Related Experiment Video
Updated: Oct 26, 2025
Matrix-based DNA Extraction for Targeted Next-Generation Sequencing on Decontaminated Sputum Samples
Published on: June 6, 2025
A population-based genomic epidemiological study of the source of tuberculosis infections in an emerging city:
Tingting Yang1,2, Yunxia Wang3, Qingyun Liu1
1Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Medical College and Shanghai Public Health Clinical Center, Fudan University, Room 201, Fuxing Building, Dongan Road No. 131, Shanghai 200032, China.
Background:
Tuberculosis (TB) in emerging cities is often a disease of recent immigrants, and understanding this epidemiology is crucial for designing effective control and prevention strategies.
Methods:
We conducted a retrospective population-based genomic epidemiological study of culture-positive pulmonary TB patients diagnosed between June 2014 and November 2017 in the Bao'an District of Shenzhen, a Chinese city with dramatic recent growth. After whole genome sequencing, transmission clusters were defined as strains differing by no more than 12 SNPs.
Findings:
Of 1696 culture-positive TB patients, 93•8% (1591/1696) were migrants, with 51•6% (821/1591) employed in housekeeping or unemployed. Of the 1460 migrants with known residence time, 47•7% (697/1460) developed TB within two years after arriving in Bao'an. Only 12•2% (207/1696) of Bao'an isolates were in genomic clusters, indicating that recent transmission was not the primary cause of TB in Bao'an. The isolates' median terminal branch length was 56 SNPs, more than could have accumulated since the arrival of the migrants in Bao'an. The migrants' isolates had genotypic distributions similar to those in their home provinces. One strain isolated in Bao'an belonged to a clade circulating in the patient's home province, providing further evidence that the strains were brought to Bao'an with the migrants.
Interpretation:
TB in the Bao'an District is principally caused by reactivation of infections acquired by migrants in their home provinces. Nearly half developed TB within two years after arriving in Bao'an, suggesting a need for increased TB screening of migrants, especially housekeeping workers and the unemployed.
Funding:
Sanming Project of Medicine in Shenzhen; National Science and Technology Major Project of China; Natural Science Foundation of China.
Related Concept Videos
01:26Pulmonary Tuberculosis IV
Several diagnostic approaches are used to detect TB. The conventional method is the Tuberculin Skin Test (TST), also known as the Mantoux test. However, this method has...
01:29Pulmonary Tuberculosis I
Causative Organism
The primary infectious agent causing tuberculosis is Mycobacterium tuberculosis, a slow-growing, acid-fast, aerobic rod that exhibits sensitivity to heat and ultraviolet light. Instances of Mycobacterium bovis and Mycobacterium avium contributing to the development of TB infection are rare.
Mode of...
01:31Pulmonary Tuberculosis III
The first classification is based on the development of the disease, and it includes the following categories:
01:05Single Nucleotide Polymorphisms-SNPs
01:28Pulmonary Tuberculosis II
Here is a detailed explanation of its pathophysiology:
Transmission: The process begins when a person inhales droplet nuclei containing M. tuberculosis. These are typically released into the air when an individual with pulmonary or...
01:28Pulmonary Tuberculosis V
Latent tuberculosis infection occurs when TB bacteria are present in a person's body, but are not causing illness or symptoms. It is not contagious, and preventive treatment is crucial to avoid the...