seroprevalence and molecular investigation of toxoplasmosis among working children in tehran

Background: toxoplasma gondii is a pathogenic protozoan that causes toxoplasmosis and spreads worldwide.objectives: this study aimed to investigate the prevalence of toxoplasmosis by serological and molecular methods in working children and a control group in tehran.methods: the study participants comprised 460 children aged 7 - 14 years, including 278 working children and 182 age-matched controls. blood samples were collected, and a serological test was performed to evaluate igm and igg antibodies against t. gondii. peripheral blood mononuclear cells (pbmcs) were isolated from the blood specimens by gradient centrifugation method. real-time polymerase chain reaction (pcr) was performed using primer b1 on pbmc samples in children’s blood to determine the status of toxoplasma infection.results: seroprevalence of igg and igm antibodies against t. gondii was 24.8% and 0.7%, respectively, in working children; however, in the control group, 12.1% and 2.2% had igg and igm antibodies against t. gondii, respectively. the mean igg titer was 160 ± 86.39 iu/ml and 69.36 ± 88 iu/ml for working children and the control group, respectively (p < 0.0001); however, the mean igm titer was 4.65 ± 3.04 iu/ml and 3.85 ± 4 iu/ml for working children and control group, respectively (p = 0.8187). real-time pcr results indicated two (0.7%) positive cases among working children and three (1.65%) samples in the control group. the present study showed a significant di erence between working children and the control group regarding the frequency of igg antibodies (p = 0.0012). however, there was no significant di erence in the frequency of igm antibodies in the two mentioned groups.conclusions: seroprevalence of igg antibody against t. gondii was more in working children than in the control group in tehran. this investigation revealed a significant di erence in frequency and titer of igg antibodies between working children and the con-trol group. more exposure to the soil and contaminated hands before drinking water or food may be considered factors in the development of toxoplasmosis infection in these children.