SALT LAKE CITY — There are plenty of dog people out there who would love to know what anyone could ever see in a cat. As it turns out, cats have a trick that's been working for centuries: single-celled, mind-controlling parasites.
Of course, that's an overstatement. But Toxoplasmosa gondii, a parasite related to malaria, has been known to cause rats to feel much more friendly toward cats, even running toward them and not away. The idea of the crazy cat lady may even be related to Toxoplasmosa, as it infects humans as well. The parasite is spread almost exclusively through cat feces.
But there is even some limited evidence from recent studies connecting infections of Toxoplasmosa, with problems like schizophrenia in adulthood, increased risk for suicide and neurosis in men and women.
About one-third of the people in the world are infected with the parasite, with extremely low rates in the U.S. and much higher rates in warm, tropical and underdeveloped countries. Despite the relative rarity in the States, a new review in the journal Trends in Parasitology claims that the Toxoplasmosa problem may be much more widespread than previously thought in the U.S.
The review estimated that there are some 1.2 million metric tons of cat feces introduced into the environment, with about 1 percent of cats shedding the egg-like oocyst of Toxoplasmosa at any time, according to the review. Any given area can contain between 3 and 434 of these parasites-to-be. Even one oocyst can cause infection, at least in a study on pigs.
Cats prefer to do their business in specific locations, often with loose sand or gravel that is easy to cover. That makes sandboxes especially problematic. One study cited in the review looked at three sandboxes in Japan. Over 900 defecations took place in the boxes over 20 weeks. Under certain conditions, that could mean as many as 325 million Toxoplasmosa oocyst could be found in one of the sandboxes, according to the review.
That could be a huge risk once you consider that a child puts something in his or her mouth every two or three minutes and can eat a median of 40 mg of soil every day.
However, Jodee Baker, an epidemiologist with the Utah Department of Health, said that the disease is not really a problem in Utah.
"It's a rare disease, first of all, but it's rare in Utah because we don't have the correct climate that houses it," she said.
It's much more common in warm and moist climates like the South.
It's so rare and folks recover so quickly from the infection that the state doesn't keep track of the disease.
However, she said that pregnant women and people with weak immune symptoms are at special risk. Toxoplasmosis, the disease caused by Toxoplasmosa, can cause flu-like symptoms, but in severe cases may lead to encephalitis and eye problems like blurred or double vision.
Baker said that, among other things, covering a sandbox, making sure to wash your hands, cleaning fruits and cooking meant thoroughly can help prevent infections. Pregnant women or people with weak immune system should also avoid cleaning the litter box.
The review also suggested that even if Toxoplasmosa may be a bigger problem than we all think, nevertheless there are things we can do as a society to help.
"The proper disposal of cat litter, keeping cats indoors, reducing the feral cat population, and protecting the play areas of children might potentially reduce the oocyst burden," the authors wrote.