Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 17 3 2022 09 05 385 392 Ahmad Zarei 1. Department of Parasitology and Mycology, School of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran 2. Student Research Committee, Baqiyatallah University of Medical Sciences, Tehran, Iran Mehdi Mohebali Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran Mahmoud Agholi Department of Medical Parasitology and Mycology, School of Medicine, Fasa University of Medical Sciences, Fasa, Iran Nematollah Jonaidi Jafari Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran Tahereh Mohammadzadeh 1. Department of Parasitology and Mycology, School of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran 2. Health Research Center, Life Style Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran 2021 06 11 2021 10 13 Background: Intestinal parasitic infections (IPIs) are still considered a public health problem of mankind, particularly in immunocompromised patients. We aimed to determine the prevalence of IPIs with an emphasis on immunocompromised patients in a referral hospital in Tehran Province, Iran. Methods: In this cross-sectional study, 442 fecal specimens were collected randomly from patients, referred to Baqiyatallah Hospital in Tehran Province, Iran from May to September 2020. The collected specimens were examined using wet-mount, trichrome and modified Ziehl-Neelsen staining, formalin-ether concentration, and agar plate culture. Results: The prevalence of IPIs was found 17.0% (95% CI: 13.6-20.8%). The prevalence of protozoan parasites (16.3%; 95% CI: 13.0-20.1%) was significantly higher than helminthic parasites (0.7%; 95% CI: 0.1-2.0%). Blastocystis spp., Giardia lamblia, and Entamoeba coli were the most common intestinal protozoan with a prevalence of 12.2%, 1.6%, and 1.4%, respectively. E. histolytica/E. dispar/E.  moshkovskii, Iodamoeba bütschlii, Cryptosporidium spp., Chilomastix mesnili as protozoan species and Hymenolepis nana, Dicrocoelium dendriticum, and Ascaris lumbricoides as helminthic species were the other detected parasites. Multiple logistic regression revealed a significant association of IPIs infections with stool consistency and the status of immune system. Conclusion: The prevalence of IPIs among the patients who are immunocompromised was significantly higher than immunocompetent patients (P< 0.05). Periodic stool examinations for screening of IPIs should be included as a part of routine medical check-up in these patients. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/3360 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/3360/1234