Diagnosis

A diagnosis of toxoplasmosis is based on blood tests. Laboratory tests can detect two types of antibodies. One antibody is an immune system agent that is present during a new and active infection with the parasite. The other antibody is present if you had an infection at any time in the past. Depending on the results, your health care provider may repeat a test after two weeks.

More diagnostic tests are used depending on other symptoms, your health and other factors.

Eye symptoms

If you have eye symptoms, you will need an exam by a doctor who specializes in eye disease, called an ophthalmologist. An exam may include the use of special lenses or cameras that allow the doctor to see tissues inside the eye.

Brain and other nervous system symptoms

If there are symptoms of brain inflammation, tests might include the following:

  • Brain imaging. MRI or CT scans are used to create images of the brain. These may detect irregular structures in the brain related to toxoplasmosis.
  • Cerebral spinal fluid (CSF) test. CSF is the fluid that surrounds and protects the brain and spinal cord. Laboratory tests may detect toxoplasma in CSF if there is infection in the brain.
  • Brain tissue. Rarely, tissue is removed from the brain to detect the parasite.

Pregnancy

In the United States, pregnant people are not routinely screened for toxoplasmosis. Recommendations for screening vary in other countries.

Your health care provider may order a diagnostic blood test for you if:

  • Your symptoms might be from an active toxoplasma infection.
  • Ultrasound images of your baby show irregular features linked to toxoplasmosis.

If you have an active infection, it may pass to your baby in the womb. A diagnosis is based on tests of the fluid surrounding the baby, called amniotic fluid. The sample is taken with a fine needle that goes through your skin and into the fluid-filled sac holding the baby.

Your care provider will order a test if:

  • You test positive for the parasite.
  • Your test results are not clear.
  • Ultrasound images of the fetus show irregular features linked to toxoplasmosis.

Newborn

Blood tests are ordered for diagnosis of toxoplasmosis in a newborn baby if infection is suspected. A baby who tests positive will have many tests to detect and keep an eye on the disease. These would likely include:

  • Ultrasound or CT imaging of the brain.
  • Tests of the fluid surrounding the brain and spinal column.
  • Eye tests.
  • Hearing tests.
  • Test of brain activity, called electrocephalogram.

Treatment

Medication is used to treat active infections. How much and how long you take medicine depends on different factors. These include how seriously ill you are, your immune system health and where the infection is located. Your stage of pregnancy is also a factor.

Your provider may give you a combination of prescription drugs. They include:

  • Pyrimethamine (Daraprim). This fights infections caused by microscopic organisms. It can block the body's use of folic acid. Other possible side effects with long-term use include bone marrow suppression and liver toxicity.
  • Leucovorin calcium helps correct the effects of pyrimethamine on folic acid activity.
  • Sulfadiazine is an antibiotic often prescribed with pyrimethamine. Other medication includes clindamycin (Cleocin), azithromycin (Zithromax) and others.

Treatment for infants

Drug treatment for infants may last 1 to 2 years. Regular and frequent follow-up appointments are needed to watch for side effects, vision problems, and physical, intellectual and overall development.

Additional treatment for eye disease

In addition to the regular drug treatment, eye disease also may be treated with anti-inflammatory steroids called glucocorticosteroids.

Preparing for your appointment

You're likely to start by seeing your health care provider. If you're pregnant, you'll likely see your obstetrician. You also may see a provider who specializes in fetal health, called a perinatologist. In some cases, you'll see a provider who specializes in infectious diseases.

You can prepare for your appointment by being ready to answer the following questions:

  • What are your symptoms?
  • When did they start?
  • Have you been diagnosed with toxoplasmosis in the past?
  • Do you have a cat? Is it an indoor or outdoor cat? Do you change the litter?
  • Have you recently eaten raw or undercooked meat or fish?
  • Have you had unpasteurized goat's milk products?
  • Do you garden or work outdoors? Do you wear gloves?
  • What medications, vitamins or supplements do you take?
By Mayo Clinic Staff