Abstract
Sera from most of the Tristan da Cunha community were tested for toxoplasma antibody. In a comparison with sera from ‘normal’ inhabitants of South Wales there was a significantly higher incidence of dye tests positive at 1/16 or more in the Tristan community at all age groups. The incidence of retinitis was also found to be much higher than in Britain. It appears unlikely that toxoplasmosis caused any cases of mental defect or abortion on the Island.