Contact with pigs and cats associated with high prevalence of Toxoplasma antibodies among farmers.

Antibodies to Toxoplasma were measured by enzyme linked immunosorbent assay (ELISA) in sera from 159 abattoir workers, 142 pig farmers, and 106 grain or berry farmers. Farmers occupationally exposed to pigs had antibodies in 53 (37%) cases, abattoir workers in 40 (25%) cases, and farmers not exposed to pigs in 24 (23%) cases. In each group antibodies were more prevalent among those who had a cat or cats in the household. Controlling for age and cat contacts changed the prevalences less than one percent. The results indicate that pig farmers might have an occupational risk of toxoplasmosis. As the prevalence of antibodies among abattoir workers was about the same as among the referent farmers, it seems unlikely that infection from Toxoplasma could be acquired by mere handling of raw meat.