of serum, is required to allow all necessary tests to be performed:

• For non-frozen serum: transport at room temperature
• In the case of frozen serum: preferably transport in frozen condition

Unacceptable requests

• Incomplete application form
• Insufficient sample
• Sample not suitable for analysis
• Application does not meet the criteria

Turn around time  

Depends on the number of confirmation tests required. Response time may be up to 1 week.

Reporting of test results  

The laboratory reports the results and comments and sends it to the requesting laboratory by post or via medibridge (UZ Brussel).