Toxoplasmosis is considered to be a leading cause of death attributed to foodborne illness in the United States. More than 40 million men, women, and children in the U.S. carry the Toxoplasma parasite, but very few have symptoms because the immune system usually keeps the parasite from causing illness.However, women newly infected with Toxoplasma during or shortly before pregnancy and anyone with a compromised immune system should be aware that toxoplasmosis can have severe consequences.

Diagnosis

A Toxoplasma-positive reaction, stained by immunofluroescence (IFA). (CDC Photo)

The diagnosis of toxoplasmosis is typically made by serologic testing. A test that measures immunoglobulin G (IgG) is used to determine if a person has been infected. If it is necessary to try to estimate the time of infection, which is of particular importance for pregnant women, a test which measures immunoglobulin M (IgM) is also used along with other tests such as an avidity test.

Diagnosis can also be made by direct observation of the parasite in stained tissue sections, cerebrospinal fluid (CSF), or other biopsy material. These techniques are used less frequently because of the difficulty of obtaining these specimens.

Treatment

On this Page

• Healthy people (nonpregnant)
• Pregnant women, newborns, and infants
• Persons with ocular disease
• Persons with compromised immune systems

Healthy people (nonpregnant)

Most healthy people recover from toxoplasmosis without treatment. Persons who are ill can be treated with a combination of drugs such as pyrimethamine and sulfadiazine, plus folinic acid.

Pregnant women, newborns, and infants

Pregnant women, newborns, and infants can be treated, although the parasite is not eliminated completely. The parasites can remain within tissue cells in a less active phase; their location makes it difficult for the medication to completely eliminate them.

Persons with ocular disease

Persons with ocular toxoplasmosis are sometimes prescribed medicine to treat active disease by their ophthalmologist. 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).

Persons with compromised immune systems

Persons with compromised immune systems need to be treated until they have improvement in their condition. For AIDS patients, it may be necessary to continue medication for the rest of their lives, or for as long as they are immunosuppressed