Multicenter Evaluation of the Molecular Line Probe Assay for Multidrug Resistant Mycobacterium Tuberculosis Detection in China

In order to evaluate the performance of a molecular Hain line probe assay （Hain LPA） for rapid detection of rifampicin and isoniazid resistance of Mycobocterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing （DST）. The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value {PPV） and negative predictive value （NPV） for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.

Cost-Effectiveness Analysis of Combined Chemotherapy Regimen Containing Bedaquiline in the Treatment of Multidrug-Resistant Tuberculosis in China

Objective This study aims to estimate the cost-effectiveness of the combined chemotherapy regimen containing Bedaquiline(BR)and the conventional treatment regimen(CR,not containing Bedaquiline)for the treatment of adults with multidrug-resistant tuberculosis(MDR-TB)in China.Methods A combination of a decision tree and a Markov model was developed to estimate the cost and effects of MDR patients in BR and CR within ten years.The model parameter data were synthesized from the literature,the national TB surveillance information system,and consultation with experts.The incremental cost-effectiveness ratio(ICER)of BR vs.CR was determined.Results BR(vs.CR)had a higher sputum culture conversion rate and cure rate and prevented many premature deaths(decreased by 12.8%),thereby obtaining more quality-adjusted life years(QALYs)(increased by 2.31 years).The per capita cost in BR was as high as 138,000 yuan,roughly double that of CR.The ICER for BR was 33,700 yuan/QALY,which was lower than China's 1×per capita Gross Domestic Product(GDP)in 2020(72,400 yuan).Conclusion BR is shown to be cost effective.When the unit price of Bedaquiline reaches or falls below57.21 yuan per unit,BR is expected to be the dominant strategy in China over CR.

Inferring Mycobacterium Tuberculosis Drug Resistance and Transmission using Whole-genome Sequencing in a High TB-burden Setting in China

Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health concern.Kashgar Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in China.However,molecular epidemiological studies of Kashgar are lacking.Methods A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission patterns.Results A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated cases.Known resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,P<0.001.The estimated proportion of recent transmissions was 25.9%(432/1,668).Multivariate logistic analyses indicated that sex,age,occupation,lineage,and drug resistance were the risk factors for recent transmission.Despite the low rate of drug resistance,drug-resistant strains had a higher risk of recent transmission than the susceptible strains(adjusted odds ratio,1.414;95%CI,1.023–1.954;P=0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB strains.Conclusion Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

Comparison of Xpert MTB/RIF, Real Amp, and CPA Tests in Detecting Mycobacterium tuberculosis

Today, tuberculosis (TB) remains a global public health threat associated with significantly high rates of morbidity and mortality. The World Health Organization's (WHO) Global Tuberculosis Report 2018[1] has reported that in 2017, 10.0 million people across the world had developed TB diseases that resulted in an estimated 1.6 million deaths, and 889, 000 people developed TB in China that led to 39, 000 TB-related deaths. Therefore, rapid and accurate detection of Mycobacterium tuberculosis (MTB) is important for initiating early treatment and reducing mortality. Traditional diagnostic methods for pulmonary TB incorporate chest radiography and sputum smear microscopy;however, several cases of tuberculosis go undiagnosed because of the low sensitivity of smear microscopy[2].

Changes in Notified Incidence of Pulmonary Tuberculosis in China,2005–2020

Objective To evaluate the trend of notified incidence of pulmonary tuberculosis(PTB)in China at different periods by population and region and to explore the effect of TB prevention and control in recent years.Methods Using pooled data on TB cases reported by the TB Information Management Reporting System(TBIMS)from 2005 to 2020,we calculated the annual percentage change(APC)using the Joinpoint regression model.Results From 2005 to 2020,a total of 16.2 million cases of PTB were reported in China,with an average notified incidence of 75.5 per 100,000 population.The age standardization rate(ASR)continued to decline from 116.9(/100,000)in 2005 to 47.6(/100,000)in 2020,with an average annual decrease of5.6%[APC=-5.6,95%confidence interval(CI):-7.0 to-4.2].The smallest decline occurred in2011–2018(APC=-3.4,95%CI:-4.6 to-2.3)and the largest decrease in 2018–2020(APC=-9.2,95%CI:-16.4 to-1.3).From 2005 to 2020,the ASR in males(159.8 per 100,000 in 2005,72.0 per 100,000 in2020)was higher than that in females(62.2 per 100,000 in 2005,32.3 per 100,000 in 2020),with an average annual decline of 6.0%for male and 4.9%for female.The average notified incidence was the highest among older adults(65 years and over)(182.3/100,000),with an average annual decline of6.4%;children(0–14 years)were the lowest(4.8/100,000),with an average annual decline of 7.3%,but a significant increase of 3.3%between 2014 and 2020(APC=3.3,95%CI:1.4 to 5.2);middle-aged(35–64years)decreased by 5.8%;and youth(15–34 years)decreased by an average annual rate of 4.2%.The average ASR in rural areas(81.3/100,000)is higher than that in urban areas(76.1/100,000).The average annual decline in rural areas was 4.5%and 6.3%in urban areas.South China had the highest average ASR(103.2/100,000),with an average annual decline of 5.9%,while North China had the lowest(56.5/100,000),with an average annual decline of 5.9%.The average ASR in the southwest was 95.3(/100,000),with the smallest annual decline(APC=-4.5,95%CI:-5.5 to-3.5);the average ASR in the Northwest China was 100.1(/100,000),with the largest annual decline(APC=-6.4,95%CI:-10.0 to-2.7);Central,Northeastern,and Eastern China declined by an average of 5.2%,6.2%,and 6.1%per year,respectively.Conclusions From 2005 to 2020,the notified incidence of PTB in China continued to decline,falling by55%.For high-risk groups such as males,older adults,high-burden areas in South,Southwest,and Northwest China,and rural regions,proactive screening should be strengthened to provide timely and effective anti-TB treatment and patient management services for confirmed cases.There is also a necessity to be vigilant about the upward trend of children in recent years,the specific reasons for which need to be further studied.

Evaluation of Multidrug Resistant Loop-mediated Isothermal Amplification Assay for Detecting the Drug Resistance of Mycobacterium tuberculosis

Objective To evaluate multidrug resistant loop-mediated isothermal amplification(MDR-LAMP)assay for the early diagnosis of multidrug-resistant tuberculosis and to compare the mutation patterns associated with the rpoB,katG,and inhA genes at the Chinese Center for Disease Control and Prevention.Methods MDR-LAMP assay was evaluated using 100 Mycobacterium tuberculosis(Mtb)isolates obtained from the National Reference Laboratory for Tuberculosis in China.Phenotypic resistance to isoniazid and rifampicin and whole-genome sequencing served as reference standards.Results The sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)of MDR-LAMP were 85.5%,93.6%,96.7%,and 74.4%for the detection of resistance to isoniazid and rifampicin,respectively,and 80.5%,92.3%,98.6%,and 41.4%for the detection of Mtb cultured from smear-positive sputum samples,respectively.When DNA sequencing was used as the reference standard,the sensitivity,specificity,PPV,and NPV of MDR-LAMP were 93.1%,92.3%,97.2%,and 82.8%for the detection of katG and inhA gene mutations,respectively,and 89.1%,88.9%,93.4%,and 81.1%for the detection of rpoB gene mutation,respectively.Conclusion MDR-LAMP is a rapid and accessible assay for the laboratory identification of rifampicin and isoniazid resistance of Mtb isolates.

Comparing the Genotype and Drug Susceptibilities between Mycobacterium avium and Mycobacterium intracellulare in China

Objective Mycobacterium avium （M. avium） and Mycobacterium intracellulare （M. intracellulare） are the major causative agents of nontuberculous mycobacteria （NTM）-related pulmonary infections. However, little is known about the differences in drug susceptibility profiles between these two species. Methods A total of 393 NTM isolates were collected from Shanghai Pulmonary Disease Hospital. Sequencing of partial genes was performed to identify the strains at species level. The minimum inhibitory concentration （MIC） was used to evaluate the drug susceptibility against 20 antimicrobial agents. Variable number of tandem repeat （VNTR） typing was conducted to genotype these two species. Results A total of 173 （44.0%） M. avium complex （MAC） isolates were identified, including 41 （10.4%） M. avium isolates and 132 （33.6%） M. intracellulare isolates. Clarithromycin and amikacin were the two most effective agents against MAC isolates. The Hunter-Gaston Discriminatory Index （HGDI） values for VNTR typing of M. avium and M. intracellulare isolates were 0.993 and 0.995, respectively. Levofloxacin resistance was more common among the unclustered strains than among the clustered strains of M. intracellulare. Conclusion M. intrecellulare was the most common NTM species in China. Clarithromycin and amikacin had high antimicrobial activities against MAC. VNTR typing of MAC isolates revealed a high discriminatory power. Levofloxacin resistance was associated with unclustered strains of M. intracellulare.

Prevalence and Risk Factors of Primary Drug-Resistant Tuberculosis in China

Objective To 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）. Methods A 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. Results Among 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 S531 L rpoB mutation. Conclusion This 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.

Mutual Impact of Diabetes Mellitus and Tuberculosis in China

China has a double burden of diabetes mellitus and tuberculosis, and many studies have been carried out on the mutual impact of these two diseases. This paper systematically reviewed studies conducted in China covering the mutual impact of epidemics of diabetes and tuberculosis, the impact of diabetes on multi-drug resistant tuberculosis and on the tuberculosis clinical manifestation and treatment outcome, the yields of bi-directional screening, and economic evaluation for tuberculosis screening among diabetes patients.

Comparison of Two Molecular Assays For Detecting Smear Negative Pulmonary Tuberculosis

Objective To compare the performance of MTBDRplus V2 and Xpert MTB/RIF for detecting smear negative pulmonary tuberculosis （PTB）. Methods Clinical PTB suspects were enrolled consecutively in Anhui Chest Hospital and Xi＇an Chest Hospital from January to December in 2014. The sputum samples of smear negative PTB suspects were collected and decontaminated. The sediment was used to conduct MTBDRplus V2, Xpert MTB/RIF and drug susceptibility test （DST）. All the samples with discrepant drug susceptibility result between molecular methods and phenotypic method were confirmed by DNA sequencing. Results A total of 1973 cases were enrolled in this study. The detection rates of Mycobacterium tuberculosis complex （MTBC） by MTBDRplus V2 and Xpert MTB/RIF were 27.67% and 27.98%, respectively. When setting MGIT culture result as a gold standard, the sensitivity and specificity of MTBDRplus V2 were 86.74% and 93.84%, and the sensitivity and specificity of Xpert MTB/RIF were 86.55% and 93.43%, respectively. For the detection of the resistance to rifampin, the sensitivity and specificity of MTBDRplus V2 were 94.34% and 96.62%, and the sensitivity and specificity of Xpert MTB/RIF were 88.68% and 95.96%, respectively. For the detection of the resistance to isoniazid, the sensitivity and specificity of MTBDRplus V2 were 77.38% and 98.02%, respectively. Conclusion MTBDRplus V2 and Xpert MTB/RIF can be used to detect MTBC in smear negative samples with satisfactory performance.

The Feasibility of Sputum Transportation System in China: Effect of Sputum Storage on the Mycobacterial Detection

Sputum transportation from county-level to prefecture-level is an ideal strategy to cover the shortage of the laboratory capability in the resource-poor setting. Here, we firstly evaluated the feasibility of sputum transportation system in China by analyzing the culture and molecular diagnosis results from 1982 smear-positive patients with different delay in processing for culture.

Evaluation of the New Automatic Mycob.T Stainer andScanner for Detecting Acid-fast Bacilli in China

Objective To validate the performance of Mycob. T Stainer and Scanner(MTSS) for detecting acid-fast bacilli(AFB). Methods A total of 3,816 sputum samples from 1,515 tuberculosis(TB) suspects were tested at the Anhui Provincial Chest Hospital and the Linyi People’s Hospital from April-August, 2016. Each specimen was placed on two smear slides. One slide was stained by the ziehl-neelsen(ZN) method to be read by conventional microscopy(CM). The other slide was stained and scanned by MTSS. All specimens were decontaminated with 4% NaO H, and then inoculated into solid culture. The performance of MTSS was assessed. Results MTSS produced higher average positivity rate(27.96%) as compared with the CM(26.83%). The overall sensitivity and specificity of MTSS were 78.9% and 93.9%, respectively. The sensitivity and specificity of CM was 77.4% and 95.0%, respectively. Conclusion MTSS exhibited a favorable performance in the detection of AFB. It may be an alternative to CM for screening TB.

Genetic Diversity and Drug Susceptibility of Mycobacterium tuberculosis Isolates in a Remote Mountain Area of China

Objective We determined the genetic diversity of Mycobacterium tuberculosis（MTB） in a remote mountainous area of southwest China and evaluated the resolving ability of single nucleotide polymorphism（SNP） genotyping combined with variable number tandem repeat（VNTR） genotyping for Beijing family strains in association with drug resistance status.Methods Three hundred thirty-one MTB strains were isolated from patients living in mountainous regions of southwest China,and 8-loci SNP,VNTR-15 genotyping assays,and drug susceptibility testing of 9 drugs were performed.Results A total of 183 [55.29%（183/331）] strains were classified into the Beijing family.Of the 183 strains,111（60.66%） were defined as modern Beijing strains.The most predominant modern Beijing sub-lineage and ancient Beijing sub-lineage were Bmyc10 [39.34%（72/183）] and Bmyc25 [20.77%（38/183）],respectively.Of the isolates,19.64%（65/331） were resistant to at least 1 of the 9 anti-TB drugs and 17 [4.98%（17/331）] MTB isolates were multi-drug resistant tuberculosis（MDR-TB）.Two hundred sixty-one isolates showed a clustering rate of 14.18%（37/261） and a discriminatory index of 0.9990.The Beijing lineage exhibited a significantly higher prevalence of MDR-TB,as well as resistance to isoniazid（INH）,rifampin（RIF）,and para-aminosalicylic acid（PAS） when analyzed independently（P = 0.005,P = 0.017,P = 0.014,and P = 0.006 respectively）.The Beijing lineage was not associated with genetic clustering or resistance to any drug.In addition,genetic clustering was not associated with drug resistance.Conclusion MTB strains demonstrate high genetic diversity in remote mountainous areas of southwest China.Beijing strains,especially modern Beijing strains,are predominant in remote mountainous area of China.The combination of 8-loci SNPs and VNTR-15 genotyping is a useful tool to study the molecular epidemiology of MTB strains in this area.

The Current Status and Challenges Regarding Tuberculosis Infection Control in Health Care Facilities in China

Health care facilities are a high-risk environment for generating and spreading respiratory infectious diseases such as tuberculosis （TB）. The TB prevention and treatment staff in health care facilities are responsible for the identification, diagnosis, treatment, supervision, and management of TB patients .

Antimicrobial Susceptibility Testing and Molecular Characterization of Mycobacterium fortuitum Isolates in China

We performed molecular identification of clinical isolates of Mycobacterium fortuitum（M. fortuitum） and conducted drug susceptibility testing to analyze the in vitro susceptibility of clinical M. fortuitum isolates and potential molecular mechanism conferring resistance to fluoroquinolone and macrolide drugs. The results showed that moxifloxacin had the highest in vitro activity against M. fortuitum, and most M. fortuitum isolates were resistant to clarithromycin and linezolid in China. The loss of genetic mutation in clarithromycin-and amikacin-resistant isolates indicates that some other intrinsic mechanism conferring clarithromycin and amikacin resistance plays an essential role in M. fortuitum infection.

Evaluation of Microsphere-based xMAP Test for gyrA Mutation Identification in Mycobacterium Tuberculosis

Drug-resistant(DR) tuberculosis(TB) is a growing threat to public health[1]. Fluoroquinolone(FQ) antibiotics have long been used as anti-tuberculosis drugs, and their widespread application has led to the development of resistance in clinical isolates of Mycobacterium tuberculosis complex(MTBC).