1st order laboratory parameters – obligatory laboratory tests.
- Small blood count
- Differential blood count
- Inflammatory parameter – CRP (C-reactive protein)
- Direct microscopic detection of the pathogen in the blood.
- Toxoplasma gondii antibody detection (IgM/IgG detection in immunofluorescence)Note: Limited significance would be logical test method in patients with immunosuppression.
- PCR (polymerase chain reaction) for direct detection of the parasite – in patients with immunosuppression.
Pregnancy and toxoplasmosis
In pregnant women, serology should be repeated 14 days after a positive IgM test. In pregnant women without immunity, repeated tests should be performed preferably at intervals of eight weeks, but at least not greater than twelve weeks until the end of pregnancy, so as not to miss a late seroconversion in the last trimester (third of pregnancy).
Interpretation
| Toxoplasma gondii IgG | Toxoplasma gondii-IgM | Results, usually indicate the following infection status. |
| Low | Low | Not relevant, inactive infection |
| High | Low | Decaying infection |
| High | High | Recent infection |
| Low | High | Acute infection |
If connatal infection is suspected, parallel testing of maternal and fetal serum is required. The IgG antibodies of the newborn detected by comparative immunoblot or/and the persistence or increase in concentration of IgG serum antibodies in the postnatal course are indicative of a connatal infection.
The direct or indirect detection of “Toxoplasma gondii” in connatal infections is notifiable according to the Infection Protection Act (IfSG).
2nd order laboratory parameters – depending on the results of the medical history, physical examination, etc. – for differential diagnostic clarification.
- Toxoplasma gondii DNA detection.
- Liver parameters – alanine aminotransferase (ALT, GPT), aspartate aminotransferase (AST, GOT), glutamate dehydrogenase (GLDH), gamma-glutamyl transferase (γ-GT, gamma-GT; GGT), alkaline phosphatase, bilirubin.
- Renal parameters – creatinine, urea, uric acid.
- CSF puncture (collection of cerebrospinal fluid by puncture of the spinal canal) for CSF diagnosis – in the case of involvement of the central nervous system.
- TPHA search test – in case of suspected syphilis (lues).
- HIV antibody screening test
- EBV antibody test – if Epstein-Barr infection is suspected.
- Rubella antibody test
- Tuberculin test or test for acid-fast rods – if tuberculosis is suspected.
- Blood tests for pathogens such as histoplasmosis, herpes simplex virus or varicella zoster virus.
