Spatial distribution of pulmonary tuberculosis in Sichuan and Chongqing, 2018−2022

Objective To analyze the spatial distribution of pulmonary tuberculosis (TB) in Sichuan province and Chongqing municipality from 2018 to 2022, explore the clustering areas and provide evidence for TB prevention and control in Sichuan and Chongqing.

Methods The reported incidence data of TB in Sichuan and Chongqing from 2018 to 2022 were collected from national information system for disease prevention and control. Software arcgis 10.3 was used for spatial autocorrelation analysis and hotspot analysis.

Results From 2018 to 2022, the annual average reported incidence rate of pulmonary TB was 55.7/100000 in Sichuan and 65.0/100000 in Chongqing and, with annual decline rates of 3.00% and 8.37%, respectively. The reported pulmonary TB cases in Sichuan and Chongqing were mainly distributed in people aged ＞50 years, accounting for 45.91% and 55.58% of the total reported cases, respectively. The reported incidence rate in men was higher than that in women, with a statistically significant difference (P<0.001), and there were two incidence peaks in people aged 15–25 years and 65–80 years. Global spatial autocorrelation analysis showed a spatial positive correlation in the distribution of TB epidemics in Sichuan and Chongqing (P<0.001), showing spatial clustering distribution. Local autocorrelation analysis showed that the distribution of pulmonary TB in the Sichuan and Chongqing showed high-high, low-low, and high-low clustering. Southeastern Chongqing had high-high clustering areas, and high-high clustering showed a decrease trend. Western Sichuan had high-low clustering areas, and the high-low clustering showed an increase trend. The area bordering Sichuan and Chongqing showed a low-low clustering. Hotspot analysis showed that both western Sichuan and southeastern Chongqing had hotspot areas, but the hotspot areas in western Sichuan increased year by year, and hotspot areas in southeastern Chongqing decreased year by year.

Conclusion The incidence of TB in Sichuan and Chongqing showed spatial clustering. The high-incidence areas included Ganzi, Liangshan and Aba prefectures in western Sichuan and Pengshui county in southeastern Chongqing, while the area in Chengdu-Chongqing economic circle had low incidence of pulmonary TB.