The U.S. NHANES (2004-2005) national probability sample found that 33.1% of U.S. persons above 12 years of age had Toxoplasma-specific IgG antibodies, indicating that they had been infected with the organism. This prevalence has significantly increased from the 1999-2000 data.
It is estimated that between 30% and 65% of all people worldwide are infected with Toxoplasmosis. However, there is large variation countries: in France, for example, around 88% of the population are carriers, probably due to a high consumption of raw and lightly cooked meat. Germany, the Netherlands and Brazil also have high prevalences of around 80%, over 80% and 67% respectively. In Britain, about 22% are carriers, and South Korea’s rate is only 4.3%.
Correlations have been found between latent Toxoplasma infections and various characteristics:
Increased risk taking behavior
Feelings of insecurity and self-doubt
Neuroticism (one of the Big Five personality traits)
Several studies have found significantly higher levels of Toxoplasma antibodies in schizophrenia patients compared to the general population.