Toxoplasmosis

What is toxoplasmosis?

Toxoplasmosis is infection with the parasite Toxoplasma gondii. In the United States, more than 60 million people probably are infected with the parasite, but very few have symptoms because the immune system is usually able to fight the disease.¹

Toxoplasmosis is dangerous to a pregnant woman and her fetus. For more information, see the topic Toxoplasmosis During Pregnancy.

What causes toxoplasmosis?

Toxoplasmosis can result from:

• Accidentally swallowing Toxoplasma gondii eggs from soil or other contaminated surfaces. This can happen by putting your hands to your mouth after gardening, cleaning a cat’s litter box, or touching anything that has come into contact with cat feces.
• Eating raw or partly cooked meat, especially pork, lamb, or venison, or touching your hands to your mouth after touching the meat.

If you are pregnant when first infected with Toxoplasma gondii, you can give the infection to your baby.

You may also receive it through an organ transplantation or a transfusion, although this is rare.

What are the symptoms?

Most people with toxoplasmosis don't have symptoms. When symptoms are present, they are often flu-like and may include swollen lymph glands or muscle aches and pains that last for a few days to several weeks.

Severe toxoplasmosis may develop in people who have impaired immune systems, are taking certain types of chemotherapy, or have recently received an organ transplant and in infants. Severe toxoplasmosis results in damage to the eye or the brain. Infants who became infected before birth may be born with serious mental or physical problems.

How is toxoplasmosis diagnosed?

Because there are generally no symptoms, it is difficult to know whether you are infected. If you think that you may have toxoplasmosis, talk to your health professional. He or she may do specific blood tests for toxoplasmosis.

• If you have an impaired immune system, get the blood test for Toxoplasma gondii. If your test is positive, it means that you have been infected at some time in your life, and your health professional can tell you if and when you need to take medicine to prevent the infection from reactivating. If your test is negative, you have not been infected, and you can take precautions to avoid infection.
• If you are planning to become pregnant, consider being tested for Toxoplasma gondii. If the test is positive, it means you have already been infected at some time in your life and you probably don't have to worry about passing the infection to your future baby (discuss this with your health professional). If the test is negative, take necessary precautions to avoid infection.
• If you are pregnant, you and your health professional should discuss your risk of toxoplasmosis. Your health professional may order a blood sample for testing.

How is it treated?

In an otherwise healthy person who is not pregnant, treatment is not needed. Symptoms will usually go away within a few weeks.

For pregnant women or people who have weakened immune systems, medicines are available to treat toxoplasmosis. For more information, see the topic Toxoplasmosis During Pregnancy.

How can I prevent toxoplasmosis?

Because toxoplasmosis usually has no symptoms or only mild symptoms, most people don't need to worry about getting it. However, if you have a weakened immune system or are pregnant, you should take steps to prevent toxoplasmosis.

• Wear gloves when you garden or do anything outdoors that involves handling soil. Cats may pass the parasite in their feces and often use gardens and sandboxes as litter boxes. Wash your hands well with soap and warm water after outdoor activities, especially before you eat or prepare any food.
• Have someone who is healthy and not pregnant handle raw meat for you. If this is not possible, wear clean latex gloves when you touch raw meat, and wash any cutting boards, sinks, knives, and other utensils that might have touched the raw meat. Wash your hands well with soap and warm water afterwards.
• Cook foods until they are well done. Use a meat thermometer to be sure foods are cooked to a safe temperature. Do not use the color of the meat (such as when it is no longer "pink") to tell you that it is done.
• Have someone who is healthy and not pregnant change your cat’s litter box. If this is not possible, wear gloves and clean the litter box daily. Wash your hands well with soap and warm water afterwards.

What can you tell me about my cat and toxoplasmosis?

Cats only spread Toxoplasma gondii in their feces for a few weeks after they are first infected with the parasite. They rarely have symptoms when first infected, so most people don't know whether their cat has been exposed to Toxoplasma gondii. Good tests are not available to determine whether your cat is passing Toxoplasma gondii in its feces.

Otherwise healthy people should not worry about their cat and Toxoplasma gondii. However, if you have an impaired immune system or are pregnant:

• Help prevent your cat from getting infected with Toxoplasma gondii. Keep the cat indoors, and feed it dry or canned cat food. Cats can become infected by eating or being fed raw or undercooked meat.
• Don't 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 and kittens.

Your veterinarian can answer other questions you may have regarding your cat and the risk for toxoplasmosis.

Citations

1. Centers for Disease Control and Prevention (2004). Toxoplasmosis. Available online: http://www.cdc.gov/ncidod/dpd/parasites/toxoplasmosis/factsht_toxoplasmosis.htm.