14 DAY TRIAL // The purring pussycat on your arms can bring you down. Aliments or water containing parasite eggs from Cat feces can contaminate water and food with eggs from the protozoan parasite Toxoplasma gondii, as the cat is the only species hosting the parasite during the sexual stage of its life cycle. The parasite can be transmitted to humans also from consumption of raw or undercooked meat of an intermediate host (like sheep, cattle and rabbit).
20% to 80% of human populations worldwide are infected with Toxoplasma. Initial exposure usually causes only mild flu-like symptoms. After that, the parasite passes down into an inactive cyst stage that stays resident in muscles and other tissues. Latent toxoplasmosis is asymptomatic but is usually a life-long infection, and its presence is proved by the presence of anti-Toxoplasma antibodies in the blood. But this is not so unharmful as previously thought: a new research published in the American Journal of Psychiatry has discovered it boosts the risk of developing schizophrenia, a mental disorder characterized by paranoia, delusions and hallucinations. You may have found some Napoleons in you life...
The new study was carried out among U.S. troops by a team from Walter Reed Army Institute of Research and Johns Hopkins Children's Center. Of the 180 subjects diagnosed with schizophrenia, 7 % had toxoplasmosis before being diagnosed with schizophrenia, compared to 5% in the case of the 532 healthy subjects. Toxoplasma appeared to increase by 24% the risk of turning schizophrenic.
"The difference, while seemingly small, is important, because the ability to explain even a small portion of the 2 million cases of schizophrenia in the United States may offer clues to the disease and some possible treatments," the authors wrote.
Future researches could check if toxoplasmosis treatment of schizophrenic patients could hamper the disease's advance.
"Our findings reveal the strongest association we've seen yet between infection with this very common parasite and the subsequent development of schizophrenia," said co-author Dr. Robert Yolken, a neurovirologist at Hopkins Children's.
"Previous studies have reported on the link between schizophrenia and the presence of toxoplasma antibodies, which are evidence of past infection, but this is the first study to show that infection with the parasite can precede the initial onset of symptoms and subsequent diagnosis with schizophrenia," said Yolken.
The time line between infection and schizophrenia diagnosis could be made because American troops are routinely tested for blood samples.
"Until now, the only thing we could say is that some people with schizophrenia also had been infected with toxoplasma at some point, but we couldn't tease out which came first. With our current study, we were able to show that infection came first. While most people infected with toxoplasma never develop schizophrenia, the parasite may be a trigger in those genetically predisposed to the disorder, a classic example of how genes and environment come together in the development of disease," Yolken concluded.