Publication date: Jun 13, 2024
Extrapulmonary tuberculosis (EPTB) without symptomatic pulmonary involvement has been thought to be non-transmissible, but EPTB with asymptomatic pulmonary tuberculosis (PTB) could transmit tuberculosis (TB). Genomic investigation of Mycobacterium tuberculosis (Mtb) isolates from EPTB may provide insight into its epidemiological role in TB transmission. Between January 2017 and May 2020, 107 Mtb isolates were obtained from surgical drainage of bone TB patients at the Beijing Chest Hospital, and 218 Mtb strains were isolated from PTB cases. These 325 Mtb isolates were whole-genome sequenced to reconstruct a phylogenetic tree, identify transmission clusters, and infer transmission links using a Bayesian approach. Possible subclinical PTB in the bone TB patients was investigated with chest imaging by two independent experts. Among 107 bone TB patients, 10 were in genomic clusters (≤12 SNPs). Phylogenetic analysis suggested that three bone TB patients transmitted the infection to secondary cases, supported by epidemiological investigations. Pulmonary imaging of 44 bone TB patients revealed that 79. 5 % (35/44) had radiological abnormalities suggestive of subclinical PTB. This study provides genomic evidence that bone TB patients without clinically diagnosed PTB can be sources of TB transmission, underscoring the importance of screening for subclinical, transmissible PTB among EPTB cases.
| Concepts | Keywords |
|---|---|
| Beijing | Bone tuberculosis |
| Experts | Epidemiology |
| Mycobacterium | Transmission |
| Tuberculosis | Whole genome sequence |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | bone tuberculosis |
| disease | MESH | pulmonary tuberculosis |
| disease | MESH | Extrapulmonary tuberculosis |
| pathway | KEGG | Tuberculosis |
| disease | MESH | tuberculosis |
| disease | MESH | infection |
| disease | MESH | abnormalities |