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Disease

Toxoplasmosis

 

 

 

Definition: Toxoplasma gondii (T gondii) is a common intracellular protozoan that preferentially infects the central nervous system (CNS) of immunodeficient patients, causing severe neurologic disease. T gondii also can cause local disease such as chorioretinitis or pneumonia.

 

 

 Causes and Risk Factors:   A Toxoplasma infection occurs by:

• Accidentally swallowing cat feces from a Toxoplasma-infected cat that is shedding the organism in its feces. This might happen if you were to accidentally touch 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 contaminated raw or partly cooked meat, especially pork, lamb, or venison; by touching your hands to your mouth after handling undercooked meat.
• Contaminating food with knives, utensils, cutting boards and other foods that have had contact with raw meat.
• Drinking water contaminated with Toxoplasma.
• Receiving an infected organ transplant or blood transfusion, though this is rare.

People who are most likely to develop severe toxoplasmosis include:

• Infants born to mothers who became infected with Toxoplasma for the first time during or just before pregnancy.
• Persons with severely weakened immune systems, such as individuals with HIV/AIDS, those taking certain types of chemotherapy, and those who have recently received an organ transplant.

Signs & Symptoms:

Symptoms of the infection vary.

• Most people who become infected with Toxoplasma 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.

In non-immunosuppressed people:

• mild illness with fever, resembling mononucleosis
• enlarged lymph nodes in the head and neck
• headache
• sore throat
• muscle pain

In an immunosuppressed person:

• brain lesions are associated with fever, headache, confusion, seizures, and abnormal neurological findings
• retinal inflammation causing blurred vision

Diagnostic Testing: Tests to determine infection or presence of cysts:

• serologic titers for toxoplasmosis
• MRI of head
• cranial CT scan
• brain biopsy
• slit lamp examination reveals characteristic retinal lesions

Treatment: No treatment is recommended for people without symptoms, except children, to prevent retinal inflammation. Treatment of women in pregnancy is controversial because of the toxicity of the medications, but treatment is still advocated.

Medications to treat the infection include: pyrimethamine, sulfonamide drugs, folinic acid, clindamycin, and trimethoprim-sulfamethoxazole. Treatment in AIDS patients is continued as long as the immune system is weak, to prevent reactivation of the disease.

Prevention:

Take the following precautions:

• Thoroughly cook all meat.
• After touching raw meat, wash your hands, any surface the meat touched, and all utensils.
• Wash fruit and vegetables before you eat them.
• Avoid raw, unpasteurized, cow or goat milk.
• Wear gloves while gardening.
• Have someone else clean the litter box.
• Wear gloves if you must change cat litter.
• Change cat litter daily.