Prevalence of Kaschin-Beck disease among Tibetan children in Aba Tibetan and Qiang Autonomous Prefecture: a 3-year epidemiological survey.

BACKGROUND: Kaschin-Beck disease (KBD), a special type of osteoarthritis, is a disabling degenerative disease and it can cause severe dysarthrosis of joints. This study was undertaken to investigate the prevalence of KBD among Tibetan children in the Aba Tibetan and Qiang Autonomous Prefecture in Sichuan Province and to provide evidence for KBD control in the western regions of China. METHODS: Eleven counties were selected as the monitoring regions and all Tibetan children aged 6-13 years were selected as the study subjects. A questionnaire survey and clinical and radiological examinations (right hand and wrist) were performed. KBD was diagnosed according to the Chinese Radiological Criteria of Kaschin-Beck Disease Diagnosis (GB16003-1995). RESULTS: X-ray analysis showed that all counties belonged to controlled endemic areas, and 4 of them were confirmed as active endemic areas for KBD. The overall detection rate of KBD in the Aba Tibetan and Qiang Autonomous Prefecture was 2.09% in 2007, 2.66% in 2008, and 1.20% in 2009. The majority of pediatric patients were found in Jinchuan and Markang counties. CONCLUSIONS: Although the prevalence of KBD showed a decreasing trend in the Aba Tibetan and Qiang Autonomous Prefecture, some new pediatric cases are still emerging. Therefore, comprehensive measures should be taken to prevent the occurrence of the disease in children, and an effective preventive program should be set up in the prefecture.

[Surveillance on Keshan disease from 1990 to 2008 in Sichuan province].

OBJECTIVE: 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. METHODS: Based on KD related data from 1990 to 2008, descriptive method was used to analyze the epidemiological characteristics of KD. RESULTS: 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. CONCLUSION: 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.