Objective: To understand the recent transmission of Mycobacterium tuberculosis (MTB), and to identify the influencing factors of recent transmission among pulmonary tuberculosis (TB) patients in Jing'an district, Shanghai. Methods: The genotypes and drug resistances of MTB isolated from TB patients registered in the TB designated hospitals in Jing'an district during 2010-2015 were analyzed through 12-loci Mycobacterial interspersed repetitive unit-variable number tandem repeat (MIRU-VNTR)(QUB11b, QUB18, Mtub21, Miru26, QUB26, Mtub04, Miru31, Miru40, VNTR2372, VNTR3820, 3232, 4120), and tested for drug susceptibility as well. With the results of field epidemiological investigation, univariate and multivariate analyses were performed to analyze the distribution of the clusters and influencing factors on recent transmission. Results: This study enrolled 80 TB patients, 23 (28.75%) had a resistance to at least one anti-TB drug, and the prevalence of multidrug-resistant tuberculosis (MDR-TB) was 16.25%. A total of 65 genotypes were identified with 58 (72.50%, 58/80) being unique and 7 clusters with 2-10 isolated in each cluster. The proportion of clustering was 27.50% (22/80). Results from the multivariate analysis revealed that multidrug- resistance (OR=35.799, 95%CI: 4.239-302.346) and having comorbidity with TB (OR=7.695, 95%CI: 1.421-41.658) were independently associated with the clustering, which suggesting a recent transmission. The field investigation to the clustered cases proved that the patients in two clusters had epidemiological links, one was between family members, and the other contained 10 MDR-TB patients with 9 knowing each other which have a definite connection and 1 having the possible connection with them. Conclusion: Recent transmission of tuberculosis happened among TB patients in Jing'an district, with high risks among the MDR-TB patients.
China ; Cluster Analysis ; Genotype ; Humans ; Mycobacterium tuberculosis/isolation & purification* ; Tuberculosis ; Tuberculosis, Multidrug-Resistant/transmission* ; Tuberculosis, Pulmonary/transmission*

Tuberculosis (TB) has remained an ongoing concern in China. The national scale-up of the Directly Observed Treatment, Short Course (DOTS) program has accelerated the fight against TB in China. Nevertheless, many challenges still remain, including the spread of drug-resistant strains, high disease burden in rural areas, and enormous rural-to-urban migrations. Whether incident active TB represents recent transmission or endogenous reactivation has helped to prioritize the strategies for TB control. Evidence from molecular epidemiology studies has delineated the recent transmission of Mycobacterium tuberculosis (M. tuberculosis) strains in many settings. However, the transmission patterns of TB in most areas of China are still not clear. Studies carried out to date could not capture the real burden of recent transmission of the disease in China because of the retrospective study design, incomplete sampling, and use of low-resolution genotyping methods. We reviewed the implementations of molecular epidemiology of TB in China, the estimated disease burden due to recent transmission of M. tuberculosis strains, the primary transmission of drug-resistant TB, and the evaluation of a feasible genotyping method of M. tuberculosis strains in circulation.
China ; epidemiology ; Genotyping Techniques ; Humans ; Molecular Epidemiology ; Mycobacterium tuberculosis ; genetics ; Tuberculosis, Multidrug-Resistant ; epidemiology ; transmission ; Whole Genome Sequencing

China/epidemiology* ; Humans ; Minisatellite Repeats ; Molecular Typing ; Mycobacterium tuberculosis/genetics* ; Polymerase Chain Reaction ; Tuberculosis, Multidrug-Resistant/transmission*

The global emergence of multidrugresistant (MDR) tuberculosis (TB) and extensively drug-resistant (XDR)-TB threatens to derail the efforts of TB control programmes worldwide. From 2000 to 2010, 161 pulmonary MDR-TB cases (including six XDR-TB cases) were reported in Singapore, and of these, 80% occurred among the foreign-born, with an increasing trend seen after 2004. Among new pulmonary TB cases, the highest incidence of MDR-TB occurred among patients from Myanmar (8%), followed by Vietnam (4.4%) and China (2.3%), while among those previously treated, the highest incidence was found in patients from Vietnam (50%), followed by Indonesia (33%) and Bangladesh (33%). Although the proportion of Singapore-born pulmonary TB cases with MDR-TB has remained comparatively low (0.2% and 1.3% in new and previously treated cases, respectively), there is no room for complacency. Top priority must be accorded toward the proper treatment of drug-susceptible TB cases under strict programme conditions so as to prevent the development of MDR-TB in the first place.
Antitubercular Agents ; therapeutic use ; Emigrants and Immigrants ; Extensively Drug-Resistant Tuberculosis ; epidemiology ; Humans ; Mycobacterium tuberculosis ; Singapore ; epidemiology ; Tuberculosis, Multidrug-Resistant ; drug therapy ; epidemiology ; transmission

BACKGROUNDDiagnosis and appropriate treatment of multidrug-resistant tuberculosis (MDR-TB) remain major challenges. We sought to elucidate that persons who share a household with drug resistance tuberculosis patients are at high risk for primary drug resistance tuberculosis and how to prevent these outbreaks.

METHODSWe used 12-locus mycobacterial interspersed repetitive unit and 7-locus variable-number tandem repeat to identify household transmission of extensively drug resistant and multiple drug resistant Mycobacterium tuberculosis in three families admitted in Shanghai Pulmonary Hospital affiliated with Tongji University. Drug susceptibility tests were done by the modified proportion method in the MGIT 960 system in the same time. Clinical data were also obtained from the subjects' medical records.

RESULTSAll of the six strains were defined as Beijing genotype by the deletion-targeted multiplex PCR (DTM-PCR) identification on the genomic deletion RD105. Strains from family-1 had the same minisatellite interspersed repetitive unit (MIRU) pattern (232225172531) and the same MIRU pattern (3677235). Strains from family-2 had the same MIRU pattern (2212261553323) and the same MIRU pattern (3685134). Strains from family-3 did not have the same MIRU pattern and they differed at only one locus (223326173533, 223325173533), and did not have the same VNTR pattern with two locus differed (3667233, 3677234).

CONCLUSIONSHousehold transmission exists in the three families. A clear chain of tuberculosis transmission within family exists. Tuberculosis susceptibility should be considered when there is more than one tuberculosis patients in a family. Household tuberculosis transmission could be prevented with adequate treatment of source patients.

Adult ; Female ; Genotype ; Humans ; Male ; Middle Aged ; Multiplex Polymerase Chain Reaction ; Mycobacterium tuberculosis ; classification ; genetics ; pathogenicity ; Radiography ; Tuberculosis, Multidrug-Resistant ; diagnostic imaging ; transmission ; Young Adult

OBJECTIVETo investigate the prevalence of primary drug-resistant tuberculosis (TB) and associated risk factors in China. We also explored factors contributing to the transmission of multidrug-resistant tuberculosis (MDR-TB).

METHODSA total of 2794 representative, Mycobacterium tuberculosis isolates from treatment-naive patients were subjected to drug susceptibility testing, and risk factors for drug-resistant TB were analyzed. We also analyzed MDR-TB strain sublineages, drug-resistance-conferring mutations, and risk factors associated with clustered primary MDR strains.

RESULTSAmong 2794 Mycobacterium tuberculosis isolates from treatment-naive patients, the prevalence of any resistance to first-line drugs was 33.2% and the prevalence of MDR-TB was 5.7%. We did not find any risk factors significantly associated with resistance to first-line drugs. The 93 primary MDR-TB isolates were classified into six sublineages, of which, 75 (80.6%) isolates were the RD105-deleted Beijing lineage. The largest sublineage included 65 (69.9%) isolates with concurrent deletions of RD105, RD207, and RD181. Twenty-nine (31.2%) primary MDR strains grouped in clusters; MDR isolates in clusters were more likely to have S531L rpoB mutation.

CONCLUSIONThis study indicates that primary drug-resistant TB and MDR-TB strains are prevalent in China, and multiple measures should be taken to address drug-resistant TB.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; China ; epidemiology ; Drug Resistance, Multiple, Bacterial ; genetics ; Female ; Humans ; Male ; Middle Aged ; Prevalence ; Risk Factors ; Tuberculosis, Multidrug-Resistant ; epidemiology ; transmission ; Young Adult