Anti-toxoplasma serotitres in uveitis and ocular toxoplasmosis

This study was based on anti-toxoplasma serotitres obtained from 80 normal healthy adults and 103 consecutive patients with anterior, posterior and panuveitis over a 42 month period. Twelve out of 80 (15%) normal healthy sera were found to have low titres (1:64 to 1:256), while 3 (3.8%) had high titres (1:1024 or higher). The distribution of serotitres in patients with clinical toxoplasmosis was significantly different from the population sample (p less than 0.001, chi-squared test). Similarly, the distribution of serotitres in patients with posterior uveitis (of which 28 out of 54 were clinically ocular toxoplasmosis) having serotitres of 1:1024 or greater, was found to be significantly different from the normal population (p less than 0.001, Chi-squared test), but not statistically different from those with clinical ocular toxoplasmosis. Hence, anti-toxoplasma serotitre is useful as a diagnostic screening tool only in patients with posterior uveitis. It is also useful in confirming cases of suspected clinically positive ocular toxoplasmosis in our local population.