Toxoplasma Antibody (IgG)

The Toxoplasma Antibody (IgG) test contains 1 test with 1 biomarker.

Brief Description: The Toxoplasma IgG Antibody test is a specialized serological assay that detects the presence of IgG antibodies specific to Toxoplasma gondii—a parasitic protozoan. This test aids in diagnosing past or recent infections and assessing an individual's immune response against the parasite.

Also Known As: Toxoplasma gondii antibody test, toxoplasma gondii test, t. gondii antibody test, t. gondii test, toxoplasmosis test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a Toxoplasma Antibody IgG test ordered?

Testing for T. gondii antibodies isn't typically done on expectant women, but it may be done if a doctor wishes to know if the woman has ever had toxoplasmosis and if she's been around cat excrement, raw or undercooked meat, or contaminated food or water. During the course of the pregnancy, the test may be performed once or more times if the antibody test is negative but suspicion is still high.

A person with a compromised immune system who exhibits flu-like symptoms or anyone else with symptoms or problems that point to toxoplasmosis may be required to undergo antibody testing. Toxoplasmosis symptoms and signs may include:

• enlarged lymph nodes
• Night sweats and a fever
• weakness, exhaustion
• Headache
• Body pains
• Occasionally, a sore throat

A more severe infection that affects the brain and central nervous system could, for example, produce seizures or impairments in vision and cognition.

When a toxoplasmosis infection in an immunocompromised person is suspected or to find out if a baby has been infected, molecular testing may be used. When a mother exhibits symptoms of an acute infection, as shown by a positive Toxoplasma IgM antibody test result, amniotic fluid may be analyzed during pregnancy.

What does a Toxoplasma Antibody IgG Blood test check for?

The parasite Toxoplasma gondii is the source of the infection known as toxoplasmosis. Testing can identify parasite genetic material in the blood or identify antibodies in the blood that are created in response to an infection. Testing is carried out to identify and classify a recent or old infection.

The parasite T. gondii is invisible to the unaided eye. In the majority of healthy people, the infection either has no symptoms or produces a mild illness that resembles the flu. However, the parasite can have serious consequences if it infects a pregnant woman and spreads to her unborn child or a person with a compromised immune system.

A lot of people have T. gondii. It is widespread throughout the world and has affected up to 95% of the population in some nations. The CDC estimates that 23% of people aged 12 and up have toxoplasmosis. By consuming infected food or water, particularly raw or undercooked meat, handling contaminated kitty litter or engaging in polluted play areas, passing from mother to child, and infrequently during organ donation or blood transfusion, are all ways to catch the virus.

Wild and domestic cats are T. gondii's exclusive hosts. T. gondii reproduces and creates eggs coated in protective coverings when cats contract the disease by eating infected birds, rats, or contaminated raw meat. Millions of tiny oocysts may be released into the cat's stool for several weeks while the infection is ongoing. Within a few days, the oocysts become infectious and can endure for several months. T. gondii only completes a small section of its lifecycle in all other hosts, including humans, before forming dormant cysts in the muscles, brain, and eyes. These cysts are kept dormant by the host's immune system, which also defends the body against further infection. Unless the immune system is weakened, the latent stage can last the entirety of the host's life.

People with compromised immune systems, such as those with HIV/AIDS, those undergoing chemotherapy, those who have recently undergone an organ transplant, or those who are taking immunosuppressant drugs, are more susceptible to developing severe symptoms and complications from a new or reactivated Toxoplasma gondii infection. In addition to headaches, seizures, confusion, fever, encephalitis, lack of coordination, and blurred vision, it can also have an impact on the nervous system and the eyes.

A woman's unborn child has a 30–40% chance of contracting the virus if she contracts it while she is pregnant. Early on in the pregnancy, this congenital infection can result in miscarriages, stillbirths, or serious difficulties for the child, such as mental retardation, convulsions, blindness, and an enlarged liver or spleen. Many infected infants, particularly those exposed later in the pregnancy, will look fine at birth but may experience symptoms years later, including serious eye infections, hearing loss, and learning impairments.

Lab tests often ordered with a Toxoplasma Antibody IgG test:

When a Toxoplasma IgG test is ordered, it's often part of a broader evaluation for infectious diseases or prenatal screening. Here are some tests commonly ordered alongside it:

1. Toxoplasma IgM Antibody Test:

   • Purpose: To detect a recent or acute infection with Toxoplasma gondii.
   • Why Is It Ordered: IgM antibodies typically appear soon after infection and may indicate a recent or current infection, which is especially important in pregnancy and in immunocompromised patients.

2. Complete Blood Count (CBC):

   • Purpose: To evaluate overall blood health.
   • Why Is It Ordered: To check for signs of infection or other hematological abnormalities, such as anemia or leukopenia.

3. TORCH Infections Screening:

   • Purpose: To screen for a group of infections that can cause congenital conditions if a woman is infected during pregnancy.
   • Why Is It Ordered: To ensure comprehensive prenatal screening and to identify any potential risks to the fetus.

4. Liver Function Test:

   • Purpose: To assess liver health.
   • Why Is It Ordered: To evaluate liver function, as toxoplasmosis can sometimes cause liver inflammation.

5. Serum Creatinine and Blood Urea Nitrogen (BUN):

   • Purpose: To assess kidney function.
   • Why Is It Ordered: To evaluate kidney health, particularly in the context of systemic infection or in patients with known renal issues.

These tests, when ordered alongside a Toxoplasma IgG Antibody test, provide a comprehensive evaluation of toxoplasmosis infection and its potential impacts. They are particularly important for managing infections during pregnancy, assessing the risk to immunocompromised individuals, and for overall infectious disease evaluation. The specific combination of tests will depend on the individual’s symptoms, risk factors (such as pregnancy or immunocompromised status), and medical history.

Conditions where a Toxoplasma Antibody IgG test is recommended:

The Toxoplasma IgG Antibody test is essential for diagnosing and monitoring various conditions, including:

1. Congenital Toxoplasmosis: Pregnant women are screened to assess the risk of transmitting the infection to the fetus, as congenital toxoplasmosis can lead to severe health issues in newborns.

2. Weakened Immune System: Individuals with compromised immune systems, such as those with HIV/AIDS or undergoing immunosuppressive therapy, are at higher risk of developing severe Toxoplasma infections.

How does my health care provider use a Toxoplasma Antibody IgG test?

The parasite Toxoplasma gondii can infect humans and can be detected by a toxoplasmosis test. Most frequently, it might be done for:

• a woman before or during pregnancy to see if she has ever been exposed to Toxoplasma gondii, and if exposure is suspected during pregnancy.
• a person with flu-like symptoms and a compromised immune system.
• a person who exhibits toxoplasmosis symptoms or indicators.
• a developing child, in which case the amniotic fluid might be examined.

T. gondii is a tiny parasite that lives in the soil and infects cats. By consuming contaminated food or water, handling contaminated cat litter, or by passing from mother to kid, the virus can be contracted. Toxoplasmosis typically has no symptoms in healthy individuals or manifests as a mild flu-like disease. Unless the immune system becomes compromised, in which case the infection can reactivate, a person's immune system maintains the infection dormant and guards the body against additional infection.

There are various ways to check for T. gondii. The individual, their symptoms, and the clinical findings of the healthcare provider all influence the tests and samples that are selected.

Antibody evaluation

An individual's immune system reacts to T. gondii exposure by creating antibodies against the parasite. IgM and IgG antibodies against Toxoplasma may be present in the blood.

The body first produces IgM antibodies in response to a Toxoplasma infection. Within a week or two of the initial exposure, they are present in the majority of people. Production of IgM antibodies increases for a brief period before declining. The level of IgM antibody eventually drops below a measurable level in the majority of persons, sometimes months after the initial infection. When a person has a persistent infection or when dormant T. gondii is reactivated, more IgM may be produced.

Several weeks after the original infection, the body begins to manufacture IgG antibodies, which offer long-term defense. IgG levels increase during the period of active infection and then stabilize as the infection with Toxoplasma clears up and the parasite goes dormant. After being exposed to T. gondii, an individual will continue to have detectable levels of IgG antibody in their blood for the remainder of their lives.

A TORCH panel may occasionally include antibody testing. The term TORCH stands for toxoplasmosis, rubella, cytomegalovirus, and herpes simplex virus testing and refers to a number of illnesses that can harm an unborn child.

T. gondii DNA can be found and measured via molecular testing in samples of blood, cerebrospinal fluid, or amniotic fluid.

What do my Toxoplasma Antibody IgG test results mean?

When analyzing the findings of a toxoplasmosis test, caution must be used. Even though they have an active case of toxoplasmosis, an immunocompromised person may not have a strong antibody response to the T. gondii infection—their IgM and IgG levels may be lower than predicted.

detection of antibodies

IgM IgG Potential Meaning

In the affirmative a current or ongoing infection that may be a sign of reactivation; Several months after the infection has cleared up, IgM may still be positive.

False positive results can happen. A second test technique should usually be used to confirm positive IgM antibody tests, usually by sending the sample to a reference lab that specializes in toxoplasmosis testing.

Only IgM antibodies are made by developing infants. A congenital infection is indicated when a newborn has Toxoplasma IgM antibodies.

DNA analysis

The individual tested has an active toxoplasmosis infection if the molecular test for T. gondii DNA is positive. A negative test result indicates that toxoplasmosis is less likely to be present but does not exclude infection because there may not be enough toxoplasma in the blood or fluid sample to allow for detection.

Reference Range(s) 

• <7.20 IU/mL  Negative
• 7.20-8.79 IU/mL. Equivocal
• >8.79 IU/mL. Positive

Most Common Questions About the Toxoplasma IgG Antibody test:

Purpose and Indications for the Toxoplasma IgG Antibody Test

Why is the Toxoplasma IgG Antibody test ordered?

The Toxoplasma IgG Antibody test is typically ordered to determine if an individual has been previously infected with the parasite Toxoplasma gondii. The presence of IgG antibodies indicates a past infection, while the absence suggests that the individual is susceptible to a primary infection.

What conditions or symptoms might lead a physician to order this test?

A physician might order this test if a person is exhibiting symptoms suggestive of toxoplasmosis, such as swollen lymph nodes, muscle aches, and fever. The test can also be recommended for individuals with weakened immune systems to check for an active or past infection.

Clinical Significance of Test Results

What do positive results in the Toxoplasma IgG Antibody test indicate?

A positive result indicates that the individual has been exposed to Toxoplasma gondii and has developed antibodies against it. It usually means the person had a past infection, is now immune, and cannot be infected again by the same strain.

Do negative results mean that the person is not infected with the parasite?

A negative result generally means that the person hasn't been infected. However, if the exposure was recent, the test might not detect antibodies right away, as it can take some time for the body to produce them.

Interpretation and Follow-up

If the Toxoplasma IgG Antibody test indicates positive results, what should one do next?

If the test is positive, especially in someone with symptoms or with a weakened immune system, further tests, like the Toxoplasma IgM test or PCR, might be ordered to determine if the infection is recent or active. It's essential to consult with a healthcare professional to understand the results and get appropriate advice.

What treatments are available for someone with a confirmed Toxoplasma gondii infection?

Toxoplasmosis is typically treated with a combination of antimalarial and antibiotic drugs. The specific regimen can vary based on the individual's health and whether the infection is acute or chronic.

Dietary Influence and Recommendations

Is there a connection between diet and the risk of contracting Toxoplasma gondii?

Yes, consuming undercooked or raw meat, especially pork, lamb, or venison, can increase the risk of toxoplasmosis. It's advised to cook meat to safe temperatures and practice good hygiene in the kitchen to reduce the risk.

Conditions and Medications Influencing the Test

Can other infections or conditions cause a false-positive result in the Toxoplasma IgG Antibody test?

While the test is generally specific, there are instances where other infections, like rubella or mononucleosis, could potentially produce a false positive. If there's doubt about the result, additional testing may be needed.

Are there any medications known to affect the outcome of the Toxoplasma IgG Antibody test?

There aren't specific medications that interfere with the detection of antibodies in this test. However, medications that suppress the immune system might delay or reduce antibody production.

The Toxoplasma IgG Antibody test provides valuable insights into an individual's exposure to Toxoplasma gondii. It's crucial for detecting infections, especially in vulnerable populations, and ensuring timely treatment.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.