Abstract: Objective To analyze the epidemiological characteristics and spatial clustering of pulmonary tuberculosis in Ya'an City from 2019 to 2025, so as to provide evidence for optimizing prevention and control strategies. Method Based on the surveillance data of pulmonary tuberculosis from 2019 to 2025, the epidemiological characteristics were described. The Joinpoint regression model was used to analyze the temporal trends of the reported incidence rate and etiological positive rate. Spatial autocorrelation analysis was applied to identify the clustering areas and types of cases. Result A total of 4,526 pulmonary tuberculosis cases were reported in Ya'an City from 2019 to 2025, with an average annual reported incidence rate of 44.16 per 100 000 population; there were 3,034 etiologically positive cases, with an average annual etiological positive rate of 67.03%. The overall reported incidence rate showed a downward trend (AAPC=-3.866%, P<0.05), while the overall etiological positive rate showed an upward trend (AAPC = 11.677%, P<0.05). The reported incidence rate of males (62.35 per 100 000 population) was significantly higher than that of females (25.82 per 100 000 population), with a statistically significant difference (χ²=774.294, P<0.05). The elderly aged ≥60 years had the highest average annual reported incidence rate (74.05 per 100 000 population), with no statistically significant downward trend (χ²_trend=0.350, P>0.05). Farmers accounted for the highest proportion (68.10%) in pulmonary tuberculosis cases, followed by homemakers and unemployed people (14.60%), and there was a statistically significant difference in the proportion of cases among different occupations (χ²=6696.304, P<0.05). Spatial analysis revealed that the reported incidence of pulmonary tuberculosis fluctuated dynamically, with significant spatial clustering in 2024, yet no sustained and stable "high-high" clustering areas were formed. Conclusion The overall epidemic of pulmonary tuberculosis in Ya'an City showed a downward trend from 2019 to 2025, with obvious spatial clustering of cases in 2024 but no persistent high-incidence areas. Targeted prevention and control should be implemented for key populations such as males, people aged ≥60 years and farmers to effectively reduce the tuberculosis epidemic.

Key words: Pulmonary tuberculosis, Epidemiology characteristics, Spatial clustering, Spatial autocorrelation analysis, Joinpoint regression model, Ya'an city