Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 49 10 2020 10 01 1983 1991 Ahmad HOSSEINI-SAFA Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Saeedeh SHOJAEE Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Seyed Alireza SALAMI Department Biotechnology, School of Agricultural Sciences and Engineering, University of Tehran, Tehran, Iran Mehdi MOHEBALI Department 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 (CREPI), Tehran University of Medical Sciences, Tehran, Iran Sedigheh HANTOUSHZADEH Maternal, Fetal and Neonatal Research Center, Vali-Asr Hospital, Imam Khomeini Hospital Complexes, Tehran University of Medical Sciences, Tehran, Iran Parisa MOUSAVI Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Seyed Ali DEHGHAN MANSHADI Department of Infectious Diseases and Tropical Medicine and Iranian Research Center for HIV/AIDS, Tehran University of Medical Sciences, Tehran, Iran Hosein KESHAVARZ VALIAN Department 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 (CREPI), Tehran University of Medical Sciences, Tehran, Iran 2019 09 02 2019 11 05 Background: Toxoplasma gondii is an obligate intracellular protozoan with worldwide distribution. Diagnosis of toxoplasmosis is a very critical issue, especially in pregnant women and immunocompromised patients. The aim of this study was rapid detection of T. gondii DNA in peripheral blood samples (PBS) employing HRM technique and using RE gene. Methods: Totally, 242 samples from pregnant women and human immunodeficiency virus (HIV) patients were collected from different hospitals and medical centers of Tehran during Oct 2017 to Dec 2018. High resolution melting analysis (HRM) using partial sequences of repetitive element (RE) gene was done and compared with ELISA test. Results: Overall, 51 were positive for acute toxoplasmosis that among them, 12 and 20 reported as positive in pregnant women and HIV+ patients, respectively using HRM technique. Among 70 patients in chronic phase of disease, 10 and 3 samples were reported as positive for pregnant women and HIV+ patients respectively. From 121 negative control, 3 (4.62%) samples associated with HIV+ patients, showed positive real-time PCR and HRM analysis results. Conclusion: For the first time, HRM technique via employing RE gene was used for detection of T. gondii infection in PBS. This method is suitable, helpful and in parallel with serological methods for early diagnosis of acute as well as active form of toxoplasmosis in pregnant women and HIV+ patients. The use of techniques based on melt curve and through employing next-generation dyes for diagnosis of T. gondii would be accessible for patients in developing countries. https://ijph.tums.ac.ir/index.php/ijph/article/view/18231 https://ijph.tums.ac.ir/index.php/ijph/article/download/18231/7016