Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 13 3 2018 09 23 373 381 EN Parisa MOUSAVI Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Hossein MIRHENDI Dept. of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran Mehdi MOHEBALI Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND Center for Research of Endemic Parasites of Iran, Tehran University of Medical Sciences, Tehran, Iran Saeedeh SHOJAEE Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Hossein KESHAVARZ VALIAN Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran AND Center for Research of Endemic Parasites of Iran, Tehran University of Medical Sciences, Tehran, Iran Shirzad FALLAHI Dept. of Medical Parasitology and Mycology, Faculty of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Setareh MAMISHI Dept. of Infectious Diseases, Children Medical Center, Tehran University of Medical Sciences, Tehran, Iran 2018 02 05 2018 09 23 Background: Toxoplasma gondii, cause severe medical complications in infants and immune-compromised individuals. As using early, sensitive and rapid technique has major in diagnosis of toxoplasmosis, the present study was aimed to detect parasite by using from repetitive element (RE) and B1genes, in blood samples of seropositive immunocompromised patients and pregnant women. Methods: A total of 110 peripheral blood samples were collected from seropositive cases with anti-T. gondii antibodies, including immunocompromised patients and pregnant women. DNA was extracted by a commercial kit and subjected to TaqMan probe-based real-time PCR assay by using primers and probes specific for RE and B1 genes, separately. The data were analyzed by Kappa test and SPSS-22 software. Results: In the pregnant women, 17 (68%) and 14 (56%) samples from 25 IgM+/ IgG+ cases and, 7 (25%) and 6 (21.4%) samples from 28 IgG+/IgM- cases were positive by RE and B1 real time PCR, respectively. Likewise, in immunocompromised group, 20 (66.6%) and 17 (56.6%) samples from 30 IgM+/ IgG+ cases and 2 (7.4%) and 2 (7.4%) samples from 27 IgG+/ IgM- cases were positive by RE and B1 real time PCR, respectively. Conclusion: Probe-based real time PCR assay is a quantitative approach for early diagnosis of T. gondii infection in clinical samples. Moreover, this method can be more appropriate in diagnosis of acute and reactivated toxoplasmosis. In addition our results indicated that RE gene is more sensitive than B1 gene. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/1988 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/1988/870