Toxoplasma Test - IgM

Toxoplasma Encephalitis, Ocular Toxoplasmosis, Congenital toxoplasmosis

A protozoan parasite, Toxoplasma gondii, can live inside cells. It can infect humans as well as a variety of other life forms. Toxoplasmosis is a parasitic infection that can induce flu-like symptoms. Many warm-blooded creatures, such as birds and mammals, can transmit it.

Infected definitive hosts (cats) excrete oocysts in their faeces, which mature and become infectious in the soil. Humans contract toxoplasmosis through:

• Ingesting cat faeces-contaminated food or drink.
• By eating undercooked meat containing live oocysts.
• Drinking unpasteurised goat's milk.
• Eating contaminated meat causes toxoplasmosis.
• Consumption of parasites in raw meat.
• Casual handling of cat litter.
• Contaminated vegetables and other foods.
• Ingestion of parasites in the soil by dirt-eating children infects humans.
• It can also be passed down through the placenta during pregnancy.

During the acute stage of acquired maternal illness, parasites can pass through the placenta and cause congenital toxoplasmosis. The risk of foetal infection varies by the month of maternal infection during pregnancy. Congenital toxoplasmosis becomes more common as the pregnancy proceeds.

The Toxoplasmosis antibody test is a blood test that analyses specific immunoglobulins. Antibodies are proteins produced by the immune system to combat the antigens of a protozoan called Toxoplasma gondii. The first antibody produced by the body to fight toxoplasmosis is immunoglobulin M (IgM). It is found primarily in the blood and lymph fluid (a clear white fluid rich in white blood cells). While it can detect an infection early on, it only lasts for around 18 months at most.

Congenital toxoplasmosis causes severe systemic or neurologic disease in around 20% to 30% of infants infected in pregnancy. Approximately 10% have only eye involvement and the rest are asymptomatic at birth. Premature delivery and consequent neurologic, intellectual and hearing abnormalities may arise from infection.

Adults, especially immunodeficient or immunosuppressed adults, are usually asymptomatic when infected with this parasite. But in symptomatic cases, the affected person often shows inflammation and other nonspecific symptoms. It is difficult to make a precise diagnosis due to these symptoms that are similar to those of many other illnesses.

Moreover, the symptoms of toxoplasmosis could be fatal in people who are immunodeficient or immunosuppressed. In many cases, these infections affect the central nervous system due to the reactivation of previous infections.

A research study of Toxoplasma gondii in Indian women of childbearing age shows the prevalence rate of this infection is highest in South India at 37.3% and the lowest in West India at 8.8%.

Other Names of the Toxoplasma IgM Test

• T. gondii
• Toxoplasma gondii
• Toxoplasma IgM Antibody Assays
• Toxoplasma IgM Antibody Serum
• Toxoplasmosis

What Does the Toxoplasmosis IgM Test Detect and Who is This Prescribed For?

The Toxoplasma IgM antibodies are produced as a reaction to T. Gondii infection. The Toxo IgM test measures levels of these IgM antibodies. Toxo antibodies are elevated during the toxoplasmosis and a few months after the infection.

Toxoplasmosis testing is suggested for:

• Women who are trying to conceive.
• Newly pregnant women should determine if they have a history of parasite exposure.
• The amniotic fluid test is essential in an unborn baby whose mother has a history of exposure to T. gondii.
• Those who have symptoms of toxoplasmosis.
• People with weak immune systems and experiencing flu-like symptoms.

Toxoplasmosis is requested if the doctor suspects any of the conditions listed above.

Most women with toxoplasmosis infection are asymptomatic. Although the toxoplasmosis IgM test is indicated for those with the following:

• Lymphadenopathy

The clinical symptom of a recent infection is lymphadenopathy. Typically, there are enlarged nodes that are distinct, non-tender and without pus. Some other infections are polymyositis, dermatomyositis and chorioretinitis.

Some other symptoms related to infection are:

• Flu-like symptoms
• Fever
• Chills
• Fatigue
• Headache
• Eye inflammation and fever
• Diarrhoea
• Vomiting
• Weight loss
• Neurological symptoms
• Jaundice
• Difficulty in breathing due to pneumonia
• Lethargy, Tiredness
• Anorexia

The Toxoplasma IgM test determines the presence of antibodies to the parasite T. gondii. Doctors also recommend Toxo IgM testing to monitor the course of treatment.

Although, the result of a single sample is insufficient evidence for a recent infection diagnosis. IgM antibodies to T gondii may be missing if a serum sample is taken too soon after infection. Whenever this is suspected, a second serum sample is taken and the test is repeated after two to three weeks.

The Toxoplasma IgM test identifies the presence and absence of IgM antibodies. The readings will be within normal ranges if the person does not have the infection.

The range of Toxoplasma IgM tests are:

• Equivocal is 2 to 3 IU/ml
• Non-Reactive is equal to or greater than 0.6 (IgM)
• Positive is above 3 IU/ml

The detection of IgM-class antibodies to T. gondii helps in screening for Toxoplasma gondii infection. According to the FDA, IgM-positive screening assay results should be validated by a Toxoplasma reference laboratory.

The findings of a TOXO test are equivocal, positive or negative. Positive results indicate higher IgM antibodies and negative results indicate lower numbers of IgM antibodies.

Equivocal Toxoplasma IgM Test

• Toxo IgM status not determined.
• Obtain an extra sample for re-testing within a reasonable timeframe (two to three weeks).

Positive Toxoplasma IgM Test

Toxo IgM antibody detected, which may indicate a current or recent infection.

• A single IgM-positive result indicates that the person has been exposed to Toxoplasma gondii in the past.
• Identifies the patient has a history of exposure to Toxoplasma gondii.
• The patient has a current infection with Toxoplasma gondii.
• Suffering from active toxoplasmosis.
• An acute infection that could have occurred up to a year ago.

Negative Toxoplasma IgM Test

• Toxoplasma IgM test findings that are negative suggest that the person is immune to toxoplasmosis.
• A single negative result from this assay does not rule out toxoplasmosis, as the sample may have been obtained too soon after infection before detectable antibodies had grown.

The single negative result cannot rule out toxoplasmosis.

For patients at high risk of infection, doctors may find it essential to repeat the test. Only a combination of clinical and serological evidence can diagnose a recent Toxoplasma gondii infection.

The results of toxoplasmosis IgM tests are based on the analysis of blood samples. A blood sample can be collected at a hospital or laboratory. Usually, blood is extracted from an arm vein. For more specific instructions, consult the concerned doctor.

An amniotic fluid (a protective liquid around a baby during pregnancy) is also used to detect toxoplasmosis infections in the unborn child if the mother is diagnosed positive for toxoplasmosis antibodies.

Test Preparation

The toxoplasmosis IgM test is just like other blood tests. It does not require any special preparation like fasting. The FDA issued a Public Health Advisory recommending that the sample found to be positive for T gondii IgM antibodies be forwarded to a Toxoplasma reference laboratory for toxoplasmosis confirmation.

Toxoplasmosis IgM Test Inclusions: What are the Parameters Included?

The Toxoplasma IgM test measures the presence of antibodies to the T. Gondii parasite in the blood. These values give an idea about the presence of IgM antibodies, a sign of an immune response to infection. The Toxoplasma IgM test result is expressed as positive or negative, which is an indicator of toxoplasma infection.

How Frequently Should You Take the Toxoplasmosis IgM Test?

The frequency of the Toxoplasma IgM test is dependent on the symptoms and interpretation by the doctor.

The result of a single serum sample is insufficient evidence for a recent infection diagnosis. IgM antibodies to T gondii could be missing if the sample was taken too soon after infection.

In this case, a second sample is taken and the test is repeated two to three weeks later.

If the test results are inconclusive, they should be repeated on a second sample three weeks following the initial test.