Tehran University of Medical Sciences Iranian Journal of Parasitology 1735-7020 8 2 2013 06 15 323 326 EN H Mohammadzadeh Hajipirloo Department of Medical Parasitology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran. A Bozorgomid Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran T Alinia Department of Epidemiology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran Kh Hazrati Tappeh Department of Medical Parasitology, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran R Mahmodlou Department of General Surgery, School of Medicine, Urmia University of Medical Sciences, Urmia, Iran 2015 10 14 Background: The aim of this study was to determine the prevalence of hydatidosis in west Azerbaijan, Iran during a 10 year period (2000-2009). Methods: We surveyed medical records of infected patients with hydatid cyst who had been oper-ated in four hospitals in Urmia City, the capital of West Azerbaijan Province, Iran. Several parame-ters were analyzed including age, sex, place of residency, hospitalization time, and the location of cysts. Results: Of 294 cases, 53.3% were female and 46.7% were male with the mean age of 39.4 years (5– 93). The average number of operated cysts per year was 29.4 (0.98/100,000 of population). The most affected age group was 20-30 year olds (18.7% of the cases). Cysts were localized in liver and lung in 57.5% and 21.8% of cases respectively and the average hospitalization time was 9 days. Single organ involvement was seen in the majority of patients and 28 (9.5%) cases had multiple involvement. The distribution of residence in patients showed 108 (36.9%) of them to have urban origin and 185 (63.1%) were rural residents. The lowest number (n=17) and the highest number of operation (n= 48) recorded in 2000 and 2007, respectively. Conclusion: The prevalence of hydatidosis is high in this city and further studies are needed for evaluation of economic burden and risk factors for CE in this region. https://ijpa.tums.ac.ir/index.php/ijpa/article/view/489 https://ijpa.tums.ac.ir/index.php/ijpa/article/download/489/455