[Toxoplasmosis in Iran. Results of a seroepidemiological study].

A toxoplasmosis seroepidemiological survey was effected with 13,018 sera collected by stratified cluster random sampling method from 12 provinces in Iran. The samples were studied by indirect immunofluorescent assay (IFA) for the presence of Toxoplasma. In this study, 52.6% of the subjects were male and the remaining 47.4% were female. Anti-Toxoplasma antibody was detected in a total of 51.8% of the samples with no significant difference between male and female affected subjects. The distribution of the infected samples was also investigated in various age groups, the level of infection to Toxoplasma increasing from childhood, culminating to 30 years of age and gradually declining from there after. Between the various age groups, the 10-19 years old demonstrated a 50% increase in relative risk to the infection with high antibody titer. Within the provinces under study, the highest relative frequency of Toxoplasma antibody titer was indicated in Mazandaran province (20.5%), while the lowest frequency was detected in Hormozgan (2.9%). In general, there was a decrease in the number of infected samples from humid areas in north to dry provinces in south of Iran. In the clinical symptoms study, no significant difference between male and female patients was demonstrated. According to the type of clinical manifestation, lymphadenopathy and central nervous system symptoms (encephalitis) were respectively the most and the least frequent manifestations.