Rates and risk factors for drug resistance tuberculosis in Northeastern China

Epidemiological characteristics and risk factors of multidrug-resistant tuberculosis in Luoyang, China

Objective

We aimed to examine the prevalence of multidrug-resistant tuberculosis (MDR-TB) in Luoyang, China, identify related risk factors, inform clinical practices, and establish standardized anti-tubercular treatment regimens.

Methods

We conducted a retrospective analysis of high-resolution melting curve (HRM) data from 17,773 cases (2,748 of which were positive) between June 2019 and May 2022 to assess the prevalence of MDR-TB and to identify its associated risk factors.

Results

Between June 2019 and May 2022, out of the 17,773 HRM results, 2,748 were HRM-positive, and 312 were MDR-TB cases. The detection rates for HRM-positive and MDR-TB were 17.0 and 12.1% for males, and 12.4 and 8.2% for females, respectively. The MDR-TB detection rate was higher in the urban areas (14.6%) than in the rural areas (10.6%) and more common among individuals under 51 years of age (14.1%) than those over 50 years of age (9.3%). Notably, the rate of detecting MDR-TB was 18.3% higher in new male patients than in new female patients, which was at 10.6%, and this difference was statistically significant (p < 0.001). Moreover, the rate of MDR detection in females who had received anti-tuberculosis treatment (21.3%) was higher than that in males (16.9%). In the multivariate model that considered the results of the sputum smear and detection time, MDR-TB was positively correlated with a history of tuberculosis (TB) treatment, being male, being younger than 51 years, and living in urban areas.

Conclusion

Local TB infections are complex and diverse; therefore, more comprehensive monitoring methods are needed to curb the spread of MDR-TB.

Risk factors associated with drug-resistant tuberculosis in Ethiopia: A systematic review and meta-analysis

The emergence of drug-resistant tuberculosis (DR-TB) is becoming a challenge to the national TB control programmes including Ethiopia. Different risk factors are associated with DR-TB. Identifying these risk factors in a local setting is important to strengthen the effort to prevent and control DR-TB. Thus, this study aimed to assess the risk factors associated with DR-TB in Ethiopia. The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist was followed to conduct this study. We systematically searched the articles from electronic databases and grey literature sources. We used the JBI tools to assess the quality of studies. Data were analysed using STATA version 15. We estimated the pooled odds ratio (OR) along with 95% Confidence Interval (CI). The forest plot and I2 heterogeneity test were used to assess heterogeneity among studies. We explored the presence of publication bias through visual inspection of the funnel plot and Egger's regression test. After screening 2238 articles, 27 studies were included in the final analysis. Based on the pooled analysis of the OR, unemployment (OR; 2.71, 95% CI; 1.64, 3.78), previous TB history (OR; 4.83, 95% CI; 3.02, 6.64), contact with known TB patient (OR; 1.72, 95% CI; 1.05, 2.40), contact with the known multi-drug resistant (MDR) TB patient (OR; 2.54, 95% CI; 1.46, 3.63) and having pulmonary TB (PTB; OR; 1.80, 95% CI; 1.14, 2.45) were found to be the risk factors of DR-TB, while elders (OR; 0.77, 95%CI; 0.60, 0.95) including above 45 years (OR; 0.76, 95%CI; 0.55, 0.97) and males (OR; 0.86, 95%CI; 0.76, 0.97) had lower DR-TB risk, compared to their counterparts. A previous history of TB treatment is a major risk factor for acquiring DR-TB in Ethiopia that might be due to poor adherence during the first-line anti-TB treatment. Besides, having contact with a TB patient, contact with an MDR-TB patient, having PTB and being unemployed were the risk factors of DR-TB in Ethiopia. Thus, active screening of TB contacts for DR-TB might help to detect DR-TB cases as early as possible and could help to mitigate its further transmission across the community.

Association between body mass index and newly diagnosed drug-resistant pulmonary tuberculosis in Shandong, China from 2004 to 2019

BACKGROUND

Drug-resistant tuberculosis (DR-TB), obesity, and malnutrition are growing public health problems in the world. However, little has discussed the impact of different BMI status on the emergence of TB drug resistance. We aimed to explore the drug-resistant profiles of DR-TB and its clinical predictors among underweight, overweight or obesity population.

METHODS

8957 newly diagnosed TB cases with drug susceptibility results and BMI data in Shandong China, from 2004 to 2019 were enrolled. Multivariable and univariable logistic regression models were applied to investigate the impact of BMI on different drug-resistance. Clinical predicators and drug-resistant profiles of DR-TB among obesity, underweight, normal TB group were also described.

RESULTS

Among 8957 TB cases, 6417 (71.64%) were normal weight, 2121 (23.68%) were underweight, 373 (4.16%) were overweight, and 46 (0.51%) were obese. The proportion of drug resistance and co-morbidity among normal weight, underweight, overweight, obese TB groups were 18.86%/18.25%/20.38%/23.91% (DR-TB), 11.19%/11.74%/9.65%/17.39% (mono-resistant tuberculosis, MR-TB), 3.41%/3.06%/5.36%/0.00% (multidrug resistant tuberculosis, MDR-TB), 4.21%/3.39%/5.36%/6.52% (polydrug resistant tuberculosis, PDR-TB), 10.57%/8.44%/19.57%/23.91% (co-morbidity), respectively. Compared with normal weight group, underweight were associated with lower risk of streptomycin-related resistance (OR 0.844, 95% CI 0.726-0.982), but contributed to a higher risk of MR-TB (isoniazid) (odds ratio (OR) 1.347, 95% CI 1.049-1.730; adjusted OR (aOR) 1.31, 95% CI 1.017-1.686), P < 0.05. In addition, overweight were positively associated with MDR-TB (OR 1.603, 95% CI 1.002-2.566; aOR 1.639, 95% CI 1.02-2.633), isoniazid + rifampicin + streptomycin resistance (OR 1.948, 95% confidence interval (CI): 1.061-3.577; aOR 2.113, 95% CI 1.141-3.912), Any isoniazid + streptomycin resistance (OR 1.472, 95% CI 1.013-2.14; aOR 1.483, 95% CI 1.017-2.164), P < 0.05.

CONCLUSIONS

The higher risk of MDR-TB, isoniazid + rifampicin + streptomycin resistance, Any isoniazid + streptomycin resistance, and co-morbidity among overweight population implies that routine screening for drug sensitivity and more attention on co-morbidity among overweight TB cases may be necessary. In addition, underweight TB cases have a higher risk of isoniazid resistance. Our study suggests that an in-depth study of the interaction between host metabolic activity and infection of DR-TB may contribute more to novel treatment options or preventive measures, and accelerate the implementation of the STOP TB strategy.

Age and sex distribution of Mycobacterium tuberculosis infection and rifampicin resistance in Myanmar as detected by Xpert MTB/RIF

Background

Detection of tuberculosis disease (TB) and timely identification of Mycobacterium tuberculosis (Mtb) strains that are resistant to treatment are key to halting tuberculosis transmission, improving treatment outcomes, and reducing mortality.

Methods

We used 332,657 Xpert MTB/RIF assay results, captured as part of the Myanmar Data Utilization Project, to characterize Mtb test positivity and rifampicin resistance by both age and sex, and to evaluate risk factors associated with rifampicin resistance.

Results

Overall, 70% of individuals diagnosed with TB were males. Test positivity was higher among males (47%) compared to females (39%). The highest positivity by age occurred among individuals aged 16–20, with test positivity for females (65%) higher than for males (57%). Although a greater absolute number of males were rifampicin resistant, a greater proportion of females (11.4%) were rifampicin resistant as compared to males (9.3%). In the multivariate model, history of previous treatment, age less than 30, testing in the Yangon region, and female sex were significantly positively associated with rifampicin resistance after adjusting for HIV status and year test was performed.

Conclusions

Our results indicate that young adults were more likely to test positive for TB and be identified as rifampicin resistant compared to older adults.

Differential yield of universal versus selective drug susceptibility testing of patients with tuberculosis in high-burden countries: a systematic review and meta-analysis

Introduction

Although universal drug susceptibility testing (DST) is a component of the End-TB Strategy, over 70% of drug-resistant tuberculosis (DR-TB) cases globally remain undetected. This detection gap reflects difficulties in DST scale-up and substantial heterogeneity in policies and implemented practices. We conducted a systematic review and meta-analysis to assess whether implementation of universal DST yields increased DR-TB detection compared with only selectively testing high-risk groups.

Methods

PubMed, Embase, Global Health, Cochrane Library and Web of Science Core Collection were searched for publications reporting on the differential yield of universal versus selective DST implementation on the proportion of DR-TB, from January 2007 to June 2019. Random-effects meta-analyses were used to calculate respective pooled proportions of DR-TB cases detected; Higgins test and prediction intervals were used to assess between-study heterogeneity. We adapted an existing risk-of-bias assessment tool for prevalence studies.

Results

Of 18 736 unique citations, 101 studies were included in the qualitative synthesis. All studies used WHO-endorsed DST methods, and most (87.1%) involved both high-risk groups and the general population. We found only cross-sectional, observational, non-randomised studies that compared universal with selective DST strategies. Only four studies directly compared the testing approaches in the same study population, with the proportion of DR-TB cases detected ranging from 2.2% (95% CI: 1.4% to 3.2%) to 12.8% (95% CI: 11.4% to 14.3%) with selective testing, versus 4.4% (95% CI: 3.3% to 5.8%) to 9.8% (95% CI: 8.9% to 10.7%) with universal testing. Broad population studies were very heterogeneous. The vast majority (88/101; 87.1%) reported on the results of universal testing. However, while 37 (36.6%)/101 included all presumptive TB cases, an equal number of studies applied sputum-smear as a preselection criterion. A meaningful meta-analysis was not possible.

Conclusion

Given the absence of randomised studies and the paucity of studies comparing strategies head to head, and selection bias in many studies that applied universal testing, our findings have limited generalisability. The lack of evidence reinforces the need for better data to inform policies.

A bioinformatics analysis to identify novel biomarkers for prognosis of pulmonary tuberculosis

Background

Due to the fact that pulmonary tuberculosis (PTB) is a highly infectious respiratory disease characterized by high herd susceptibility and hard to be treated, this study aimed to search novel effective biomarkers to improve the prognosis and treatment of PTB patients.

Methods

Firstly, bioinformatics analysis was performed to identify PTB-related differentially expressed genes (DEGs) from GEO database, which were then subjected to GO annotation and KEGG pathway enrichment analysis to initially describe their functions. Afterwards, clustering analysis was conducted to identify PTB-related gene clusters and relevant PPI networks were established using the STRING database.

Results

Based on the further differential and clustering analyses, 10 DEGs decreased during PTB development were identified and considered as candidate hub genes. Besides, we retrospectively analyzed some relevant studies and found that 7 genes (CCL20, PTGS2, ICAM1, TIMP1, MMP9, CXCL8 and IL6) presented an intimate correlation with PTB development and had the potential serving as biomarkers.

Conclusions

Overall, this study provides a theoretical basis for research on novel biomarkers of PTB, and helps to estimate PTB prognosis as well as probe into targeted molecular treatment.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12890-020-01316-2.

Prevalence and factors associated with multidrug-resistant tuberculosis in South India

India accounts for about one-fourth of the global burden of MDR-TB. This study aims to assess  the prevalence and factors associated with tuberculosis drug resistance among patients from South India. MTBDRplus assay and MGIT liquid culture performed on 20,245 sputum specimens obtained from presumptive MDR-TB cases during a six-year period from 2013 to 2018 were analyzed retrospectively. Univariate and multivariate logistic regression analysis was carried out to evaluate factors associated with MDR, Rifampicin mono-resistance, and Isoniazid mono-resistance. MDR, Rifampicin mono- resistant and Isoniazid mono-resistant TB were  found in 5.4%, 2.5%, and 11.4% cases of presumptive MDR-TB, respectively. Based on the rpoB gene, true resistance, hetero-resistance, and inferred resistance to Rifampicin was found in 38%, 29.3%, and 32.7% of the 1582 MDR cases, respectively. S450L (MUT3) was the most common rpoB mutation present in 59.4% of the Rifampicin resistant cases. Of the 3390 Isoniazid resistant cases, 72.5% had mutations in the katG gene, and 27.5% had mutations in the inhA gene. True resistance, heteroresistance, and inferred resistance accounted for 42.9%, 22.2%, and 17.3% of the 2459 katG resistant cases, respectively. True resistance, heteroresistance, and inferred resistance for the inhA gene were found in 54.5%, 40.7%, and 4.7% cases, respectively. MDR-contact (AOR 3.171 95% CI: 1.747–5.754, p-0.000) treatment failure (AOR 2.17595% CI: 1.703–2.777, p-0.000) and female gender (AOR 1.315 95% CI: 1.117–1.548, p-0.001), were positively associated with MDR-TB. Previous TB treatment did not show a significant positive association with MDR (AOR 1.113 95% CI: 0.801–1.546, p-0.523). Old age (AOR 0.994 95% CI: 0.990–0.999, p-0.023) and HIV seropositivity (AOR 0.580 95% CI: 0.369–0.911, p-0.018) were negatively associated with MDR-TB. Although Rifampicin mono-resistance had a positive association with treatment failure (AOR 2.509 95% CI: 1.804–3.490, p < .001), it did not show any association with previous TB treatment (AOR 1.286 95% CI: 0.765–2.164, p-0.342) or with history of contact with MDR-TB (AOR 1.813 95% CI: 0.591–5.560, p-0.298). However, INH mono-resistance showed a small positive association with the previous history of treatment for TB (AOR 1.303 95% CI: 1.021–1.662, p-0.033). It was also positively associated (AOR 2.094 95% CI: 1.236–3.548, p-0.006) with MDR-TB contacts. Thus INH resistance may develop during treatment if compliance has not adhered too and may be easily passed on to the contacts while Rifampicin resistance is probably due to factors other than treatment compliance. MDR-TB, i.e. resistance to both Rifampicin and Isoniazid, is strongly correlated with treatment failure, spread through contact, and not to treatment compliance. The temporal trend in this region shows a decrease in MDR prevalence from 8.4% in 2015 to 1.3% in 2018. A similar trend is observed for Rifampicin mono-resistance and Isoniazid mono-resistance, pointing to the effectiveness of the TB control program. The higher proportion of inferred resistance observed for Rifampicin compared with INH may indicate a surfeit of mechanisms that enable rifampicin resistance. Association of MDR-TB with age, gender, and HIV status suggest the role of the immune system in the emergence of the MDR phenotype.

Determinants of Drug-Resistant Tuberculosis in Southern Ethiopia: A Case-Control Study

Background

In most developing countries, including in Ethiopia, the magnitude and risk factors of drug-resistant tuberculosis (DR-TB) are expected to be high. However, this is not well reported because of lack of laboratory facilities, poor surveillance system and limited reporting. The aim of this study was to determine the risk factors of DR-TB among TB patients in southern Ethiopia.

Patients and Methods

Facility-based case–control study was conducted from November 2016 to January 2017 in Sidama Zone and Gurage Zone of the southern Ethiopia region. DR-TB cases were confirmed by drug-susceptibility testing who were on treatment for DR-TB at Yirgalem and Butajira Hospitals. Controls were smear-positive pulmonary tuberculosis (TB) patients who were taking first-line anti-TB medications and sputum smear-negative at the 5^th month of commencing TB treatment. Data were entered and cleaned using EPI-Info version 7 software and analyzed using SPSS version 22 statistical software.

Results

A total of 84 cases and 243 controls participated in the study. About 59% (49 cases) and 55% (132 controls) were male. The median (interquartile range) age was 28 (21–37) years for cases and 27 (25–33) years for controls. Living in a one-roomed house (adjusted odds ratio [AOR]: 6.8, 95% CI: 1.8–25.8), history of contact with DR-TB cases (AOR: 6.8, 95% CI: 1.8–25.3), treatment failure TB cases (AOR: 4.2, 95% CI: 1.1–15.5) and relapsed TB cases (AOR: 4.8, 95% CI: 1.3–18.1) were independent factors associated with DR-TB.

Conclusion

Providing standardized first-line regimen for new case and retreatment TB cases and practicing basic TB-infection control measures could help to minimize the spread of DR-TB.

Antibiotic sensitivity of Mycobacterium tuberculosis isolates; a retrospective study from a Saudi tertiary hospital

OBJECTIVES

This study aims to examine the antibiotic sensitivity of Mycobacterium tuberculosis isolates and its drug resistance. We also evaluated the relationship between demographic characteristics and tuberculosis (TB) drug susceptibilities.

METHODS

A retrospective study was conducted to analyse the antibiotic sensitivity of M. tuberculosis isolates and its resistance to first-line anti-TB drugs. During the period 2008-2013, the medical records of 191 patients from the TB ward and the Out-Patient Department in an Eastern KSA tertiary hospital were reviewed.

RESULTS

We classified the specimens into two categories: extra-pulmonary and pulmonary TB. Among the extra-pulmonary TB specimens, 36.5% were from body fluids, 29.2% from tissue cultures and 5.2% from body abscesses. In case of pulmonary TB, sputum samples accounted for the highest proportion of the specimens (28.6%), followed by bronchial aspirates and pleural fluid (13.2% and 5.7%, respectively). Clinical isolates from women showed higher resistance to ethambutol compared to those from men. Isoniazid showed the highest resistance pattern among all antibiotics tested (17%). Meanwhile, tissue cultures had higher resistance to Isoniazid antibiotic compared to the other specimens.

CONCLUSION

Resistance to first-line TB drugs is higher in extra-pulmonary TB isolates than pulmonary isolates. Nearly one-fourth of all M. tuberculosis clinical strains were resistant to the antibiotics tested in mono-resistant or multi-resistant manners. Women had greater resistance to TB drug ethambutol as compared to men. Meanwhile, extra-pulmonary TB specimens, specifically that from tissue cultures, showed greater resistance to Isoniazid than other clinical specimens.

Epidemiology of drug-resistant tuberculosis in Chongqing, China: A retrospective observational study from 2010 to 2017

China is one of the top 30 countries with high multidrug-resistant tuberculosis (MDR-TB) and rifampin-resistant tuberculosis (RR-TB) burden. Chongqing is a southwest city of China with a large rural population. A retrospective observational study has been performed based on routine tuberculosis (TB) surveillance data in Chongqing from 2010 to 2017. The MDR/RR-TB notification rate increased from 0.03 cases per 100,000 population in 2010 to 2.1 cases per 100,000 population in 2017. The extensively drug-resistant TB (XDR-TB) notification rate has increased to 0.09 cases per 100,000 population in 2017. There was a decreasing detection gap between the number of notified MDR/RR-TB cases and the estimate number of MDR/RR-TB cases in new TB cases. The treatment success rate of MDR/RR-TB was 59% (95% confidence interval [CI], 53%-65%) in this period. Despite the progress achieved, the prevalence of MDR/RR-TB was still high facing challenges including detection gaps in new TB cases, the regional disparity, and the high risk for MDR/RR-TB in elderly people and farmers. Sustained government financing and policy support should be guaranteed in the future.

Primary drug resistance of mycobacterium tuberculosis in Shandong, China, 2004-2018

BACKGROUND

Primary drug-resistant tuberculosis (DR-TB) has contributed to a significant health and economic burden on a global scale, especially in China. we sought to estimate epidemiological characteristics of primary DR-TB in China from 2004 to 2018.

METHODS

Eleven thousand four hundred sixty-seven newly diagnosed and 1981 retreated TB cases with drug susceptibility data were included. Chi-Square test for trends, linear regression, a joinpoint regression model and temporal trend in proportions of the different resistance patterns were carried out.

RESULTS

The proportion of primary DR-TB and mono-resistant TB (MR-TB) in China had reduced by more than 12% since 2004, and were 21.38%, 13.35% in 2018 respectively. Among primary DR-TB cases (2173,18.95%), the percentage of multiresistant TB (MDR-TB, from 5.41 to 17.46%), male (from 77.03 to 84.13%), cavity (from 13.51 to 43.92%), rifampicin(RFP)-resistant TB (from 8.11 to 26.98%), streptomycin(SM)-resistant TB (from 50.00 to 71.43%) increased significantly (P < 0.05). On the contrary, the proportion of female, non-cavity, isoniazide(INH)-resistant TB (from 55.41 to 48.15%) and MR-TB (from 82.43 to 62.43%) decreased significant (P < 0.05). The primary drug resistance rate among female, cavity, smoking, drinking, 15 to 44 year-old TB subgroups increased by 0.16, 6.24, 20.95, 158.85, 31.49%, respectively. The percentage of primary DR-TB, RFP-resistant TB dropped significantly during 2004-2007 in Joinpoint regression model.

CONCLUSION

The total rate of drug resistance among new TB cases showed a downward trend in Shandong, China, from 2004 to 2018. Primary drug resistance patterns were shifting from female, non-cavity, INH-resistant TB, and MR-TB groups to male, cavity, RFP/SM-resistant TB, and MDR-TB groups. Considering the rising drug resistance rate among some special population, future control of primary DR-TB in China may require an increased focus on female, cavity, smoking, drinking, or 15 to 44 year-old TB subgroups.

First-line tuberculosis drug resistance patterns and associated risk factors in Germany, 2008-2017

Background

Drug-resistant tuberculosis (TB), especially multidrug-resistant TB (MDR-TB), poses a threat to public health. While standard surveillance focuses on Rifampicin and/or Isoniazid resistance, little is known about other resistance patterns. This study aims to identify predominant drug resistance (DR) patterns in Germany and risk factors associated with them in order to inform diagnostic and treatment strategies.

Methods

Case-based TB surveillance data notified in Germany from 2008–2017 were utilized to investigate DR and MDR-TB patterns for Isoniazid (H), Rifampicin (R), Pyrazinamide (Z), Ethambutol (E), and Streptomycin (S). Predominant patterns were further analyzed stratified by sex, age, country of birth, prior TB, and disease site. Multivariable logistic regression was conducted to determine risk factors associated with any resistance, MDR-TB, and complete HRZES resistance.

Results

26,228 cases with complete DST results were included in the study, among which 3,324 cases had any DR (12.7%). Four patterns were predominant, representing about ¾ of all cases with any resistance (S: 814 [3.1%]; H: 768 [2.9%]; HS: 552 [2.1%]; Z: 412 [1.6%]). High proportions of S and H resistances were found among both German and foreign-born populations, especially those born in Eastern Europe, and were unexpectedly high among children (H: 4.3%; S: 4.6%). Foreign-born cases had significantly higher proportion of any resistance (16.0%) and MDR-TB (3.3%) compared to German-born cases (8.3% and 0.6%). Of 556 MDR-TB cases, 39.2% showed complete HRZES resistance. Logistic regression revealed having prior TB and being foreign-born as consistently strong risk factors for any DR, MDR-TB, and complete HRZES resistance.

Conclusions

DR patterns observed in Germany, particularly for MDR-TB were more complex than expected, highlighting the fact that detailed drug-testing results are crucial before incorporating HRZES drugs in MDR-TB treatment. Furthermore, the relatively high rate of H-resistance in Germany provides strong rationale against the use of only H-based preventive therapy for LTBI.

Drug resistance profile of Mycobacterium tuberculosis and predictors associated with the development of drug resistance

OBJECTIVES

Drug-resistant tuberculosis (DR-TB) is a major challenge to national TB control programmes in developing countries. In the Pakistan province of Punjab, the extent and development of DR-TB is not well known. The current study was therefore conducted to assess the incidence and predictors of DR-TB in Punjab Province.

METHODS

Drug susceptibility testing was performed for 863 confirmed culture-positive Mycobacterium tuberculosis isolates using the proportion method. Patients were enrolled in the Programmatic Management of Drug-Resistant TB Unit of Gulab Devi Chest Hospital (Lahore, Pakistan) from August 2011 to September 2013. Data analysis was performed using IBS SPSS Statistics v.20. Multivariate logistic regression analysis was performed to assess risk factors for DR-TB.

RESULTS

The rate of resistance to at least one drug (i.e. DR-TB) was 35.0% (302/863) and the rate of multidrug-resistant TB (MDR-TB) was 30.0% (259/863). Among DR-TB cases, the number of females was relatively higher (167/302; 55.3%) compared with males. The majority of DR-TB patients resided in a rural area (229/302; 75.8%). Significant predictors of DR-TB were age 18-45 years, previous TB treatment, rural residence, being a housewife, being married, duration of sickness >1year and unemployment.

CONCLUSION

The problem of DR-TB in Pakistan is significant. The strongest risk factors were young age and previous anti-TB treatment. Being married, being a housewife, rural residence and unemployment were also risk factors, culminating in an urgent need for effective control, early diagnosis and treatment policies for DR-TB.

Epidemiological characteristics of pulmonary tuberculosis in mainland China from 2004 to 2015: a model-based analysis

BACKGROUND

We used data released by the government to analyze the epidemiological distribution of pulmonary tuberculosis in mainland China from 2004 to 2015, in order to provide a deeper understanding of trends in the epidemiology of pulmonary tuberculosis in China and a theoretical basis to assess the effectiveness of government interventions and develop more targeted prevention and control strategies.

METHODS

A discrete dynamic model was designed based on the epidemiological characteristics of pulmonary tuberculosis and fitted to data published by the government to estimate changes in indicators such as adequate contact rate, prevalence of non-treated pulmonary tuberculosis (abbreviated as prevalence), and infection rate. Finally, we performed sensitivity analyses of the effects of parameters on the population infection rate.

RESULTS

The epidemiological features of pulmonary tuberculosis in China include a pattern of seasonal fluctuations, with the highest rates of infection in autumn and winter. The adequate contact rate has increased slightly from an average of 0.12/month in 2010 to an average of 0.21/month in 2015. The prevalence in the population has continued to decrease from 3.4% in early 2004 to 1.7% in late 2015. The Mycobacterium tuberculosis (M. tuberculosis) infection rate in the population decreased gradually from 42.3% at the beginning of 2004 to 36.7% at the end of 2015. The actual number of new infections gradually decreased from 1,300,000/year in 2010 to 1,100,000/year in 2015. The actual number of new patients each year has been relatively stable since 2010 and remains at approximately 2,600,000/year.

CONCLUSIONS

The population prevalence and the M. tuberculosis infection rate have decreased year by year since 2004, indicating that the tuberculosis epidemic in China has been effectively controlled. However, pulmonary tuberculosis has become increasingly contagious since 2010. China should focus on the prevention and control of pulmonary tuberculosis during autumn and winter.

Risk factors of multidrug-resistant tuberculosis in China: A meta-analysis

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) brings major challenges to the health care workers (HCWs). This study is to determine the risk factors for MDR-TB, latent tuberculosis infection (LTBI), and tuberculosis (TB) disease among HCWs in China.

METHODS

A meta-analysis was conducted to evaluate the risk factors for MDR-TB, LTBI, and TB disease among HCWs using a random-effects model, and the pooled odds ratios (ORs) with 95% confidence interval (CI) were used as effect indicators.

RESULTS

We identified 46 eligible studies and found eight factors were associated with MDR. The ORs with 95% CI are migrant population 1.96 (95% CI, 1.50-2.57), low family income 2.23 (95% CI, 1.74-2.85), retreatment 7.22 (95% CI, 5.63-9.26), anti-TB treatment history 5.65 (95% CI, 4.80-6.65), multiple episodes of treatment 3.28 (95% CI, 2.60-4.13), adverse reactions 3.48 (95% CI, 2.54-4.76), interrupted treatment 3.18 (95% CI, 2.60-3.89), and lung cavities 1.42 (95% CI, 1.14-1.77). Work duration as a HCW for 5 years and above increased the risk of LTBI and TB. HCWs aged 30 years and above were more susceptible to TB (OR = 1.70, 95% CI: 1.37-2.09).

CONCLUSION

The risk factors for MDR-TB in China are possibly migrant population, low family income, retreatment, anti-TB treatment history, adverse reactions, interrupted treatment, and lung cavities. Longer work duration and greater age are risk factors for LTBI and TB among HCWs.

Drug resistance characteristics of Mycobacterium tuberculosis isolates between 2014 and 2017 in Sichuan, China: A retrospective study

Background

The prevalence of drug-resistant tuberculosis (DR-TB) has brought severe challenges to the prevention and control of tuberculosis. Studies have explored the status of antituberculosis drug (ATD) resistance in different regions of China. However, few studies have focused on DR-TB in Sichuan to date. Due to the large population in Sichuan, detailed investigations of the DR-TB burden in Sichuan are needed. The objective of this study was to investigate the drug resistance characteristics of TB isolates from tuberculosis patients with and without HIV (TB-HIV patients and TBw/oHIV patients) in Chengdu, Sichuan, China.

Methods

Isolates from respiratory samples of TBw/oHIV patients and TB-HIV patients hospitalized between January 2014 and December 2017 were collected. Nontuberculosis mycobacteria (NTM) were excluded. Drug sensitivity testing (DST) was performed according to the dilution method in microplates with 4 first-line ATDs and 8 second-line ATDs. TB strains were separated according to patient treatment history, patient age, calendar year and GeneXpert MTB/RIF (GeneXpert) assay results for further analysis.

Results

For the 7470 patients recruited, the multidrug-resistant tuberculosis (MDR-TB) rate was 2.1-fold (14.6% vs. 6.8%) higher than the national baseline level. The repeatedly admitted patients were more likely to have a resistance profile than the first-time-admitted cases in both the TB-only group (P<0.05) and the TB-HIV corresponding group (P<0.05). Among the 7273 TBw/oHIV cases and 197 TB-HIV cases, the positivity rates of acid-fast bacilli (AFB) in the TB-HIV group were significantly lower than those in the TBw/oHIV group (P<0.05). The repeatedly admitted TB-HIV patients had lower resistance rates to INH than the repeatedly admitted TBw/oHIV patients (24.4% vs. 41.5%, P<0.05). The Rifampicin-resistant TB strains in the TBw/oHIV group were more likely to be resistant to INH in the repeatedly admitted group than those in the first-time admitted patients (P<0.05). The proportions of XDR (3.6% vs. 1.3%, P<0.05) and XDR-TB/MDR-TB (7.3% vs. 2.2%, P<0.05) in all TB-HIV patients were significantly higher than those in all TBw/oHIV patients. The ratio of XDR-TB was significantly higher in the TB-HIV group than in the TBw/oHIV group (30.4% vs. 9.0%, P<0.05) and the all TB group (9.0% vs. 10.1%, P<0.05). Regarding age, the <25-year-old TB-HIV patients (9.1% vs. 0.7%, P<0.05) and 25~44-year-old TB-HIV patients (5.2% vs. 2.4%, P<0.05) were more likely to have a higher XDR proportion than their TBw/oHIV counterparts. The ATD-resistance profile in terms of different years from high to low was 2014>2015>2016≈2017 for TBw/oHIV patients. The same trend was also observed for TB-HIV patients: 2014>2015>2016≈2017. The GeneXpert TB-positive rate in the TBw/oHIV group was higher than that in the TB-HIV group [81%(639/792) vs. 65% (13/20), P<0.05]. In TBw/oHIV cases, the agreement was 92.3% and the Kappa value was 0.75. In TB-HIV cases, the agreement was 85.0% and the Kappa value was 0.32.

Conclusion

In Sichuan, ATD resistance has improved since 2014, but to date, it remains severe. The different resistance profiles of TBw/oHIV patients and TB-HIV patients indicates the need for personalized treatment plans. Specifically, the GeneXpert assay might be more suitable for TBw/oHIV patients than for TB-HIV patients.

Factors affecting time to sputum culture conversion and treatment outcome of patients with multidrug-resistant tuberculosis in China

BACKGROUND

Few prospective cohort studies, none in China, have investigated the relationship between treatment outcomes of multidrug-resistant tuberculosis (MDR-TB) patients and sputum culture conversion. Factors affecting the time of the culture conversion throughout the whole course of the treatment have rarely been investigated.

METHODS

This study was performed in four cities in Jiangsu province, China. MDR-TB patients were consecutively enrolled between December 2011 and March 2014. Rates of sputum culture conversion were calculated and Cox proportional-hazards model was performed. Factors contributing to sputum culture conversion were investigated.

RESULTS

In all, 139 MDR-TB patients with treatment outcomes were enrolled. Median time to culture conversion among those who converted was 91.5 days (interquartile range, 34.0-110.8 days). After multivariable analysis, smoking (HR = 0.44; 95% CI: 0.23-0.83), drinking (HR = 0.41; 95% CI: 0.21-0.81), ofloxacin resistance (HR = 0.43; 95% CI: 0.24-0.76) and sputum smear grade > 1 (HR = 0.51; 95% CI: 0.31-0.83) were less likely to have culture conversion.

CONCLUSIONS

MDR-TB patients who smoke, drink, have ofloxacin resistance, or a high smear grade are less likely to respond to treatment and should be meticulously followed up.

Association of Immune Factors with Drug-Resistant Tuberculosis: A Case-Control Study

Background

Presently, studies of factors associated with drug-resistant tuberculosis (TB) focus on patients’ socio-demographic characteristics and living habits, to the exclusion of biochemical indicators, especially immune factors. This study was carried out to determine whether immune factors are associated with drug-resistant TB.

Material/Methods

A total of 227 drug-resistant pulmonary TB patients and 225 drug-susceptible pulmonary TB patients were enrolled in this study. Information on socio-demographic characteristics and biochemical indicators were obtained through their clinical records. Non-conditional logistic regression was used to analyze the association of these indicators with drug-resistant TB.

Results

There were significant differences in re-treatment, marital status, alanine aminotransferase (ALT), blood uric acid (BUA), carcino-embryonic antigen (CEA), T-spot, and CD3 and CD4 counts between the 2 groups. In multivariable analysis, re-treatment [Odds Ratio (OR)=5.290, 95% Confidence Interval [CI]=2.652–10.551); CD3 (OR=1.034, 95% CI=1.001–1.068); CD4 (OR=1.035, 95% CI =1.001–1.070) and IgM (OR=1.845, 95% CI=1.153–2.952) were associated with drug-resistant TB.

Conclusions

These results suggest the need for greater attention to re-treatment cases and immune function when treating drug-resistant TB.

Identification of Risk Factors of Multidrug-Resistant Tuberculosis by using Classification Tree Method

Multidrug-resistant tuberculosis (MDR-TB) has become a major public health problem. We tried to apply the classification tree model in building and evaluating a risk prediction model for MDR-TB. In this case-control study, 74 newly diagnosed MDR-TB patients served as the case group, and 95 patients without TB from the same medical institution served as the control group. The classification tree model was built using Chi-square Automatic Interaction Detectormethod and evaluated by income diagram, index map, risk statistic, and the area under receiver operating characteristic (ROC) curve. Four explanatory variables (history of exposure to TB patients, family with financial difficulties, history of other chronic respiratory diseases, and history of smoking) were included in the prediction model. The risk statistic of misclassification probability of the model was 0.160, and the area under ROC curve was 0.838 (P < 0.01). These suggest that the classification tree model works well for predicting MDR-TB. Classification tree model can not only predict the risk of MDR-TB effectively but also can reveal the interactions among variables.

Distinct Prevalence of Drug-Resistant Tuberculosis in Gansu, China: A Retrospective Study on Drug Susceptibility Profiles Between 2010 and 2014

Limited knowledge is available on regional distribution of antituberculosis (TB) drug resistance and on province-specific time-trends in TB drug susceptibility in China. To obtain the latest information about the dynamics of drug-resistant TB in Gansu province, we conducted a retrospective study and analyzed data on drug resistance among new TB cases diagnosed between June 2010 and May 2014 in Gansu, China. The data were collected from the only TB surveillance and treatment hospital in Gansu and, therefore, represented the epidemiology of TB in the province. The drug resistance was defined based on diagnostic drug susceptibility testing. Overall, 17.3% of TB new cases diagnosed during 2010 to 2014 in Gansu presented resistance to at least one anti-TB drug. And a total of 2.9% of new TB cases have multidrug resistance. The prevalence of multidrug-resistant TB in Gansu was found to resurge after 2013 (2.0%) after a steady decline between 2010 and 2012 (from 7.1% to 1.2%). The drug resistance patterns of TB and their revolution trends in Gansu differed from other regions of China. We report the first epidemiological description of drug-resistant TB in Gansu, which is distinct when compared to other regions. Our data demonstrate that the distribution of drug-resistant TB varies to a great extent among different geographic regions. And the results of our study greatly suggest that the implementation of individualized TB management and regimen policy based on the regional epidemiology of TB drug susceptibility is highly required.

Time to sputum culture conversion and treatment outcome of patients with multidrug-resistant tuberculosis: a prospective cohort study from urban China

Sputum culture plays an important role in monitoring treatment response in patients with multidrug-resistant tuberculosis (MDR-TB), and sputum culture conversion is a clinical tool used to predict therapeutic efficacy [1]. Monthly culture monitoring is essential for earlier detection of treatment failure in patients with MDR-TB. More sensitive signals of nonresponse would further avoid adverse outcomes [2].

The timing of testing for culture conversion has potential as a marker of MDR-TB treatment successhttp://ow.ly/borO308pPXg

Molecular detection of multidrug-resistant tuberculosis among smear-positive pulmonary tuberculosis patients in Jigjiga town, Ethiopia

Background

Molecular methods that target drug resistance mutations are suitable approaches for rapid drug susceptibility testing to detect multidrug-resistant tuberculosis (MDR-TB). The aim of the study was to determine MDR-TB cases and to analyze the frequency of gene mutations associated with rifampicin (RIF) and/or isoniazid (INH) resistance of Mycobacterium tuberculosis among smear-positive pulmonary tuberculosis patients.

Methods

Institution-based cross-sectional study design was employed. Sputum specimens were collected, and using a pretested questionnaire, data for associated risk factors for drug resistance were collected from 105 consecutive smear-positive pulmonary tuberculosis patients in Karamara General Hospital. Specimens were transported to Harar Health Research and Regional Laboratory, Harar, where molecular drug susceptibility testing was performed using GenoType^® MTBDRplus assay.

Results

Of the total 105 sputum specimens, 98 (93.3%) gave interpretable results, in which 67 (68.4%) were new cases and 31 (31.6%) were previously treated cases. Of these, 80 (81.6%) were sensitive to both drugs and 18 (18.4%) were resistant to RIF and/or INH. The prevalences of MDR-TB in total cases, new, and previously treated cases were 10 (10.2%), 3 (4.5%), and 7 (22.6%), respectively. Among the ten total RIF-resistant specimens, eight (80%) had resulted because of absence of rpoB WT8 and presence of MUT3 and in all specimens, the amino acids changed were Ser531Lue. Of the 18 total INH-resistant specimens, 15 (83.3%) had mutations in the katG gene (katG MUT1, Ser315Thr1), indicating high-level resistance, while 3 (14.7%) had mutations in the inhA promoter gene (Cys15Thr), indicating low-level resistance.

Conclusion

Among the mutations associated with resistance to RIF and INH, the majority were in codon 531 of the rpoB gene and codon 315 of the katG gene. Relatively high prevalence of MDR-TB was observed in the study.

Persistently high prevalence of primary resistance and multidrug resistance of tuberculosis in Heilongjiang Province, China

Background

The spread of multidrug-resistant tuberculosis (MDR-TB) Mycobacterium tuberculosis (M. tuberculosis) strains has been a big challenge to the TB control and prevention in China. Knowledge about patterns of drug resistance in TB high-burden areas of China is crucial to develop appropriate control strategies. We conducted a comprehensive investigation of the resistance pattern of M. tuberculosis in Heilongjiang Province.

Methods

1427 M. tuberculosis clinical strains were isolated from pulmonary TB patients hospitalized between 2007 and 2012. The susceptibility of the isolates to the first-line anti-TB drugs and the resistance of MDR M. tuberculosis to fluoroquinolones were examined. We also performed a statistical analysis to identify the correlated risk factors for high burden of MDR-TB.

Results

The global resistance rates of 2007–2012 to the first-line drugs and MDR were 57.0 and 22.8 %, respectively. Notably, the primary MDR-TB and pan-resistance rates were as high as 13.6 and 5.0 %, respectively. Of MDR M. tuberculosis isolates (2009), approximately 13 % were not susceptible to any of the fluoroquinolones tested. Being age of 35 to 54, high re-treatment proportion, the presence of cavity lesion, and high proportion of shorter hospitalization are correlated with the development of MDR-TB.

Conclusions

The high prevalence of drug resistant, MDR-TB, and fluoroquinolone-resistant MDR-TB is a big concern for TB control. More importantly, in order to control the development of MDR-TB effectively, we need to pay more attention to the primary resistance. Targeting reducing the prevalence of the risk factors may lead to better TB control in China.

Rifampicin resistance mutations in the 81 bp RRDR of rpoB gene in Mycobacterium tuberculosis clinical isolates using Xpert MTB/RIF in Khyber Pakhtunkhwa, Pakistan: a retrospective study

BACKGROUND

Multi-drug resistant tuberculosis (MDR-TB) is a major public health problem especially in developing countries. World Health Organization (WHO) recommends use of Xpert MTB/RIF assay to simultaneously detecting Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance. The primary objective of this study was to determine the frequency of MDR-TB in patients suspected to have drug resistance in Khyber Pakhtunkhwa. The frequency of probes for various rpoB gene mutations using Xpert MTB/RIF assay within 81 bp RRDR (Rifampicin Resistance Determining Region) was the secondary objective.

METHODS

A total of 2391 specimens, received at Programmatic Management of Drug Resistant TB (PMDT) Unit, Lady Reading Hospital (LRH) Peshawar, Pakistan, between October 2011 and December 2014, were analyzed by Xpert MTB/RIF test. MTB positive with rifampicin resistance were further analyzed to first line anti-mycobacterial drug susceptibility testing (DST) using middle brook 7H10 medium. The data was analyzed using statistical software; SPSS version 18.

RESULTS

Out of 2391 specimens, 1408 (59 %) were found positive for MTB and among them, 408 (29 %) showed rifampicin-resistance with four different rpoB gene mutations within 81 bp RRDR. The frequency of various probes among RIF-resistant isolates was observed as: probe E, in 314 out of 408 isolates; B, 44 out of 408; A, 5 out of 408; D, 34 out of 408; and probe C was observed among 6 out of 408 RIF-resistant isolates. The probe A&B and E&D mutation combination was found in only 1 isolate in each case, while B&D mutation combination was detected among 3 out of 408 RIF-resistant isolates.

CONCLUSIONS

Hence, it is concluded from our study on a selected population, 29 % of patients had MDR-TB. Probe E related mutations (also known as codon 531and 533) were the most common rpoB genetic mutation [314 (77 %)], acknowledged by Xpert MTB/RIF assay. Least mutation was detected within the sequence 511 (1.2 %).

Later emergence of acquired drug resistance and its effect on treatment outcome in patients treated with Standard Short-Course Chemotherapy for tuberculosis

Backgrounds

The failure of current Standard Short-Course Chemotherapy (SCC) in new and previously treated cases with tuberculosis (TB) was mainly due to drug resistance development. But little is known on the characteristics of acquired drug resistant TB during SCC and its correlation with SCC failure. The objective of the study is to explore the traits of acquired drug resistant TB emergence and evaluate their impacts on treatment outcomes.

Methods

A prospective observational study was performed on newly admitted smear positive pulmonary TB (PTB) cases without drug resistance pretreatment treated with SCC under China’s National TB Control Program (NTP) condition from 2008 to 2010. Enrolled cases were followed up through sputum smear, culture and drug susceptibility testing (DST) at the end of 1, 2, and 5 months after treatment initiation. The effect factors of early or late emergence of acquired drug resistant TB , such as acquired drug resistance patterns, the number of acquired resistant drugs and previous treatment history were investigated by multivariate logistic regression; and the impact of acquired drug resistant TB emergence on treatment failure were further evaluated.

Results

Among 1671 enrolled new and previously treated cases with SCC, 62 (3.7 %) acquired different patterns of drug resistant TB at early period within 2 months or later around 3–5 months of treatment. Previously treated cases were more likely to develop acquired multi-drug resistant TB (MDR-TB) (OR, 3.8; 95 %CI, 1.4–10.4; P = 0.015). Additionally, acquired MDR-TB cases were more likely to emerge at later period around 3-5 months after treatment starting than that of non-MDR-TB mainly appeared within 2 months (OR, 8.3; 95 %CI, 1.7–39.9; P = 0.008). Treatment failure was associated with late acquired drug resistant TB emergence (OR, 25.7; 95 %CI, 4.3–153.4; P < 0.001) with the reference of early acquired drug resistant TB emergence.

Conclusions

This study demonstrates that later development of acquired drug resistant TB during SCC is liable to suffer treatment failure and acquired MDR-TB pattern may be one of the possible causes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-016-0187-3) contains supplementary material, which is available to authorized users.

Fluoroquinolone-resistant tuberculosis: implications in settings with weak healthcare systems

Fluoroquinolones (FQ) play an essential role in the treatment and control of multidrug-resistant tuberculosis (MDR-TB). They are also being evaluated as part of newer regimens under development for drug-sensitive TB. As newer FQ-based regimens are explored, knowledge of FQ resistance data from high TB burden countries becomes essential. We examine available FQ resistance data from high TB burden countries and demonstrate the need for comprehensive surveys to evaluate FQ resistance in these countries. The factors driving FQ resistance in such conditions and the cost of such resistance to weak healthcare systems are discussed. The need for a comprehensive policy for addressing the issue of FQ resistance is highlighted.

Association between Multidrug-Resistant Tuberculosis and Risk Factors in China: Applying Partial Least Squares Path Modeling

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) resulting from various factors has raised serious public health concerns worldwide. Identifying the ecological risk factors associated with MDR-TB is critical to its prevention and control. This study aimed to explore the association between the development of MDR-TB and the risk factors at the group-level (ecological risk factors) in China.

METHODS

Data on MDR-TB in 120 counties were obtained from the National Tuberculosis Information Management System, and data on risk-factor variables were extracted from the Health Statistical Yearbook, provincial databases, and the meteorological bureau of each province (municipality). Partial Least Square Path Modeling was used to detect the associations.

RESULTS

The median proportion of MDR-TB in new TB cases was 3.96% (range, 0-39.39%). Six latent factors were extracted from the ecological risk factors, which explained 27.60% of the total variance overall in the prevalence of MDR-TB. Based on the results of PLS-PM, TB prevention, health resources, health services, TB treatment, TB detection, geography and climate factors were all associated with the risk of MDR-TB, but socioeconomic factors were not significant.

CONCLUSIONS

The development of MDR-TB was influenced by TB prevention, health resources, health services, TB treatment, TB detection, geography and climate factors. Such information may help us to establish appropriate public health intervention strategies to prevent and control MDR-TB and yield benefits to the entire public health system in China.

Clinical and epidemiological profiles of individuals with drug-resistant tuberculosis

Drug-resistant tuberculosis (TB) is a growing global threat. Approximately 450,000 people developed multidrug-resistant TB worldwide in 2012 and an estimated 170,000 people died from the disease. This paper describes the sociodemographic, clinical-epidemiological and bacteriological aspects of TB and correlates these features with the distribution of anti-TB drug resistance. Mycobacterium tuberculosis (MT) cultures and drug susceptibility testing were performed according to the BACTEC MGIT 960 method. The results demonstrated that MT strains from individuals who received treatment for TB and people who were infected with human immunodeficiency virus were more resistant to TB drugs compared to other individuals (p < 0.05). Approximately half of the individuals received supervised treatment, but most drug-resistant cases were positive for pulmonary TB and exhibited positive acid-fast bacilli smears, which are complicating factors for TB control programs. Primary healthcare is the ideal level for early disease detection, but tertiary healthcare is the most common entry point for patients into the system. These factors require special attention from healthcare managers and professionals to effectively control and monitor the spread of TB drug-resistant cases.

Diagnostic value of GeneChip for detection of resistant Mycobacterium tuberculosis in patients with differing treatment histories

The increasing burden of drug-resistant tuberculosis (TB) poses an escalating threat to national TB control programs. To assist appropriate treatment for TB patients, accurate and rapid detection of drug resistance is critical. The GeneChip test is a novel molecular tool for the diagnosis of TB drug resistance. Performance-related data on GeneChip are limited, and evaluation in new and previously treated TB cases has never been performed. We evaluated the diagnostic performance of GeneChip in detecting resistance to rifampin (RMP) and isoniazid (INH) and in detecting multidrug-resistant tuberculosis (MDR-TB) in comparison with standard drug susceptibility testing (DST) and compared the results in a group of previously treated and newly detected TB patients in an urban area in southeastern China. One thousand one hundred seventy-three (83.8%) new cases and 227 (16.2%) previously treated cases were collected between January 2011 and September 2013. The GeneChip showed a specificity of 97.8% and a sensitivity of 94.8% for detection of RMP resistance and 97.3% and 70.9%, respectively, for INH resistance in new cases. For previously treated cases, the overall sensitivity, specificity, and agreement rate are 94.6%, 91.3%, and 92.1%, respectively, for detection of RMP resistance and 69.7%, 95.4%, and 86.8%, respectively, for INH resistance. The sensitivity and specificity of MDR-TB were 81.8% and 99.0% in new cases and 77.8% and 93.4% in previously treated cases, respectively. The GeneChip system provides a simple, rapid, reliable, and accurate clinical assay for the detection of TB drug resistance, and it is a potentially important diagnostic tool in a high-prevalence area.