Transmission dynamics of tuberculosis in a high-burden area of China: An 8-year population-based study using whole genome sequencing.

ABSTRACT

OBJECTIVES: This study investigated the transmission patterns of tuberculosis (TB) and its associated risk factors in Hunan province to inform the development of prevention and control strategies in the region. METHODS: An 8-year retrospective population-based genomic epidemiological study was conducted. Genomic clusters were defined using distance thresholds of 12-single-nucletide-polymorphisms. Risk factors associated with TB transmission were analyzed using logistic regression model. Kernel Density analysis was used to locate hotspots where transmission occurred. RESULTS: Among 2649 TB cases included in this study, 275 clusters were identified, with an overall clustering rate of 24.7% (654/2649). Nearly 95% (620/654) of clustered strains were isolated from the same county. Of the 275 clusters, 23 (8.4%, 23/275) had differences in drug-resistant profiles, with FQs resistance mutations occurring most frequently (52.2%, 12/23). Multivariate analysis identified male TB patients, those aged 30-60 years, ethnic minorities, nonfarmers, retreated TB patients, and individuals infected with MDR/RR-TB as independent risk factors for TB transmission (P < 0.05). Kernel density analysis showed that among the 5 drug-resistant surveillance sites, Leiyang had the highest clustering rate, followed by Yongshun, Qidong, Hecheng, and Taojiang. CONCLUSION: Recent transmission in the region is predominantly occurring within counties. The risk factors related to TB transmission and the hotspots where transmission occurs can provide a scientific basis for the formulation of targeted TB prevention and control strategies.