Incidence and Risk Factors of Active Tuberculosis Among Hospitalized Patients with Latent Tuberculosis Infection in China: A Cohort Study

Ye Liu; Lifan Zhang; Yan Chen; Guiren Ruan; Yuchen Liu; Shi Chen; Lantian Xie; Fengying Wu; Xiaochun Shi; Xiaoqing Liu

doi:10.2147/IDR.S447245

Incidence and Risk Factors of Active Tuberculosis Among Hospitalized Patients with Latent Tuberculosis Infection in China: A Cohort Study

Infect Drug Resist. 2024 Mar 11:17:953-960. doi: 10.2147/IDR.S447245. eCollection 2024.

Authors

Ye Liu^#¹, Lifan Zhang^#^{1

2

3

4}, Yan Chen^#¹, Guiren Ruan^{1

2

3}, Yuchen Liu¹, Shi Chen¹, Lantian Xie¹, Fengying Wu¹, Xiaochun Shi^{1

2

3}, Xiaoqing Liu^{1

2

3

4}

Affiliations

¹ Division of Infectious Diseases, Department of Internal Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
² State Key Laboratory of Complex Severe and Rare Disease, Peking Union Medical College Hospital, Beijing, People's Republic of China.
³ Center for Tuberculosis Research, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
⁴ Clinical Epidemiology Unit, Peking Union Medical College, International Clinical Epidemiology Network, Beijing, People's Republic of China.

^# Contributed equally.

Abstract

Background: The population with latent tuberculosis infection (LTBI) represents a potential pool of patients with active tuberculosis (ATB). T-SPOT.TB is an important test tool for screening LTBI. Owing to the large population of LTBI patients in China, it is necessary to identify a high-risk group for LTBI and enlarge tuberculosis preventive treatment (TPT) to reduce the incidence of ATB.

Methods: Hospitalized patients with positive T-SPOT.TB results were recruited from January 2013 to December 2016. Patients with ATB were excluded. Basic information was collected and the development of ATBs was examined during follow-up. The life-table method was used to calculate cumulative incidence rates. Potential risk factors were analyzed through Cox regression analysis.

Results: A total of 1680 patients with LTBI were recruited in the follow-up cohort, and 377 (22.44%) patients dropped out. With a median follow-up time of 81 months [interquartile range (IQR):61-93], 19 of 1303 patients with LTBI developed ATB. The 1-year incidence of ATB was 614 per 100,000 individuals [95%confidence interval (95% CI):584-644]. Over 5-year period, the cumulative incidence of ATB was 1496 per 100,000 [95% CI:1430-1570], and the incidence density was 240 per 100,000 person-years[95% CI:144-375]. In the Cox regression model, exposure of pulmonary tuberculosis (PTB) [adjusted hazard ratio (aHR)=10.557, 95% CI:2.273-49.031], maximum daily dosage of glucocorticoids (GCs)≥ 50 mg/d (aHR=2.948, 95% CI:1.122-7.748), leflunomide (LEF) treatment (aHR=8.572, 95% CI:2.222 -33.070), anemia (aHR=2.565, 95% CI:1.015-6.479) and T-SPOT.TB level≥300SFCs/10⁶ PBMCs (aHR=4.195, 95% CI:1.365-12.892) were independent risk factors for ATB development in LTBI patients.

Conclusion: The incidence of ATB is significantly higher in hospitalized patients with LTBI than in the general population. The exposure history of PTB, maximum daily dosage of GCs≥ 50 mg/day, LEF treatment, anemia, and T-SPOT.TB level≥300SFCs/10⁶PBMCs, were the risk factors of tuberculosis reactivation. Hospitalized LTBI patients with the above factors may need TPT.

Keywords: active tuberculosis; incidence; latent tuberculosis infection; risk factors.

Grants and funding

This study was supported by National High Level Hospital Clinical Research Funding (2022-PUMCH-C-013 and 2022-PUMCH-A-043).