Journal of Ardabil University of Medical Sciences Vol. 19, No. 4, Winter 2020, Pages 430-438 Detection of Free Living Amoeba Acanthamoeba in the Nasal and Oral Discharges of HIV + / HIV - Sample in Arak Ghane Azabadi O 1 , Didgar F 2 , Zarinfar N 2 , Rafiei F 3 , Eslamirad Z * 1 1. Department of Parasitology and Mycology, School of Medicine, Arak University of Medical Sciences, Arak, Iran 2. Department of Infectious Diseases, School of Medicine, Arak University of Medical Sciences, Arak, Iran 3. Department of Biostatistics and Epidemiology, School of Health, Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran * Corresponding author. Tel: +9834173503-9, Fax: +9834173520, E-mail: dr.eslami@arakmu.ac.ir Received: Oct 22, 2019 Accepted: Dec 21, 2019 ABSTRACT Background & objectives: Impaired immune system provides favorable conditions for colonization by Acanthamoeba in the human body. In this case control study, we compared the molecular and culture methods in identifying Acanthamoeba in the nasal and oral secretions of HIV + /HIV - human. Methods: In a current case control study, nasal and oral discharge of 53, HIV + patients and 53, HIV - people were evaluated. The nasal and oral secretions of each patient were prepared by sterile swabs and transferred to the laboratory. All samples were cultured but only the positive samples used for molecular analysis. Results: By cultivation method, of the 53, HIV + patients, a total of 11 samples, including 5 nasal and 6 oral samples, were contaminated with Acanthamoeba. Of the 53, HIV- people, 3 samples of nasal discharge were contaminated with this parasite. The molecular method approved the contamination of 10 samples, including 5 oral and 5 nasal samples from HIV + patients with this parasite. Statistical analysis showed the rate of infection in HIV + patients was significantly different compared to HIV - people Conclusion: The results of the current study showed that the rate of Acanthamoeba infection in HIV + patients was higher than that of HIV - individuals. Also, considering that in the control group (HIV- individuals) only the nasal discharge were infected with the parasite, it seems that in the case group (HIV + patients) the infection of the oral discharge with the parasites is due to the entry of its cysts into the nose and transmission to the mouth . Keywords: Acanthamoeba; Free-living Amoeba; Nose; Mouth; HIV