Hydatidosis is one of the most important infectious diseases which is mainly in the animal husbandby area such as Iran. The disease is caused by a worm called Echinococcus granlosus. Surgery seems to be the only treatment From medicine, psychology and economy points of view, study about the spreading and intensity of this disease in each area is necessary. In this study, 250 patients with hydatidosis under surgical treatment were studied. All these patients were residing in surgical sections of various hospitals in Markazi Province during 1991 to 1997. Only 143 patients had full hospital data. Different demographic factors such as sex, age, location, occupation, affected organ and course of treatment were considered. Among them 83% were female and 39.16% were male. The minimum and maximum age of patients were 7 and 79 years old, respectively. The most affected age groups were between 49-10 years old. The majority of patients were living in Arak. Among the patients, 62.26% were living in cities and 87.76% were living in villages and 51.04% of cases were housewives. Liver with 49.18% of cases was considered as second affected organ (M:26.44% , F:42.5% ). Lung with 16.26% was considered as the most affected organ (M:57.6% , F:42.5%). The mean duration for treatment was 12.83%.
