Toxoplasmosis (IgG/IgM)
Tests for antibodies to Toxoplasma gondii, the parasite that causes toxoplasmosis, to determine current or past infection status.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
This test detects IgG and IgM antibodies produced by the immune system in response to infection with Toxoplasma gondii, a protozoan parasite that infects a wide range of warm-blooded animals, including humans. Infection most commonly occurs through ingesting undercooked contaminated meat, exposure to cat feces containing the parasite, or transmission from mother to fetus during pregnancy.
Once inside the body, T. gondii forms tissue cysts that can persist for the lifetime of the host, most commonly in skeletal muscle, heart tissue, brain, and eyes. The two antibody classes measured by this test provide information about timing. IgM antibodies typically appear first during a new infection and can remain detectable for months to years in some individuals. IgG antibodies develop somewhat later, rise over several weeks, and persist indefinitely, indicating that the immune system has encountered the parasite at some point. Healthcare providers order this test when evaluating symptoms suggestive of toxoplasmosis, during pregnancy screening, and in immunocompromised individuals who are at higher risk of serious complications from active infection.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals who have been exposed to cats or cat litter boxes and are experiencing flu-like symptoms, as cats are the primary hosts for the Toxoplasma gondii parasite.
- People who regularly consume undercooked or raw meat, particularly pork, lamb, or venison, which can harbor tissue cysts of the parasite.
- Pregnant individuals or those planning pregnancy, since maternal infection during pregnancy can potentially be transmitted to the developing baby and may cause serious complications.
- Immunocompromised patients, including those with HIV, cancer patients receiving chemotherapy, or organ transplant recipients, who are at higher risk for severe complications from toxoplasmosis.
- Individuals experiencing unexplained swollen lymph nodes, muscle aches, or persistent fatigue that could be consistent with toxoplasmosis infection.
What to expect
Preparation
No special preparation is required for this test. Individuals can eat and drink normally before their appointment, and no fasting is necessary. There are no medication restrictions for this test.
Sample Type
The test requires a simple blood draw from a vein in the arm. A healthcare professional will insert a small needle into a vein, typically in the inner elbow area, to collect a blood sample.
Collection
The blood collection typically takes just a few minutes and causes minimal discomfort. After the sample is collected, a small bandage will be applied to the puncture site, and normal activities can be resumed immediately.
Turnaround
Results are typically available within 1-3 business days after the sample reaches the laboratory. Results will be securely delivered through the patient portal or as directed during the ordering process.
Understanding your results
Results are reported for both IgM and IgG antibodies. Elevated IgM suggests recent or current infection, though IgM can sometimes persist well beyond the acute phase, so a positive IgM alone does not definitively confirm a new infection. Elevated IgG with negative IgM generally indicates past exposure and established immunity. Negative results for both antibody classes suggest that no prior exposure has occurred. Healthcare providers interpret the combination of IgM and IgG results alongside symptoms, exposure history, immune status, and clinical context to determine infection timing and whether treatment or monitoring is necessary.
| Population | Reference Range | Notes |
|---|---|---|
| Adults (IgG) | Negative: <7.2 IU/mL; Positive: ≥8.8 IU/mL | Values between 7.2-8.7 IU/mL may be considered equivocal |
| Adults (IgM) | Negative: <8 AU/mL; Positive: ≥10 AU/mL | Values between 8-9.9 AU/mL may be considered equivocal |
Reference ranges may vary by laboratory and individual factors. Results should be interpreted by a healthcare provider in the context of your overall health.
What does a “Low” result mean?
Negative results for both antibodies typically mean the individual has likely never had a toxoplasma infection and may be susceptible to future infection. Most people with healthy immune systems who are infected with Toxoplasma gondii do not know they have it because they do not have any symptoms. Negative results may also occur in very early infection before antibodies have developed or in severely immunocompromised individuals who cannot produce adequate antibody responses.
What does a “High” result mean?
Positive IgG antibody results generally indicate past exposure and immunity, with detectable levels of Toxoplasma antibody indicating exposure to Toxoplasma gondii. Positive IgM results can indicate recent infection if testing occurs within one or two weeks of infection, while positive IgG results after several weeks suggest current or past infection. However, both antibody types can persist for extended periods, so positive results should always be interpreted by healthcare providers in the context of symptoms and clinical history.
Privacy & confidentiality
All toxoplasmosis test results are kept strictly confidential and HIPAA-compliant. Results are not shared with insurance companies or added to insurance explanation of benefits. No doctor visit is required to order this test, and results are securely delivered only to the individual who ordered the testing.
Frequently asked questions
Related tests
Complete Blood Count (CBC)
May show elevated white blood cells or other changes that can accompany infections
View TestHIV Test
Important for immunocompromised individuals who are at higher risk for severe toxoplasmosis
View TestHCG Pregnancy Test
Essential for women of reproductive age since maternal infection can affect pregnancy outcomes
View TestCMV Test
Another common infection that can cause similar symptoms and complications in pregnancy and immunocompromised patients
View TestLast reviewed: April 2026
CPT Code: 86777, 86778
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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