Toxoplasmosis (tok-so-plaz-MO-sis) is a disease that results from infection with the Toxoplasma gondii parasite. This organism is one of the world's most common parasites.
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 can cause extremely serious complications.
If you're generally healthy, you probably won't need any treatment for toxoplasmosis. If you're pregnant or have lowered immunity, certain medications can help reduce the infection's severity. The best approach, though, is prevention.
You probably won't know if you've contracted toxoplasmosis, although some people may develop toxoplasmosis symptoms similar to those of the flu or mononucleosis, such as:
In people with weakened immune systems
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, and children who do 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, infected children don't develop signs and symptoms — including hearing loss, mental disability or serious eye infections — until their teens or later.
When to see a doctor
Toxoplasma gondii (T. gondii) is a single-celled parasitic organism that can infect most animals and birds. But because it reproduces sexually only in cats, wild and domestic felines are the parasite's ultimate host.
When a person becomes infected with T. gondii, the parasite forms cysts that can affect almost any part of the body — often your brain and muscles, 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 resistance is weakened by disease or certain medications, the infection can be reactivated, leading to serious complications.
Although you can't "catch" toxoplasmosis from an infected child or adult, you can become infected if you:
Anyone can become infected with toxoplasmosis. The parasite is found throughout the world.
You're at risk of serious health problems if:
If you have a normal immune system, you're not likely to experience any complications of toxoplasmosis, although otherwise healthy people sometimes develop eye infections.
But if your immune system is compromised, especially as a result of HIV/AIDS, toxoplasmosis can lead to seizures and life-threatening illnesses such as encephalitis — a serious brain infection. In people living with AIDS, untreated encephalitis resulting from toxoplasmosis is fatal. Relapse is a constant concern for immunocompromised people with toxoplasmosis.
Children with congenital toxoplasmosis may develop disabling complications, including hearing loss, mental disability and blindness.
Preparing for your appointment
You're likely to start by seeing your regular health care provider, or if you're pregnant, your obstetrician. You may be referred to a doctor who specializes in infectious diseases. If you're pregnant, you may be referred to a doctor who specializes in fetal health (perinatologist) or newborn health (neonatologist).
Here's some information to help you get ready for your appointment, as well as what information your doctor might want from you.
What you can do
For toxoplasmosis, some basic questions to ask your doctor include:
In addition to the questions that you've prepared, don't hesitate to ask questions during your appointment.
What to expect from your doctor
Tests and diagnosis
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.
Testing in pregnancy
What test results mean
A positive result could mean that you have an active infection, or it could mean that you were infected at some point in your life and you're now 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.
Testing your baby
Testing in severe cases
Treatments and drugs
Most healthy people don't require toxoplasmosis treatment. But if you're otherwise healthy and have signs and symptoms of acute toxoplasmosis, your doctor may prescribe the following drugs:
Treating people with HIV/AIDS
You may need to take these medications for life. Your doctor may consider stopping toxoplasmosis therapy if your CD4 count — the amount of a particular white blood cell in your blood — remains very high for at least three to six months. Side effects of most drugs can be more severe in people with HIV/AIDS.
Treating pregnant women and babies
If tests show that your unborn child has toxoplasmosis, your doctor may suggest treatment with pyrimethamine and sulfadiazine — but only in extreme circumstances. These drugs can have serious side effects for both women and their unborn babies, so they're normally not used during pregnancy. Drug treatment may lessen the severity of the disease, but it can't undo any damage that's already been done.
Certain precautions can help prevent toxoplasmosis:
For cat lovers
Last Updated: 2011-06-24
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