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Toxoplasma gondii IgG Antibody (Serum/Plasma)

Published: August 9, 2026Updated: August 16, 2026

This test checks for antibodies to the parasite Toxoplasma gondii, which can indicate past or current infection.

Quick summary

["Your body’s immune response to a parasite infection may be detected here."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
100119-7
Short code
T gondii 45kD Ab Ser Ql IB
Synonyms
T gondii 45kD Ab Ser Ql IB
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ib
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Does This Test Measure?

The test detects IgG antibodies in your blood. IgG is a type of antibody your immune system produces in response to an infection by Toxoplasma gondii, a parasite that can affect many organs, including the brain and eyes. These antibodies stay in your blood for years after recovery, helping the immune system remember the infection for future protection.

Why Might This Test Be Ordered?

Doctors may order this test if you have symptoms like fever, fatigue, or muscle aches that could suggest infection, especially if you’ve recently traveled to areas with high parasite exposure (e.g., parts of the world where Toxoplasma is common). It’s also used to monitor people with weakened immune systems, such as those with HIV/AIDS or undergoing chemotherapy, to ensure they’re protected against Toxoplasma.

What Does a Positive Result Mean?

A positive result means your body has likely been exposed to Toxoplasma gondii in the past, and your immune system has produced antibodies to fight it. This doesn’t necessarily mean you’re currently sick, but it confirms past infection. If you’re immunocompromised, this test helps assess your risk of severe complications.

What Does a Negative Result Mean?

A negative result suggests you either haven’t been exposed to Toxoplasma or your immune system hasn’t yet produced detectable antibodies. If you’re at risk (e.g., pregnant or immunocompromised), further testing or prevention strategies may be recommended.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Who Should Be Tested?

Short name

IgG Antibody to Toxoplasma

Frequently asked questions

Why might my doctor want to check this?
Your doctor may recommend this test if you have symptoms of Toxoplasma infection (like unexplained fevers, muscle pain, or neurological issues), if you’re at higher risk (e.g., pregnant, HIV-positive, or undergoing cancer treatment), or if you’ve traveled to areas with higher parasite exposure. It’s also used to screen people before organ transplants to prevent severe infections.
How is this test different from a Toxoplasma IgM test?
This test measures IgG antibodies, which appear later in infection and can persist for years. IgM tests detect a different type of antibody that appears sooner but fades faster. IgG is often used to confirm past exposure, while IgM helps track acute (current) infection.
What should I do if my test is positive?
If your test is positive, your doctor may recommend follow-up testing (like IgM) to check for active infection. If you’re immunocompromised, they may monitor you closely for symptoms. Prevention (like avoiding raw meat and proper food handling) is also important to avoid re-exposure.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy