Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 17 2 2022 05 28 231 239 Meysam Yusefi 1. Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2. Research Center of Tropical and Infectious Diseases, Kerman University of Medical Sciences, Kerman, Iran Zahra Arab-Mazar 1. Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2. Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Shirzad Fallahi Hepatitis Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran AND Department of Medical Parasitology and Mycology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Amirreza Javadi Mamaghani Department of Parasitology and Mycology, Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran Shahnaz Sali Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Naeem Nikpour Department of Hematology and Oncology, Shahid Beheshti University of Medical Sciences, Tehran, Iran Meisam Barati Department of Cellular and Molecular Nutrition, Shahid Beheshti University of Medical Sciences, Tehran, Iran Arian Karimi Rouzbahani 1. Student Research Committee, Lorestan University of Medical Sciences, Khorramabad, Iran 2. USERN Office, Lorestan University of Medical Sciences, Khorramabad, Iran Farnaz Kheirandish Department of Medical Parasitology and Mycology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran 2. Razi Herbal Medicines Research Center, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran 2021 05 14 2022 05 28 Background: We aimed to estimate the incidence of Toxoplasma infection in T. gondii-seropositive patients under allogeneic hematopoietic stem cell transplantation (HSCT). Methods: The present research was a prospective study on 54 whole blood samples of allogeneic HSCT recipients, who were referring to bone narrow transplantation centers affiliated to Shahid Beheshti University of Medical Sciences, Tehran, Iran in 2018. All patients were IgG positive against T. gondii. Results: Overall, 54 Toxoplasma positive pre-HCTSP patients were enrolled. 53.7% (n= 29) were male, also 1.9% (n=1) had germ-line type of the disease. The Multiple myeloma patients had higher age in comparison with other disease, but pairwise comparison showed the difference of age between Multiple myeloma patients were statistically significant with Acute lymphoblastic leukemia, Acute myeloblastic leukemia and Huntington's disease (P< 0.05). The results of PCR assay showed 5.6% (n= 3) of the patients were infected with Toxoplasma. Conclusion: PCR method has detected considerable incidence of Toxoplasma infection for monitoring HSCT recipients at risk for toxoplasmosis, and many patients who showed the incidence of toxoplasmosis had previous infections with the Toxoplasma parasite. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3336 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3336/1216