Surveillance on Keshan disease from 1990 to 2008 in Sichuan province

Abstract

To study the epidemiological characteristics of Keshan disease (KD) and its trend so as to provide evidences for further research, prevention and treatment of the disease in Sichuan province. Based on KD related data from 1990 to 2008, descriptive method was used to analyze the epidemiological characteristics of KD. 87 KD cases were identified during the 19 years. All cases were children from the countryside, with majority of them were Yi nationality. Age of the patients ranged from 5 months to 18 years, with majority at 2 - 6 year-olds. The annual incidence rates were from 0/100 000 to 1.73/100 000 with 1999 the highest (1.73/100 000). A total number of 310 preclinical or chronic KD cases were identified and the total detection rates were between 0.28% and 2.8%, with 1992 the highest. As for levels of blood selenium during the 19 years: 1995 appeared the lowest (0.1345 microg/g), followed by 1990 - 2000 (0.1558 microg/g) but all of them fell in to the level in the KD epidemic areas. There were 5 stages in the development trend of KD disease in Sichuan province, with 2 ascending and 3 descending. The differences between any of the two stages were statistically significant. The 3 descending stages all appeared right after the selenium supplement intervention was taken. Our data showed that the program of selenium supplement was closely related to the incidence of KD, suggesting that a long term mechanism of Selenium supplement in the epidemic areas should be taking into account.