ObjectiveTo investigate the distribution of Kashin-Beck disease(KBD) in Tibet, and assess the disease status. Methods Between 2007 and 2008, a survey was done on KBDepidemiology which was carried out in four prefectures of 26 counties according to the east, south, west, north and center in Nakchu,Lhoca, Nyingtri and Shigatse districts of Tibet, with towns and villages as baseline survey points. According to the KBD e survey scheme, KBD clinical examination for adults was also carried out and at the same time clinical and right hand anteroposterior X-ray examinations were given to children aged 4 - 13. The partition of endemic area was based on the criteria of national standards for Kashin-Beck disease diagnoses《GB 16395-1996》. Slight KBD area:clinical prevalence of Kashin-Beck disease grade Ⅰ and above was less than 10％ or X-ray detection rate ＜ 10％ of children; the moderate prevalent KBD area: clinical prevalence of Kashin-Beck disease grade Ⅰ and above was between 10％ and 20％ or X-ray detection rate was between 10％ and 30％ of children; severe KBD area: clinical prevalence of KBD grade Ⅰ and above was more than 20％ or X-ray detection rate was higher than 30％ of children.ResultsA total of 108 townships of 26 counties were surveyed, 14 686 adults were clinically examined, cases detection of grade Ⅰ and above were 637 people, the prevalence was 4.34％, and no case of grade Ⅲ was detected.Of 5769 children's right anteroposterior X-ray film, 102 were detected positive; the prevalence rate was 1.77％.Metaphysis was affected in most of the child cases, which accounting for 89.2％ (91/102). Amongst all the counties, there were 10 counties, clinical detection rate of adult KBD was 0, and children's X-ray detection rate of KBD was also 0. In 1 county the clinical prevalence rate for adults KBD was 0 and X-ray detection rate for children was 3.66(7/191 ). In 12 counties the clinical prevalence rate for adults KBD was between 1.03％ and 7.54％, X-ray detection rate for children was between 0 and 7.76％, amongst all these counties surveyed there were 5 counties,the detection rate for children was 0. In 3 counties the clinical prevalence rate for adult KBD was between 10.69％and 13.88％, the X-ray detection rate for children was between 5.31％ and 7.76％. Conclusions According to the criteria for diagnoses of KBD, within the 26 counties surveyed, 10 counties are non-endemic areas, 13 counties are slight endemic areas, 3 counties are medium endemic areas. So far, KBD is prevalent in 52 counties of 7 prefectures (cities) in Tibet, the disease is widely distributed, the situation is still severe, and there is a need to continue to strengthen KBD surveillance.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Male ; Osteoarthritis ; epidemiology ; Tibet ; epidemiology