Summary
Background
Multidrug-resistant tuberculosis (MDR-TB) is a significant threat to
tuberculosis elimination worldwide. Understanding the transmission pattern
is crucial for its control. We used a genomic epidemiological approach to
assess the recent transmission of MDR-TB and potential risk factors for
transmission.
Methods
In a population-based retrospective study, we performed
variable-number-of-tandem-repeat (VNTR) genotyping, followed by whole-genome
sequencing (WGS) of isolates from all MDR-TB patients in Shanghai, China,
2009-2012. We measured strain diversity within and between genomically
clustered patients. Genomic and epidemiologic data were combined to
construct transmission networks.
Findings
367 (5%) of 7982 patients with tuberculosis had MDR tuberculosis and
324 (88%) of these had isolates available for genomic analysis. 103 (32%) of
the 324 MDR strains were in 38 genomic clusters that differed by 12 or fewer
single nucleotide polymorphisms (SNPs), indicating recent transmission of
MDR strains. Patients who had delayed diagnosis or were older than 45 years
had high risk of recent transmission. 235 (73%) patients with MDR
tuberculosis probably had transmission of MDR strains. Transmission network
analysis showed that 33 (87%) of the 38 clusters accumulated additional
drug-resistance mutations through emergence or fixation of mutations during
transmission. 68 (66%) of 103 clustered MDR strains had compensatory
mutations of rifampicin resistance.
Interpretation
Recent transmission of MDR strains, with increasing drug-resistance,
helps drive the MDR-TB epidemic in Shanghai, China. WGS provides a measure
of the heterogeneity of drug-resistant mutations within and between hosts
and enhances our ability to determine the transmission patterns of
MDR-TB.
Funding
National Science and Technology Major Project, National Natural
Science Foundation of China, and US National Insitutes of Health.
The prevalence of myopia was lower or comparable to that reported in other populations from age 3 to 5 years, but increased dramatically after 6 years, consistent with a strong environmental role of schooling on myopia development.
There have been obstacles for internal migrants in China in accessing local public health services for some time. This study aimed to estimate the utilization of local public health services and its determinants among internal migrants. Data were from the 2014 and 2015 nationally representative cross-sectional survey of internal migrants in China. Multivariate logistic regressions were used to estimate the relationship between socioeconomic, migration, and demographic characteristics and public health services utilization. Our results showed that internal migrants in more developed eastern regions used less public health services. Those with higher socioeconomic status were more likely to use public health services. The years of living in the city of residence were positively associated with the utilization of public health services. Compared to migration within the city, migration across provinces significantly reduced the probability of using health records (OR = 0.88, 95% CI: 0.86–0.90), health education (OR = 0.97, 95% CI: 0.94–1.00), and health education on non–communicable diseases (OR = 0.92, 95% CI: 0.89–0.95) or through the Internet (OR = 0.96, 95% CI: 0.94–0.99). This study concludes that public health services coverage for internal migrants has seen great improvement due to government subsidies. Internal migrants with lower socioeconomic status and across provinces need to be targeted. More attention should be given to the local government in the developed eastern regions in order to narrow the regional gaps.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.