human cystic echinococcosis in zanjan area, northwest iran: a retrospective hospital based survey between 2007 and 2013

background: hydatidosis is the most important zoonotic disease that causes significant economic losses and public health problems worldwide. this study was conducted to evaluate retrospectively 136 patients diagnosed with hydatid cyst disease at two university medical centers between 2007 and 2013 in in zanjan area, northwest iran. methods: we surveyed medical records of infected patients with hydatid cyst who had been operated in two hospitals in zanjan city, northwest, iran. several parameters were studied including age, sex, place of habitation, and the location of cysts. results: of 136 cases, 54.4% were female with the mean age of 45 yr (4– 86). the most affected age group was 21-40 yr old (36.02% of the cases). cysts were localized in liver and lung in 64% and 23.5% of cases, respectively. single organ involvement was seen in the majority of patients and 13 (9.5%) cases had multiple involvement. in 69.9% of cases, there was only one cyst, 8.1% had two cysts, 17.6% with three cysts, and 4.4% had four cysts or more. the distribution of residence of patients showed that 33 (24.3%) of them were urban residents. conclusion: the prevalence of hydatidosis is high in this city and further studies are required to determine the prevalence, economic impact and risk factors of the disease in the area.