Toxoplasmosis: little-known but not rare
It's hard to imagine that an illness affecting more than 60 million men, women, and children in the U.S. - a disease that has been targeted for public health action by the Centers for Disease Control-could be relatively unheard of by the general public. With toxoplasmosis, however, that's exactly the case.
In fact, up to a third of the world's population is estimated to carry the infection. Fortunately, of those infected, very few have symptoms. A healthy person's immune system usually keeps the parasite in check. When illness does occur, it is usually mild with "flu-like" symptoms (e.g., tender lymph nodes, muscle aches, etc.) that last for several weeks and then go away.
What is toxoplasmosis?
Toxoplasmosis is a parasitic disease caused by protozoa known as Toxoplasma gondii. It is considered to be a leading cause of death attributed to food-borne illness in the country. Most who become infected are completely unaware of it.
Once a diagnosis of toxoplasmosis is confirmed, your healthcare provider can determine if treatment is necessary. In an otherwise healthy person treatment usually is not needed. Symptoms typically go away within a few weeks to months. For those at greater risk, such as pregnant women or persons who have weakened immune systems, effective medications are available.
Women exposed to the parasite during pregnancy can pass the infection to the fetus. Although the majority of such infected infants show no symptoms at birth, many develop signs of infection later in life. These children may suffer from loss of vision, mental developmental disability, loss of hearing, and, in severe cases, death. Women infected before pregnancy will have antibodies to the parasite, and are not at risk of passing the infection to their unborn child.
Persons with compromised immune systems, such as those with human immunodeficiency virus (HIV) are also at increased risk. Toxoplasmosis in these patients can result in severe neurologic disease, convulsions, paralysis, coma and death despite appropriate treatment.
How do people get toxoplasmosis? The most common ways that humans become infected are:
Ingesting contaminated meat or other foods directly contaminated by knives, utensils or cutting boards 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 cleaning a cat's litter box or ingesting anything that has come into contact with cat feces that contains toxoplasma.
If you're pregnant or have a compromised immune system and you are a cat owner, consult your veterinarian about safety precautions you can take.
Toxoplasmosis linked to behavioral problems
Scientific studies have shown that the toxoplas-mosis parasite can affect behavior and may be a contributing factor in various psychiatric disorders such as depression, anxiety and schizophrenia. Individuals with schizophrenia are also more likely to report a clinical history of toxoplasmosis than those in the general population.
Dr Glenn McConkey, lead researcher on one such research project at the University of Leeds' Faculty of Biological Sciences says: "Toxoplasmosis changes some of the chemical messages in the brain, and these changes can have an enormous effect on behavior. Studies have shown there is a direct statistical link between incidences of schizophrenia and toxoplasmosis infection and our study is the first step in discovering why there is this link."