Infection Control for Drug-Resistant Tuberculosis: Early Diagnosis and Treatment Is the Key

Factors influencing false-positive results of rifampicin resistance detected by Xpert MTB/RIF: A retrospective study in Zhejiang, China

Objective

This study aimed to explore the factors influencing false-positive results for rifampicin resistance (RIF-R) detected using Xpert MTB/RIF (Xpert).

Methods

This retrospective analysis included the clinical data of patients from September 2019 to February 2023. The chi-square and rank sum tests were used to compare differences in patient characteristics between the true-positive and false-positive groups. Logistic regression was used to analyze the factors influencing false positives in the detection of RIF-R by Xpert.

Results

A total of 384 patients were included. Logistic regression analysis revealed that, with mutation of probe E as the reference, mutations on probe A or C (OR = 72.68, P < 0.001), probe D (OR = 6.44, P < 0.001), and multiple probes (OR = 5.94, P = 0.002) were associated with false-positive results in Xpert detection of RIF-R. Taking probe delay ΔCt <4 as the reference, ΔCt (4-5.9) (OR = 13.54, P < 0.001), ΔCt (6-7.9) (OR = 48.08, P < 0.001) probe delays were associated with false positives in Xpert detection of RIF-R. When very low quantification is accompanied by a probe delay, the probability of false-positive RIF-R detection can reach 80 %.

Conclusions

Clinicians should consider factors such as probe mutation type, probe delay, and very low quantification accompanied by probe delay when interpreting Xpert results, which can reduce the misdiagnosis of tuberculosis drug resistance.

Investigating socio-ecological factors influencing implementation of tuberculosis infection prevention and control in rural Papua New Guinea

BACKGROUND

Tuberculosis (TB) is a highly transmissible infectious disease killing millions of people yearly, particularly in low-income countries. TB is most likely to be transmitted in healthcare settings with poor infection control practices. Implementing TB infection prevention and control (TB-IPC) is pivotal to preventing TB transmission in healthcare settings. This study investigated diverse stakeholders' perspectives relating to barriers and strategies for TB-IPC in rural hospitals in Papua New Guinea.

METHODS

Multiple qualitative case studies were conducted with 32 key stakeholders with experience in TB services. Data collection drew on three primary sources to triangulate data: semi-structured interviews, document reviews and field notes. The data were analyzed using hybrid deductive-inductive thematic analysis.

RESULTS

Our results reveal that key stakeholders perceive multiple interdependent factors that affect TB-IPC practice. The key emerging themes include strategic planning for and prioritizing TB-IPC guidelines; governance, leadership and accountability at the provincial level; community attitudes towards TB control; institutional capacity to deliver TB care, healthcare workers' safety, and long-term partnership and integration of TB-IPC programmes into the broad IPC programme.

CONCLUSIONS

The evidence suggests that a multi-perspective approach is crucial for TB-IPC guidelines in healthcare institutions. Interventions focusing on addressing health systems strengthening may improve the implementation of TB-IPC guidelines.

Diagnostic accuracy of oral swab for detection of pulmonary tuberculosis: a systematic review and meta-analysis

Objectives

Tuberculosis (TB) remains a significant concern in terms of public health, necessitating the timely and accurate diagnosis to impede its advancement. The utilization of oral swab analysis (OSA) presents a promising approach for diagnosing pulmonary TB by identifying Mycobacterium tuberculosis (MTB) within oral epithelial cells. Due to disparities in the diagnostic performance of OSA reported in the original studies, we conducted a meticulous meta-analysis to comprehensively assess the diagnostic efficacy of OSA in pulmonary TB.

Methods

We conducted a comprehensive investigation across multiple databases, namely PubMed, Cochrane Library, Embase, Web of Science, ClinicalTrials.gov, Chinese BioMedical Literature Database (CBM), China National Knowledge Infrastructure Database (CNKI), and Wanfang China Science and Technology Journal Database to identify relevant studies. Out search query utilized the following keywords: oral swab, buccal swab, tongue swab, tuberculosis, and TB. Subsequently, we employed STATA 16.0 to compute the combined sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for both the overall and subgroup analyses.

Results

Our findings indicated that OSA has a combined sensitivity of 0.67 and specificity of 0.95 in individuals with pulmonary TB. Subgroup analysis further revealed that among adult individuals with pulmonary TB, the sensitivity and specificity of OSA were 0.73 and 0.93, respectively. In HIV-negative individuals with pulmonary TB, the sensitivity and specificity were 0.68 and 0.98, respectively. The performance of OSA in detecting pulmonary TB correlated with the bacteria load in sputum. Additionally, the sensitivity for diagnosing pulmonary TB using tongue specimens was higher (0.75, 95% CI: 0.65-0.83) compared to cheek specimens (0.52, 95% CI: 0.34-0.70), while both types of specimens demonstrated high specificity.

Conclusions

To conclude, oral swabs serve as a promising alternative for diagnosing pulmonary TB, especially in adult patients. In addition, tongue swabs yield better sensitivity than cheek swabs to identify pulmonary TB patients.

Systematic review registration

identifier: CRD42023421357.

Risk factors for diagnosis and treatment delay among patients with multidrug-resistant tuberculosis in Hunan Province, China

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a global health threat associated with high morbidity and mortality rates. Diagnosis and treatment delays are associated with poor treatment outcomes in patients with MDR-TB. However, the risk factors associated with these delays are not robustly investigated, particularly in high TB burden countries such as China. Therefore, this study aimed to measure the length of diagnosis and treatment delays and identify their risk factors among patients with MDR-TB in Hunan province.

METHODS

A retrospective cohort study was conducted using MDR-TB data from Hunan province between 2013 and 2018. The main outcomes of the study were diagnosis and treatment delay, defined as more than 14 days from the date of symptom to diagnosis confirmation (i.e., diagnosis delay) and from diagnosis to treatment commencement (i.e., treatment delay). A multivariable logistic regression model was fitted, and an adjusted odds ratio (AOR) with a 95% confidence interval (CI) was used to identify factors associated with diagnosis and treatment delay.

RESULTS

In total, 1,248 MDR-TB patients were included in this study. The median length of diagnosis delays was 27 days, and treatment delays were one day. The proportion of MDR-TB patients who experienced diagnosis and treatment delay was 62.82% (95% CI: 60.09-65.46) and 30.77% (95% CI: 28.27-33.39), respectively. The odds of experiencing MDR-TB diagnosis delay among patients coming through referral and tracing was reduced by 41% (AOR = 0.59, 95% CI: 0.45-0.76) relative to patients identified through consultations due to symptoms. The odds of experiencing diagnosis delay among ≥ 65 years were 65% (AOR = 0.35, 0.14-0.91) lower than under-15 children. The odds of developing treatment delay among foreign nationalities and people from other provinces were double (AOR = 2.00, 95% CI: 1.31-3.06) compared to the local populations. Similarly, the odds of experiencing treatment delay among severely ill patients were nearly 2.5 times higher (AOR = 2.49, 95% CI: 1.41-4.42) compared to patients who were not severely ill. On the other hand, previously treated TB cases had nearly 40% (AOR = 0.59, 95% CI: 0.42-0.85) lower odds of developing treatment delay compared with new MDR-TB cases. Similarly, other ethnic minority groups had nearly 40% (AOR = 0.57, 95% CI: 0.34-0.96) lower odds of experiencing treatment delay than the Han majority.

CONCLUSIONS

Many MDR-TB patients experience long diagnosis and treatment delays in Hunan province. Strengthening active case detection can significantly reduce diagnosis delays among MDR-TB patients. Moreover, giving attention to patients who are new to MDR-TB treatment, are severely ill, or are from areas outside Hunan province will potentially reduce the burden of treatment delay among MDR-TB patients.

Healthcare seeking behavior and delays in case of Drug-Resistant Tuberculosis patients in Bangladesh: Findings from a cross-sectional survey

The emergence of Drug-Resistant Tuberculosis (DR-TB) has become a major threat globally and Bangladesh is no exception. Delays in healthcare seeking, proper diagnosis and initiation of treatment cause continuous transmission of the resistant tubercule bacilli through the communities. This study aimed to assess the different health care-seeking behaviors and delays among DR-TB patients in Bangladesh. A prospective cross-sectional study was conducted from November to December 2018, among 92 culture positive and registered DR-TB patients in four selected hospitals in Bangladesh. Data were collected through face-to-face interviews with survey questionnaire as well as record reviews. Among the 92 study participants, the median patient delay was 7 (IQR 3, 15) days, the median diagnostic delay was 88 (IQR 36.5, 210), the median treatment delay was 7 (IQR 4,12) days, and the median total delay among DR-TB patients was 108.5 (IQR 57.5, 238) days. 81.32% sought initial care from informal healthcare providers. The majority (68.48%) of the informal healthcare providers were drug sellers while 60.87% of patients sought care from more than four healthcare points before being diagnosed with DR-TB. The initial care seeking from multiple providers was associated with diagnostic and total delays. In Bangladesh, DR-TB cases usually seek care from multiple providers, particularly from informal providers, and among them, alarmingly higher healthcare-seeking related delays were noted. Immediate measures should be taken both at the health system levels and, in the community, to curb transmission and reduce the burden of the disease.

Lived experiences of patients and families with decentralised drug-resistant tuberculosis care in the Eastern Cape, South Africa

BACKGROUND

South Africa adopted the decentralised Drug Resistant Tuberculosis (DR-TB) care model in 2011 with a view of improving clinical outcomes.

AIM

This study explores the experiences and perceptions of patients and family members on the effectiveness of a decentralised community DR-TB care model in the Oliver Reginald Kaizana (OR) Tambo district municipality of the Eastern Cape, South Africa.

METHOD

In this phenomenological qualitative research design, a semi-structured interview with prompts was conducted on 30 participants (15 patients and 15 family members). Framework approach to thematic content analysis was adopted for qualitative data analysis.

RESULTS

Four themes emerged from the patients' interviews: adequate knowledge of DR-TB and its transmission, fear of death and isolation, long travel distances, and exorbitant transportation cost. A 'ready' health system influenced the effectiveness of community DR-TB management, while interviews with family members yielded five themes: misconceptions about DR-TB, rapid diagnosis and adherence counselling, long travel distances, activated healthcare workers, and little role of traditional healer.

CONCLUSION

A perceived effectiveness of a community DR-TB care model in the OR Tambo district was demonstrated through the quality and comprehensiveness of care rendered by a 'ready' health system with activated health care workers (HCWs) who provided robust support and adequate knowledge of DR-TB and its treatment/side effects. However, misconceptions about DR-TB, long travel distances to treatment facilities, high cost of transportation and stigma remained challenging for most patients and family members.Contribution: This study provides insight into the lived experiences of a decentralised community DR-TB care model in the OR Tambo district in 2020.

Time-to-Treatment Initiation in a Decentralised Community-Care Model of Drug-Resistant Tuberculosis Management in the OR Tambo District Municipality of South Africa

BACKGROUND

Drug-resistant tuberculosis (DR-TB) continues to challenge global efforts toward eradicating and having a tuberculosis-free world. Considering the high early mortality, especially among HIV-infected individuals, early diagnosis and prompt initiation of effective treatment are needed to significantly reduce mortality and halt transmission of DR-TB in the community.

AIM

This study aims to assess the effectiveness of a community DR-TB care model with the specific objective of determining the Time-to-treatment initiation of DR-TB among patients in the OR Tambo district municipality.

METHODS

A prospective cohort study of patients with DR-TB was conducted in the OR Tambo district municipality of Eastern Cape Province, South Africa. Patients were enrolled as they presented for treatment initiation at the decentralised facilities following a diagnosis of DR-TB and compared with a centralised site.

RESULTS

A total of 454 DR-TB patients from six facilities between 2018 and 2020 were included in the analysis. The mean age was 37.54 (SD = 14.94) years. There were slightly more males (56.2%) than females (43.8%). Most of the patients were aged 18-44 years (67.5%), without income (82.3%). Results showed that slightly over thirteen percent (13.4%) of patients initiated treatment the same day they were diagnosed with DR-TB, while 36.3% were on the time-to-treatment target of being initiated within 5 days. However, about a quarter (25.8%) of patients failed to initiate treatment two weeks after diagnosis. Time-to-treatment initiation (TTTI) varied according to the decentralised sites, with progressive improvement with each successive year between 2018 and 2021. No demographic factor was significantly associated with TTTI.

CONCLUSION

Despite rapid diagnosis, only 36% of patients were initiated on treatment promptly. Operational challenges remained, and services needed to be reorganised to maximise the exceptional potentials that a decentralised community DR-TB care model brings.

Do private providers initiate anti-tuberculosis therapy on the basis of chest radiographs? A standardised patient study in urban India

Background

The initiation of anti-tuberculosis treatment (ATT) based on results of WHO-approved microbiological diagnostics is an important marker of quality tuberculosis (TB) care. Evidence suggests that other diagnostic processes leading to treatment initiation may be preferred in high TB incidence settings. This study examines whether private providers start anti-TB therapy on the basis of chest radiography (CXR) and clinical examinations.

Methods

This study uses the standardized patient (SP) methodology to generate accurate and unbiased estimates of private sector, primary care provider practice when a patient presents a standardized TB case scenario with an abnormal CXR. Using multivariate log-binomial and linear regressions with standard errors clustered at the provider level, we analyzed 795 SP visits conducted over three data collection waves from 2014 to 2020 in two Indian cities. Data were inverse-probability-weighted based on the study sampling strategy, resulting in city-wave-representative results.

Findings

Amongst SPs who presented to a provider with an abnormal CXR, 25% (95% CI: 21-28%) visits resulted in ideal management, defined as the provider prescribing a microbiological test and not offering a concurrent prescription for a corticosteroid or antibiotic (including anti-TB medications). In contrast, 23% (95% CI: 19-26%) of 795 visits were prescribed anti-TB medications. Of 795 visits, 13% (95% CI: 10-16%) resulted in anti-TB treatment prescriptions/dispensation and an order for confirmatory microbiological testing.

Interpretation

One in five SPs presenting with abnormal CXR were prescribed ATT by private providers. This study contributes novel insights to empiric treatment prevalence based on CXR abnormality. Further work is needed to understand how providers make trade-offs between existing diagnostic practices, new technologies, profits, clinical outcomes, and the market dynamics with laboratories.

Funding

This study was funded by the Bill & Melinda Gates Foundation (grant OPP1091843), and the Knowledge for Change Program at The World Bank.

Treatment of Infection as a Core Strategy to Prevent Rifampicin-Resistant/Multidrug-Resistant Tuberculosis

An estimated 19 million people are infected with rifampicin-resistant/multidrug-resistant strains of tuberculosis worldwide. There is little done to prevent these individuals from becoming sick with RR/MDR-TB, a disease that is associated with high rates of morbidity, mortality, and suffering. There are multiple phase III trials currently being conducted to assess the effectiveness of treatment of infection (i.e., "preventive therapy") for RR/MDR-TB, but their results are likely years away. In the meantime, there is sufficient evidence to support a more comprehensive management of people who have been exposed to RR/MDR-TB so that they can maintain their health. We present a patient scenario and share our experience in implementing a systematic post-exposure management program in South Africa with the goal of inspiring similar programs in other high-burden RR/MDR-TB settings.

Acquired drug resistance during the turnaround time for drug susceptibility testing impacts outcome of tuberculosis

BACKGROUND

The impacts of acquired resistance to first-line drugs other than rifampicin during turnaround time (TAT) for drug susceptibility testing (DST) on tuberculosis (TB) treatment are unclear.

METHOD

We performed a prospective cohort study to test acquired resistance to isoniazid, ethambutol and pyrazinamide during TAT for DST as risk factors for prolonged time to sputum culture conversion (SCC) and treatment failure in China. Participants included had a baseline DST result for a Mycobacterium tuberculosis (Mtb) isolate collected at TB diagnosis and a follow-up DST result for a Mtb isolate collected upon baseline DST results availability. Acquired drug resistance was identified by comparing baseline and follow-up DST results.

RESULTS

This study included 65 patients with acquired resistance Mtb isolates and 130 patients with consistent drug susceptibility profiles. Cox proportional hazard regression analysis demonstrated acquired isoniazid resistance (aHR 0.50, 95%CI: 0.29-0.85) and acquired pyrazinamide resistance (aHR 0.54, 95%CI: 0.36-0.81) were associated with prolonged time to SCC. Moreover, acquired isoniazid resistance (aOR 7.64, 95%CI: 2.39-16.08) and acquired pyrazinamide resistance (aOR 5.71, 95%CI: 2.31-14.12) were independently associated with treatment failure.

CONCLUSION

Acquired resistance to isoniazid and/or pyrazinamide during TAT for DST was associated with prolonged time to SCC as well as treatment failure.

Nanopore-based metagenomic sequencing for the rapid and precise detection of pathogens among immunocompromised cancer patients with suspected infections

Cancer patients are at high risk of infections and infection-related mortality; thereby, prompt diagnosis and precise anti-infectives treatment are critical. This study aimed to evaluate the performance of nanopore amplicon sequencing in identifying microbial agents among immunocompromised cancer patients with suspected infections. This prospective study enlisted 56 immunocompromised cancer patients with suspected infections. Their body fluid samples such as sputum and blood were collected, and potential microbial agents were detected in parallel by nanopore amplicon sequencing and the conventional culture method. Among the 56 body fluid samples, 47 (83.9%) samples were identified to have at least one pathogen by nanopore amplicon sequencing, but only 25 (44.6%) samples exhibited a positive finding by culture. Among 31 culture-negative samples, nanopore amplicon sequencing successfully detected pathogens in 22 samples (71.0%). Nanopore amplicon sequencing showed a higher sensitivity in pathogen detection than that of the conventional culture method (83.9% vs. 44.6%, P<0.001), and this advantage both existed in blood samples (38.5% vs. 0%, P=0.039) and non-blood samples (97.7% vs. 58.1%, P<0.001). Compared with the culture method, nanopore amplicon sequencing illustrated more samples with bacterial infections (P<0.001), infections from fastidious pathogens (P=0.006), and co-infections (P<0.001). The mean turnaround time for nanopore amplicon sequencing was about 17.5 hours, which was shorter than that of the conventional culture assay. This study suggested nanopore amplicon sequencing as a rapid and precise method for detecting pathogens among immunocompromised cancer patients with suspected infections. The novel and high-sensitive method will improve the outcomes of immunocompromised cancer patients by facilitating the prompt diagnosis of infections and precise anti-infectives treatment.

The probability of diagnostic delays for tuberculosis and its associated risk factors in northwest Iran from 2005 to 2016: a survival analysis using tuberculosis surveillance data

OBJECTIVES

Early diagnosis is essential for effective tuberculosis (TB) control programs. Therefore, this study examined the risk of delays in TB diagnosis and associated factors in Ardabil Province in northwest Iran from 2005 to 2016.

METHODS

This longitudinal retrospective cohort study was conducted using data obtained from the Iranian National Tuberculosis Control Program at the provincial level between 2005 and 2016. The total delay in diagnosis was defined as the time interval (days) between the onset of symptoms and TB diagnosis. Survival analysis was conducted to analyze the delay in diagnosis. Associated factors were identified using a Cox proportional hazards model.

RESULTS

A total of 1,367 new TB cases were identified. The 12-year median diagnostic delay was 45 days (interquartile range [IQR], 30-87). The annual median diagnostic delay decreased from 68 days (IQR, 33-131) in 2005 to 31 days (IQR, 30-62) in 2016. The probability of a delay in TB diagnosis decreased by 5.0% each year (hazard ratio [HR], 1.05; 95% confidence interval [CI], 1.04 to 1.07). Residence in a non-capital county (HR, 0.83; 95% CI, 0.74 to 0.92) and referral from the private health system (HR, 0.74%; 95% CI, 0.65 to 0.84) were significantly associated with an increased risk of delay in TB diagnosis over the 12-year study period.

CONCLUSIONS

The median delay decreased during the study period. We identified factors associated with a longer delay in TB diagnosis. These findings may be useful for further TB control plans and policies in Iran.

Diagnostic Yield of Xpert MTB/RIF Assay Using Bronchoalveolar Lavage Fluid in Detecting Mycobacterium tuberculosis among the Sputum-Scarce Suspected Pulmonary TB Patients

Tuberculosis (TB) remains one of the leading causes of death worldwide and is caused by the single infectious agent Mycobacterium tuberculosis (Mtb). Although sputum is the most common specimen for pulmonary TB detection, some other respiratory specimens, such as bronchoalveolar lavage (BAL) fluid, gastric lavage (GL), and induced sputum (IS), are also collected from patients who are unable to deliver sputum. In this study, we aimed to evaluate the diagnostic performances of different test methods for TB diagnosis using BAL fluid specimens from sputum-scarce pulmonary TB patients. In this current study, a total of 210 BAL fluid specimens were collected and subjected to culture on Lowenstein–Jensen (L-J) medium, using an N-acetyl-L-cysteine-Sodium Hydroxide decontamination and digestion method, Xpert MTB/RIF (Xpert, Cepheid, Sunnyvale, CA, USA) assay, and acid-fast bacilli (AFB) microscopy with a Ziehl–Neelsen staining method for the detection of pulmonary TB. The sensitivity and specificity of these methods were then analyzed against the composite reference standard (CRS). Additionally, the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic value of these assays. Among the 210 specimens, 39 (18.6%), 27 (12.8%), and 12 (5.7%) were found positive with Xpert assay, culture, and AFB microscopy, respectively. Considering the CRS, 42 (20%) were positive as the final diagnosis. The Xpert assay had a significantly higher sensitivity (92.9%, 95% CI: 80.5–98.5) compared to culture (64.3%, 95% CI: 48.0–78.4) and AFB microscopy (28.6%, 95% CI: 15.7–44.6) against the CRS. Additionally, the area under the ROC curve (AUC) for the Xpert assay, culture, and AFB microscopy accounted for 0.964, 0.821, and 0.655, respectively, when using CRS as the reference. In conclusion, our study findings demonstrated that the Xpert assay conferred a considerable diagnostic potential compared to other conventional methods for the diagnosis of pulmonary TB from BAL fluid specimens.

Re-Evaluating the Merits of Decentralisation as a Core Strategy for Effective Delivery of Drug-Resistant Tuberculosis Care in Pakistan

Decentralized, person-centred models of care delivery for drug-resistant tuberculosis (DR-TB) continue to be under-resourced in high-burden TB countries. The implementation of such models—made increasingly urgent by the COVID-19 pandemic—are key to addressing gaps in DR-TB care. We abstracted data of rifampicin-resistant (RR)/multidrug-resistant tuberculosis (MDR-TB) patients initiated on treatment at 11 facilities between 2010 and 2017 in Sindh and Balochistan provinces of Pakistan. We analysed trends in treatment outcomes relating to programme expansion to peri-urban and rural areas and estimated driving distance from patient residence to treatment facility. Among the 5586 RR/MDR-TB patients in the analysis, overall treatment success decreased from 82% to 66% between 2010 and 2017, as the programme expanded. The adjusted risk ratio for unfavourable outcomes was 1.013 (95% confidence interval 1.005–1.021) for every 20 km of driving distance. Our analysis suggests that expanding DR-TB care to centralized hubs added to increased unfavourable outcomes for people accessing care in peri-urban and rural districts. We propose that as enrolments increase, expanding DR-TB services close to or within affected communities is essential.

Dependence of Xpert MTB/RIF Accuracy for Detecting Rifampin Resistance in Bronchoalveolar Lavage Fluid on Bacterial Load: A Retrospective Study in Beijing, China

INTRODUCTION

We assessed the effect of Mycobacterium tuberculosis (MTB) bacterial load on Xpert MTB/RIF accuracy for detection of rifampicin (RIF)-resistant MTB in bronchoalveolar lavage fluid (BALF) specimens obtained at a national tuberculosis (TB) specialized hospital in Beijing, China.

METHODS

A retrospective study was conducted at Beijing Chest Hospital. Patients with symptoms suggestive of pulmonary TB who provided BALF specimens for routine MTB detection between June 2019 and July 2020 were enrolled in the study. Chi-square test and Student's t-test were used to compare results across groups stratified according to BALF bacterial load.

RESULTS

In total, 1125 patients with positive Xpert results who were enrolled in final analysis, 263 provided BALF specimens that tested positive for RIF-resistant MTB via Xpert MTB/RIF. The RIF-resistance rate of specimens with very low MTB bacterial load was 30.9%, a resistance rate significantly greater than rates obtained for groups with high (25.0%), medium (17.3%) and low (19.2%) MTB loads (P<0.01). Notably, false-positive results obtained for the very low bacterial load group led to markedly reduced positive predictive value of Xpert MTB/RIF to provide correct RIF-resistance predictions for that group (67.1%, 95% CI: 56.1%-78.1%5) relative to the predictive value obtained for all other groups combined (about 90%, P<0.05). Sanger sequencing data obtained for 20 (32.8%) MTB isolates deemed RIF-resistant via Xpert (Probe E) lacked rpoB RRDR mutations. Meanwhile, of another group of 23 isolates deemed RIF-susceptible via DST but RIF-resistant via Xpert MTB/RIF, 20 isolate sequences (87.0%) lacked rpoB RRDR mutations, while sequences of the remaining 3 isolates harbored single rpoB RRDR mutations predicted to cause amino acid substitutions.

CONCLUSION

Xpert MTB/RIF assay performed alarmingly poorly when used to detect RIF-resistant MTB in BALF specimens with very low bacterial loads. A high rate of Xpert probe E hybridization failure was the main driver of false-positive RIF-resistant results.

Utility of the Interferon-Gamma Release Assay for Latent Tuberculosis Infection Screening among Indian Health-Care Workers

Background

The utility of interferon-gamma release assays (IGRAs) for latent tuberculosis infection (LTBI) screening among health-care workers (HCWs) in low- and middle-income countries (LMICs) remains unclear.

Methods

This was a prospective cohort study among HCW trainees undergoing annual LTBI screening via tuberculin skin test (TST) and QuantiFERON^® TB Gold Test-in-tube (QFT-GIT) in Pune, India. TST induration ≥ 10 mm and QFT-GIT ≥ 0.35 IU/ml were considered positive. Test concordance was evaluated at entry among the entire cohort and at 1 year among baseline TST-negative participants with follow-up testing. Overall test agreement was evaluated at both timepoints using the kappa statistic: fair (k < 0.40), good (0.41 ≥ k ≤0.60), or strong (k > 0.60).

Results

Of 200 participants, prevalent LTBI was detected in 42 (21%) via TST and 45 (23%) via QFT-GIT; QFT-GIT was positive in 27/42 (64%) TST-positive and 18/158 (11%) TST-negative trainees. Annual TST conversion was 28% (40/142) and included 11 trainees with baseline TST-/IGRA+; QFT-GIT was positive in 17/40 (43%) TST-positive and 5/102 (5%) TST-negative trainees. Overall test concordance was 84% (k = 0.52; 95% confidence interval [CI]: 0.38-0.66) and 80% (k = 0.44; 95% CI: 0.29-0.59) at baseline and 12 months, respectively.

Conclusions

We observed good overall agreement between TST and QFT-GIT, and QFT-GIT detected additional LTBI cases among TST-negative trainees with possible early detection of LTBI conversion. Overall, our results support the use of IGRA for annual LTBI screening among HCWs in a high burden LMIC setting.

Sputum smear grading and associated factors among bacteriologically confirmed pulmonary drug-resistant tuberculosis patients in Ethiopia

Background

The sputum smear bacilliary load is a fundamental indicator of the level of infectiousness in DR-TB patients. However, evidence on DR-TB sputum smear grading and its factors in the study setting is limited. This study was aimed to determine the level of sputum smear grading and associated factors among DR-TB patients in Ethiopia.

Methods

This was an institution based cross-sectional study on 520 bacteriological confirmed pulmonary DR-TB patients from September 2010 to December 2017 in the northwest Ethiopia. Epidata 4.2.00 and SPSS 20 were used for data entry and management, respectively. Ordinary logistic regression was fitted. A cut of p-value less than 0.05 in the multivariable ordinary logistic regression was considered to declare statistically significant variables.

Results

Of all 520 bacteriological confirmed pulmonary DR-TB patients; 34.42% had 3⁺, 15.77% had 2⁺, 18.27% had 1⁺, 15.19% had scanty, and 16.35% had negative sputum smear grading results. The odds of having higher sputum smear grades were significantly associated with the patient’s educational status of secondary (Adjusted Odds Ratio (AOR) = 0.43, 95% Confidence Interval (CI): 0.21, 0.89), body mass index of 16 to 18.49 kg/m² (AOR = 1.81, 95%CI: 1.16, 2.84), and TB treatment history of two and more times (AOR = 1.78, 95%CI: 1.24, 2.55).

Conclusions

More than a third of the bacteriological confirmed pulmonary DR-TB patients in the study setting was highly infectious with the highest bacillary load. The odds of having a high bacillary load were significantly associated with the patient’s TB treatment history, nutritional, and educational status.

Comparing the impact of genotypic based diagnostic algorithm on time to treatment initiation and treatment outcomes among drug-resistant tuberculosis patients in Amhara region, Ethiopia

Background

To end Tuberculosis (TB) by 2030, early detection and timely treatment of Drug-Resistant Tuberculosis (DR-TB) is vital. The role of rapid, accurate, and sensitive DR-TB diagnostic tool is indispensable to accelerate the TB control program. There are evidence breaks in the time difference and its effect on treatment outcomes among different DR-TB diagnostic tools in Ethiopia. This article aimed to compare the different DR-TB diagnostic tools with time pointers and evaluate their effect on the treatment outcomes.

Method

We performed a retrospective chart review of 574 DR-TB patients from September 2010 to December 2017 to compare the impact of molecular DR-TB diagnostic tests (Xpert MTB/RIF, Line Probe Assay (LPA), and solid culture-based Drug Susceptibility Testing (DST)) on time to diagnosis, treatment initiation, and treatment Outcomes. Kruskual-Wallis test was employed to assess the presence of a significant difference in median time among the DR-TB diagnostic tests. Chi-Square and Fisher exact tests were used to test the presence of relations between treatment outcome and diagnostic tests.

Result

The data of 574 DR-TB patients were included in the analysis. From these, 321, 173, and 80 patients were diagnosed using Xpert MTB/RIF, Line Probe Assay (LPA), and solid culture-based DST, respectively. The median time in a day with (Interquartile range (IQR)) for Xpert MTB/RIF, LPA, and solid culture-based DST was from a first care-seeking visit to diagnosis: 2(0, 9), 4(1, 55), and 70(18, 182), from diagnosis to treatment initiation: 3(1, 8), 33(4, 76), and 44(9, 145), and from a first care-seeking visit to treatment initiation: 4(1, 11), 3(1, 12) and 76(3.75, 191) respectively. The shorter median time was observed in the Xpert MTB/RIF followed by the LPA, and this was statistically significant with a p-value <0.001. There was no statistically significant difference concerning treatment outcomes among the three DST tests.

Conclusion

Xpert MTB/RIF can mitigate the transmission of DR-TB significantly via quick diagnosis and treatment initiation followed by LPA as equating to the solid culture base DST, particularly in smear-positive patients. However, we didn’t see a statistically significant impact in terms of treatment outcomes. Xpert MTB/RIF can be used as the first test to diagnose DR-TB by further complimenting solid culture base DST to grasp the drug-resistance profile.

'It has become everybody's business and nobody's business': Policy actor perspectives on the implementation of TB infection prevention and control (IPC) policies in South African public sector primary care health facilities

South Africa is increasingly offering screening, diagnosis and treatment of tuberculosis (TB), and especially drug-resistant TB, at the primary care level. Nosocomial transmission of TB within primary health facilities is a growing concern in South Africa, and globally. We explore here how TB infection prevention and control (IPC) policies, historically focused on hospitals, are being implemented within primary care facilities. We spoke to 15 policy actors using in-depth interviews about barriers to effective TB-IPC and opportunities for improving implementation. We identified four drivers of poor policy implementation: fragmentation of institutional responsibility and accountability for TB-IPC; struggles by TB-IPC advocates to frame TB-IPC as an urgent and addressable policy problem; barriers to policy innovation from both a lack of evidence as well as a policy environment dependent on 'new' evidence to justify new policy; and the impact of professional medical cultures on the accurate recognition of and response to TB risks. Participants also identified examples of TB-IPC innovation and described conditions necessary for these successes. TB-IPC is a long-standing, complex health systems challenge. As important as downstream practices like mask-wearing and ventilation are, sustained, effective TB-IPC ultimately requires that we better address the upstream barriers to TB-IPC policy formulation and implementation.

The Diagnosis and Treatment of Tuberculosis

BACKGROUND

Around 10 million people worldwide contract tuberculosis every year. According to the World Health Organization (WHO), approximately one-quarter of the world's population is latently infected with Mycobacterium tuberculosis. In Ger- many, the incidence of tuberculosis was in decline over several decades but rose in 2015 to 7.3 new cases per 100 000 persons. In 2018, a total of 5429 new cases were documented, corresponding to 6.5 new cases per 100 000 persons.

METHODS

This article is based on literature retrieved by a selective search in PubMed and on the authors' clinical experience.

RESULTS

Tuberculosis involves the lungs in almost 75% of patients but can generally involve any organ. In Germany, the majority of patients come from high-incidence countries. If a patient's differential diagnosis includes tuberculosis, the main tests for the detection of the pathogen in sputum and tissue samples are culture (the gold standard), microscopy, and nucleic acid amplification tests. Imaging studies are also used for diagnosis and follow-up. The standard treatment consists of a combination of isoniazid, rifampicin, ethambutol, and pyrazinamide, followed by a combination of isoniazid and rifampicin only. Liver damage is one of the more common adverse effects of this treatment, arising in 2.4% of patients. Multidrug-resistant tuberculosis, which is rare in Germany (around 100 cases per year), should be treated in special- ized centers.

CONCLUSION

Rapid diagnosis and targeted treatment are essential to prevent an unfavorable course of the disease as well as its transmission to other individuals. In patients presenting with unclear symptoms, tuberculosis should always be considered as a differential diagnosis. The diagnosis of latent tuberculosis and decision-making regarding its treatment are difficult because of the lack of specific biomarkers and of relevant data from clinical trials.

Nurses' Safety in Caring for Tuberculosis Patients at a Teaching Hospital in South West Nigeria

Background

Tuberculosis remains the leading cause of death due to infectious diseases worldwide ranking above HIV/AIDS, and Nigeria is rated as the 7^th worldwide and the 2^nd in Africa among the 30 countries highly burdened with tuberculosis worldwide.

Aim

To investigate the challenges encountered by nurses in the care of TB patients in a Federal Teaching Hospital in Nigeria. Setting. Ekiti State, Southwest Nigeria.

Methods

A qualitative contextual method was utilized with the sample size determined by data saturation. Data collection was done through an audiotaped, semistructured interview. The study sample consisted of 20 professional nurses working in the medical and paediatric wards of a selected Federal Teaching Hospital in South West, Nigeria. Data was analysed using Tesch's content analysis approach.

Results

The majority of the participants were females within the age group of 31–40 years. Challenges included inadequate availability of personal protective equipment (PPE), lack of isolation wards, delegating the care of tuberculosis patients to young inexperienced nurses, long process in diagnosing patients with tuberculosis, lack of policies protecting the nurses from exposure to tuberculosis, and inadequate training. The major concern was the fear of contracting tuberculosis.

Conclusion

The study suggested that there should be a provision of adequate personal protective equipment; tuberculosis designated wards and provision of periodic training to update the nurses on care of tuberculosis patients. Establishment and execution of hospital policies and practices along with support are equally essential in facilitating a safe workplace for nurses.

Increased prevalence of levofloxacin-resistant Mycobacterium tuberculosis in China is associated with specific mutations within the gyrA gene

OBJECTIVES

To compare the prevalence of levofloxacin (LFX) resistance and the population structure of Mycobacterium tuberculosis (MTB) with different mutations conferring LFX resistance between 2005 and 2015.

METHODS

A total 542 MTB isolates were randomly selected from pulmonary tuberculosis (TB) patients in 2005 and 2015 and analyzed regarding minimum inhibitory concentrations (MICs) and quinolone resistance-determining regions (QRDR).

RESULTS

One hundred and eleven of the 542 MTB isolates analyzed (20.5%) were resistant to LFX. There were 42 and 69 LFX-resistant isolates from 2005 and 2015, respectively, and MIC high-level LFX resistance was significantly higher in 2015 (40.6%, 28/69) than in 2005 (16.7%, 7/42) (p = 0.02). There were 87 (78.4%) mutations of these 111 LFX-resistant isolates. In addition, a significant difference in proportion was observed in the isolates with mutations in codon 90 of the gyrA gene between 2005 and 2015 (11.9% in 2005 versus 29.0% in 2015, p = 0.04).

CONCLUSIONS

There was an alarming increase in prevalence of LFX-resistant TB in China between 2005 and 2015. This dynamic change is mostly attributed to the increase in high-level LFX resistance. Moreover, a significant difference was noted in the proportion of LFX-resistant isolates harboring specific mutations within the gyrA gene between 2005 and 2015.

"A very humiliating illness": a qualitative study of patient-centered Care for Rifampicin-Resistant Tuberculosis in South Africa

BACKGROUND

Patient-centered care is pillar 1 of the "End TB" strategy, but little has been documented in the literature about what this means for people living with rifampicin-resistant (RR-TB). Optimizing care for such individuals requires a better understanding of the challenges they face and the support they need.

METHODS

A qualitative study was done among persons living with RR-TB and members of their support network. A purposive sample was selected from a larger study population and open-ended interviews were conducted using a semi-standard interview guide. Interviews were recorded and transcribed and the content analyzed using an iterative thematic analysis based in grounded theory.

RESULTS

16 participants were interviewed from three different provinces. Four distinct periods in which support was needed were identified: 1) pre-diagnosis; 2) pre-treatment; 3) treatment; and 4) post-treatment. Challenges common in all four periods included: socioeconomic issues, centralized care, and the need for better counseling at multiple levels.

CONCLUSIONS

Beyond being a "very humiliating illness", RR-TB robs people of their physical, social, economic, psychological, and emotional well-being far beyond the period when treatment is being administered. Efforts to tackle these issues are as important as new drugs and diagnostics in the fight against TB.

TB treatment delay associated with drug resistance and admission at Daru General Hospital in Papua New Guinea

SETTING

Daru General Hospital, Daru Island, Papua New Guinea, where high rates of tuberculosis (TB) have been reported. Prompt diagnosis and effective treatment are needed for improving TB outcomes and to prevent nosocomial transmission.

OBJECTIVE

To assess the time to treatment initiation and the risk factors associated with delayed treatment for patients started on TB treatment at Daru General Hospital from January to September 2017.

DESIGN

This was a retrospective cohort study that entailed reviewing the records from treatment, admission, discharge and presumptive TB registers.

RESULTS

The study included 360 patients on TB treatment. The median time from presentation to treatment initiation was 7 days [IQR 3-11]. Treatment was started <7 days for 215 patients (60%); however, only 16.2% commenced treatment <2 days. Risk factors for delayed treatment were diagnosis of TB as an inpatient (OR 2.67, 95% CI 1.35-5.28, P = 0.005) and having drug-resistant TB (OR 2.65, 95% CI 1.5-4.68. P = 0.001).

CONCLUSION

A high proportion of TB patients commenced treatment <7 days. Inpatient status, DR-TB and lack of microbiological confirmation were associated with delays in treatment initiation. We recommend that programmes monitor the time from presentation to treatment initiation, and propose that a period of >3 days from presentation to treatment initiation be considered as delayed treatment initiation.

Challenges and controversies in childhood tuberculosis

Children bear a substantial burden of suffering when it comes to tuberculosis. Ironically, they are often left out of the scientific and public health advances that have led to important improvements in tuberculosis diagnosis, treatment, and prevention over the past decade. This Series paper describes some of the challenges and controversies in paediatric tuberculosis, including the epidemiology and treatment of tuberculosis in children. Two areas in which substantial challenges and controversies exist (ie, diagnosis and prevention) are explored in more detail. This Series paper also offers possible solutions for including children in all efforts to end tuberculosis, with a focus on ensuring that the proper financial and human resources are in place to best serve children exposed to, infected with, and sick from all forms of tuberculosis.

Turning Off the Tap: Using the FAST Approach to Stop the Spread of Drug-Resistant Tuberculosis in the Russian Federation

Background

We report the association of the FAST strategy (find cases actively, separate safely, and treat effectively) with reduction of hospital-based acquisition of multidrug-resistant tuberculosis in the Russian Federation.

Methods

We used preintervention and postintervention cohorts in 2 Russian hospitals to determine whether the FAST strategy was associated with a reduced odds of converting MDR tuberculosis within 12 months among patients with tuberculosis susceptible to isoniazid and rifampin at baseline.

Results

Sixty-three of 709 patients (8.9%) with isoniazid and rifampin–susceptible tuberculosis acquired MDR tuberculosis; 55 (12.2%) were in the early cohort, and 8 (3.1%) were in the FAST cohort. The FAST strategy was associated with a reduced odds (adjusted odds ratio, 0.16; 95% confidence interval, .07–.39) and 9.2% absolute reduction in the risk of MDR tuberculosis acquisition.

Conclusion

Use of the FAST strategy in 2 Russian hospitals was associated with significantly less MDR tuberculosis 12 months after implementation.

High incidence of drug-resistant Mycobacterium tuberculosis in Hainan Island, China

OBJECTIVES

To assess the proportion of drug-resistant tuberculosis (TB) cases and to identify independent risk factors associated with drug-resistant TB in Hainan.

METHODS

Descriptive analysis of demographic and clinical data of culture-positive TB patients to assess the trends in drug-resistant TB at the Provincial Clinical Center on Tuberculosis of Hainan between 2014 and 2017.

RESULTS

994 patients were recruited into the study. Overall, the proportion of patients resistant to at least one TB drug tested was 36.1% (359/994). The most frequent resistance was to isoniazid (INH, 29.8%), followed by rifampin (RIF, 29.3%), streptomycin (19.3%), ofloxacin (OFX, 17.4%), ethambutol (9.5%) and kanamycin (KAN, 3.2%). Of 291 RIF-resistant isolates, 228 (78.4%) were also resistant to INH, while the remaining 63 (21.6%) were susceptible to INH. Among those with multidrug-resistant tuberculosis (MDR-TB), 41.2% had additional resistance to OFX and 3.9% to KAN. 8.8% of MDR-TB patients were affected by extensively drug-resistant (XDR-TB). Females were more likely to infected with MDR-TB than males, and young people (<20 years old) were more likely to have MDR-TB; patients exhibited decreasing MDR-TB risk with increasing age.

CONCLUSIONS

Our data provide the first primary understanding of the drug-resistant TB epidemic in Hainan. The high incidence of drug resistance, especially RIF and FQ resistance, highlight the importance of interventions for preventing epidemics of drug-resistant TB. Younger age is an independent predictor of MDR-TB, reflecting the potential transmission in this population.

High risk for latent tuberculosis infection among medical residents and nursing students in India

Defining occupational latent tuberculosis infection (LTBI) risk among healthcare workers is needed to support implementation of prevention guidelines. Prospective cohort study of 200 medical residents and nursing students in India was conducted May 2016—December 2017. Tuberculin skin test (TST) and QuantiFERON TB Gold Test-in-tube (QFT-GIT) were performed at study entry and 12 months. Primary outcome was incident LTBI (≥10mm TST induration and/or ≥0.35IU/mL QFT-GIT) at 12 months; secondary outcomes included baseline LTBI prevalence and risk factors for incident and prevalent LTBI using Poisson regression. Among 200, [90 nursing students and 110 medical residents], LTBI prevalence was 30% (95% CI, 24–37); LTBI incidence was 26.8 (95% CI, 18.6–37.2) cases per 100 person-years and differed by testing method (28.7 [95% CI, 20.6–38.9] vs 17.4 [95% CI, 11.5–25.4] cases per 100 person-years using TST and QFT-GIT, respectively). Medical residents had two-fold greater risk of incident LTBI than nursing students (Relative Risk, 2.16; 95% CI, 1.05–4.42). During study period 6 (3%) HCWs were diagnosed with active TB disease. Overall, median number of self-reported TB exposures was 5 (Interquartile Range, 1–15). Of 60 participants with prevalent and incident LTBI who were offered free isoniazid preventive therapy (IPT), only 2 participants initiated and completed IPT. High risk for LTBI was noted among medical residents compared to nursing students. Self-reported TB exposure is underreported, and uptake of LTBI prevention therapy remains low. New approaches are needed to identify HCWs at highest risk for LTBI.

Reducing tuberculosis transmission: a consensus document from the World Health Organization Regional Office for Europe

Evidence-based guidance is needed on 1) how tuberculosis (TB) infectiousness evolves in response to effective treatment and 2) how the TB infection risk can be minimised to help countries to implement community-based, outpatient-based care.This document aims to 1) review the available evidence on how quickly TB infectiousness responds to effective treatment (and which factors can lower or boost infectiousness), 2) review policy options on the infectiousness of TB patients relevant to the World Health Organization European Region, 3) define limitations of the available evidence and 4) provide recommendations for further research.The consensus document aims to target all professionals dealing with TB (e.g TB specialists, pulmonologists, infectious disease specialists, primary healthcare professionals, and other clinical and public health professionals), as well as health staff working in settings where TB infection is prevalent.

Waiting to inhale: factors associated with healthcare workers' fears of occupationally-acquired tuberculosis (TB)

Background

Fear of TB infection is rooted in historical and social memories of the disease, marked by stigma, segregation and exclusion. Healthcare workers (HCWs) face these same fears today, and even seek to hide their TB status when infected. This study sought to investigate factors associated with HCWs fears of acquiring TB while at work, including selected biographic characteristics, TB knowledge, infection control and perceptions that their colleagues stigmatise co-workers with TB/ presumed to have TB.

Methods

In the Free State Province, South Africa, a representative sample of 882 HCWs from eight hospitals completed self-administered questionnaires on issues related to fear of occupationally acquired TB, infection control, TB knowledge and workplace TB stigma. The data were analysed using descriptive statistics as well as binomial logistic regression.

Results

Most of the HCWs (67.2%) were concerned about contracting TB at work. Support staff were less likely to worry about acquiring TB than clinical staff (OR = 0.657, P = 0.041). Respondents who indicated that there were inadequate numbers of disposable respirators at work, were 1.6 times more likely to be afraid of contracting TB at work (P = 0.040). With every unit increase on the TB stigma scale, respondents were 1.1 times more likely to fear acquiring TB at work (P = 0.000).

Conclusions

Being a professional clinical HCW, not having adequate disposable respirators available and seeing/perceiving co-workers stigmatise colleagues with (presumptive) TB were all significantly associated with the fear of occupationally-acquired TB. It is recommended that campaigns to destigmatise TB, as well as appropriate TB infection control education and measures, are necessary to alleviate HCWs fears of acquiring the disease in the workplace. Ultimately this should create a health-enabling working environment, where HCWs are not afraid to function and are free to seek treatment and support when necessary.

Missed opportunities for earlier diagnosis of rifampicin-resistant tuberculosis despite access to Xpert® MTB/RIF

OBJECTIVE

To assess the proportion of rifampicin-resistant tuberculosis (RR-TB) patients with potential earlier RR-TB diagnoses in Khayelitsha, South Africa.

DESIGN

We conducted a retrospective analysis among RR-TB patients diagnosed from 2012 to 2014. Patients were considered to have missed opportunities for earlier diagnosis if 1) they were incorrectly screened according to the Western Cape diagnostic algorithm; 2) the first specimen was not tested using Xpert® MTB/RIF; 3) no specimen was ever tested; or 4) the initial Xpert test showed a negative result, but no subsequent specimen was sent for follow-up testing in human immunodeficiency virus-positive patients.

RESULTS

Among 543 patients, 386 (71%) were diagnosed with Xpert and 112 (21%) had had at least one presentation at a health care facility within the 6 months before the presentation at which RR-TB was diagnosed. Overall, 95/543 (18%) patients were screened incorrectly at some point: 48 at diagnostic presentation only, 38 at previous presentation only, and 9 at both previous and diagnostic presentations.

CONCLUSIONS

These data show that a significant proportion of RR-TB patients might have been diagnosed earlier, and suggest that case detection could be improved if diagnostic algorithms were followed more closely. Further training and monitoring is required to ensure the greatest benefit from universal Xpert implementation.

Effectiveness of control measures to prevent occupational tuberculosis infection in health care workers: a systematic review

Background

A number of guideline documents have been published over the past decades on preventing occupational transmission of tuberculosis (TB) infection in health care workers (HCWs). However, direct evidence for the effectiveness of these controls is limited particularly in low-and middle-income (LMIC) countries. Thus, we sought to evaluate whether recommended administrative, environmental and personal protective measures are effective in preventing tuberculin skin test conversion among HCWs, and whether there has been recent research appropriate to LMIC needs.

Methods

Using inclusion criteria that included tuberculin skin test (TST) conversion as the outcome and longitudinal study design, we searched a number of electronic databases, complemented by hand-searching of reference lists and contacting experts. Reviewers independently selected studies, extracted data and assessed study quality using recommended criteria and overall evidence quality using GRADE criteria.

Results

Ten before-after studies were found, including two from upper middle income countries. All reported a decline in TST conversion frequency after the intervention. Among five studies that provided rates, the size of the decline varied, ranging from 35 to 100%. Since all were observational studies assessed as having high or unclear risk of bias on at least some criteria, the overall quality of evidence was rated as low using GRADE criteria.

Conclusion

We found consistent but low quality of evidence for the effectiveness of combined control measures in reducing TB infection transmission in HCWs in both high-income and upper-middle income country settings. However, research is needed in low-income high TB burden, including non-hospital, settings, and on contextual factors determining implementation of recommended control measures. Explicit attention to the reporting of methodological quality is recommended.

Trial registration

This systematic review was registered with PROSPERO in 2014 and its registration number is CRD42014009087.

Precision medicine for drug-resistant tuberculosis in high-burden countries: is individualised treatment desirable and feasible?

Treatment for drug-resistant tuberculosis is largely delivered through standardised, empirical combination regimens in low-resource, high-burden settings. However, individualised treatment, guided by detailed drug susceptibility testing, probably results in improved individual outcomes and is the standard of care in well-resourced settings. Driven by the urgent need to scale up treatment provision, new tuberculosis drugs, incorporated into standardised regimens, are being tested. Although standardised regimens are expected to improve access to treatment in high-burden settings, they are also likely to contribute to the emergence of resistance, even with good clinical management. We argue that a balance is required between the need to improve treatment access and the imperative to minimise resistance amplification and provide the highest standard of care, through a precision medicine approach. In tuberculosis, as in other diseases, we should aim to reduce the entrenched inequalities that manifest as different standards of care in different settings.

Better than a pound of cure: preventing the development of multidrug-resistant tuberculosis

Diagnostic and treatment delays contribute to increased death and disability among the 490,000 adults and children who develop multidrug-resistant (MDR) tuberculosis every year. Since the treatment of MDR tuberculosis is complex, costly and often toxic, tuberculosis control programs should prioritize strategies to prevent drug-resistant tuberculosis. Opportunities to limit transmission and prevent disease progression in close contacts of MDR tuberculosis cases are often neglected. Effective MDR tuberculosis preventive strategies could minimize the costs for patients and healthcare systems. This review characterizes the biological basis for the development of MDR tuberculosis, outlines the evidence for strategies to reduce transmission and highlights programmatic approaches to the management of patients infected with drug-resistant strains of Mycobacterium tuberculosis.

Improvement in clinical outcome and infection control using molecular diagnostic techniques for early detection of MDR tuberculous spondylitis: a multicenter retrospective study

There has been limited research on the therapeutic efficacy of molecular diagnosis of spinal tuberculosis. We attempted to determine whether the utilization of molecular diagnosis to detect multidrug-resistant spinal tuberculosis can improve clinical outcomes. A multicenter retrospective study was conducted from February 2009 to June 2015. Ninety-two consecutive culture-confirmed multidrug-resistant tuberculosis (MDR-TB) patients with spinal tuberculosis who were diagnosed clinically and by imaging were enrolled in the study. The initial time to treatment for MDR-TB, the method of infection control, the erythrocyte sedimentation rate (ESR) and the occurrence of complications in patients who were diagnosed using molecular methods were compared with those of patients diagnosed using standard culture and drug susceptibility test methods. Of 92 MDR-TB patients with spinal tuberculosis, 41 (45%) were diagnosed by standard culture and drug susceptibility test methods (Group A), and 51 (55%) were diagnosed following implementation of detection using molecular diagnosis (Group B). The patients in Group B began the rational use of second-line drugs earlier than patients in Group A (5 days vs 73 days, P<0.05). Among patients who were admitted to a general tuberculosis ward, those in Group B spent less time in the ward than those in Group A (4 days vs 33 days, P<0.05). At the one-month follow-up, the ESR was significantly lower in Group B. In patients who completed 6 months of follow-up (n=92), the incidence of complications was significantly lower in Group B. The use of molecular diagnosis resulted in noteworthy clinical advances, including earlier initiation of MDR-TB treatment, improved infection control, better clinical outcome, a more rapid decrease in ESR and fewer complications.

Time to treatment for rifampicin-resistant tuberculosis: systematic review and meta-analysis

BACKGROUND

To reduce transmission and improve patient outcomes, rapid diagnosis and treatment of rifampicin-resistant tuberculosis (RR-TB) is required.

OBJECTIVE

To conduct a systematic review and meta-analysis assessing time to treatment for RR-TB and variability using diagnostic testing methods and treatment delivery approach.

DESIGN

Studies from 2000 to 2015 reporting time to second-line treatment initiation were selected from PubMed and published conference abstracts.

RESULTS

From 53 studies, 83 cohorts (13 034 patients) were included. Overall weighted mean time to treatment from specimen collection was 81 days (95%CI 70-91), and was shorter with ambulatory (57 days, 95%CI 40-74) than hospital-based treatment (86 days, 95%CI 71-102). Time to treatment was shorter with genotypic susceptibility testing (38 days, 95%CI 27-49) than phenotypic testing (108 days, 95%CI 98-117). The mean percentage of diagnosed patients initiating treatment was 76% (95%CI 70-83, range 25-100).

CONCLUSION

Time to second-line anti-tuberculosis treatment initiation is extremely variable across studies, and often unnecessarily long. Reduced delays are associated with genotypic testing and ambulatory treatment settings. Routine monitoring of the proportion of diagnosed patients initiating treatment and time to treatment are necessary to identify areas for intervention.

[Multidrug-resistant tuberculosis: a barrier to achieving the Sustainable Development Goals]

Señor editor: Dentro de los Objetivos de Desarrollo Sostenible para el año 2035 propuestos por la OMS está la eliminación de la tuberculosis a nivel mundial. Esto podría ser factible si tomamos en cuenta que los objetivos propuestos por la OMS para el año 2015 fueron logrados...

Whole genome sequencing of clinical strains of Mycobacterium tuberculosis from Mumbai, India: A potential tool for determining drug-resistance and strain lineage

Amplification of drug resistance in Mycobacterium tuberculosis (M.tb) and its transmission are significant barriers in controlling tuberculosis (TB) globally. Diagnostic inaccuracies and delays impede appropriate drug administration, which exacerbates primary and secondary drug resistance. Increasing affordability of whole genome sequencing (WGS) and exhaustive cataloguing of drug resistance mutations is poised to revolutionise TB diagnostics and facilitate personalized drug therapy. However, application of WGS for diagnostics in high endemic areas is yet to be demonstrated. We report WGS of 74 clinical TB isolates from Mumbai, India, characterising genotypic drug resistance to first- and second-line anti-TB drugs. A concordance analysis between phenotypic and genotypic drug susceptibility of a subset of 29 isolates and the sensitivity of resistance prediction to the 4 drugs was calculated, viz. isoniazid-100%, rifampicin-100%, ethambutol-100% and streptomycin-85%. The whole genome based phylogeny showed almost equal proportion of East Asian (27/74) and Central Asian (25/74) strains. Interestingly we also found a clonal group of 9 isolates, of which 7 patients were found to be from the same geographical location and accessed the same health post. This provides the first evidence of epidemiological linkage for tracking TB transmission in India, an approach which has the potential to significantly improve chances of End-TB goals. Finally, the use of Mykrobe Predictor, as a standalone drug resistance and strain typing tool, requiring just few minutes to analyse raw WGS data into tabulated results, implies the rapid clinical applicability of WGS based TB diagnosis.

Towards understanding the drivers of policy change: a case study of infection control policies for multi-drug resistant tuberculosis in South Africa

Background

Explaining policy change is one of the central tasks of contemporary policy analysis. In this article, we examine the changes in infection control policies for multi-drug resistant tuberculosis (MDR-TB) in South Africa from the time the country made the transition to democracy in 1994, until 2015. We focus on MDR-TB infection control and refer to decentralised management as a form of infection control. Using Kingdon’s theoretical framework of policy streams, we explore the temporal ordering of policy framework changes. We also consider the role of research in motivating policy changes.

Methods

Policy documents addressing MDR-TB in South Africa over the period 1994 to 2014 were extracted. Literature on MDR-TB infection control in South Africa was extracted from PubMed using key search terms. The documents were analysed to identify the changes that occurred and the factors driving them.

Results

During the period under study, five different policy frameworks were implemented. The policies were meant to address the overwhelming challenge of MDR-TB in South Africa, contextualised by high prevalence of HIV infection, that threatened to undermine public health programmes and the success of antiretroviral therapy rollouts. Policy changes in MDR-TB infection control were supported by research evidence and driven by the high incidence and complexity of the disease, increasing levels of dissatisfaction among patients, challenges of physical, human and financial resources in public hospitals, and the ideologies of the political leadership. Activists and people living with HIV played an important role in highlighting the importance of MDR-TB as well as exerting pressure on policymakers, while the mass media drew public attention to infection control as both a cause of and a solution to MDR-TB.

Conclusion

The critical factors for policy change for infection control of MDR-TB in South Africa were rooted in the socioeconomic and political environment, were supported by extensive research, and can be framed using Kingdon’s policy streams approach as an interplay of the problem of the disease, political forces that prevailed and alternative proposals.

Animal Models for Tuberculosis in Translational and Precision Medicine

Tuberculosis (TB) is a health threat to the global population. Anti-TB drugs and vaccines are key approaches for TB prevention and control. TB animal models are basic tools for developing biomarkers of diagnosis, drugs for therapy, vaccines for prevention and researching pathogenic mechanisms for identification of targets; thus, they serve as the cornerstone of comparative medicine, translational medicine, and precision medicine. In this review, we discuss the current use of TB animal models and their problems, as well as offering perspectives on the future of these models.

De-isolation of patients with pulmonary tuberculosis after start of treatment - clear, unequivocal guidelines are missing

The study review guidelines on isolation of patients with tuberculosis, TB, from the World Health Organization, WHO, Centers for Disease Control and Prevention, CDC, and the European Center for Disease Control, ECDC. The review found that unequivocal guidelines for removing patients out of negative-pressure isolation and de-isolation patients from either single rooms or isolation at home is needed. Studies show that the time of effective treatment is the key parameter to follow to determine if patients are contagious to others or not. This means that standard treatment of multi-drug resistant, MDR, TB will not result in the patient being non-infectious. Thus it is important right from the time of diagnosis to know if the patient is infected with MDR TB or not. Thus the early use of molecular techniques to reveal drug susceptibility is important. Clear guidelines stating if patient with microscopy negative sputum no matter infected with fully susceptible or MDR TB, no matter HIV positive or not is needed.