Toxoplasmosis

• Toxoplasmosis [tok-so-plaz-MO-sis] is a parasitic infection that is mainly a risk to unborn infants and to persons with weakened immune systems.
• People can get toxoplasmosis by: 1) eating food, drinking water, or having contact with soil contaminated with tool from an infected cat, or 2) eating inadequately cooked meat that is contaminated with the parasite. Women who become infected during or just before pregnancy can pass the infection to their unborn infants.
• Most infected people have no symptoms and are never diagnosed. People with weakened immune systems can develop severe toxoplasmosis, which results in damage to the eye or the brain. Infants who are infected before birth can have serious mental or physical handicaps.
• Most people do not need to be treated unless they are pregnant or have a weakened immune system.
• Pregnant women, women who are planning to become pregnant, and persons with weakened immune systems should take precautions to avoid infection.

What is toxoplasmosis?

Toxoplasmosis is a common parasitic infection worldwide. People at risk for severe infection are pregnant women and persons with weakened immune systems.

What is the infectious agent that causes toxoplasmosis?

Toxoplasmosis is caused by Toxoplasma gondii, a one-celled parasite.

Where is toxoplasmosis found?

The parasite that causes toxoplasmosis is found worldwide.

Who is at risk for toxoplasmosis?

Anyone can get toxoplasmosis, but some people are at risk for severe infection:

• Babies born to mothers who are first exposed to Toxoplasma infection during pregnancy or several months before -- Women who are first exposed to the parasite more than 6 months before becoming pregnant are not likely to pass the infection to their babies.
• People with severely weakened immune systems, such as persons with HIV infection, those taking certain types of chemotherapy, and persons who have recently received an organ transplant -- In these people, an infection that occurred anytime during life can reactivate and cause the severe symptoms of toxoplasmosis.

How do people get toxoplasmosis?

People can get toxoplasmosis by:

• Eating food, drinking water, or having contact with soil or anything else that contains or has touched stool from an infected cat -- For about 2 weeks after infection with Toxoplasma, cats pass millions of parasites in their stool every day. The parasites mature and can infect people for 2 to 5 days after they are passed in a cat's stool. No treatment can prevent cats from being infected or from passing the parasite.
• Eating raw or inadequately cooked meat -- Toxoplasma infects many kinds of birds and mammals. They get toxoplasmosis in the same way that people do: by eating food or drinking water that contains infected cat stool. After the parasite infects an animal, it spreads throughout the animal's body. As a result, people can become infected by eating raw or undercooked meat.

Women who become infected with Toxoplasma during pregnancy or within several months before pregnancy can pass the infection to their unborn infants.

What are the signs and symptoms of toxoplasmosis?

Most infected people have no signs or symptoms. Those who do might have flu-like symptoms, swollen lymph glands, or muscle aches and pains that last for a few days to several weeks. People with weakened immune systems can develop severe toxoplasmosis, which results in damage to the eye or the brain. Infants who are infected before birth can have serious mental or physical handicaps.

How is toxoplasmosis diagnosed?

Diagnosis is by blood test.

What is the treatment for toxoplasmosis?

In an otherwise healthy person who is not pregnant, no treatment is needed. Symptoms will usually go away in a few weeks. For pregnant women or persons with weakened immune systems, drugs are available to treat toxoplasmosis.

How common is toxoplasmosis?

More than 60 million people in the United States probably carry the Toxoplasma parasite, but very few have symptoms because their immune systems keep the parasite from causing illness.

How can toxoplasmosis be prevented?

Pregnant women and people with weakened immune systems should take precautions to prevent toxoplasmosis.

1. Consider being tested for toxoplasmosis:

• If you have a weakened immune system, you may want to consider getting a blood test for Toxoplasma. If the test is positive, your health-care provider can tell you if and when you need to take medicine to prevent the infection from reactivating. If the test is negative, you can take precautions to avoid infection.
• If you are planning to become pregnant, you may want to consider being tested for Toxoplasma. If the test is positive, there is no need to worry about passing the infection to your baby. Women who are first exposed to the parasite more than 6 months before becoming pregnant are not likely to pass the infection to their babies. If the test is negative, take precautions to avoid infection.
• If you are pregnant, you and your health-care provider should discuss your risk of toxoplasmosis. Your health-care provider might order a blood sample for testing.

2. Take precautions to avoid infection:

• Wear gloves when gardening or doing anything outside that involves handling soil. Cats often use gardens and sandboxes as litter boxes, and they can pass the Toxoplasma parasite in their feces.
• Wash hands well with soap and warm water after touching raw meat, after gardening and other outdoor activities, and before preparing or eating food.
• Have someone who is healthy and not pregnant handle raw meat. If this is not possible, wear clean latex gloves when touching raw meat, and wash any cutting boards, surfaces, and utensils that might have touched raw meat. Wash hands well with soap and warm water afterwards.
• Cook all meat thoroughly, until it is no longer pink in the center or until the juices run clear. Do not sample meat before it is fully cooked.

3. Avoid being exposed to Toxoplasma from cats. There are no good tests to determine if a cat is passing Toxoplasma in its feces. Like humans, cats rarely have symptoms when first infected, so most people do not know if their cat has been exposed to Toxoplasma. However, they only spread Toxoplasma in their feces for a few weeks after infection. To prevent infection from cats, follow these steps:

• Help prevent cats from getting infected. Keep cats indoors, and feed them dry or canned cat food.
• Do not bring a new cat into your house that might have been an outdoor cat or might have been fed raw meat. Avoid handling stray cats or kittens. Your vet can answer any other questions about your cat and your risk for toxoplasmosis.
• Have someone who is not at risk for toxoplasmosis change a cat's litter box. If this is not possible, wear gloves and clean the litter box every day to get rid of any parasites before they become infectious. Wash hands well with soap and warm water afterwards.

This fact sheet is for information only and is not meant to be used for self-diagnosis or as a substitute for consultation with a health-care provider. If you have any questions about the disease described above or think that you might have a parasitic infection, consult a health-care provider.

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