Li Meng, Lu Liping, Jiang Qi, Jiang Yuan, Yang Chongguang, Li Jing, Zhang Yangyi, Zou Jinyan, Li Yong, Dai Wenqi, Hong Jianjun, Takiff Howard, Shen Xin, Guo Xiaoqin, Yuan Zhengan, Gao Qian
Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Science, Shanghai Medical College, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, China.
Department of Tuberculosis Control, Songjiang District Center for Disease Control and Prevention, Shanghai, China.
Lancet Reg Health West Pac. 2023 Jun 29;38:100833. doi: 10.1016/j.lanwpc.2023.100833. eCollection 2023 Sep.
With improved tuberculosis (TB) control programs, the incidence of TB in China declined dramatically over the past few decades, but recently the rate of decrease has slowed, especially in large cities such as Shanghai. To help formulate strategies to further reduce TB incidence, we performed a 10-year study in Songjiang, a district of Shanghai, to delineate the characteristics, transmission patterns, and dynamic changes of the local TB burden.
We conducted a population-based study of culture-positive pulmonary TB patients diagnosed in Songjiang during 2011-2020. Genomic clusters were defined with a threshold distance of 12-single-nucleotide-polymorphisms based on whole-genome sequencing, and risk factors for clustering were identified by logistic regression. Transmission inference was performed using phybreak. The distances between the residences of patients were compared to the genomic distances of their isolates. Spatial patient hotspots were defined with kernel density estimation.
Of 2212 enrolled patients, 74.7% (1652/2212) were internal migrants. The clustering rate (25.2%, 558/2212) and spatial concentrations of clustered and unclustered patients were unchanged over the study period. Migrants had significantly higher TB rates but less clustering than residents. Clustering was highest in male migrants, younger patients and both residents and migrants employed in physical labor. Only 22.1% of transmission events occurred between residents and migrants, with residents more likely to transmit to migrants. The clustering risk decreased rapidly with increasing distances between patient residences, but more than half of clustered patient pairs lived ≥5 km apart. Epidemiologic links were identified for only 15.6% of clustered patients, mostly in close contacts.
Although some of the TB in Songjiang's migrant population is caused by strains brought by infected migrants, local, recent transmission is an important driver of the TB burden. These results suggest that further reductions in TB incidence require novel strategies to detect TB early and interrupt urban transmission.
Shanghai Municipal Science and Technology Major Project (ZD2021CY001), National Natural Science Foundation of China (82272376), National Research Council of Science and Technology Major Project of China (2017ZX10201302-006).
随着结核病防控项目的改进，中国结核病发病率在过去几十年中大幅下降，但最近下降速度放缓，尤其是在上海等大城市。为了帮助制定进一步降低结核病发病率的策略，我们在上海松江区进行了一项为期10年的研究，以描述当地结核病负担的特征、传播模式和动态变化。
我们对2011年至2020年期间在松江诊断出的痰培养阳性肺结核患者进行了一项基于人群的研究。基于全基因组测序，以12个单核苷酸多态性的阈值距离定义基因组簇，并通过逻辑回归确定聚类的危险因素。使用phybreak进行传播推断。比较患者居住地之间的距离与其分离株的基因组距离。使用核密度估计定义空间患者热点。
在2212名登记患者中，74.7%（1652/2212）为外来务工人员。在研究期间，聚类率（25.2%，558/2212）以及聚类和非聚类患者的空间聚集情况没有变化。外来务工人员的结核病发病率显著高于本地居民，但聚类情况少于本地居民。男性外来务工人员、年轻患者以及从事体力劳动的本地居民和外来务工人员的聚类情况最为严重。只有22.1%的传播事件发生在本地居民和外来务工人员之间，本地居民更有可能传播给外来务工人员。随着患者居住地之间距离的增加，聚类风险迅速降低，但超过一半的聚类患者对居住距离≥5公里。仅为15.6%的聚类患者确定了流行病学联系，大多数是密切接触者。
虽然松江外来务工人员中的一些结核病是由受感染的外来务工人员带来的菌株引起的，但本地近期传播是结核病负担的重要驱动因素。这些结果表明，进一步降低结核病发病率需要新的策略来早期发现结核病并阻断城市传播。
上海市科技重大专项（ZD2021CY001）、国家自然科学基金（82272376）、中国国家科技重大专项（2017ZX10201302-006）。
