Toxoplasma gondii IgG antibody (serum/plasma)

What This Test Measures

The test detects IgG antibodies—proteins produced by your immune system in response to past exposure to *Toxoplasma gondii*. If present, it suggests you’ve likely encountered the parasite at some point, even if you don’t currently have symptoms.

Why It’s Ordered

Doctors may order this test if you have symptoms like fatigue, fever, or muscle pain that could be linked to toxoplasmosis, especially if you’ve recently traveled to areas with high parasite exposure or have weakened immunity (e.g., from HIV, chemotherapy, or organ transplant). It’s also used in pregnancy to check for antibodies before or after exposure.

When You Might Need It

You might need this test if you’re planning pregnancy, have an immune-compromised condition, or if you’ve had recent contact with cats (a common source of the parasite). Some people with chronic illnesses also get it periodically to monitor exposure risk.

What to Expect

A small blood sample is drawn from a vein in your arm. The sample is sent to a lab where it’s tested for IgG antibodies. Results are typically ready within a few days. No special preparation is needed, but avoid heavy exercise or eating a large meal before the test.