ABSTRACT
Objective To know the prevalence tendency of Keshan disease(KSD) under control after 10 years in Shaanxi Province, the factors that causes or relative to the disease, to provide scientific reference for disease's prevention and control. Methods Through stratified cluster sampling, based on the severity of KSD in endemic area of Shaanxi Province, 12 villages from 6 counties were randomly selected as investigation points in 2006. The people older than 3 year-old were chosen to do clinical check up and electrocardiogram tracing. Among them, suspicious or abnormal cases were asked to take chest X-ray and cardiac ultrasound. Maize and rice, hair and whole blood were randomly collected to test the selenium content, the activity of Glutathione peroxidase (GSH-Px). Results The total detection rate of potential or chronic KSD was 2.44%(139/5694), the detection rate of abnormal ECG was 9.19% (523/5692), the detection rate of cardiac enlargement from chest X-ray and cardiac ultrasound were 45.6%(72/158) and 34.5%(59/171) respectively. The average content of selenium in staple foods(wheat and corn) were[(0.045±0.036), (0.035±0.025)mg/kg, respectively]. The level of hair selenium in patients and healthy people were [(0.376±0.091), (0.384±0.077)mg/kg, respectively], with non-significant different (u=0.77, P>0.05). There were significant differences in whole blood selenium of patients, healthy people in KSD areas and healthy people in non-KSD areas[(0.071±0.017), (0.077±0.017), (0.090±0.016)mg/L, respectively; F=4.55, P<0.05), the whole blood selenium in patients lower than in healthy people in KSD areas (P<0.05), in healthy people in KSD areas lower than in non-KSD areas (P<0.05). Conclusions After the KSD condition being controlled, the situation in Shaanxi Province has become stable and exhibited a decreasing tendency. The selenium level of both internal and external environment in the endemic area increased significantly, that is the main factors of controlling disease.