Toxoplasma gondii is a parasite that infects up to one third of the population worldwide. Ingestion of food or water contaminated with the parasite can lead to toxoplasmosis. The infection may be initially subclinical, but carries greater long-term risks. When left untreated, toxoplasmosis can cause eye disease, cervical lymphadenopathy, encephalitis, neurological disorders, psychological disorders, and brain tumors.
Toxoplasmosis Risk Factors
Good hygiene and proper handling of food are two of the most important steps to preventing toxoplasmosis. Once a person has ingested the toxoplasma gondii parasite, it enters the blood stream and spreads throughout the body. The parasite typically settles in muscular tissue and throughout the nervous system. This places extreme risks on pregnant women and patients with preexisting immune deficiencies.
A person may come into contact with toxoplasma gondii through several methods, including:
- Contamination by cat feces. If the person comes into contact with a cat, toxoplasma gondii parasites may end up on their hands. Certain tasks such as cleaning the litter box are frequent methods of contamination. Immediate and thorough hand-washing is typically sufficient in getting rid of the parasite.
- Eating raw or undercooked meat.
- Eating raw or unwashed produce.
- Gardening or other activities involving soil.
- Traveling to developing countries.
- Organ transplantation.
- Blood transfusion.
Studies have determined that:
- 60 million people in the United States carry toxoplasma gondii parasites
- This equals close to 1 in 4 people, or 22.5% of American population
- 4,000 cases of congenital toxoplasmosis documented each year in the United States
- 750 American deaths from toxoplasmosis each year
- 40% infection rate in Australia
- 47% infection rate in France
- 60% infection rate in Brazil
- 75% infection rate in El Salvador
- Germany and the Netherlands also have large prevalence rates
- Prevalence rates tend to be higher in tropical climates
Progression of Toxoplasmosis
Toxoplasma gondii is a very common parasite that can survive without a host for about a year. People with compromised immune systems should take extra care to avoid contamination. Pregnant women need to be especially cautious, since they can pass the parasite through the placenta to the fetus.
Toxoplasmosis infections frequently settle into a latent phase in patients with stable immune systems. While the parasite may initially cause flu-like symptoms, most infected patients do not display any signs during the latent phase. This makes toxoplasmosis difficult to identify. The parasite can remain inactive within the human body for years. If the parasite does become active at a later time, serious health problems will result.
Toxoplasmosis Symptoms and Effects
Symptoms may vary depending on the patient, but they can involve:
- Blurred vision
- Focal neurological deficit, or difficulty controlling a particular part of the body
- Slurred speech
- Vomiting or diarrhea
- Uneven walking patterns
- Blue-grey nodules beneath the skin
- Fever or fluctuating temperature
Other diseases that toxoplasmosis may cause include:
- Hepatitis, or inflammation of the liver
- Pneumonitis, or inflammation of the lung
- Myocarditis, or inflammation of the heart muscle
- Chorioretinitis, or inflammation of the eye
- Encephalitis, or inflammation of the brain
- Brain tumors and other neurologic disease
- Lymphadenopathy, a disorder of the lymph nodes
- Schizophrenia and other mental illness
Diagnosis of Toxoplasmosis
Toxoplasmosis can easily be confused with primary nervous system lymphoma. Symptoms typically do not present themselves until the infection has progressed to severe stages. Once toxoplasmosis has progressed, it becomes harder to treat. If a medical professional suspects a toxoplasmosis infection, a blood test for specific antibodies can indicate the presence of the toxoplasma gondii parasite. This blood test will also show if the parasite is currently active or latent, allowing for the most efficient management of the infection.