Pre-extensively Drug-Resistant Congenital Tuberculosis in an Extremely Premature Baby

We describe a case of congenital tuberculosis in an extremely premature baby, with rapid molecular detection of a pre-extensively drug-resistant (XDR) pattern of drug resistance. The baby was treated successfully with a regimen including bedaquline and delamanid, drugs not previously described in the treatment of congenital tuberculosis (TB).

Rapid artefact removal and H&E-stained tissue segmentation

We present an innovative method for rapidly segmenting haematoxylin and eosin (H&E)-stained tissue in whole-slide images (WSIs) that eliminates a wide range of undesirable artefacts such as pen marks and scanning artefacts. Our method involves taking a single-channel representation of a low-magnification RGB overview of the WSI in which the pixel values are bimodally distributed such that H&E-stained tissue is easily distinguished from both background and a wide variety of artefacts. We demonstrate our method on 30 WSIs prepared from a wide range of institutions and WSI digital scanners, each containing substantial artefacts, and compare it to segmentations provided by Otsu thresholding and Histolab tissue segmentation and pen filtering tools. We found that our method segmented the tissue and fully removed all artefacts in 29 out of 30 WSIs, whereas Otsu thresholding failed to remove any artefacts, and the Histolab pen filtering tools only partially removed the pen marks. The beauty of our approach lies in its simplicity: manipulating RGB colour space and using Otsu thresholding allows for the segmentation of H&E-stained tissue and the rapid removal of artefacts without the need for machine learning or parameter tuning.

The APPRISE Virtual Biobank for Infectious Diseases

The Australian Partnership for Preparedness Research on InfectiouS disease Emergencies (APPRISE) has developed a virtual biobank to support infectious disease research in Australia. The virtual biobank (https://apprise.biogrid.org.au) integrates access to existing distributed infectious disease biospecimen collections comprising multiple specimen types, including plasma, serum, and peripheral blood mononuclear cells. Through the development of a common data model, multiple collections can be searched simultaneously via a secure web portal. The portal enhances the visibility and searchability of existing collections within their current governance and custodianship arrangements. The portal is easily scalable for integration of additional collections.

Long-term outcomes of the global tuberculosis and COVID-19 co-infection cohort

BACKGROUND

Longitudinal cohort data of patients with tuberculosis (TB) and coronavirus disease 2019 (COVID-19) are lacking. In our global study, we describe long-term outcomes of patients affected by TB and COVID-19.

METHODS

We collected data from 174 centres in 31 countries on all patients affected by COVID-19 and TB between 1 March 2020 and 30 September 2022. Patients were followed-up until cure, death or end of cohort time. All patients had TB and COVID-19; for analysis purposes, deaths were attributed to TB, COVID-19 or both. Survival analysis was performed using Cox proportional risk-regression models, and the log-rank test was used to compare survival and mortality attributed to TB, COVID-19 or both.

RESULTS

Overall, 788 patients with COVID-19 and TB (active or sequelae) were recruited from 31 countries, and 10.8% (n=85) died during the observation period. Survival was significantly lower among patients whose death was attributed to TB and COVID-19 versus those dying because of either TB or COVID-19 alone (p<0.001). Significant adjusted risk factors for TB mortality were higher age (hazard ratio (HR) 1.05, 95% CI 1.03-1.07), HIV infection (HR 2.29, 95% CI 1.02-5.16) and invasive ventilation (HR 4.28, 95% CI 2.34-7.83). For COVID-19 mortality, the adjusted risks were higher age (HR 1.03, 95% CI 1.02-1.04), male sex (HR 2.21, 95% CI 1.24-3.91), oxygen requirement (HR 7.93, 95% CI 3.44-18.26) and invasive ventilation (HR 2.19, 95% CI 1.36-3.53).

CONCLUSIONS

In our global cohort, death was the outcome in >10% of patients with TB and COVID-19. A range of demographic and clinical predictors are associated with adverse outcomes.

Stain normalization gives greater generalizability than stain jittering in neural network training for the classification of coeliac disease in duodenal biopsy whole slide images

Around 1% of the population of the UK and North America have a diagnosis of coeliac disease (CD), due to a damaging immune response to the small intestine. Assessing whether a patient has CD relies primarily on the examination of a duodenal biopsy, an unavoidably subjective process with poor inter-observer concordance. Wei et al. [11] developed a neural network-based method for diagnosing CD using a dataset of duodenal biopsy whole slide images (WSIs). As all training and validation data came from one source, there was no guarantee that their results would generalize to WSIs obtained from different scanners and laboratories. In this study, the effects of applying stain normalization and jittering to the training data were compared. We trained a deep neural network on 331 WSIs obtained with a Ventana scanner (WSIs; CD: n = 190 ; normal: n = 141 ) to classify presence of CD. In order to test the effects of stain processing when validating on WSIs scanned on varying scanners and from varying laboratories, the neural network was validated on 4 datasets: WSIs of slides scanned on a Ventana scanner (WSIs; CD: n = 48 ; normal: n = 35 ), WSIs of the same slides rescanned on a Hamamatsu scanner (WSIs; CD: n = 48 ; normal: n = 35 ), WSIs of the same slides rescanned on an Aperio scanner (WSIs; CD: n = 48 ; normal: n = 35 ), and WSIs of different slides scanned on an Aperio scanner (WSIs; CD: n = 38 ; normal: n = 37 ). Without stain processing, the F1 scores of the neural network were 0.947 , 0.619 , 0.746 , and 0.727 when validating on the Ventana validation WSIs, Hamamatsu and Aperio rescans of the Ventana validation WSIs, and Aperio WSIs from a different source respectively. With stain normalization, the performance of the neural network improved significantly with respective F1 scores 0.982 , 0.943 , 0.903 , and 0.847 . Stain jittering resulted in a better performance than stain normalization when validating on data from the same source F1 score 1.000 , but resulted in poorer performance than stain normalization when validating on WSIs from different scanners (F1 scores 0.939 , 0.814 , and 0.747 ). This study shows the importance of stain processing, in particular stain normalization, when training machine learning models on duodenal biopsy WSIs to ensure generalizability between different scanners and laboratories.

Impact of COVID-19 on diagnosis of TB, MDR-TB and on mortality in 11 countries in Europe, Northern America and Australia. A Global Tuberculosis Network study

OBJECTIVE

Although evidence is growing on the overall impact of the COVID-19 pandemic on tuberculosis (TB) services, global studies based on national data are needed to better quantify the extent of the impact and the countries' preparedness to tackle the two diseases. The aim of this study was to compare the number of people with new diagnosis or recurrence of TB disease, the number of drug-resistant (DR)-TB, and the number of TB deaths in 2020 versus 2019 in 11 countries in Europe, Northern America and Australia.

METHODS

TB managers or directors of national reference centres of the selected countries provided the agreed-upon variables through a validated questionnaire on a monthly basis. A descriptive analysis compared incidence of TB and drug-resistant TB and mortality of the pre-COVID-19 year (2019) versus the first year of the COVID-19 pandemic (2020).

RESULTS

Comparing 2020 vs 2019, lower number of TB cases (new diagnosis or recurrence) was notified in all countries (except USA-Virginia and Australia), and less DR-TB notifications (apart from France, Portugal and Spain). The deaths among TB cases were higher in 2020 compared to 2019 in most countries with three countries (France, Netherlands, USA-Virginia) reporting minimal TB-related mortality.

What Makes People With Chronic Illnesses Discontinue Treatment? A Practice Theory Informed Analysis of Adherence to Treatment among Patients With Drug-Resistant Tuberculosis in Pakistan

BACKGROUND

Non-adherence to treatment is a frequently observed phenomenon amongst those on long-term treatment for chronic illnesses. This qualitative study draws upon the tenets of 'practice theory' to reveal what shapes patients' ability to adhere to the demanding treatment for drug-resistant tuberculosis (DR-TB) at three treatment sites in Khyber-Pakhtunkhwa (KP) province of Pakistan.

METHODS

This qualitative study involved observation of service provision over a period of nine months of stay at, and embedment within the three treatment sites and in-depth interviews with 13 service providers and 22 patients who became non-adherent to their treatment.

RESULTS

Consistent with the extensive research based on the barriers and facilitator approach, both patients, and providers in our study also talked of patients' doubts about diagnosis and treatment efficacy, side-effects of drugs, economic constraints, unreliable disbursements of monetary incentive, attitude of providers and co-morbidities as reasons for non-adherence to treatment. Applying a practice theory perspective yielded more contextualised insights; inadequate help with patients' physical complaints, unempathetic responses to their queries, and failure to provide essential information, created conditions which hindered the establishment and maintenance of the 'practice' of adhering to treatment. These supply-side gaps created confusion, bred resentment, and exacerbated pre-existing distrust of public health services among patients, and ultimately drove them to disengage with the TB services and stop their treatment.

CONCLUSION

We argue that the lack of supply-side 'responsiveness' to patient needs beyond the provision of a few material inputs is what is lacking in the existing DR-TB program in Pakistan. We conclude that unless Pakistan's TB program explicitly engages with these supply side, system level gaps, patients will continue to struggle to adhere to their treatments and the TB program will continue to lose patients. Conceptually, we make a case for reimagining the act of adherence (or not) to long-term treatment as a 'Practice.'

Whole genome sequencing for tuberculosis in Victoria, Australia: A genomic implementation study from 2017 to 2020

BACKGROUND

Whole genome sequencing (WGS) is increasingly used by tuberculosis (TB) programs to monitor Mycobacterium tuberculosis (Mtb) transmission. We aimed to characterise the molecular epidemiology of TB and Mtb transmission in the low-incidence setting of Victoria, Australia, and assess the utility of WGS.

METHODS

WGS was performed on all first Mtb isolates from TB cases from 2017 to 2020. Potential clusters (≤12 single nucleotide polymorphisms [SNPs]) were investigated for epidemiological links. Transmission events in highly-related (≤5 SNPs) clusters were classified as likely or possible, based on the presence or absence of an epidemiological link, respectively. Case characteristics and transmission settings (as defined by case relationship) were summarised. Poisson regression was used to examine associations with secondary case number.

FINDINGS

Of 1844 TB cases, 1276 (69.2%) had sequenced isolates, with 182 (14.2%) in 54 highly-related clusters, 2-40 cases in size. Following investigation, 140 cases (11.0% of sequenced) were classified as resulting from likely/possible local-transmission, including 82 (6.4%) for which transmission was likely. Common identified transmission settings were social/religious (26.4%), household (22.9%) and family living in different households (7.1%), but many were uncertain (41.4%). While household transmission featured in many clusters (n = 24), clusters were generally smaller (median = 3 cases) than the fewer that included transmission in social/religious settings (n = 12, median = 7.5 cases). Sputum-smear-positivity was associated with higher secondary case numbers.

INTERPRETATION

WGS results suggest Mtb transmission commonly occurs outside the household in our low-incidence setting. Further work is required to optimise the use of WGS in public health management of TB.

FUNDING

The Victorian Tuberculosis Program receives block funding for activities including case management and contact tracing from the Victorian Department of Health. No specific funding for this report was received by manuscript authors or the Victorian Tuberculosis Program, and the funders had no role in the study design, data collection, data analysis, interpretation or report writing.

Multiple-instance-learning-based detection of coeliac disease in histological whole-slide images

We present a multiple-instance-learning-based scheme for detecting coeliac disease, an autoimmune disorder affecting the intestine, in histological whole-slide images (WSIs) of duodenal biopsies. We train our model to detect 2 distinct classes, normal tissue and coeliac disease, on the patch-level, and in turn leverage slide-level classifications. Using 5-fold cross-validation in a training set of 1841 (1163 normal; 680 coeliac disease) WSIs, our model classifies slides as normal with accuracy (96.7±0.6)%, precision (98.0±1.7)%, and recall (96.8±2.5)%, and as coeliac disease with accuracy (96.7±0.5)%, precision (94.9±3.7)%, and recall (96.5±2.9)% where the error bars are the cross-validation standard deviation. We apply our model to 2 test sets: one containing 191 WSIs (126 normal; 65 coeliac) from the same sources as the training data, and another from a completely independent source, containing 34 WSIs (17 normal; 17 coeliac), obtained with a scanner model not represented in the training data. Using the same-source test data, our model classifies slides as normal with accuracy 96.5%, precision 98.4% and recall 96.1%, and positive for coeliac disease with accuracy 96.5%, precision 93.5%, and recall 97.3%. Using the different-source test data the model classifies slides as normal with accuracy 94.1% (32/34), precision 89.5%, and recall 100%, and as positive for coeliac disease with accuracy 94.1%, precision 100%, and recall 88.2%. We discuss generalising our approach to screen for a range of pathologies.

Clinical standards for drug-susceptible pulmonary TB

BACKGROUND: The aim of these clinical standards is to provide guidance on 'best practice´ for diagnosis, treatment and management of drug-susceptible pulmonary TB (PTB).METHODS: A panel of 54 global experts in the field of TB care, public health, microbiology, and pharmacology were identified; 46 participated in a Delphi process. A 5-point Likert scale was used to score draft standards. The final document represents the broad consensus and was approved by all 46 participants.RESULTS: Seven clinical standards were defined: Standard 1, all patients (adult or child) who have symptoms and signs compatible with PTB should undergo investigations to reach a diagnosis; Standard 2, adequate bacteriological tests should be conducted to exclude drug-resistant TB; Standard 3, an appropriate regimen recommended by WHO and national guidelines for the treatment of PTB should be identified; Standard 4, health education and counselling should be provided for each patient starting treatment; Standard 5, treatment monitoring should be conducted to assess adherence, follow patient progress, identify and manage adverse events, and detect development of resistance; Standard 6, a recommended series of patient examinations should be performed at the end of treatment; Standard 7, necessary public health actions should be conducted for each patient. We also identified priorities for future research into PTB.CONCLUSION: These consensus-based clinical standards will help to improve patient care by guiding clinicians and programme managers in planning and implementation of locally appropriate measures for optimal person-centred treatment for PTB.

Integrated immune networks in SARS-CoV-2 infected pregnant women reveal differential NK cell and unconventional T cell activation

Although pregnancy poses a greater risk for severe COVID-19, the underlying immunological changes associated with SARS-CoV-2 infection during pregnancy are poorly understood. We defined immune responses to SARS-CoV-2 in pregnant and non-pregnant women during acute and convalescent COVID-19 up to 258 days post symptom onset, quantifying 217 immunological parameters. Additionally, matched maternal and cord blood were collected from COVID-19 convalescent pregnancies. Although serological responses to SARS-CoV-2 were similar in pregnant and non-pregnant women, cellular immune analyses revealed marked differences in key NK cell and unconventional T cell responses during COVID-19 in pregnant women. While NK cells, γδ T cells and MAIT cells displayed pre-activated phenotypes in healthy pregnant women when compared to non-pregnant age-matched women, activation profiles of these pre-activated NK and unconventional T cells remained unchanged at acute and convalescent COVID-19 in pregnancy. Conversely, activation dynamics of NK and unconventional T cells were prototypical in non-pregnant women in COVID-19. In contrast, activation of αβ CD4+ and CD8+ T cells, T follicular helper cells and antibody-secreting cells was similar in pregnant and non-pregnant women with COVID-19. Elevated levels of IL-1β, IFN-γ, IL-8, IL-18 and IL-33 were also found in pregnant women in their healthy state, and these cytokine levels remained elevated during acute and convalescent COVID-19. Collectively, our study provides key insight to innate T cell and NK cell perturbations occurring in pregnant women with COVID-19, which will potentially inform patient management and education for those with COVID-19 during pregnancy.

Supported by National Health and Medical Research Council, Australia

Risk factors for TB in Australia and their association with delayed treatment completion

BACKGROUND: Australia has a low incidence of TB and has committed to eliminating the disease. Identification of risk factors associated with TB is critical to achieving this goal.METHODS: We undertook a prospective cohort study involving persons receiving TB treatment in four Australian jurisdictions. Risk factors and their association with delayed treatment completion (treatment delayed by at least 1 month) were analysed using univariate analyses and multivariate logistic regression.RESULTS: Baseline surveys were completed for 402 persons with TB. Most (86.1%) were born overseas. Exposure to a person with TB was reported by 19.4%. Diabetes mellitus (10.2%), homelessness (9.2%), cigarette smoking (8.7%), excess alcohol consumption (6.0%) and mental illness (6.2%) were other common risk factors. At follow-up, 24.8% of patients had delayed treatment completion, which was associated with adverse events (34.1%, aOR 6.67, 95% CI 3.36-13.27), excess alcohol consumption (6.0%, aOR 21.94, 95% CI 6.03-79.85) and HIV co-infection (2.7%, aOR 8.10, 95% CI 1.16-56.60).CONCLUSIONS: We identified risk factors for TB and their association with delayed treatment completion, not all of which are routinely collected for surveillance purposes. Recognition of these risk factors should facilitate patient-centred care and assist Australia in reaching TB elimination.

Country-specific lockdown measures in response to the COVID-19 pandemic and its impact on tuberculosis control: a global study

The objective of this study was to describe country-specific lockdown measures and tuberculosis indicators collected during the first year of the COVID-19 pandemic. Data on lockdown/social restrictions (compulsory face masks and hand hygiene; international and local travel restrictions; restrictions to family visits, and school closures) were collected from 24 countries spanning five continents. The majority of the countries implemented multiple lockdowns with partial or full reopening. There was an overall decrease in active tuberculosis, drug-resistant tuberculosis, and latent tuberculosis cases. Although national lockdowns were effective in containing COVID-19 cases, several indicators of tuberculosis were affected during the pandemic.

Screening for Tuberculosis in Migrants: A Survey by the Global Tuberculosis Network

Tuberculosis (TB) does not respect borders, and migration confounds global TB control and elimination. Systematic screening of immigrants from TB high burden settings and-to a lesser degree TB infection (TBI)-is recommended in most countries with a low incidence of TB. The aim of the study was to evaluate the views of a diverse group of international health professionals on TB management among migrants. Participants expressed their level of agreement using a six-point Likert scale with different statements in an online survey available in English, French, Mandarin, Spanish, Portuguese and Russian. The survey consisted of eight sections, covering TB and TBI screening and treatment in migrants. A total of 1055 respondents from 80 countries and territories participated between November 2019 and April 2020. The largest professional groups were pulmonologists (16.8%), other clinicians (30.4%), and nurses (11.8%). Participants generally supported infection control and TB surveillance established practices (administrative interventions, personal protection, etc.), while they disagreed on how to diagnose and manage both TB and TBI, particularly on which TBI regimens to use and when patients should be hospitalised. The results of this first knowledge, attitude and practice study on TB screening and treatment in migrants will inform public health policy and educational resources.

Receiving healthcare for drug-resistant TB: a cross-sectional survey from Pakistan

OBJECTIVE

To describe and quantify patients' self-reported experiences of receiving healthcare from Pakistan's Programmatic Management of Drug-Resistant Tuberculosis (PMDT) model of care, and to understand these experiences within the broader context of Pakistan's health system.

METHOD

This was a cross-sectional survey of patients attending three PMDT clinics in Khyber-Pakhtunkhwa Province in Pakistan.

RESULTS

The median consultation time at the PMDT clinics was 10 minutes. In their most recent visit to the PMDT clinic, 34.9% of patients spent >40% of their monthly income to access treatment. To specify, 71% of patients reported spending out-of-pocket for ancillary medicines and 44.7% for laboratory tests. In 10.5% of cases, medicines for drug-resistant TB (DR-TB) were dispensed without the patient attending the clinic. Only 43.7% of treatment supporters regularly accompanied patients to the clinic, and 6% supervised the patient's intake of medicines. Disbursement of financial support was irregular in 98.6% of cases. Only 6.2% of patients received their daily injections from a public facility, the rest went elsewhere.

CONCLUSION

Several shortcomings in PMDT services, including hurried consultations, irregularities in financial support, and gaps in Pakistan's broader health system undermined healthcare experience of patients with DR-TB. To improve health outcomes and patients' care experience these service gaps need to be addressed.

Gauging the impact of the COVID-19 pandemic on tuberculosis services: a global study

The effects of the coronavirus disease 2019 (COVID-19) pandemic on tuberculosis (TB) disease and TB services emerged in the beginning of 2020 [1, 2]. Epidemiological and clinical studies, including mortality rates of the first cohort of patients with COVID-19 and TB co-infection were described [3, 4]. Several reports from individual countries suggested that the COVID-19 pandemic significantly affected TB services [5–9], including validation by modelling studies [10]. The Global Tuberculosis Network (GTN) reported that the COVID-19 pandemic affected TB services in 33 TB centres from 16 countries in the first 4 months of 2020 [11]. An increased use of telehealth during the COVID-19 pandemic was observed in some TB centres [11]. The major limitations of that study were the short period of observation (January to April 2020 compared to the same period in 2019) and the limited number of variables analysed [11–14].

This global study of 43 TB centres from 19 countries demonstrates the impact of COVID-19 pandemic on TB services. Newly diagnosed TB disease, drug-resistant TB, TB deaths, outpatient clinic attendances and newly diagnosed TB infection were reduced.https://bit.ly/3sdHbfk

BCG vaccination: An update on current Australian practices

BACKGROUND

The Bacille Calmette-Guérin (BCG) vaccine is primarily used to prevent tuberculosis (TB) infection and disease in settings with high TB incidence.

OBJECTIVE

The aim of this review article is to describe the current uses of BCG vaccination in Australia, including the indications and contraindications, efficacy and other off-target effects, and the role of the general practitioner.

DISCUSSION

BCG vaccination in Australia is primarily used to prevent TB in neonates and children with a high risk of TB exposure. The BCG vaccine is most effective at preventing severe disseminated TB disease in young children and has variable efficacy in preventing adult disease. The BCG vaccine is usually well tolerated; however, given the small risk of adverse effects, vaccination should be undertaken by a practitioner experienced in its administration. When indicated, the BCG vaccine is available from specialist TB or travel medicine centres.

WHO ethics guidance on TB care and migration: challenges to the implementation process

We summarise the current ethical guidance on tuberculosis (TB) care and migration, as set out in the WHO "Ethics Guidance for the Implementation of the End TB Strategy." Among other aspects, the Ethics Guidance states that there should be firm legal principles in place that ensure the enforcement of migration law on the one hand and the protection of human rights, including the right to health, on the other are separated from one another. As a challenge to the Ethics Guidance and its implementation, we describe two cases, each of which typifies particular problems. Case one describes the experience of a migrant worker in the United Arab Emirates who is deported when mandatory medical exams show evidence of current or prior TB. Case two raises the issue of providing more than TB care, which may also be needed for holistic care. The paper concludes with our suggestions for ways in which we could make progress towards ethically optimal TB care for migrants.

High-degeneracy Potts coarsening

I examine the fate of a kinetic Potts ferromagnet with a high ground-state degeneracy that undergoes a deep quench to zero temperature. I consider single spin-flip dynamics on triangular lattices of linear dimension 8≤L≤128 and set the number of spin states q equal to the number of lattice sites L×L. The ground state is the most abundant final state, and is reached with probability ≈0.71. Three-hexagon states occur with probability ≈0.26, and hexagonal tessellations with more than three clusters form with probabilities of O(10^{-3}) or less. Spanning stripe states-where the domain walls run along one of the three lattice directions-appear with probability ≈0.03. "Blinker" configurations, which contain perpetually flippable spins, also emerge, but with a probability that is vanishingly small with the system size.

Worldwide Effects of Coronavirus Disease Pandemic on Tuberculosis Services, January-April 2020

Coronavirus disease has disrupted tuberculosis services globally. Data from 33 centers in 16 countries on 5 continents showed that attendance at tuberculosis centers was lower during the first 4 months of the pandemic in 2020 than for the same period in 2019. Resources are needed to ensure tuberculosis care continuity during the pandemic.

Tuberculosis notifications in Australia, 2015-2018

Abstract

In 2018, the National Notifiable Diseases Surveillance System received 1,438 tuberculosis (TB) notifications, representing a rate of 5.8 per 100,000 population, consistent with the preceding three years. Australia has achieved and maintained good tuberculosis (TB) control since the mid-1980s, sustaining a low annual TB incidence rate of approximately five to six cases per 100,000 population. The number of multi-drug-resistant TB (MDR-TB) cases diagnosed in Australia is low by international standards, with approximately 2% of TB notifications per year classified as MDR-TB. Australia's overseas-born population continue to represent the majority of TB notifications (between 86% to 89% across the four reporting years) and the Aboriginal and Torres Strait Islander population continues to record TB rates around four to five times higher than the Australian-born Non-Indigenous population. Whilst Australia has achieved and maintained excellent control of TB in Australia, sustained effort is required to reduce local rates further, especially among Aboriginal and Torres Strait Islander populations, and to contribute to the achievement of the World Health Organization's goal to end the global TB epidemic by 2035.

Latent tuberculosis in the general practice context

BACKGROUND

Latent tuberculosis infection (LTBI) is an asymptomatic condition that may progress to active tuberculosis (TB), sometimes decades after exposure. Most people with active TB in Australia have not had recent contact and have been unaware of their risk. Tests for LTBI are available, allowing for diagnosis and preventive therapy to avoid active disease.

OBJECTIVE

The aim of this article is to review current approaches to the diagnosis and management of LTBI, with particular focus on the Australian general practice setting. Groups at elevated risk of having LTBI and progressing to active disease are outlined. Recent research into the prevalence and distribution of LTBI in Australia is reviewed, and Australian guidelines for testing and treatment are summarised.

DISCUSSION

LTBI occurs in an estimated 5% of all Australian residents. However, this is a particular issue for those born in TB-endemic countries. Approximately 17% of all overseas-born Australian residents, but only 0.4% of Australian-born residents, have LTBI. Appropriate diagnosis and management is an important long-term health promotion activity, and many people with LTBI can be managed safely and effectively in Australian general practice settings.

Perspectives of Vietnamese, Sudanese and South Sudanese immigrants on targeting migrant communities for latent tuberculosis screening and treatment in low-incidence settings: A report on two Victorian community panels

Background

Tuberculosis (TB) elimination strategies in Australia require a focus on groups who are at highest risk of TB infection, such as immigrants from high‐burden settings. Understanding attitudes to different strategies for latent TB infection (LTBI) screening and treatment is an important element of justifiable elimination strategies.

Method

Two community panels were conducted in Melbourne with members of the Vietnamese (n = 11), Sudanese and South Sudanese communities (n = 9). Panellists were provided with expert information about LTBI and different screening and health communication strategies, then deliberated on how best to pursue TB elimination in Australia.

Findings

Both panels unanimously preferred LTBI screening to occur pre‐migration rather than in Australia. Participants were concerned that post‐migration screening would reach fewer migrants, noted that conducting LTBI screening in Australia could stigmatize participants and that poor awareness of LTBI would hamper participation. If targeted screening was to occur in Australia, the Vietnamese panel preferred ‘place‐based’ communication strategies, whereas the Sudanese and South Sudanese panel emphasized that community leaders should lead communication strategies to minimize stigma. Both groups emphasized the importance of maintaining community trust in Australian health service providers, and the need to ensure targeting did not undermine this trust.

Conclusion

Pre‐migration screening was preferred. If post‐migration screening is necessary, the potential for stigma should be reduced, benefit and risk profile clearly explained and culturally appropriate communication strategies employed. Cultural attitudes to health providers, personal health management and broader social vulnerabilities of targeted groups need to be considered in the design of screening programs.

Tools to implement the World Health Organization End TB Strategy: Addressing common challenges in high and low endemic countries

AIM

The purpose of this viewpoint is to summarize the advantages and constraints of the tools and strategies available for reducing the annual incidence of tuberculosis (TB) by implementing the World Health Organization (WHO) End TB Strategy and the linked WHO TB Elimination Framework, with special reference to Oman.

METHODS

The case-study was built based on the presentations and discussions at an international workshop on TB elimination in low incidence countries organized by the Ministry of Health, Oman, which took place from September 5 to September 7, 2019, and supported by the WHO and European Society of Clinical Microbiology and Infectious Diseases (ESCMID).

RESULTS

Existing tools were reviewed, including the screening of migrants for latent TB infection (LTBI) with interferon-gamma release assays, clinical examination for active pulmonary TB (APTB) including chest X-rays, organization of laboratory services, and the existing centres for mandatory health examination of pre-arrival or arriving migrants, including examination for APTB. The need for public-private partnerships to handle the burden of screening arriving migrants for active TB was discussed at length and different models for financing were reviewed.

CONCLUSIONS

In a country with a high proportion of migrants from high endemic countries, screening for LTBI is of high priority. Molecular typing and the development of public-private partnerships are needed.

Surveillance of adverse events in the treatment of drug-resistant tuberculosis: first global report

The World Health Organization (WHO) recommends that countries implement pharmacovigilance and collect information on active drug safety monitoring (aDSM) and management of adverse events.The aim of this prospective study was to evaluate the frequency and severity of adverse events to anti-tuberculosis (TB) drugs in a cohort of consecutive TB patients treated with new (i.e. bedaquiline, delamanid) and repurposed (i.e. clofazimine, linezolid) drugs, based on the WHO aDSM project. Adverse events were collected prospectively after attribution to a specific drug together with demographic, bacteriological, radiological and clinical information at diagnosis and during therapy. This interim analysis included patients who completed or were still on treatment at time of data collection.Globally, 45 centres from 26 countries/regions reported 658 patients (68.7% male, 4.4% HIV co-infected) treated as follows: 87.7% with bedaquiline, 18.4% with delamanid (6.1% with both), 81.5% with linezolid and 32.4% with clofazimine. Overall, 504 adverse event episodes were reported: 447 (88.7%) were classified as minor (grade 1-2) and 57 (11.3%) as serious (grade 3-5). The majority of the 57 serious adverse events reported by 55 patients (51 out of 57, 89.5%) ultimately resolved. Among patients reporting serious adverse events, some drugs held responsible were discontinued: bedaquiline in 0.35% (two out of 577), delamanid in 0.8% (one out of 121), linezolid in 1.9% (10 out of 536) and clofazimine in 1.4% (three out of 213) of patients. Serious adverse events were reported in 6.9% (nine out of 131) of patients treated with amikacin, 0.4% (one out of 221) with ethionamide/prothionamide, 2.8% (15 out of 536) with linezolid and 1.8% (eight out of 498) with cycloserine/terizidone.The aDSM study provided valuable information, but implementation needs scaling-up to support patient-centred care.

Ending TB in Australia: Organizational challenges for regional tuberculosis programs

The World Health Organization's End TB Strategy aims to eliminate tuberculosis (TB) by 2050. Low-burden countries such as Australia are targeted for early elimination (2035), which will require an increase in the intensity and scope of case finding and treatment of people with latent TB infection (LTBI). Because 80 % of TB disease in Australia occurs in metropolitan Sydney (New South Wales) and Melbourne (Victoria), the commitment to move towards elimination has major implications for TB programs in these jurisdictions. We report on a case study analysis that compares and contrasts key attributes of each of these healthcare organizations. Such analysis has important implications for all countries seeking to implement international agreements within local health structures. Differences in the organizational structure, culture and systems of care in NSW and Victoria may facilitate or create barriers to changes in organizational system functions, especially the way in which TB prevention and LTBI treatment is delivered. Ratification of global health treaties and the development of national strategies, alone, is insufficient for realizing the promised outcomes. Even in high income countries, global health agendas such as TB elimination can be complicated by differences in local system structure and funding. As the timelines tighten towards 2035, more work must be done to identify the organizational conditions and service models that will facilitate progress towards TB elimination.

Topology-controlled Potts coarsening

We uncover unusual topological features in the long-time relaxation of the q-state kinetic Potts ferromagnet on the triangular lattice that is instantaneously quenched to zero temperature from a zero-magnetization initial state. For q=3, the final state is either the ground state (frequency ≈0.75), a frozen three-hexagon state (frequency ≈0.16), a two-stripe state (frequency ≈0.09), or a three-stripe state (frequency <2×10^{-4}). Other final state topologies, such as states with more than three hexagons, occur with probability 10^{-5} or smaller, for q=3. The relaxation to the frozen three-hexagon state is governed by a time that scales as L^{2}lnL. We provide a heuristic argument for this anomalous scaling and present additional new features of Potts coarsening on the triangular lattice for q=3 and for q>3.

Multidrug-resistant tuberculosis in Australia, 1998-2012

OBJECTIVE

To describe the epidemiology and outcomes of multidrug-resistant tuberculosis (MDR-TB) diagnosed in Australia between 1998 and 2012.

DESIGN

A retrospective review was undertaken involving all patients with laboratory-confirmed MDR-TB notified in Australia between 1998 and 2012 inclusive. Demographic, clinical and laboratory features are described. Clinical outcomes were defined according to World Health Organization definitions of treatment success (cure and treatment completion), treatment failure, death, loss to follow-up (including transfer out), or not evaluated at treatment completion.

RESULTS

A total of 244 cases of MDR-TB were diagnosed in Australia during the study period, representing 1.4% of all TB cases notified. The majority were born outside Australia, including one third in Papua New Guinea. Of those with treatment outcome data available, treatment success was demonstrated in 81%. Treatment success was positively associated with use of a second-line injectable agent. Those born in Papua New Guinea were less likely to achieve treatment success.

CONCLUSION

MDR-TB is uncommon in Australia. The large number of cases born in Papua New Guinea, and the poorer outcomes in this cohort, represent challenges with cross-border management of MDR-TB in the Torres Strait. Australia has an ongoing role in the prevention and management of MDR-TB locally and in the region.

Surveillance of adverse events in the treatment of drug-resistant tuberculosis: A global feasibility study

The World Health Organization launched a global initiative, known as aDSM (active TB drug safety monitoring and management) to better describe the safety profile of new treatment regimens for drug-resistant tuberculosis (TB) in real-world settings. However, comprehensive surveillance is difficult to implement in several countries. The aim of the aDSM project is to demonstrate the feasibility of implementing national aDSM registers and to describe the type and the frequency of adverse events (AEs) associated with exposure to the new anti-TB drugs. Following a pilot study carried out in 2016, official involvement of TB reference centres/countries into the project was sought and cases treated with bedaquiline- and/or delamanid-containing regimens were consecutively recruited. AEs were prospectively collected ensuring potential attribution of the AE to a specific drug based on its known safety profile. A total of 309 cases were fully reported from 41 centres in 27 countries (65% males; 268 treated with bedaquiline, 20 with delamanid, and 21 with both drugs) out of an estimated 781 cases the participating countries had committed to report by the first quarter of 2019.

High Prevalence of Non-Communicable Disease Risk Factors among Adolescents in Pohnpei, Micronesia

Non-communicable disease (NCD) related behaviors among adolescents are on the rise globally and in the Pacific region. To better understand and elucidate the prevalence of NCD risk factors among adolescents in Pohnpei state, Federated States of Micronesia, a cross-sectional study was conducted among secondary school students. Of 2965 students enrolled in the 2015-2016 academic year, 2555 (86.2%) completed the survey, and 2386 (80.5%) were included in the final analysis. Of the survey respondents, 21.7% of students self-reported smoking tobacco in the past 30 days, 30.3% self-reported drinking alcohol in the past 30 days, 40.9% self-reported chewing betel nut in the past 30 days, and 21.2% self-reported chewing tobacco with or without betel nut in the last 30 days. Male students, older students, and public school students had higher prevalence of substance use. Additionally, about 17.3% of students were overweight and 10.1% were obese according to physical measures of height and weight. Female students and private school students had higher prevalence of overweight and obesity than male students, and prevalence of overweight was higher in older age groups. These findings indicate a cohort of adolescents at substantial risk for the development of NCDs and signal an urgent need for public health interventions to address NCD risk factors.

Trends in Tuberculosis Incidence in the Australian-Born in Victoria: Opportunities and Challenges to Elimination

Australia is a low tuberculosis incidence country. In the setting of increasing migration, we aimed to investigate the epidemiology and trends of tuberculosis in the Australian-born population in the state of Victoria between 1992 and 2017. We performed a retrospective descriptive analysis of demographic, clinical and outcome data extracted from a centralized notifiable disease database. The mean incidence of tuberculosis was 1.19 cases per 100,000 population per year with a small but significant reduction of 0.98% per year. The median age of cases decreased from 67.5 years in 1994 to 17 years in 2017. Among 0–14 year-olds, there was an increase from 0.13 cases per 100,000 population in 1996 to 2.15 per 100,000 population in 2017. Data for risk factors were available from 2002 onwards. The most common risk factor in the 0–14 year age group was a household contact with tuberculosis (85.1%), followed by having a parent from a high tuberculosis incidence country (70.2%). We found the rate of tuberculosis in the Australian-born population in Victoria is low. However, there has been an increase in incidence in children, particularly among those with links to countries with high tuberculosis incidence. This could threaten progress towards tuberculosis elimination in Australia.

Cytokine biomarkers for the diagnosis of tuberculosis infection and disease in adults in a low prevalence setting

OBJECTIVE

Accurate and timely diagnosis of tuberculosis (TB) is essential to control the global pandemic. Currently available immunodiagnostic tests cannot discriminate between latent tuberculosis infection (LTBI) and active tuberculosis. This study aimed to determine whether candidate mycobacterial antigen-stimulated cytokine biomarkers can discriminate between TB-uninfected and TB-infected adults, and additionally between LTBI and active TB disease.

METHODS

193 adults were recruited, and categorised into four unambiguous diagnostic groups: microbiologically-proven active TB, LTBI, sick controls (non-TB lower respiratory tract infections) and healthy controls. Whole blood assays were used to determine mycobacterial antigen (CFP-10, ESAT-6, PPD)-stimulated cytokine (IL-1ra, IL-2, IL-10, IL-13, TNF-α, IFN-γ, IP-10 and MIP-1β) responses, measured by Luminex multiplex immunoassay.

RESULTS

The background-corrected mycobacterial antigen-stimulated cytokine responses of all eight cytokines were significantly higher in TB-infected participants compared with TB-uninfected individuals, with IL-2 showing the best performance characteristics. In addition, mycobacterial antigen-stimulated responses with IL-1ra, IL-10 and TNF-α were higher in participants with active TB compared those with LTBI, reaching statistical significance with PPD stimulation, although there was a degree of overlap between the two groups.

CONCLUSION

Mycobacterial antigen-stimulated cytokine responses may prove useful in future immunodiagnostic tests to discriminate between tuberculosis-infected and tuberculosis-uninfected individual, and potentially between LTBI and active tuberculosis.

Tuberculosis in adolescents and young adults: epidemiology and treatment outcomes in the Western Cape

SETTING

Western Cape Province, South Africa.

OBJECTIVES

To characterise tuberculosis (TB) epidemiology, disease presentation and treatment outcomes among adolescents (age 10-19 years) and young adults (age 20-24 years) in the Western Cape.

DESIGN

A retrospective, cross-sectional review of routine patient-level data from the Electronic TB Register (ETR.Net) for 2013. Site of TB disease, human immunodeficiency virus (HIV) status and TB treatment outcomes were analysed by 5-year age groups (<5, 5-9, 10-14, 15-19, 20-24 and 25 years of age). TB notification rates were calculated using census data.

RESULTS

Adolescents and young adults comprised 18.0% of all new TB notifications in 2013. The notification rate was 141 TB cases/100 000 person-years (py) among 10-14 year olds, 418/100 000 py among 15-19 year olds and 627/100 000 py among 20-24 year olds. HIV prevalence among TB patients was 10.9% in 10-14 year olds, 8.8% in 15-19 year olds and 27.2% in 20-24 year olds. Older adolescents (age 15-19 years) and young adults (age 20-24 years) with HIV co-infection had poor treatment outcomes: 15.6% discontinued treatment prematurely and 4.0% died.

CONCLUSIONS

Young people in the Western Cape suffer a substantial burden of TB, and those with TB-HIV co-infection are at high risk of treatment discontinuation.

The incidence of tuberculosis among adolescents and young adults: a global estimate

Historical data show that the risk of tuberculosis increases dramatically during adolescence, and young people face unique challenges in terms of case detection and effective treatment. However, little is known about the burden of tuberculosis among young people in the modern era. This study aimed to provide the first estimates of the global and regional incidence of tuberculosis among young people aged 10–24 years.

Using the World Health Organization (WHO) database of tuberculosis notifications for 2012, we estimated the burden of tuberculosis among young people by WHO region. Adjustments were made for incomplete age disaggregation and underreporting, using supplementary data from several countries representing diverse tuberculosis epidemics.

We estimate that 1.78 million (uncertainty interval (UI) 1.23–3.00 million) young people developed tuberculosis in 2012, accounting for 17% of all new tuberculosis cases globally. Young people in the WHO South East Asian Region (721 000, UI 473 000–1.35 million) and the WHO African Region (534 000, UI 359 000–912 000) experienced the greatest number of tuberculosis episodes.

Young people suffer a considerable burden of tuberculosis. Age-specific burden of disease estimation for this age group is complicated by incomplete age disaggregation of tuberculosis data, highlighting the importance of continued surveillance system strengthening.

Gender differences in tuberculosis diagnosis, treatment and outcomes in Victoria, Australia, 2002–2015

BACKGROUND: Gender has a significant impact on tuberculosis (TB) diagnosis and outcomes in many settings worldwide. We explored gender differences in Victoria, Australia, a low-incidence setting.METHODS: Retrospective cohort study: 2002–2015. Gender was included as an independent variable in multivariate statistical analyses assessing TB management.RESULTS: There were 2655 (54.5%) males and 2212 (45.5%) females notified (male:female ratio = 1.2:1). Among cases with pulmonary involvement, males underwent a chest X-ray or CT scan (CXR) sooner (hazard ratio [HR] 1.2, 95%CI 1.04–1.31, P = 0.010), began treatment sooner after presentation (HR 1.2, 95%CI 1.08–1.34, P = 0.001) and were more likely to have a sputum smear sample performed (OR 1.3, 95%CI 1.01–1.55, P = 0.037). Male cases with extra-pulmonary TB sought health care sooner after symptom onset (HR 1.3, 95%CI 1.03–1.58, P = 0.024) and were more likely to have an abnormal CXR (OR 1.9, 95%CI 1.54–2.32, P < 0.001). Males were more likely to die before or during treatment (OR 1.5, 95%CI 1.06–2.11, P = 0.024).CONCLUSIONS: Women experienced small delays in management compared with men, with no obvious detriment to assessment results or treatment outcomes. Differences were consistent with the hypothesis that males manifest more severe disease at presentation, which could be related to a range of biological and social factors.

How much does tuberculosis cost? An Australian healthcare perspective analysis

Tuberculosis (TB) remains a disease of high morbidity in Australia, with implications for both public health and the individual. Cost analyses is relevant for programmatic evaluation of TB. There is minimal published TB cost data in the Australian setting. Patients with drug sensitive active pulmonary TB (DS-PTB) and latent TB (LTBI) were enrolled in a single tertiary referral centre to evaluate healthcare provider costs. The median cost of treating drug susceptible pulmonary TB in this case series was 11,538 AUD. Approximately 50% of total costs is derived from inpatient hospitalisation bed days. In comparison, the average cost of managing latent TB was 582 AUD per completed course. We find the median provider cost of our DS-PTB treatment group comparable to costs from other regions globally with similar economic profiles. A program designed to detect and treat LTBI to prevent subsequent disease may be cost effective in appropriately selected patients and warrants further study.

Eliminating latent tuberculosis in low-burden settings: are the principal beneficiaries to be disadvantaged groups or the broader population?

Tuberculosis (TB) remains a leading cause of morbidity and mortality worldwide, and the burdens of this disease continue to track prior disadvantage. In order to galvanise a coordinated global response, WHO has recently launched the End TB Campaign that aims to eliminate TB by 2050. Key to this is the introduction of population screening programmes in low-burden settings to identify and treat people who have latent TB infection (LTBI). The defining features of LTBI are: that it is not an active disease but confers an increased risk of disease; the socially disadvantaged are those most in danger and uncertainty persists as to who will be harmed or benefitted from screening-led prophylactic interventions. Systematic screening programmes that include surveillance, case-finding and treatment of asymptomatic individuals inevitably redistribute the risk of harms and the potential for benefits within a population. The extent to which those targeted within such programmes should be exposed to higher levels of risk in the pursuit of individual or community benefits requires careful consideration prior to implementation. As currently construed, it remains unclear who stands to benefit most from how LTBI screening in high-income countries is being organised, and whose health is being prioritised: members of disadvantaged groups or the broader community. Unless the aims of LTBI screening programmes in these settings are made transparent and their prioritisation ethically justified, there is a significant danger that such a targeted intervention will further disadvantage those who have the least capacity to bear the burdens of TB elimination.

Effectiveness and safety of bedaquiline-containing regimens in the treatment of MDR- and XDR-TB: a multicentre study

Large studies on bedaquiline used to treat multidrug-resistant (MDR-) and extensively drug-resistant tuberculosis (XDR-TB) are lacking. This study aimed to evaluate the safety and effectiveness of bedaquiline-containing regimens in a large, retrospective, observational study conducted in 25 centres and 15 countries in five continents.428 culture-confirmed MDR-TB cases were analysed (61.5% male; 22.1% HIV-positive, 45.6% XDR-TB). MDR-TB cases were admitted to hospital for a median (interquartile range (IQR)) 179 (92-280) days and exposed to bedaquiline for 168 (86-180) days. Treatment regimens included, among others, linezolid, moxifloxacin, clofazimine and carbapenems (82.0%, 58.4%, 52.6% and 15.3% of cases, respectively).Sputum smear and culture conversion rates in MDR-TB cases were 63.6% and 30.1%, respectively at 30 days, 81.1% and 56.7%, respectively at 60 days; 85.5% and 80.5%, respectively at 90 days and 88.7% and 91.2%, respectively at the end of treatment. The median (IQR) time to smear and culture conversion was 34 (30-60) days and 60 (33-90) days. Out of 247 culture-confirmed MDR-TB cases completing treatment, 71.3% achieved success (62.4% cured; 8.9% completed treatment), 13.4% died, 7.3% defaulted and 7.7% failed. Bedaquiline was interrupted due to adverse events in 5.8% of cases. A single case died, having electrocardiographic abnormalities that were probably non-bedaquiline related.Bedaquiline-containing regimens achieved high conversion and success rates under different nonexperimental conditions.

Molecular epidemiology of tuberculosis in Victoria, Australia, reveals low level of transmission

SETTING

Victoria, Australia.

OBJECTIVE

To measure the level of Mycobacterium tuberculosis transmission in Victoria.

DESIGN

Retrospective analysis of mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing profiles from all first M. tuberculosis complex (MTC) isolates obtained from patients residing in Victoria from 2003 to 2010 was performed. State TB reference laboratory records were matched with Department of Health notification records to obtain further laboratory, demographic, contact investigation, clinical and treatment data. These data were used to assign patients to one of four categories: 1) no epidemiological link, 2) possible link, 3) likely transmission event and 4) laboratory contamination.

RESULTS

A total of 2377 MTC isolates were genotyped using 15-locus MIRU-VNTR. Of the 2298 M. tuberculosis isolates, 1029 (44.8%) had unique genotypic profiles and were considered epidemiologically unrelated, while 1269 (55.2%) isolates shared a profile with one or more other strains, defined as a genotypic cluster. Systematic investigation of all 268 genotypic clusters, including 24-locus MIRU-VNTR on selected isolates, led to a further 862 patients being classified as unrelated, bringing the total number of patients with no epidemiological links to 1891 (82.3%). Of the remaining patients, 294 (12.8%) were classified as having possible epidemiological links, 96 (4.2%) were classified as having known epidemiological links representing likely transmission events and 17 (0.7%) as the result of laboratory cross-contamination.

CONCLUSIONS

There is considerable genotypic diversity among Victorian MTC isolates, and the level of transmission is low.

Seroprotection to vaccine-preventable diseases among workers at a Victorian tertiary hospital

OBJECTIVE

To determine seroprotection for the vaccine-preventable diseases (VPDs) measles, mumps, rubella, varicella and hepatitis B among new employees seen at a Victorian tertiary hospital staff clinic.

METHODS

Employees who presented to the staff clinic for immunisation assessment between 1 January 2012 and 31 December 2013 were included. Demographic data, self-reported disease history and previous vaccination status were reviewed retrospectively to determine impact on serological results.

RESULTS

A total of 1,901 new employees were included, 83% of whom were at risk of direct contact with blood or body substances. Overall, the proportion of workers seropositive to measles was 88%, mumps 90%, rubella 78%, varicella 93% and hepatitis B 80%. Staff born before 1966 were more likely to have positive measles or mumps serology but negative rubella or hepatitis B serology (p<0.05 for each). Staff who self-reported measles (99% vs. 93%, p=0.03) or varicella infection (98% vs. 92%, p<0.001) were more likely to be seropositive, but those reporting previous vaccination to measles, mumps or rubella were no more likely to be seropositive.

CONCLUSIONS AND IMPLICATIONS

This study demonstrated levels of seropositivity of 78-93% for the five VPDs. Despite recognised limitations of serological testing, 10-20% of new employees to a healthcare institution lacking seroprotection represents a potentially unacceptable risk of nosocomial transmission of these VPDs. Our findings support ongoing serological testing of new healthcare staff at risk of direct contact with blood or body substances.