Abstract:

Objective: To examine the epidemiological trends of pulmonary tuberculosis in Yuexi County, Liangshan Yi Autonomous Prefecture, Sichuan Province, from 2005 to 2023, and to evaluate potential influencing factors including economic growth and transportation infrastructure development, with the aim of informing tuberculosis control strategies in resource-limited settings. Methods: Pulmonary tuberculosis case data from 2005 to 2023 were retrieved from the China Disease Control and Prevention Information System. Population and economic indicators were obtained from annual statistical yearbooks of Yuexi County. Descriptive epidemiological techniques were applied to assess incidence trends and their associations with macro-level socioeconomic variables. Results: Between 2005 and 2023, a total of 9856 pulmonary tuberculosis cases were reported in Yuexi County, corresponding to an average annual incidence rate of 151.66/100000 (9856/6498778). A statistically significant upward trend was observed over the study period (Z=11.519, P<0.01), with an average annual growth rate of 1.77%. A geographic shift in reporting sources was noted: from 2005 to 2018, more than half of the cases were reported locally (e.g., 86.81% (375/432) in 2008), whereas since 2019, the majority of cases were reported by medical institutions outside the county (e.g., 60.16% (379/630) in 2023). Of these out-of-county reports, 91.57% (3530/3855) were within Sichuan Province, predominantly from Xichang City (64.57%) and Chengdu City (18.13%). Marked spatial heterogeneity was observed across townships: Laji Township recorded the highest average incidence (211.58/100000, 193/91219), whereas Zhongsuo Town had the lowest (79.07/100000, 311/393300). Among all reported pulmonary tuberculosis cases, 65.57% (6463/9856) were male, with an incidence rate of 170.70/100000 (6463/3786111), significantly higher than that observed in females (92.99/100000, 3393/3648931)(χ²=867.890, P<0.001). The highest burden was observed among individuals aged 18-60 years, who constituted 75.66% (7557/9856) of all cases, with an incidence of 185.09/100000 (7457/4028798). Farmers represented the predominant occupational group, accounting for 80.32% (7916/9856) of all cases. Joinpoint regression analysis indicated that the average annual percent change (AAPC) in tuberculosis incidence from 2005 to 2023 was 1.70%, with notable surges during 2005—2007 (annual percent change (APC)=19.13%) and 2013—2016 (APC=31.87%). During the same period, the per capita gross domestic product (GDP) in Yuexi County increased at an average annual rate of 9.06%, exhibiting a weak positive correlation with the tuberculosis incidence rate, described by the fitted curve: y=121+0.00242x. Conclusion: The burden of pulmonary tuberculosis in Yuexi County has continued to rise in parallel with economic development. Improvements in transportation infrastructure have facilitated cross-regional healthcare-seeking behavior, contributing to increased case detection outside the county. Young and middle-aged male farmers represent the primary high-risk population for tuberculosis in this setting.

Key words: Tuberculosis, pulmonary, Epidemiologic studies, Small-area analysis