Rapid impact of effective treatment on transmission of multidrug-resistant tuberculosis

Critical assessment of infants born to mothers with drug resistant tuberculosis

Background

There have been no detailed descriptions of infants born to mothers treated for drug resistant TB in pregnancy. Critical case history assessment is important to identify risks and guide clinical practice.

Methods

In a cohort of pregnant women with multidrug or rifampicin resistant (MDR/RR)-TB enrolled between 1 January 2013 and 31 December 2022, we followed mother-infant pairs until the infant was 12 months old. We performed critical case history assessments to explore potential mechanisms of Mycobacterium tuberculosis transmission to the infant, and to describe the clinical presentation and disease trajectories observed in infants diagnosed with TB.

Findings

Among 101 mother-infant pairs, 23 (23%) included infants diagnosed with TB disease; 16 were clinically diagnosed and seven had microbiological confirmation (five MDR/RR-TB, two drug-susceptible TB). A positive maternal sputum culture at the time of delivery was significantly associated with infant TB risk (p = 0.023). Of the 12 infants diagnosed with TB in the first three months of life, seven (58%) of the mothers were culture positive at delivery; of whom four reported poor TB treatment adherence. However, health system failures, including failing to diagnose and treat maternal MDR/RR-TB, inadequate screening of newborns at birth, not providing appropriate TB preventive therapy (TPT), and M. tuberculosis transmission from non-maternal sources also contributed to TB development in infants.

Interpretation

Infants born to mothers with MDR/RR-TB are at greatest risk if maternal adherence to MDR/RR-TB treatment or antiretroviral therapy (ART) is sub-optimal. In a high TB incidence setting, infants are also at risk of non-maternal household and community transmission. Ensuring maternal TB diagnosis and appropriate treatment, together with adequate TB screening and prevention in all babies born to mothers or households with TB will minimise the risk of infant TB disease development.

Funding

South African Medical Research Council.

ISCCM Position Statement on the Approach to and Management of Critically Ill Patients with Tuberculosis

Tuberculosis (TB) is an important cause of morbidity and mortality globally. About 3-4% of hospitalized TB patients require admission to the intensive care unit (ICU); the mortality in these patients is around 50-60%. There is limited literature on the evaluation and management of patients with TB who required ICU admission. The Indian Society of Critical Care Medicine (ISCCM) constituted a working group to develop a position paper that provides recommendations on the various aspects of TB in the ICU setting based on available evidence. Seven domains were identified including the categorization of TB in the critically ill, diagnostic workup, drug therapy, TB in the immunocompromised host, organ support, infection control, and post-TB sequelae. Forty-one questions pertaining to these domains were identified and evidence-based position statements were generated, where available, keeping in focus the critical care aspects. Where evidence was not available, the recommendations were based on consensus. This position paper guides the approach to and management of critically ill patients with TB.

How to cite this article

Chacko B, Chaudhry D, Peter JV, Khilnani G, Saxena P, Sehgal IS, et al. isccm Position Statement on the Approach to and Management of Critically Ill Patients with Tuberculosis. Indian J Crit Care Med 2024;28(S2):S67-S91.

Management of the infant born to a mother with tuberculosis: a systematic review and consensus practice guideline

Infants born to mothers with tuberculosis disease are at increased risk of developing tuberculosis disease themselves. We reviewed published studies and guidelines on the management of these infants to inform the development of a consensus practice guideline. We searched MEDLINE, CINAHL, and Cochrane Library from database inception to Dec 1, 2022, for original studies reporting the management and outcome of infants born to mothers with tuberculosis. Of the 521 published papers identified, only three met inclusion criteria and no evidence-based conclusions could be drawn from these studies, given their narrow scope, variable aims, descriptive nature, inconsistent data collection, and high attrition rates. We also assessed a collection of national and international guidelines to inform a consensus practice guideline developed by an international panel of experts from different epidemiological contexts. The 16 guidelines reviewed had consistent features to inform the expert consultation process. Two management algorithms were developed-one for infants born to mothers considered potentially infectious at the time of delivery and another for mothers not considered infectious at the time of delivery-with different guidance for high and low tuberculosis incidence settings. This systematic review and consensus practice guideline should facilitate more consistent clinical management, support the collection of better data, and encourage the development of more studies to improve evidence-based care.

Airborne infection prevention and control implementation: A positive deviant organisational case study of tuberculosis and COVID-19 at a South African rural district hospital

There are many examples of poor TB infection prevention and control (IPC) implementation in the academic literature, describing a high-risk environment for nosocomial spread of airborne diseases to patients and health workers. We developed a positive deviant organisational case study drawing on Weick's theory of organisational sensemaking. We focused on a district hospital in the rural Eastern Cape, South Africa and used four primary care clinics as comparator sites. We interviewed 18 health workers to understand TB IPC implementation over time. We included follow-up interviews on interactions between TB and COVID-19 IPC. We found that TB IPC implementation at the district hospital was strengthened by continually adapting strategies based on synergistic interventions (e.g. TB triage and staff health services), changes in what value health workers attached to TB IPC and establishing organisational TB IPC norms. The COVID-19 pandemic severely tested organisational resilience and COVID-19 IPC measures competed instead of acted synergistically with TB. Yet there is the opportunity for applying COVID-19 IPC organisational narratives to TB IPC to support its use. Based on this positive deviant case we recommend viewing TB IPC implementation as a social process where health workers contribute to how evidence is interpreted and applied.

Cost of inaction: a framework to estimate the economic cost of missing a patient with tuberculosis in the Indian context

OBJECTIVES

To estimate the economic impact of failure to find and treat tuberculosis disease and prevent tuberculosis infection from progressing to active disease.

DESIGN

Estimating the economic cost of not finding and treating a patient suffering from tuberculosis.

SETTING

Estimation methodology is developed in the Indian context, as informed by local costs and reported tuberculosis epidemiology.

PARTICIPANTS

No individual participants were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure is the total cost of patients with drug-susceptible and drug-resistant tuberculosis who are and are not found and treated by tuberculosis programmes, including costs for medications, lost productivity, healthcare services and furthered transmission. We calculate the economic burdens by varying the number of individuals a person sick with tuberculosis infects (10 or 15 people) and the risk of progression to tuberculosis disease if infected (5 or 8%). The secondary outcome measure is the amount saved by finding a patient early or who would not have otherwise been found. All costs are presented in US dollars (exchange rate: 72 Indian rupees/1 US$).

RESULTS

By finding and treating a patient early before furthered transmission occurs-or stopping progression of tuberculosis infection to tuberculosis disease with preventive therapy-the Indian health system can save US$5502 to US$15 825 and US$5846 to US$25 575, for each individual with drug-susceptible and drug-resistant tuberculosis, respectively, across scenarios.

CONCLUSIONS

These estimates provide crude, lower bounds for the potential costs of not appropriately diagnosing and treating a single patient with active tuberculosis in a timely manner, or preventing a patient with tuberculosis infection from progressing to active disease. The actual financial burden on society is far higher than estimated using this simple, short-term cost-effective analyses. Our results highlight the limitations of tuberculosis costing models to date, and demonstrate the importance of accounting for airborne transmission of tuberculosis.

Cost of digital technologies and family-observed DOT for a shorter MDR-TB regimen: a modelling study in Ethiopia, India and Uganda

BACKGROUND

In 2017, the WHO recommended the use of digital technologies, such as medication monitors and video observed treatment (VOT), for directly observed treatment (DOT) of drug-susceptible TB. The WHO's 2020 guidelines extended these recommendations to multidrug-resistant tuberculosis (MDR-TB), based on low evidence. The impact of COVID on health systems and patients underscored the need to use digital technologies in the management of MDR-TB.

METHODS

A decision-tree model was developed to explore the costs of several potential DOT alternatives: VOT, 99DOTS (Directly-observed Treatment, Short-course) and family-observed DOT. Assuming a 9-month, all-oral regimen (as evaluated within the STREAM trial), we constructed base-case cost models for the standard-of-care DOTs in Ethiopia, India, and Uganda, as well as for the three alternative DOT approaches. The models were populated with STREAM Stage 2 clinical trial outcome and cost data, supplemented with market prices data for the digital DOT strategies. Sensitivity analyses were conducted on key parameters.

RESULTS

Modelling suggested that the standard-of-care DOT approach is the most expensive DOT strategy from a societal perspective in all three countries evaluated (Ethiopia, India, Uganda), with considerable direct- and indirect-costs incurred by patients. The second most expensive DOT approach is VOT, with high health-system costs, largely caused by up-front technology expenditure. Each of VOT, 99DOTS and family-observed DOT would reduce by more than 90% patients' direct and indirect costs compared to standard of care DOT. Results were robust to the sensitivity analyses.

CONCLUSIONS

While data on the costs and efficacy of alternative DOT approaches in the context of shorter MDR-TB treatment is limited, our modelling suggests alternative DOT approaches can significantly reduce patient costs in all three countries. Health system costs are higher for VOT and lower for 99DOTS and family-observed therapy when compared to standard of care DOT, as low smartphone penetration and internet availability requires the VOT health system to fund the cost of making them available to patients.

Finding and treating both tuberculosis disease and latent infection during population-wide active case finding for tuberculosis elimination

In recognition of the high rates of undetected tuberculosis in the community, the World Health Organization (WHO) encourages targeted active case finding (ACF) among "high-risk" populations. While this strategy has led to increased case detection in these populations, the epidemic impact of these interventions has not been demonstrated. Historical data suggest that population-wide (untargeted) ACF can interrupt transmission in high-incidence settings, but implementation remains lacking, despite recent advances in screening tools. The reservoir of latent infection-affecting up to a quarter of the global population -complicates elimination efforts by acting as a pool from which future tuberculosis cases may emerge, even after all active cases have been treated. A holistic case finding strategy that addresses both active disease and latent infection is likely to be the optimal approach for rapidly achieving sustainable progress toward TB elimination in a durable way, but safety and cost effectiveness have not been demonstrated. Sensitive, symptom-agnostic community screening, combined with effective tuberculosis treatment and prevention, should eliminate all infectious cases in the community, whilst identifying and treating people with latent infection will also eliminate tomorrow's tuberculosis cases. If real strides toward global tuberculosis elimination are to be made, bold strategies are required using the best available tools and a long horizon for cost-benefit assessment.

Time discrepancy for tuberculosis-negative microscopy and culture - the diagnostic gap remains: systematic analysis from a large tertiary care tuberculosis-clinic, Germany 2013-2017

OBJECTIVES

Patients with open pulmonary tuberculosis (opTB) are subject to strict isolation rules. Sputum smear microscopy is used to determine infectivity, but sensitivity is lower than for culture. This study aimed to investigate the clinical relevance of this mismatch in contemporary settings.

METHODS

Differential results between microscopy and culture were determined at the time of microscopic sputum conversion, from all patients with opTB between 01/2013 and 12/2017. In addition, data on HIV, multi/extensive drug-resistant TB status, time to smear- and cultural-negativity conversion were analyzed; and a Kaplan-Meier curve was developed.

RESULTS

Of 118 patients with opTB, 58 had demographic data available for microbiological and clinical follow-up analysis; among these, 26 (44.8%) had still at least one positive culture result. Median time from opTB-treatment initiation to full microscopic sputum- or culture conversion, was 16.5 days (range 2-105), and 20 days (1-105), respectively (median difference: +3.5 days). Sixteen days after de-isolation, >90% had converted culturally. HIV- or multi/extensive drug-resistant TB status did not impact conversion time.

CONCLUSION

When patients with opTB were de-isolated after 3 negative sputum smear microscopy tests, a substantial part still revealed cultural growth of Mycobacterium tuberculosis complex, but it remains unclear, whether smear-negative and culturally-positive individuals on therapy are really infective. Thus, the clinical relevance of this finding warrants further investigation.

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.

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.

Best practices for the care of pregnant people living with TB

BACKGROUND: Each year more than 200,000 pregnant people become sick with TB, but little is known about how to optimize their diagnosis and therapy. Although there is a need for further research in this population, it is important to recognize that much can be done to improve the services they currently receive.METHODS: Following a systematic review of the literature and the input of a global team of health professionals, a series of best practices for the diagnosis, prevention and treatment of TB during pregnancy were developed.RESULTS: Best practices were developed for each of the following areas: 1) screening and diagnosis; 2) reproductive health services and family planning; 3) treatment of drug-susceptible TB; 4) treatment of rifampicin-resistant/multidrug-resistant TB; 5) compassionate infection control practices; 6) feeding considerations; 7) counseling and support; 8) treatment of TB infection/TB preventive therapy; and 9) research considerations.CONCLUSION: Effective strategies for the care of pregnant people across the TB spectrum are readily achievable and will greatly improve the lives and health of this under-served population.

Caring for Adolescents and Young Adults With Tuberculosis or at Risk of Tuberculosis: Consensus Statement From an International Expert Panel

Background:

Despite being a preventable and treatable disease, tuberculosis (TB) is a leading cause of death among young people globally. Each year, an estimated 1.8 million adolescents and young adults (AYAs; 10–24 years old) develop TB. In 2019, an estimated 161,000 AYAs died of the disease. AYAs have unique developmental, psychosocial, and healthcare needs, but these needs have been neglected in both TB care and research agendas. In order to improve outcomes in this age group, the specific needs of AYAs must be considered and addressed.

Methods:

Through a consensus process, an international panel of 34 clinicians, researchers, TB survivors, and advocates with expertise in child/adolescent TB and/or adolescent health proposed interventions for optimizing AYA engagement in TB care. The process consisted of reviewing the literature on TB in AYAs; identifying and discussing priority areas; and drafting and revising proposed interventions until consensus, defined a priori , was reached.

Results:

The panel acknowledged the dearth of evidence on best practices for identifying and managing AYAs with TB. The final consensus statement, based on expert opinion, proposes nine interventions to reform current practices that may harm AYA health and well-being, and nine interventions to establish high-quality AYA-centered TB services.

Conclusion:

AYA-specific interventions for TB care and research are critical for improving outcomes in this age group. In the absence of evidence on best practices, this consensus statement from an international group of experts can help address the needs of AYA with TB or at risk for TB.

Mycobacterium tuberculosis Transmission in High-Incidence Settings-New Paradigms and Insights

Tuberculosis has affected humankind for thousands of years, but a deeper understanding of its cause and transmission only arose after Robert Koch discovered Mycobacterium tuberculosis in 1882. Valuable insight has been gained since, but the accumulation of knowledge has been frustratingly slow and incomplete for a pathogen that remains the number one infectious disease killer on the planet. Contrast that to the rapid progress that has been made in our understanding SARS-CoV-2 (the cause of COVID-19) aerobiology and transmission. In this Review, we discuss important historical and contemporary insights into M. tuberculosis transmission. Historical insights describing the principles of aerosol transmission, as well as relevant pathogen, host and environment factors are described. Furthermore, novel insights into asymptomatic and subclinical tuberculosis, and the potential role this may play in population-level transmission is discussed. Progress towards understanding the full spectrum of M. tuberculosis transmission in high-burden settings has been hampered by sub-optimal diagnostic tools, limited basic science exploration and inadequate study designs. We propose that, as a tuberculosis field, we must learn from and capitalize on the novel insights and methods that have been developed to investigate SARS-CoV-2 transmission to limit ongoing tuberculosis transmission, which sustains the global pandemic.

Impact of prolonged isolation on adolescents with drug-susceptible tuberculosis in Lima, Peru: a qualitative study

OBJECTIVES

Patients with tuberculosis (TB) generally are instructed to isolate at the beginning of treatment in order to prevent disease transmission. The duration of isolation varies and may be prolonged (ie, lasting 1 month or more). Few studies have examined the impact of isolation during TB treatment on adolescents, who may be more vulnerable to its negative effects.

METHODS

This study took place from 2018 through 2019 in Lima, Peru, where the Ministry of Health mandates the exclusion of patients with TB from educational institutions for at least 2 months. Using semi-structured guides, we conducted individual in-depth interviews with adolescents who received treatment for drug-susceptible TB, their primary caregivers and health providers. We performed thematic analysis of the transcribed interviews.

RESULTS

We interviewed 85 participants: 34 adolescents, 36 caregivers and 15 healthcare workers. At the time of their TB diagnoses, 28 adolescents were in secondary, postsecondary, vocational or military school. Adolescents with drug-susceptible TB were prescribed home isolation usually for 2 (and occasionally for 1) months. Consequently, they could neither attend school nor socialise with family members or friends. Two primary themes emerged from the interviews. First, as a result of their exclusion from school, most adolescents fell behind academically and had to repeat a semester or academic year. Second, absence from school, separation from friends and loved ones, and reinforcement of TB-related stigma (arising from fear of TB transmission) harmed adolescents' mental health.

CONCLUSION

Prolonged isolation led to educational setbacks and emotional trauma among adolescents with TB. Prolonged isolation is not supported by current evidence on TB transmission and is problematic from a human rights perspective, as it violates adolescents' rights to education and freedom of movement. Isolation recommendations should be re-evaluated to align with data on TB transmission and the principles of patient-centred care.

Health system delay and its associated factors among tuberculosis patients in Gamo Zone public health facilities, Southern Ethiopia: An institution-based cross-sectional study

Background

Delayed tuberculosis (TB) diagnosis and treatment increase morbidity, mortality, expenditure, and transmission in the community. Early diagnosis and initiation of treatment are essential for effective TB control.

Objective

The main objective of this study was to assess the magnitude and factors associated with health system delay among tuberculosis patients in Gamo Zone, Southern Ethiopia.

Methods

A cross-sectional study was conducted in Gamo Zone, Southern Ethiopia from February to April 2019. Fifteen health facilities in the study area were selected randomly and 255 TB patients who were ≥ 18 years of age were included. Data were collected using a questionnaire through face-to-face interviews and analyzed using SPSS version 20.0. Health system delay was analyzed using the median as a cut-off. Logistic regression analysis was performed to investigate factors of delays. A p-value of ≤ 0.05 at multivariable analysis was considered statistically significant.

Results

The median (inter-quartile range) of health system delays was 14(6-30) days. About 54.5% of patients had prolonged health system delays. Patients who had multiple healthcare contacts (AOR: 5.74; 95% CI: 2.47, 13.34) and aged between 25 and 44 years old (AOR: 1.98; 95% CI: 1.02, 3.86) and aged ≥ 45 years (AOR: 3.54; 95% CI: 2.17, 14.27) were significantly associated with longer health system's delay. However, female gender (AOR: 0.46; 95% CI: 0.25, 0.87) and patients presenting symptoms [Hemoptysis (AOR: 0.27; 95%CI: 0.11, 0.65) and Chest pain (AOR: 0.28; 95%CI; 0.14, 0.56)] were significantly associated with reduced health system's delay.

Conclusion

In this study, it was observed that a significant proportion of patients experienced more than the acceptable level for health system delay. The number of health care contact, presenting symptoms, age and sex were factors associated with health system delay. Hence, increasing clinician awareness of TB clinical presentation, implementing systems enabling early case detection, and ensuring rapid diagnosis of TB are required to achieve further TB control. Finally, maintenance of a high index of suspicion for tuberculosis in the vulnerable population could reduce long health system delays in the management of TB.

Predicting resistance to fluoroquinolones among patients with rifampicin-resistant tuberculosis using machine learning methods

Background

Limited access to drug-susceptibility tests (DSTs) and delays in receiving DST results are challenges for timely and appropriate treatment of multi-drug resistant tuberculosis (TB) in many low-resource settings. We investigated whether data collected as part of routine, national TB surveillance could be used to develop predictive models to identify additional resistance to fluoroquinolones (FLQs), a critical second-line class of anti-TB agents, at the time of diagnosis with rifampin-resistant TB.

Methods and findings

We assessed three machine learning-based models (logistic regression, neural network, and random forest) using information from 540 patients with rifampicin-resistant TB, diagnosed using Xpert MTB/RIF and notified in the Republic of Moldova between January 2018 and December 2019. The models were trained to predict the resistance to FLQs based on demographic and TB clinical information of patients and the estimated district-level prevalence of resistance to FLQs. We compared these models based on the optimism-corrected area under the receiver operating characteristic curve (OC-AUC-ROC). The OC-AUC-ROC of all models were statistically greater than 0.5. The neural network model, which utilizes twelve features, performed best and had an estimated OC-AUC-ROC of 0.87 (0.83,0.91), which suggests reasonable discriminatory power. A limitation of our study is that our models are based only on data from the Republic of Moldova and since not externally validated, the generalizability of these models to other populations remains unknown.

Conclusions

Models trained on data from phenotypic surveillance of drug-resistant TB can predict resistance to FLQs based on patient characteristics at the time of diagnosis with rifampin-resistant TB using Xpert MTB/RIF, and information about the local prevalence of resistance to FLQs. These models may be useful for informing the selection of antibiotics while awaiting results of DSTs.

Multidrug-resistant tuberculosis control in Rwanda overcomes a successful clone that causes most disease over a quarter century

SUMMARY BACKGROUND

Multidrug-resistant (MDR) tuberculosis (TB) poses an important challenge in TB management and control. Rifampicin resistance (RR) is a solid surrogate marker of MDR-TB. We investigated the RR-TB clustering rates, bacterial population dynamics to infer transmission dynamics, and the impact of changes to patient management on these dynamics over 27 years in Rwanda.

METHODS

We analysed whole genome sequences of a longitudinal collection of nationwide RR-TB isolates. The collection covered three important periods: before programmatic management of MDR-TB (PMDT; 1991-2005), the early PMDT phase (2006-2013), in which rifampicin drug-susceptibility testing (DST) was offered to retreatment patients only, and the consolidated phase (2014-2018), in which all bacteriologically confirmed TB patients had rifampicin DST done mostly via Xpert MTB/RIF assay. We constructed clusters based on a 5 SNP cut-off and resistance conferring SNPs. We used Bayesian modelling for dating and population size estimations, TransPhylo to estimate the number of secondary cases infected by each patient, and multivariable logistic regression to assess predictors of being infected by the dominant clone.

RESULTS

Of 308 baseline RR-TB isolates considered for transmission analysis, the clustering analysis grouped 259 (84.1%) isolates into 13 clusters. Within these clusters, a single dominant clone was discovered containing 213 isolates (82.2% of clustered and 69.1% of all RR-TB), which we named the "Rwanda Rifampicin-Resistant clone" (R3clone). R3clone isolates belonged to Ugandan sub-lineage 4.6.1.2 and its rifampicin and isoniazid resistance were conferred by the Ser450Leu mutation in rpoB and Ser315Thr in katG genes, respectively. All R3clone isolates had Pro481Thr, a putative compensatory mutation in the rpoC gene that likely restored its fitness. The R3clone was estimated to first arise in 1987 and its population size increased exponentially through the 1990s', reaching maximum size (∼84%) in early 2000 s', with a declining trend since 2014. Indeed, the highest proportion of R3clone (129/157; 82·2%, 95%CI: 75·3-87·8%) occurred between 2000 and 13, declining to 64·4% (95%CI: 55·1-73·0%) from 2014 onward. We showed that patients with R3clone detected after an unsuccessful category 2 treatment were more likely to generate secondary cases than patients with R3clone detected after an unsuccessful category 1 treatment regimen.

CONCLUSIONS

RR-TB in Rwanda is largely transmitted. Xpert MTB/RIF assay as first diagnostic test avoids unnecessary rounds of rifampicin-based TB treatment, thus preventing ongoing transmission of the dominant R3clone. As PMDT was intensified and all TB patients accessed rifampicin-resistance testing, the nationwide R3clone burden declined. To our knowledge, our findings provide the first evidence supporting the impact of universal DST on the transmission of RR-TB.

The source and fate of Mycobacterium tuberculosis complex in wastewater and possible routes of transmission

BACKGROUND

The Mycobacterium tuberculosis complex (MTBC) consists of causative agents of both human and animal tuberculosis and is responsible for over 10 million annual infections globally. Infections occur mainly through airborne transmission, however, there are possible indirect transmissions through a faecal-oral route which is poorly reported. This faecal-oral transmission could be through the occurrence of the microbe in environments such as wastewater. This manuscript, therefore, reviews the source and fate of MTBC in the wastewater environment, including the current methods in use and the possible risks of infections.

RESULTS

The reviewed literature indicates that about 20% of patients with pulmonary TB may have extra-pulmonary manifestations such as GITB, resulting in shedding in feaces and urine. This could potentially be the reason for the detection of MTBC in wastewater. MTBC concentrations of up to 5.5 × 105 (±3.9 × 105) copies/L of untreated wastewater have been reported. Studies have indicated that wastewater may provide these bacteria with the required nutrients for their growth and could potentially result in environmental transmission. However, 98.6 (± 2.7) %, removal during wastewater treatment, through physical-chemical decantation (primary treatment) and biofiltration (secondary treatment) has been reported. Despite these reports, several studies observed the presence of MTBC in treated wastewater via both culture-dependent and molecular techniques.

CONCLUSION

The detection of viable MTBC cells in either treated or untreated wastewater, highlights the potential risks of infection for wastewater workers and communities close to these wastewater treatment plants. The generation of aerosols during wastewater treatment could be the main route of transmission. Additionally, direct exposure to the wastewater containing MTBC could potentially contribute to indirect transmissions which may lead to pulmonary or extra-pulmonary infections. This calls for the implementation of risk reduction measures aimed at protecting the exposed populations.

Good citizens, perfect patients, and family reputation: Stigma and prolonged isolation in people with drug-resistant tuberculosis in Vietnam

Stigma and isolation are common in people with tuberculosis (TB). Social isolation contributes to reduced health outcomes and TB treatment adherence. Stigma and the drivers of isolation in people with Drug-Resistant (DR)-TB may include modifiable advice and practices of family and Health Care Workers (HCW). This study aimed to understand the drivers of isolation and stigma from the perspective of people with DR-TB in Vietnam. A greater understanding of stigma and isolation is important to identify and balance patients' needs and disease transmission risk. In-depth interviews were conducted with 12 people with DR-TB and seven HCWs who care for people with DR-TB in two provinces in Vietnam. Interviews were audio-recorded, transcribed verbatim and translated to English. Data collection and analysis were conducted simultaneously. The data were then analysed using a thematic framework approach. Stigma and extended isolation were common experiences among people with DR-TB. To mitigate stigma, people with DR-TB used the local term 'lao lực' to describe their condition to others which is believed to be a less infectious and less stigmatising type of TB. This study identified that although HCW informed people with DR-TB of when they were no longer infectious and isolation was no longer required, their infection control advice was not always consistent. Despite knowing they were no longer infectious, most people with DR-TB continued to self-isolate to minimise the perceived repercussions of societal stigma, to protect their 'thể diện' (honour, prestige, reputation), and eliminate all risk of transmitting DR-TB to their family. This study identified three interconnected drivers of self-isolation in Vietnam, including fear of infecting others, fear of stigmatization, and to protect family reputation. TB control programmes need to better understand the social aspects of DR-TB to enable them to better support patients. Educating HCW to provide evidence-based infection control advice is vital.

The Impact of Tuberculosis on the Well-Being of Adolescents and Young Adults

The health needs of adolescents and young adults (AYAs) have been neglected in tuberculosis (TB) care, control, and research. AYAs, who are distinct from younger children and older adults, undergo dynamic physical, psychological, emotional, cognitive, and social development. Five domains of adolescent well-being are crucial to a successful transition between childhood and adulthood: (1) Good health; (2) connectedness and contribution to society; (3) safety and a supportive environment; (4) learning, competence, education, skills, and employability; and (5) agency and resilience. This review summarizes the evidence of the impact of TB disease and treatment on these five domains of AYA well-being.

Tuberculosis infection status and risk factors among health workers: an updated systematic review

Tuberculosis (TB) infection is a common occupational risk for health workers (HWs) and poses a threat to the patients under their care and to other HWs. Hence, the development of a prevention strategy is crucial. We conducted a study to understand the status and risk factors of TB infection among HWs. The existing literature was searched for all published reports from 1 August 2010 to 31 December 2018, related to TB among HWs according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The inclusion criteria were: (1) study participants working in a health care facility; (2) TB cases diagnosed by medical professionals; (3) original research articles; and (4) English reports in a peer-reviewed journal. We finally included 61 studies from 642 articles searched initially. The TB infection rate in HWs was higher than that of the general population. Based on 39 studies, the prevalence of TB in HWs (tuberculin skin test positive) was 29.94%. In contrast, the global burden of latent TB infection was 23.0% (95% uncertainty interval: 20.4%–26.4%) in 2014. The risk factors of TB among HWs were aging, long duration of employment, nursing professionals, lack of Bacillus Calmette-Guerin vaccination, and low body mass index. HWs have an increased risk for TB infection, which can cause secondary infections in patients or other HWs. An effective prevention strategy must be developed to enable early diagnosis and prompt treatment.

FAST tuberculosis transmission control strategy speeds the start of tuberculosis treatment at a general hospital in Lima, Peru

Objective:

To evaluate the effect of the FAST (Find cases Actively, Separate safely, Treat effectively) strategy on time to tuberculosis diagnosis and treatment for patients at a general hospital in a tuberculosis-endemic setting.

Design:

Prospective cohort study with historical controls.

Participants:

Patients diagnosed with pulmonary tuberculosis during hospitalization at Hospital Nacional Hipolito Unanue in Lima, Peru.

Methods:

The FAST strategy was implemented from July 24, 2016, to December 31, 2019. We compared the proportion of patients with drug susceptibility testing and tuberculosis treatment during FAST to the 6-month period prior to FAST. Times to diagnosis and tuberculosis treatment were also compared using Kaplan-Meier plots and Cox regressions.

Results:

We analyzed 75 patients diagnosed with pulmonary tuberculosis through FAST. The historical cohort comprised 76 patients. More FAST patients underwent drug susceptibility testing (98.7% vs 57.8%; OR, 53.8; P < .001), which led to the diagnosis of drug-resistant tuberculosis in 18 (24.3%) of 74 of the prospective cohort and 4 (9%) of 44 of the historical cohort (OR, 3.2; P = .03). Overall, 55 FAST patients (73.3%) started tuberculosis treatment during hospitalization compared to 39 (51.3%) controls (OR, 2.44; P = .012). FAST reduced the time from hospital admission to the start of TB treatment (HR, 2.11; 95% CI, 1.39–3.21; P < .001).

Conclusions:

Using the FAST strategy improved the diagnosis of drug-resistant tuberculosis and the likelihood and speed of starting treatment among patients with pulmonary tuberculosis at a general hospital in a tuberculosis-endemic setting. In these settings, the FAST strategy should be considered to reduce tuberculosis transmission while simultaneously improving the quality of care.

Local Transmission Plays No Important Role in the Occurrence of Multidrug-Resistant Tuberculosis in Immigrants to Canada: An In-depth Epidemiologic Analysis

BACKGROUND

Multidrug-resistant (MDR) tuberculosis has increased among migrants in Canada. The cause(s) of this increase is unknown.

METHODS

We performed a retrospective cohort study in a Canadian province with substantially increased immigration between 1982-2001 and 2002-2019. The proportion of MDR tuberculosis among migrants arriving from high MDR (HMDR) tuberculosis burden countries during these 2 periods was used to estimate the proportion of cases due to immigration versus change in proportion in the country of birth. Epidemiologic, spatiotemporal, and drug resistance pattern data were used to confirm local transmission.

RESULTS

Fifty-two of 3514 (1.48%) foreign-born culture-positive tuberculosis patients had MDR tuberculosis: 8 (0.6%) in 1982-2001 and 44 (2.0%) in 2002-2019. Between time periods, the proportion of MDR tuberculosis among migrants with tuberculosis from HMDR tuberculosis countries increased from 1.11% to 3.62%, P = .003; 31.6% attributable to recent immigration and 68.4% to a higher proportion of MDR tuberculosis in cases arrived from HMDR tuberculosis countries. No cases of MDR tuberculosis were attributable to local transmission.

CONCLUSIONS

In stark contrast to HMDR tuberculosis countries, local transmission plays no important role in the occurrence of MDR tuberculosis in Canada. Improved tuberculosis programming in HMDR tuberculosis countries is urgently needed.

Early phase of effective treatment induces distinct transcriptional changes in Mycobacterium tuberculosis expelled by pulmonary tuberculosis patients

Effective treatment reduces a tuberculosis patient's ability to infect others even before they test negative in sputum or culture. Currently, the basis of reduced infectiousness of the Mycobacterium tuberculosis (Mtb) with effective treatment is unclear. We evaluated changes in aerosolized bacteria expelled by patients through a transcriptomic approach before and after treatment initiation (up to 14 days) by RNA sequencing. A distinct change in the overall transcriptional profile was seen post-treatment initiation compared to pretreatment, only when patients received effective treatment. This also led to the downregulation of genes associated with cellular activities, cell wall assembly, virulence factors indicating loss of pathogenicity, and a diminished ability to infect and survive in new host cells. Based on this, we identified genes whose expression levels changed with effective treatment. The observations of the study open up avenues for further evaluating the changes in bacterial gene expression during the early phase of treatment as biomarkers for monitoring response to tuberculosis treatment regimens and provide means of identifying better correlates of Mtb transmission.

Identifying barriers and facilitators to implementation of community-based tuberculosis active case finding with mobile X-ray units in Lima, Peru: a RE-AIM evaluation

OBJECTIVES

Identify barriers and facilitators to integrating community tuberculosis screening with mobile X-ray units into a health system.

METHODS

Reach, effectiveness, adoption, implementation and maintenance evaluation.

SETTING

3-district region of Lima, Peru.

PARTICIPANTS

63 899 people attended the mobile units from 7 February 2019 to 6 February 2020.

INTERVENTIONS

Participants were screened by chest radiography, which was scored for abnormality by computer-aided detection. People with abnormal X-rays were evaluated clinically and by GeneXpert MTB/RIF (Xpert) sputum testing. People diagnosed with tuberculosis at the mobile unit were accompanied to health facilities for treatment initiation.

PRIMARY AND SECONDARY OUTCOME MEASURES

Reach was defined as the percentage of the population of the three-district region that attended the mobile units. Effectiveness was defined as the change in tuberculosis case notifications over a historical baseline. Key implementation fidelity indicators were the percentages of people who had chest radiography performed, were evaluated clinically, had sputum samples collected, had valid Xpert results and initiated treatment.

RESULTS

The intervention reached 6% of the target population and was associated with an 11% (95% CI 6 to 16) increase in quarterly case notifications, adjusting for the increasing trend in notifications over the previous 3 years. Implementation indicators for screening, sputum collection and Xpert testing procedures all exceeded 85%. Only 82% of people diagnosed with tuberculosis at the mobile units received treatment; people with negative or trace Xpert results were less likely to receive treatment. Suboptimal treatment initiation was driven by health facility doctors' lack of familiarity with Xpert and lack of confidence in diagnoses made at the mobile unit.

CONCLUSION

Mobile X-ray units were a feasible and effective strategy to extend tuberculosis diagnostic services into communities and improve early case detection. Effective deployment however requires advance coordination among stakeholders and targeted provider training to ensure that people diagnosed with tuberculosis by new modalities receive prompt treatment.

Commentary: Lessons from the COVID-19 global health response to inform TB case finding

The coronavirus disease 2019 (COVID-19) has emerged as a serious threat to global public health, demanding urgent action and causing unprecedented worldwide change in a short space of time. This disease has devastated economies, infringed on individual freedoms, and taken an unprecedented toll on healthcare systems worldwide. As of 1 April 2020, over a million cases of COVID-19 have been reported in 204 countries and territories, resulting in more than 51,000 deaths. Yet, against the backdrop of the COVID-19 pandemic, lies an older, insidious disease with a much greater mortality. Tuberculosis (TB) is the leading cause of death by a single infectious agent and remains a potent threat to millions of people around the world. We discuss the differences between the two pandemics at present, consider the potential impact of COVID-19 on TB case management, and explore the opportunities that the COVID-19 response presents for advancing TB prevention and control now and in future.

Bayesian evidence synthesis to estimate subnational TB incidence: An application in Brazil

BACKGROUND

Evidence on local disease burden and the completeness of case detection represent important information for TB control programs. We present a new method for estimating subnational TB incidence and the fraction of individuals with incident TB who are diagnosed and treated in Brazil.

METHODS

We compiled data on TB notifications and TB-related mortality in Brazil and specified an analytic model approximating incidence as the number of individuals exiting untreated active disease (sum of treatment initiation, death before treatment, and self-cure). We employed a Bayesian inference approach to synthesize data and adjust for known sources of bias. We estimated TB incidence and the fraction of cases treated, for each Brazilian state and the Federal District over 2008-2017.

FINDINGS

For 2017, TB incidence was estimated as 41.5 (95 % interval: 40.7, 42.5) per 100 000 nationally, and ranged from 11.7-88.3 per 100 000 across states. The fraction of cases treated was estimated as 91.9 % (89.6 %, 93.7 %) nationally and ranged 86.0 %-94.8 % across states, with an estimated 6.9 (5.3, 9.2) thousand cases going untreated in 2017. Over 2008-2017, incidence declined at an average annual rate of 1.4 % (1.1 %, 1.9 %) nationally, and -1.1%-4.2 % across states. Over this period there was a 0.5 % (0.2 %, 0.9 %) average annual increase in the fraction of incident TB cases treated.

INTERPRETATION

Time-series estimates of TB burden and the fraction of cases treated can be derived from routinely-collected data and used to understand variation in TB outcomes and trends.

Dynamics of sputum conversion during effective tuberculosis treatment: A systematic review and meta-analysis

BACKGROUND

Two weeks' isolation is widely recommended for people commencing treatment for pulmonary tuberculosis (TB). The evidence that this corresponds to clearance of potentially infectious tuberculous mycobacteria in sputum is not well established. This World Health Organization-commissioned review investigated sputum sterilisation dynamics during TB treatment.

METHODS AND FINDINGS

For the main analysis, 2 systematic literature searches of OvidSP MEDLINE, Embase, and Global Health, and EBSCO CINAHL Plus were conducted to identify studies with data on TB infectiousness (all studies to search date, 1 December 2017) and all randomised controlled trials (RCTs) for drug-susceptible TB (from 1 January 1990 to search date, 20 February 2018). Included articles reported on patients receiving effective treatment for culture-confirmed drug-susceptible pulmonary TB. The outcome of interest was sputum bacteriological conversion: the proportion of patients having converted by a defined time point or a summary measure of time to conversion, assessed by smear or culture. Any study design with 10 or more particpants was considered. Record sifting and data extraction were performed in duplicate. Random effects meta-analyses were performed. A narrative summary additionally describes the results of a systematic search for data evaluating infectiousness from humans to experimental animals (PubMed, all studies to 27 March 2018). Other evidence on duration of infectiousness-including studies reporting on cough dynamics, human tuberculin skin test conversion, or early bactericidal activity of TB treatments-was outside the scope of this review. The literature search was repeated on 22 November 2020, at the request of the editors, to identify studies published after the previous censor date. Four small studies reporting 3 different outcome measures were identified, which included no data that would alter the findings of the review; they are not included in the meta-analyses. Of 5,290 identified records, 44 were included. Twenty-seven (61%) were RCTs and 17 (39%) were cohort studies. Thirteen studies (30%) reported data from Africa, 12 (27%) from Asia, 6 (14%) from South America, 5 (11%) from North America, and 4 (9%) from Europe. Four studies reported data from multiple continents. Summary estimates suggested smear conversion in 9% of patients at 2 weeks (95% CI 3%-24%, 1 single study [N = 1]), and 82% of patients at 2 months of treatment (95% CI 78%-86%, N = 10). Among baseline smear-positive patients, solid culture conversion occurred by 2 weeks in 5% (95% CI 0%-14%, N = 2), increasing to 88% at 2 months (95% CI 84%-92%, N = 20). At equivalent time points, liquid culture conversion was achieved in 3% (95% CI 1%-16%, N = 1) and 59% (95% CI 47%-70%, N = 8). Significant heterogeneity was observed. Further interrogation of the data to explain this heterogeneity was limited by the lack of disaggregation of results, including by factors such as HIV status, baseline smear status, and the presence or absence of lung cavitation.

CONCLUSIONS

This systematic review found that most patients remained culture positive at 2 weeks of TB treatment, challenging the view that individuals are not infectious after this interval. Culture positivity is, however, only 1 component of infectiousness, with reduced cough frequency and aerosol generation after TB treatment initiation likely to also be important. Studies that integrate our findings with data on cough dynamics could provide a more complete perspective on potential transmission of Mycobacterium tuberculosis by individuals on treatment.

TRIAL REGISTRATION

Systematic review registration: PROSPERO 85226.

Drug susceptibility patterns of Mycobacterium tuberculosis from adults with multidrug-resistant tuberculosis and implications for a household contact preventive therapy trial

BACKGROUND

Drug susceptibility testing (DST) patterns of Mycobacterium tuberculosis (MTB) from patients with rifampicin-resistant tuberculosis (RR-TB) or multidrug-resistant TB (MDR-TB; or resistant to rifampicin and isoniazid (INH)), are important to guide preventive therapy for their household contacts (HHCs).

METHODS

As part of a feasibility study done in preparation for an MDR-TB preventive therapy trial in HHCs, smear, Xpert MTB/RIF, Hain MTBDRplus, culture and DST results of index MDR-TB patients were obtained from routine TB programs. A sputum sample was collected at study entry and evaluated by the same tests. Not all tests were performed on all specimens due to variations in test availability.

RESULTS

Three hundred eight adults with reported RR/MDR-TB were enrolled from 16 participating sites in 8 countries. Their median age was 36 years, and 36% were HIV-infected. Routine testing on all 308 were confirmed as having RR-TB, but only 75% were documented as having MDR-TB. The majority of those not classified as having MDR-TB were because only rifampicin resistance was tested. At study entry (median 59 days after MDR-TB treatment initiation), 280 participants (91%) were able to produce sputum for the study, of whom 147 (53%) still had detectable MTB. All but 2 of these 147 had rifampicin DST done, with resistance detected in 89%. Almost half (47%) of the 147 specimens had INH DST done, with 83% resistance. Therefore, 20% of the 280 study specimens had MDR-TB confirmed. Overall, DST for second-line drugs were available in only 35% of the 308 routine specimens and 15% of 280 study specimens.

CONCLUSIONS

RR-TB was detected in all routine specimens but only 75% had documented MDR-TB, illustrating the need for expanded DST beyond Xpert MTB/RIF to target preventive therapy for HHC.

Time to sputum culture conversion and its predictors among patients with multidrug-resistant tuberculosis in Hangzhou, China: A retrospective cohort study

The objective is to investigate the time to initial sputum culture conversion (SCC) and its predictors among multidrug-resistant tuberculosis (MDR-TB) patients in Hangzhou, China.A retrospective cohort study was conducted among patients who initiated MDR-TB treatment from 2011 to 2015 in Hangzhou, China. Successful achievement of initial SCC was defined as 2 consecutive negative cultures taken at least 30 days apart after initiation of treatment of MDR-TB. Successful treatment outcomes included being cured and completing treatment, while poor treatment outcomes included treatment failure, loss to follow-up, and death. Time to initial SCC was analyzed using the Kaplan-Meier method, and Cox proportional hazards regression was used to identify predictors of SCC.Among 384 patients enrolled with MDR-TB, 359 (93.5%) successfully achieved initial SCC after a median of 85 days (interquartile range, 40-112 days). A higher rate of SCC was observed in participants with successful treatment outcomes than those with poor treatment outcomes (P<.01). Multivariate analysis showed that age 25 to 64 years (compared with age<25; adjusted odds ratio [AOR], 0.7; 95% confidence interval [CI], 0.5-0.9; P < .01), age ≥65 years (compared with age < 25; AOR, 0.5; 95% CI, 0.3-0.8; P < .01), and household registration in Hangzhou (compared with non-Hangzhou registration; AOR, 1.3; 95% CI, 1.0-1.5; P < .05) were found to be associated with SCC.Although high SCC and treatment success rates were observed among MDR-TB patients in Hangzhou, the prolonged duration to initial SCC underscores the importance of emphasizing measures for infection control. A new policy of shifting outpatient treatment to inpatient treatment in China may reduce the risk of transmission from patients in the time window prior to SCC.

Bacterial and host determinants of cough aerosol culture positivity in patients with drug-resistant versus drug-susceptible tuberculosis

A burgeoning epidemic of drug-resistant tuberculosis (TB) threatens to derail global control efforts. Although the mechanisms remain poorly clarified, drug-resistant strains are widely believed to be less infectious than drug-susceptible strains. Consequently, we hypothesized that lower proportions of patients with drug-resistant TB would have culturable Mycobacterium tuberculosis from respirable, cough-generated aerosols compared to patients with drug-susceptible TB, and that multiple factors, including mycobacterial genomic variation, would predict culturable cough aerosol production. We enumerated the colony forming units in aerosols (≤10 µm) from 452 patients with TB (227 with drug resistance), compared clinical characteristics, and performed mycobacterial whole-genome sequencing, dormancy phenotyping and drug-susceptibility analyses on M. tuberculosis from sputum. After considering treatment duration, we found that almost half of the patients with drug-resistant TB were cough aerosol culture-positive. Surprisingly, neither mycobacterial genomic variants, lineage, nor dormancy status predicted cough aerosol culture positivity. However, mycobacterial sputum bacillary load and clinical characteristics, including a lower symptom score and stronger cough, were strongly predictive, thereby supporting targeted transmission-limiting interventions. Effective treatment largely abrogated cough aerosol culture positivity; however, this was not always rapid. These data question current paradigms, inform public health strategies and suggest the need to redirect TB transmission-associated research efforts toward host-pathogen interactions.

Treatment outcomes of multidrug-resistant tuberculosis in Hangzhou, China, 2011 to 2015

Treatment of multidrug-resistant tuberculosis (MDR-TB) is challenging. More research is needed to understand treatment outcomes and associated factors.A retrospective cohort study was conducted to assess trends and predictors of treatment success among 398 MDR-TB and extensively drug resistant TB patients who started treatment in 2011 to 2015 in Hangzhou, China. Sociodemographic and clinical characteristic data were obtained from the national reporting database. Chi-square test for trend was used to evaluate changes in treatment success rates over the study years, and Cox regression analysis was used to identify predictors for poor treatment outcomes.The treatment success rate was 76% (301/398) for all participants, 77% (298/387) for MDR-TB cases and 27% (3/11) for extensively drug-resistant tuberculosis -TB cases. Treatment success increased significantly from 66% among patients who started treatment in 2011 to 85% in 2015 (P < .01). Of the 97 (24.4%) patients with unsuccessful treatment outcomes, 10 (2.5%) died, 64 (16.1%) failed treatment, and 23 (5.8%) were lost to follow-up. Patients who started treatment in 2013 to 2015 were less likely to have unsuccessful outcomes than those who started in 2011-2012 (adjusted odds ratio [AOR] 0.4, 95% confidence interval [CI] 0.3-0.6), patients ≥25 years were more likely to have unsuccessful outcomes than younger patients (AOR 1.6, 95% CI 1.3-2.1), and cases with kanamycin resistance was associated with three times the odds of having unsuccessful outcomes than kanamycin-susceptible cases (AOR 3.0, 95% CI 1.5-5.8).With proper case management of MDR-TB, patients can achieve a high treatment success rate. Hangzhou's program offers clinical evidence that can be used to inform MDR-TB programs elsewhere in China and abroad.

Factors influencing diagnosis and treatment initiation for multidrug-resistant/rifampicin-resistant tuberculosis in six sub-Saharan African countries: a mixed-methods systematic review

BACKGROUND

Drug-resistant tuberculosis burdens fragile health systems in sub-Saharan Africa (SSA), complicated by high prevalence of HIV. Several African countries reported large gaps between estimated incidence and diagnosed or treated cases. Our review aimed to identify barriers and facilitators influencing diagnosis and treatment for drug-resistant tuberculosis (DR-TB) in SSA, which is necessary to develop effective strategies to find the missing incident cases and improve quality of care.

METHODS

Using an integrative design, we reviewed and narratively synthesised qualitative, quantitative and mixed-methods studies from nine electronic databases: Medline, Global Health, CINAHL, EMBASE, Scopus, Web of Science, International Journal of Tuberculosis and Lung Disease, PubMed and Google Scholar (January 2006 to June 2019).

RESULTS

Of 3181 original studies identified, 55 full texts were screened, and 29 retained. The studies included were from 6 countries, mostly South Africa. Barriers and facilitators to DR-TB care were identified at the health system and patient levels. Predominant health system barriers were laboratory operational issues, provider knowledge and attitudes and information management. Facilitators included GeneXpert MTB/RIF (Xpert) diagnosis and decentralisation of services. At the patient level, predominant barriers were patients being lost to follow-up or dying due to lengthy diagnostic and treatment delays, negative public sector care perceptions, family, work or school commitments and using private sector care. Some patient-level facilitators were HIV positivity and having more symptoms.

CONCLUSION

Case detection and treatment for DR -TB in SSA currently relies on individual patients presenting voluntarily to the hospital for care. Specific interventions targeting identified barriers may improve rates and timeliness of detection and treatment.

Enhanced tenacity of mycobacterial aerosols from necrotic neutrophils

The tuberculosis agent Mycobacterium tuberculosis is primarily transmitted through air, but little is known about the tenacity of mycobacterium-containing aerosols derived from either suspensions or infected neutrophils. Analysis of mycobacterial aerosol particles generated from bacterial suspensions revealed an average aerodynamic diameter and mass density that may allow distant airborne transmission. The volume and mass of mycobacterial aerosol particles increased with elevated relative humidity. To more closely mimic aerosol formation that occurs in active TB patients, aerosols from mycobacterium-infected neutrophils were analysed. Mycobacterium-infected intact neutrophils showed a smaller particle size distribution and lower viability than free mycobacteria. In contrast, mycobacterium-infected necrotic neutrophils, predominant in M. tuberculosis infection, revealed particle sizes and viability rates similar to those found for free mycobacteria, but in addition, larger aggregates of viable mycobacteria were observed. Therefore, mycobacteria are shielded from environmental stresses in multibacillary aggregates generated from necrotic neutrophils, which allows improved tenacity but emphasizes short distance transmission between close contacts.

Prevalence and drivers of false-positive rifampicin-resistant Xpert MTB/RIF results: a prospective observational study in Rwanda

BACKGROUND

The Xpert MTB/RIF (Xpert) assay is used globally to rapidly diagnose tuberculosis and resistance to rifampicin. We investigated the frequency and predictors of false-positive findings of rifampicin resistance with Xpert.

METHODS

We did a prospective, observational study of individuals who were enrolled in a Rwandan nationwide diagnostic cohort study (DIAMA trial; NCT03303963). We included patients identified to have rifampicin resistance on initial Xpert testing. We did a repeat Xpert assay and used rpoB Sanger and deep sequencing alongside phenotypic drug susceptibility testing (pDST) to ascertain final rifampicin susceptibility status, with any (hetero)resistant result overriding. We used multivariable logistic regression to assess predictors of false rifampicin resistance on initial Xpert testing, adjusted for HIV status, tuberculosis treatment history, initial Xpert semi-quantitative bacillary load, and initial Xpert probe.

FINDINGS

Between May 4, 2017, and April 30, 2019, 175 people were identified with rifampicin resistance at initial Xpert testing, of whom 154 (88%) underwent repeat Xpert assay. 54 (35%) patients were confirmed as rifampicin resistant on repeat testing and 100 (65%) were not confirmed with resistance. After further testing and sequencing, 121 (79%) of 154 patients had a final confirmed status for rifampicin susceptibility. 57 (47%) of 121 patients were confirmed to have a false rifampicin resistance result and 64 (53%) had true rifampicin resistance. A high pretest probability of rifampicin resistance did not decrease the odds of false rifampicin resistance (adjusted odds ratio [aOR] 6·0, 95% CI 1·0-35·0, for new tuberculosis patients vs patients who needed retreatment). Ten (16%) of the 64 patients with true rifampicin resistance did not have confirmed rifampicin resistance on repeat Xpert testing, of whom four had heteroresistance. Of 63 patients with a very low bacillary load on Xpert testing, 54 (86%) were falsely diagnosed with rifampicin-resistant tuberculosis. Having a very low bacillary load on Xpert testing was strongly associated with false rifampicin resistance at the initial Xpert assay (aOR 63·6, 95% CI 9·9-410·4).

INTERPRETATION

The Xpert testing algorithm should include an assessment of bacillary load and retesting in case rifampicin resistance is detected on a paucibacillary sputum sample. Only when rifampicin resistance has been confirmed on repeat testing should multidrug-resistant tuberculosis treatment be started. When rifampicin resistance has not been confirmed on repeat testing, we propose that patients should be given first-line anti-tuberculosis drugs and monitored closely during treatment, including by baseline culture, pDST, and further Xpert testing.

FUNDING

The European & Developing Countries Clinical Trials Partnership 2 programme, and Belgian Directorate General for Development Cooperation.

Preventing Transmission of Mycobacterium Tuberculosis-A Refocused Approach

Traditional tuberculosis (TB) infection control focuses on the known patient with TB, usually on appropriate treatment. A refocused, intensified TB infection control approach is presented. Combined with active case finding and rapid molecular diagnostics, an approach called FAST is described as a convenient way to call attention to the untreated patient. Natural ventilation is the mainstay of air disinfection in much of the world. Germicidal ultraviolet technology is the most sustainable approach to air disinfection under resource-limited conditions. Testing and treatment of latent TB infection works to prevent reactivation but requires greater risk targeting in both low- and high-risk settings.

Treatment as prevention and other interventions to reduce transmission of multidrug-resistant tuberculosis

Drug-resistant tuberculosis (DR-TB) represents a major programmatic challenge at the national and global levels. Only ∼30% of patients with multidrug-resistant TB (MDR-TB) were diagnosed, and ∼25% were initiated on treatment for MDR-TB in 2016. Increasing evidence now points towards primary transmission of DR-TB, rather than inadequate treatment, as the main driver of the DR-TB epidemic. The cornerstone of DR-TB transmission prevention should be earlier diagnosis and prompt initiation of effective treatment for all patients with DR-TB. Despite the extensive scale-up of Xpert^® MTB/RIF testing, major implementation barriers continue to limit its impact. Although there is longstanding evidence in support of the rapid impact of treatment on patient infectiousness, delays in the initiation of effective DR-TB treatment persist, resulting in ongoing transmission. However, it is also imperative to address the burden of latent drug-resistant tuberculous infection because it is estimated that many DR-TB patients will become infectious before seeking care and encounter various diagnostic delays before treatment. Addressing latent DR-TB primarily consists of identifying, treating and following the contacts of patients with MDR-TB, typically through household contact evaluation. Adjunctive measures, such as improved ventilation and use of germicidal ultraviolet technology can further reduce TB transmission in high-risk congregate settings. Although many gaps remain in our biological understanding of TB transmission, implementation barriers to early diagnosis and rapid initiation of effective DR-TB treatment can and must be overcome if we are to impact DR-TB incidence in the short and long term.

MDR/XDR-TB management of patients and contacts: Challenges facing the new decade. The 2020 clinical update by the Global Tuberculosis Network

The continuous flow of new research articles on MDR-TB diagnosis, treatment, prevention and rehabilitation requires frequent update of existing guidelines. This review is aimed at providing clinicians and public health staff with an updated and easy-to-consult document arising from consensus of Global Tuberculosis Network (GTN) experts. The core published documents and guidelines have been reviewed, including the recently published MDR-TB WHO rapid advice and ATS/CDC/ERS/IDSA guidelines. After a rapid review of epidemiology and risk factors, the clinical priorities on MDR-TB diagnosis (including whole genome sequencing and drug-susceptibility testing interpretations) and treatment (treatment design and management, TB in children) are discussed. Furthermore, the review comprehensively describes the latest information on contact tracing and LTBI management in MDR-TB contacts, while providing guidance on post-treatment functional evaluation and rehabilitation of TB sequelae, infection control and other public health priorities.

"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.

Implementation strategies for infection prevention and control promotion for nurses in Sub-Saharan Africa: a systematic review

Background

Despite impressive reductions in infectious disease burden within Sub-Saharan Africa (SSA), half of the top ten causes of poor health or death in SSA are communicable illnesses. With emerging and re-emerging infections affecting the region, the possibility of healthcare-acquired infections (HAIs) being transmitted to patients and healthcare workers, especially nurses, is a critical concern. Despite infection prevention and control (IPC) evidence-based practices (EBP) to minimize the transmission of HAIs, many healthcare systems in SSA are challenged to implement them. The purpose of this review is to synthesize and critique what is known about implementation strategies to promote IPC for nurses in SSA.

Methods

The databases, PubMed, Ovid/Medline, Embase, Cochrane, and CINHAL, were searched for articles with the following criteria: English language, peer-reviewed, published between 1998 and 2018, implemented in SSA, targeted nurses, and promoted IPC EBPs. Further, 6241 search results were produced and screened for eligibility to identify implementation strategies used to promote IPC for nurses in SSA. A total of 61 articles met the inclusion criteria for the final review. The articles were evaluated using the Joanna Briggs Institute’s (JBI) quality appraisal tools. Results were reported using PRISMA guidelines.

Results

Most studies were conducted in South Africa (n = 18, 30%), within the last 18 years (n = 41, 67%), and utilized a quasi-experimental design (n = 22, 36%). Few studies (n = 14, 23%) had sample populations comprising nurses only. The majority of studies focused on administrative precautions (n = 36, 59%). The most frequent implementation strategies reported were education (n = 59, 97%), quality management (n = 39, 64%), planning (n = 33, 54%), and restructure (n = 32, 53%). Penetration and feasibility were the most common outcomes measured for both EBPs and implementation strategies used to implement the EBPs. The most common MAStARI and MMAT scores were 5 (n = 19, 31%) and 50% (n = 3, 4.9%) respectively.

Conclusions

As infectious diseases, especially emerging and re-emerging infectious diseases, continue to challenge healthcare systems in SSA, nurses, the keystones to IPC practice, need to have a better understanding of which, in what combination, and in what context implementation strategies should be best utilized to ensure their safety and that of their patients. Based on the results of this review, it is clear that implementation of IPC EBPs in SSA requires additional research from an implementation science-specific perspective to promote IPC protocols for nurses in SSA.

Use of GeneXpert MTB/RIF on a single pooled sputum specimen to exclude pulmonary tuberculosis among hospital inpatients placed in respiratory isolation

BACKGROUND

Patients with suspected pulmonary tuberculosis (PTB) are usually placed in respiratory isolation awaiting three sputum smear microscopy results for acid-fast bacilli (3AFB). GeneXpert MTB/RIF (Xpert) on a pooled sample from two sputa may allow for more rapid de-isolation.

OBJECTIVES

To compare the sensitivity and negative predictive value (NPV) of Xpert performed on a single pooled sputum sample ('pooled Xpert') to 3AFB, in order to exclude PTB in patients placed in respiratory isolation.

METHODS

Hospital inpatients in respiratory isolation for possible PTB were enrolled prospectively. Three expectorated sputum samples were obtained for smear microscopy. Two of the same samples had 0.5 ml removed from each and pooled for pooled Xpert. The diagnostic accuracy of pooled Xpert and 3AFB were assessed and compared to liquid culture at 8 weeks as the reference standard.

RESULTS

Of 56 participants, nine (16.1%) were diagnosed with PTB. Compared to liquid culture, pooled Xpert had a sensitivity of 88.9% (95% confidence interval (CI) 57-99%) and NPV of 97.9% (95% CI 89-99%). 3AFB had a sensitivity of 66.7% (95% CI 35-88%) and NPV of 93.5% (95% CI 83-98%).

CONCLUSIONS

A single pooled Xpert was non-inferior to 3AFB, with a strong trend towards greater sensitivity and better NPV. These findings support the use of a single pooled Xpert as an effective rapid screening approach for ruling out PTB in low incidence settings. Its value in high incidence settings and optimal combination with smear microscopy and culture warrant further evaluation.

Projecting the impact of variable MDR-TB transmission efficiency on long-term epidemic trends in South Africa and Vietnam

Whether multidrug-resistant tuberculosis (MDR-TB) is less transmissible than drug-susceptible (DS-)TB on a population level is uncertain. Even in the absence of a genetic fitness cost, the transmission potential of individuals with MDR-TB may vary by infectiousness, frequency of contact, or duration of disease. We used a compartmental model to project the progression of MDR-TB epidemics in South Africa and Vietnam under alternative assumptions about the relative transmission efficiency of MDR-TB. Specifically, we considered three scenarios: consistently lower transmission efficiency for MDR-TB than for DS-TB; equal transmission efficiency; and an initial deficit in the transmission efficiency of MDR-TB that closes over time. We calibrated these scenarios with data from drug resistance surveys and projected epidemic trends to 2040. The incidence of MDR-TB was projected to expand in most scenarios, but the degree of expansion depended greatly on the future transmission efficiency of MDR-TB. For example, by 2040, we projected absolute MDR-TB incidence to account for 5% (IQR: 4–9%) of incident TB in South Africa and 14% (IQR: 9–26%) in Vietnam assuming consistently lower MDR-TB transmission efficiency, versus 15% (IQR: 8–27%)and 41% (IQR: 23–62%), respectively, assuming shrinking transmission efficiency deficits. Given future uncertainty, specific responses to halt MDR-TB transmission should be prioritized.

Treatment of Drug-Resistant Tuberculosis. An Official ATS/CDC/ERS/IDSA Clinical Practice Guideline

Background: The American Thoracic Society, U.S. Centers for Disease Control and Prevention, European Respiratory Society, and Infectious Diseases Society of America jointly sponsored this new practice guideline on the treatment of drug-resistant tuberculosis (DR-TB). The document includes recommendations on the treatment of multidrug-resistant TB (MDR-TB) as well as isoniazid-resistant but rifampin-susceptible TB.Methods: Published systematic reviews, meta-analyses, and a new individual patient data meta-analysis from 12,030 patients, in 50 studies, across 25 countries with confirmed pulmonary rifampin-resistant TB were used for this guideline. Meta-analytic approaches included propensity score matching to reduce confounding. Each recommendation was discussed by an expert committee, screened for conflicts of interest, according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology.Results: Twenty-one Population, Intervention, Comparator, and Outcomes questions were addressed, generating 25 GRADE-based recommendations. Certainty in the evidence was judged to be very low, because the data came from observational studies with significant loss to follow-up and imbalance in background regimens between comparator groups. Good practices in the management of MDR-TB are described. On the basis of the evidence review, a clinical strategy tool for building a treatment regimen for MDR-TB is also provided.Conclusions: New recommendations are made for the choice and number of drugs in a regimen, the duration of intensive and continuation phases, and the role of injectable drugs for MDR-TB. On the basis of these recommendations, an effective all-oral regimen for MDR-TB can be assembled. Recommendations are also provided on the role of surgery in treatment of MDR-TB and for treatment of contacts exposed to MDR-TB and treatment of isoniazid-resistant TB.