Some epidemiological aspects of Toxoplasma infections in a population of farmers in Japan.

A total of 3606 serum samples collected from a population of farmers in Japan, were examined for antibodies to Toxoplasma by enzyme-linked immunosorbent assay, to study prevalence and possible transmission route(s). The prevalence of antibodies gradually increased with age and was significantly higher in males (28.8%) than in females (16.3%; P less than 0.001). Irrespective of age and sex, however, mean antibody levels for two distinct groups quantitatively separated on frequency distribution were almost constant. While seropositivity did not differ in people with and without cat contact, consumption of raw meat was significantly correlated with antibody prevalence. The difference in prevalence was partly explained by greater raw meat ingestion by males (41.6%) than by females (17.2%; P less than 0.001). Beef, chicken, horseflesh, whale meat, wild boar and venison were the sources of raw meat.