Seroepidemiology of ocular toxoplasmosis-profile of an urban population.

ABSTRACT

200 uveitis cases and 100 controls were serologically analysed for Toxoplasma antibodies (Ab) using indirect fluorescent antibody test (IFAT-IgG, Igm) and enzyme linked immunosorbent assay (ELISA IgG, IgM). Ophthalmologically cases were segregated into 4 groups anterior uveitis, posterior uveitis, pan uveitis and varied presentation uveitis. Toxoplasma seropositivity of 32% in cases and 4% in controls was established. IHA, IFAT, ELISA detected 20%, 18% and 32% cases as seropositive respectively, IFAT being most specific (100%) and ELISA most sensitive (41.37%). Insignificant change in Ab titre was observed in sequential samples of seropositive cases. Posterior Uveitis cases had the maximum seropositivity (41.7%). Highest seropositivity was in 16-25 years age group with no sex preponderance. Dietary habits and occupational history had no bearing on Toxoplasma infection. Results indicate that serology in mandatory for diagnosing Toxoplasma as a cause of uveitis, 2 or more tests on a single serum sample detecting IgG and Igm Ab are the best indicators of infection.