Spatiotemporal process and mechanism of Kashin-Beck disease regression in Xizang during 2000-2015

Kashin-Beck disease (KBD) control in Xizang has now entered a new stage of consolidation and improvement. Clarifying the spatiotemporal mechanism of its regression is of great significance for promoting the long-term prevention and control of endemic diseases in the plateau. Based on the detection rate data of KBD in Xizang from 2000 to 2015 and by the methods of random forest and spatial statistics, this study analyzed the spatiotemporal variation characteristics of KBD and explored the main factors affecting the regression of KBD and their regional differences. The results showed that: (1) The condition of KBD decreased steadily in all parts of Xizang during 2000-2015. The spatial distribution of KBD gradually converged to the east from the overall pattern of high in the east and low in the west, high in the south and low in the north. The disease was the most serious and had the longest duration in Qamdo wards. (2) The top four major factors affecting the regression of KBD were per capita food consumption of farmers and herdsmen, per capita GDP, per capita disposable income of farmers and herdsmen, and NDVI. Except for NDVI, all the other factors showed negative correlations with the detection rate of KBD. (3) In Ali, the prevalence of KBD was mainly influenced by per capita GDP and the income level of farmers and herdsmen, while in the middle reaches of the Yarlung Zangbo River and Qamdo, wards were more affected by dietary factors. (4) The dominant factors for the prevalence of KBD varied greatly within different years, which specifically manifested as a shift from natural factors to humanistic and social factors. Social economy, dietary nutrition and land use patterns played important roles in the prevention and control of KBD in Xizang. In view of the unique environmental conditions in Xizang, strengthening diversified food supply and adhering to returning farmland to forests and grasslands are still the basic countermeasures for preventing and controlling KBD. Meanwhile, raising the economic development level of endemic areas and enhancing the dietary nutrition of local residents are the fundamental guarantees for the long-term prevention and control of KBD in the plateau. © 2024 Science Press. All rights reserved.