Zhenzhen Wang,1,2,* Liyang Xu,2,3,* Tengfei Guo,1 Jinwei Liu,1 Junrong Jin,1 Qing Zhang,1 Tao Jiang,1 Zhanqin Zhao,4 Yun Xue2 

1The First Affiliated Hospital, and College of Clinical Medicine of Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China; 2School of Medical Technology and Engineering, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China; 3Luoyang Center for Disease Control and Prevention, Luoyang, Henan, People’s Republic of China; 4Animal Science and Technology, Henan University of Science and Technology, Luoyang, Henan, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Yun Xue, School of Medical Technology and Engineering, Henan University of Science and Technology, No. 24 Jinghua Road, Jianxi District, Luoyang, Henan, People’s Republic of China, Tel +8613633799373, Email xueyun6688@163.com

Purpose: Existing data offer limited guidance on TB control strategies for the non-elderly population, hampering effective epidemic management. This study aimed to analyze TB transmission and molecular resistance profiles among non-elderly patients (< 60 years) in Luoyang City.
Patients and Methods: From 2019– 2023, 24,706 non-duplicate sputum samples from 10 TB-designated hospitals were tested for Mycobacterium tuberculosis complex (MTBC) via IS6110-targeted real-time PCR. MTBC-positive specimens underwent multicolor melting curve analysis (MMCA) to assess resistance to isoniazid (INH), rifampin (RFP), streptomycin (SM), and ethambutol (EMB). Age-stratified analyses were performed to compare drug-resistant TB (DR-TB) prevalence between elderly and non-elderly groups, with multivariate regression identifying resistance risk factors in non-elderly patients.
Results: Non-elderly individuals exhibited significantly higher TB (17.54% vs 15.26%) and DR-TB (26.82% vs 21.62%) rates than the elderly (all, P < 0.001). Among non-elderly patients, males, retreatment cases, main urban residents and smear-positive groups had significantly elevated MTBC detection rates. The predominant resistance patterns of multidrug-resistant tuberculosis (MDR-TB) and poly-resistant tuberculosis (PDR-TB) were MDR4 (INH + RFP + EMB + SM) and PDR2 (INH + SM), with detection rates of 5.52% (142) and 2.33% (60), respectively. MTBC positive rate peaked at 30– 34 years (23.10%), while the resistance rate peaked at 35– 39 years. After adjusting for the effects of smear results and diagnosis year, the multivariate regression analysis model indicated that male sex, retreatment, and the main urban area were high-risk factors for TB resistance in non-elderly cases.
Conclusion: The non-elderly population demonstrates a significantly higher burden of both TB detection and resistance, particularly among males, retreatment cases, and main urban patients. The emergence of complex drug resistance patterns, combined with a distinct trend of younger age at infection, highlights the critical need for targeted interventions tailored to specific epidemiological and resistance profiles of MTBC-infected populations.

Keywords: TB, non-elderly, dissemination, molecular resistance