Abstract
Background: Up to now, epidemiological studies on the prevalence of Toxoplasma gondii infection among drug addicted individuals have been rarely performed. By designing an age and sex matched case-control study, we sought to determine the prevalence and associated factors with T. gondii infection in these population using serological and molecular techniques.Methods: One hundred and thirty-seven drug addicted individuals and 141 healthy subjects were enrolled in this study. Informed consent as well as a standard questionnaire were obtained from all subjects participating. Blood samples were collected from each participant and the serum was screened for anti-Toxoplasma antibodies (IgG and IgM). PCR assay was performed using the primer pair targeting the RE and GRA6 genes of T. gondii. Then, PCR products were sequenced to determine genotype.Results: The seroprevalence of T. gondii infection based on IgG titer was 34.3% in case and 9.9% in the control groups, revealing a statistically significant difference (OR = 4.37; 95% CI = 2.46-9.12; P = 0.001). After analyzing the variables studied through the questionnaire, age was the only significantly factor associated with the anti-T. gondii IgG antibody in case group. Considering PCR assays with RE genomic target, the prevalence of T. gondii infection was 5.1% in the case and 3.5% in control groups which the difference was no statistically significant (OR = 1.46; 95% CI = 0.45-4.73; P = 0.521). Subsequently, all sequenced samples were genotype #1 using the GRA6 genomic target.Conclusions: T. gondii exposure is relatively high among drug addicted individuals in Iran, and there is a need for health policymakers and researchers to establish enlightenment and prevention programs for these population at risk of infection. [ABSTRACT FROM AUTHOR]