Abstract:

Objective: To analyze the epidemiological characteristics of tuberculosis (TB) epidemic in Inner Mongolia from 2011 to 2020, and to provide scientific evidence for the development of TB control and prevention strategy. Methods: Data of patients with pulmonary tuberculosis registered in Inner Mongolia from Jan. 1st, 2011 to Dec. 31st, 2020 were collected from the tuberculosis information management system, a subsystem of the infectious disease surveillance system of China CDC. Demographic data came from the Inner Mongolia. A descriptive epidemiological method was used to describe the epidemiological characteristics of the Inner Mongolia tuberculosis epidemic. Results: From 2011 to 2020, a total of 118599 cases of tuberculosis were registered in Inner Mongolia, with an average annual registered incidence of 47.42/100000, the registered incidence rate decreased from 67.47/100000 (16743/24817100) in 2011 to 35.39/100000 (8510/24049200) in 2020. The overall trend was downward ( {\chi }_{\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{n}\mathrm{d}}^2=3442.167, P<0.001), There were 44548 cases with positive pathogen. The positive rate of pathogen decreased from 53.15% (8899/16743) in 2011 to 24.74% (2498/10095) in 2017, ( {\chi }_{\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{n}\mathrm{d}}^2=18281.481, P<0.001), and from 2018 to 2020, the positive rate of pathogens increased year by year, which was from 36.29% (4703/12958) to 52.26% (4447/8510) ( {\chi }_{\mathrm{t}\mathrm{r}\mathrm{e}\mathrm{n}\mathrm{d}}^2=8077.724, P<0.001). The epidemic situation of pulmonary tuberculosis showed obvious seasonal and periodic fluctuation, with a high incidence in spring and summer. The number of patients in March was 12571, accounting for 10.60% (12571/118599) of all registered patients. The average annual registration rate of pulmonary tuberculosis patients ranged from 25.70/100000 to 66.49/100000. The peak of the average registered incidence rate was in eastern region. Leagues (prefectures) with relatively high registered incidence were Xing’an League (66.49/100000, 10547/15862600), Tongliao (64.86/100000, 20131/31038100), and those with relatively low incidence were Ordos City (25.79/100000, 5299/20544600), Hohhot City (25.68/100000, 7925/30864800). The incidence rate of male (61.22/100000, 79090/129194300) was significantly higher than that of female (32.67/100000, 39509/120927500)(χ²=10739.668, P<0.001).The highest incidence rate was in the 45-54 age group (9.49/100000, 23726/250121800), the next was in the 55-64 age group (9.32/100000, 23315/250121800).The patients were mainly farmers (61.58%, 73032/118599), followed by the patients with housekeeping/housework/unemployment, accounting for 13.32% (15794/118599). Conclusion: From 2011 to 2020,the registered incidence rate of pulmonary tuberculosis in Inner Mongolia was decreasing year by year. More attention should be paid to men, the middle-aged and the elderly, farmers and people in eastern region. Further measures should be taken to improve the quality of work in key areas and among high-risk groups in order to end the epidemic of tuberculosis.

Key words: Tuberculosis, pulmonary/prevention and control, Epidemiologic studies, Incidence, Inner Mongolia (Autonomous Region)