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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 exposure to the parasite. It helps determine if you’ve been infected with toxoplasmosis, a condition that can affect the immune system and sometimes the eyes or brain.

Quick summary

["This test helps assess past exposure to toxoplasmosis and may guide decisions about pregnancy, immune health, or risk management."]

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

Key facts at a glance

LOINC
40677-7
Short code
T gondii IgG Ser Ql IA
Synonyms
T gondii IgG Ser Ql IA
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
82784
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

Why This Test Is Done

Doctors may order this test if you have symptoms like fever, fatigue, or muscle pain that could suggest toxoplasmosis. It’s also commonly checked in pregnant women to ensure safety for the baby, in people with weakened immune systems (like those with HIV or undergoing chemotherapy), or in individuals with eye or neurological concerns that might be linked to past infection.

What the Test Measures

The test detects IgG antibodies, which your immune system produces after recovering from an infection. These antibodies stay in your blood for years, helping your body recognize and fight the parasite if it returns.

Sample Collection and Preparation

Blood is drawn from a vein in your arm. The sample is sent to a lab where it’s tested for the presence of IgG antibodies using an immunoassay method, which identifies the antibodies without measuring their exact concentration.

What the Results Mean

A positive result means you likely had toxoplasmosis at some point. A negative result suggests you either haven’t been infected or were infected very recently. Results don’t indicate the severity of the infection or whether you’re currently infected.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

IgG Antibody to Toxoplasma

Frequently asked questions

What does a positive result mean for my health?
A positive IgG result indicates past exposure to toxoplasmosis, which is generally harmless but may affect certain groups differently. For example, pregnant women or people with weakened immune systems should discuss the findings with their doctor to assess risks or preventive measures.
Can a negative result mean I’m not infected now?
A negative result suggests you haven’t been infected recently or haven’t developed antibodies yet. However, if you suspect recent exposure, your doctor may recommend retesting or checking for IgM antibodies (another type of antibody that appears shortly after infection).
Why would my doctor order this test if I don’t have symptoms?
Your doctor may order this test for screening purposes, such as during pregnancy to protect the baby, for people at higher risk of infection (like those living in areas with contaminated water or food), or if you’ve had recent contact with someone who has toxoplasmosis.
  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