Toxoplasmosis

What is toxoplasmosis?

A single-celled parasite called Toxoplasma gondii causes a disease known as toxoplasmosis. While the parasite is found throughout the world, more than 60 million people in the United States may be infected with the Toxoplasma parasite. Of those who are infected, very few have symptoms because a healthy person’s immune system usually keeps the parasite from causing illness. However, pregnant women and individuals who have compromised immune systems should be cautious; for them, a Toxoplasma infection could cause serious health problems.

How do people get toxoplasmosis?

A Toxoplasma infection occurs by:

• Eating undercooked, contaminated meat (especially pork, lamb, and venison).
• Accidental ingestion of undercooked, contaminated meat after handling it and not washing hands thoroughly (Toxoplasma cannot be absorbed through intact skin).
• Eating food that was contaminated by knives, utensils, cutting boards and other foods that have had contact with raw, contaminated meat.
• Drinking water contaminated with Toxoplasma gondii.
• Accidentally swallowing the parasite through contact with cat feces that contain Toxoplasma. This might happen by
  1. cleaning a cat’s litter box when the cat has shed Toxoplasma in its feces
  2. touching or ingesting anything that has come into contact with cat feces that contain Toxoplasma
  3. accidentally ingesting contaminated soil (e.g., not washing hands after gardening or eating unwashed fruits or vegetables from a garden)
• Mother-to-child (congenital) transmission.
• Receiving an infected organ transplant or infected blood via transfusion, though this is rare.

What are the signs and symptoms of toxoplasmosis?

Symptoms of the infection vary.

• Most people who become infected with Toxoplasma gondii are not aware of it.
• Some people who have toxoplasmosis may feel as if they have the “flu” with swollen lymph glands or muscle aches and pains that last for a month or more.
• Severe toxoplasmosis, causing damage to the brain, eyes, or other organs, can develop from an acute Toxoplasma infection or one that had occurred earlier in life and is now reactivated. Severe cases are more likely in individuals who have weak immune systems, though occasionally, even persons with healthy immune systems may experience eye damage from toxoplasmosis.
• Signs and symptoms of ocular toxoplasmosis can include reduced vision, blurred vision, pain (often with bright light), redness of the eye, and sometimes tearing. Ophthalmologists sometimes prescribe medicine to treat active disease. Whether or not medication is recommended depends on the size of the eye lesion, the location, and the characteristics of the lesion (acute active, versus chronic not progressing). An ophthalmologist will provide the best care for ocular toxoplasmosis.
• Most infants who are infected while still in the womb have no symptoms at birth, but they may develop symptoms later in life. A small percentage of infected newborns have serious eye or brain damage at birth.

What are the signs and symptoms of toxoplasmosis?

Symptoms of the infection vary.

• Most people who become infected with Toxoplasma gondii are not aware of it.
• Some people who have toxoplasmosis may feel as if they have the “flu” with swollen lymph glands or muscle aches and pains that last for a month or more.
• Severe toxoplasmosis, causing damage to the brain, eyes, or other organs, can develop from an acute Toxoplasma infection or one that had occurred earlier in life and is now reactivated. Severe cases are more likely in individuals who have weak immune systems, though occasionally, even persons with healthy immune systems may experience eye damage from toxoplasmosis.
• Signs and symptoms of ocular toxoplasmosis can include reduced vision, blurred vision, pain (often with bright light), redness of the eye, and sometimes tearing. Ophthalmologists sometimes prescribe medicine to treat active disease. Whether or not medication is recommended depends on the size of the eye lesion, the location, and the characteristics of the lesion (acute active, versus chronic not progressing). An ophthalmologist will provide the best care for ocular toxoplasmosis.
• Most infants who are infected while still in the womb have no symptoms at birth, but they may develop symptoms later in life. A small percentage of infected newborns have serious eye or brain damage at birth.

• What is the treatment for toxoplasmosis?

  Once a diagnosis of toxoplasmosis is confirmed, you and your health care provider can discuss whether treatment is necessary. In an otherwise healthy person who is not pregnant, treatment usually is not needed. If symptoms occur, they typically go away within a few weeks to months. For pregnant women or persons who have weakened immune systems, medications are available to treat toxoplasmosis.