Toxoplasmosis (tok-so-plaz-MOE-sis) is a disease that results from infection with the Toxoplasma gondii parasite, one of the world's most common parasites. Infection usually occurs by eating undercooked contaminated meat, exposure from infected cat feces, or mother-to-child transmission during pregnancy.
Toxoplasmosis may cause flu-like symptoms in some people, but most people affected never develop signs and symptoms. For infants born to infected mothers and for people with weakened immune systems, toxoplasmosis may cause serious complications.
If you're generally healthy, not pregnant, and have been diagnosed with toxoplasmosis, you probably won't need any treatment other than conservative management. If you're pregnant or have lowered immunity, you may need medical management to avoid severe complications. The best approach, though, is prevention.
Most healthy people who are infected with toxoplasmosis have no signs or symptoms and aren't aware that they're infected. Some people, however, develop signs and symptoms similar to those of the flu, including:
If you have HIV/AIDS, are receiving chemotherapy or have recently had an organ transplant, a previous toxoplasma infection may reactivate. In that case, you may develop more-severe signs and symptoms of infection, including:
If you become infected for the first time just before or during your pregnancy, you can pass the infection to your baby (congenital toxoplasmosis), even if you don't have signs and symptoms yourself.
Your baby is most at risk of contracting toxoplasmosis if you become infected in the third trimester and least at risk if you become infected during the first trimester. On the other hand, the earlier in your pregnancy the infection occurs, the more serious the outcome for your baby.
Many early infections end in stillbirth or miscarriage. Infants who survive are likely to be born with serious problems, such as:
Only a small number of babies who have toxoplasmosis show signs of the disease at birth. Often, infants who are infected don't develop signs â which may include hearing loss, mental disability or serious eye infections â until their teens or later.
If you are living with HIV or AIDS or are pregnant or thinking of becoming pregnant, talk to your doctor about being tested if you think you may have been exposed to toxoplasmosis.
The signs and symptoms of severe toxoplasmosis â blurred vision, confusion, loss of coordination â require immediate medical care, particularly if your immune system has been weakened.
Toxoplasma gondii (T. gondii) is a single-celled parasitic organism that can infect most animals and birds. Because T. gondii infectious organisms are excreted only in cat feces, wild and domestic cats are the parasite's ultimate host.
Although you can't "catch" toxoplasmosis from an infected child or adult, you can become infected if you:
When a person becomes infected with T. gondii, the parasite forms cysts that can affect almost any part of the body â often your brain and muscle tissue of different organs, including the heart.
If you're generally healthy, your immune system keeps the parasites in check. They remain in your body in an inactive state, providing you with lifelong immunity so that you can't become infected with the parasite again. But if your immune system is weakened by disease or certain medications, the infection can be reactivated, leading to serious complications.
Most pregnant women in the United States aren't routinely screened for toxoplasmosis, and most states don't screen infants for the infection. Without specific screening, toxoplasmosis is often difficult to diagnose because signs and symptoms, when they occur, are similar to those of more common illnesses, such as the flu and mononucleosis.
If your doctor suspects you have the infection, you may have blood tests that check for antibodies to the parasite. Antibodies are proteins produced by your immune system in response to the presence of foreign substances, such as parasites. Because these antibody tests can be difficult to interpret, the Centers for Disease Control and Prevention recommends that all positive results be confirmed by a laboratory that specializes in diagnosing toxoplasmosis.
Sometimes you may be tested early in the course of the disease before your body has a chance to produce antibodies. In that case, you may have a negative result, even though you're infected. To be certain, your doctor may recommend retesting several weeks later.
In most cases, a negative toxoplasmosis test result means you've never been infected and therefore aren't immune to the disease. If you're at high risk, you can take certain precautions so that you don't become infected.
A positive result could mean that you have an active infection, or it could mean that you were once infected and are immune to the disease. Additional tests can pinpoint when the infection occurred, based on the types of antibodies in your blood. This is especially important if you're pregnant or you have HIV/AIDS.
If you are pregnant and have a current toxoplasmosis infection, the next step is to determine whether your baby also is infected. Tests your doctor may recommend include:
If you've developed a life-threatening illness such as encephalitis, you may need one or more imaging tests to check for lesions or cysts in your brain. These include:
Magnetic resonance imaging (MRI). This test uses a magnetic field and radio (electromagnetic) waves to create cross-sectional images of your head and brain. During the procedure, you lie inside a large, doughnut-shaped machine that contains a magnet surrounded by coils that send and receive radio waves.
In response to the radio waves, your body produces faint signals that are picked up by the coils and processed into images by a computer. MRI is noninvasive and poses minimal risks to your health.
If you have a normal immune system, you're not likely to experience complications of toxoplasmosis, although otherwise healthy people sometimes develop eye infections. Untreated, these infections can lead to blindness.
But if your immune system is weakened, especially as a result of HIV/AIDS, toxoplasmosis can lead to seizures and life-threatening illnesses such as encephalitis â a serious brain infection.
In people with AIDS, untreated encephalitis from toxoplasmosis is fatal. Relapse is a constant concern for people with toxoplasmosis who also have a weakened immune system.
Children with congenital toxoplasmosis may develop disabling complications, including hearing loss, mental disability and blindness.
Certain precautions can help prevent toxoplasmosis:
If you're pregnant or otherwise at risk of toxoplasmosis or its complications, take these steps to protect yourself:
Anyone can become infected with toxoplasmosis. The parasite is found throughout the world.
You're at risk of serious health problems from toxoplasmosis infection if: