Unmasking the hidden tuberculosis mortality burden in a large post mortem study in Maputo Central Hospital, Mozambique

Child Health and Mortality Prevention Surveillance (CHAMPS): Manhiça site description, Mozambique

The Manhiça Health Research Centre (Manhiça HDSS) was established in 1996 in Manhiça, a rural district at Maputo Province in the southern part of Mozambique with approximately 49,000 inhabited households, a total population of 209.000 individuals, and an annual estimated birth cohort of about 5000 babies. Since 2016, Manhiça HDSS is implementing the Child Health and Mortality Prevention Surveillance (CHAMPS) program aiming to investigate causes of death (CoD) in stillbirths and children under the age of 5 years using an innovative post-mortem technique known as Minimally Invasive Tissue sampling (MITS), comprehensive pathogen screening using molecular methods, clinical record abstraction and verbal autopsy. Both in-hospital and community pediatric deaths are investigated using MITS. For this, community-wide socio-demographic approaches (notification of community deaths by key informants, formative research involving several segments of the community, availability of free phone lines for notification of medical emergencies and deaths, etc.) are conducted alongside to foster community awareness, involvement and adherence as well as to compute mortality estimates and collect relevant information of health and mortality determinants. The main objective of this paper is to describe the Manhiça Health and Demographic Surveillance System (HDSS) site and the CHAMPS research environment in place including the local capacities among its reference hospital, laboratories, data center and other relevant areas involved in this ambitious surveillance and research project, whose ultimate aim is to improve child survival through public health actions derived from credible estimates and understanding of the major causes of childhood mortality in Mozambique.

The epidemiology, transmission, diagnosis, and management of drug-resistant tuberculosis-lessons from the South African experience

Drug-resistant tuberculosis (DR-TB) threatens to derail tuberculosis control efforts, particularly in Africa where the disease remains out of control. The dogma that DR-TB epidemics are fueled by unchecked rates of acquired resistance in inadequately treated or non-adherent individuals is no longer valid in most high DR-TB burden settings, where community transmission is now widespread. A large burden of DR-TB in Africa remains undiagnosed due to inadequate access to diagnostic tools that simultaneously detect tuberculosis and screen for resistance. Furthermore, acquisition of drug resistance to new and repurposed drugs, for which diagnostic solutions are not yet available, presents a major challenge for the implementation of novel, all-oral, shortened (6-9 months) treatment. Structural challenges including poverty, stigma, and social distress disrupt engagement in care, promote poor treatment outcomes, and reduce the quality of life for people with DR-TB. We reflect on the lessons learnt from the South African experience in implementing state-of-the-art advances in diagnostic solutions, deploying recent innovations in pharmacotherapeutic approaches for rapid cure, understanding local transmission dynamics and implementing interventions to curtail DR-TB transmission, and in mitigating the catastrophic socioeconomic costs of DR-TB. We also highlight globally relevant and locally responsive research priorities for achieving DR-TB control in South Africa.

Uncertainty in tuberculosis clinical decision-making: An umbrella review with systematic methods and thematic analysis

Tuberculosis is a major infectious disease worldwide, but currently available diagnostics have suboptimal accuracy, particularly in patients unable to expectorate, and are often unavailable at the point-of-care in resource-limited settings. Test/treatment decision are, therefore, often made on clinical grounds. We hypothesized that contextual factors beyond disease probability may influence clinical decisions about when to test and when to treat for tuberculosis. This umbrella review aimed to identify such factors, and to develop a framework for uncertainty in tuberculosis clinical decision-making. Systematic reviews were searched in seven databases (MEDLINE, CINAHL Complete, Embase, Scopus, Cochrane, PROSPERO, Epistemonikos) using predetermined search criteria. Findings were classified as barriers and facilitators for testing or treatment decisions, and thematically analysed based on a multi-level model of uncertainty in health care. We included 27 reviews. Study designs and primary aims were heterogeneous, with seven meta-analyses and three qualitative evidence syntheses. Facilitators for decisions to test included providers' advanced professional qualification and confidence in tests results, availability of automated diagnostics with quick turnaround times. Common barriers for requesting a diagnostic test included: poor provider tuberculosis knowledge, fear of acquiring tuberculosis through respiratory sampling, scarcity of healthcare resources, and complexity of specimen collection. Facilitators for empiric treatment included patients' young age, severe sickness, and test inaccessibility. Main barriers to treatment included communication obstacles, providers' high confidence in negative test results (irrespective of negative predictive value). Multiple sources of uncertainty were identified at the patient, provider, diagnostic test, and healthcare system levels. Complex determinants of uncertainty influenced decision-making. This could result in delayed or missed diagnosis and treatment opportunities. It is important to understand the variability associated with patient-provider clinical encounters and healthcare settings, clinicians' attitudes, and experiences, as well as diagnostic test characteristics, to improve clinical practices, and allow an impactful introduction of novel diagnostics.

Infectious diseases and the role of needle biopsy post-mortem

Post-mortem examinations continue to play a crucial role in understanding the epidemiology and pathogenesis of infectious diseases. However, the perceived infection risk can preclude traditional, invasive, complete diagnostic autopsy. Post-mortem examination is especially important in emerging infectious diseases with potentially unknown infection risks, but rapid acquisition of good quality tissue samples is needed as part of the scientific and public health response. Needle biopsy post-mortem is a minimally invasive, rapid, closed-body autopsy technique that was originally developed to minimise the infection risk to practitioners. Since its inception, needle biopsy post-mortem has also been used as a technique to support complete diagnostic autopsy provision in poorly resourced regions and to facilitate post-mortem examinations in communities that might have religious or cultural objections to an invasive autopsy. This Review analyses the evolution and applicability of needle biopsy post-mortem in investigating endemic and emerging infectious diseases.

Postmortem for Intensified Missed Tuberculosis Case Finding in High Human Immunodeficiency Virus and Tuberculosis-burdened Settings in Sub-Saharan Africa among Adults' Population: Systematic Review and Meta-analysis

Tuberculosis (TB) is the leading infectious cause of mortality in sub-Saharan Africa (SSA); the high prevalence of TB in this region is due to human immunodeficiency virus (HIV)-coinfection. Despite the advent of modalities to diagnose TB, undiagnosed TB-related deaths among HIV-infected patients remain significantly high. This systematic review aims at characterizing missed TB cases from postmortem studies. This review informs on the burden of TB missed diagnosis and highlights the need of improving TB case-finding strategies, especially among the high-risk groups and early TB therapy initiation to keeping in with the World Health Organization's end TB strategy. We searched PubMed, Cochrane, Web of Science, and African journals online for studies that looked into missed TB cases following postmortem using the following key terms: postmortem, TB diagnosis, and HIV; we included cross-sectional and cohorts from 1980 in the English language that were carried out in SSA among adults' population. Authors used the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines for reporting, the quality of the included studies was assessed using the Newcastle-Ottawa Scale for observational studies, and STATA 17.0 software was used for analysis. This study was registered in the International Prospective Register of Systematic Reviews with registration number CRD42024507515. The combined prevalence of postmortem missed TB diagnosis among the 6025 participants was 27.13% (95% confidence interval [CI] =14.52-41.89), with a high level of heterogeneity at 98.65% (P < 0.001). The prevalence varied significantly across the included studies, ranging from 1.21% (95% CI = 0.93-1.59) in the general population to 66.67% (95% CI = 50.98-79.37) in people living with HIV (PLWHIV). This current literature suggests that SSA is a region with a high prevalence of missed TB cases but with significant variations between countries. In addition, this study confirms a high number of missed TB infections within the PLWHIV. These results highlight the immediate need for targeted screening and diagnosis strategies and relevant policies.

Prevalence and Clinical Characteristics of Children With Nonsevere Tuberculosis in Spain

BACKGROUND

To assess the prevalence and characteristics of nonsevere TB among children in Spain. It has been recently demonstrated that these children can be treated with a 4-month regimen instead of the classical 6-month treatment regimen, with the same effectivity and outcomes, decreasing toxicity and improving adherence.

METHODS

We conducted a retrospective cohort study in a cohort of children ≤16 years of age with TB. Nonsevere TB cases included smear-negative children with respiratory TB confined to 1 lobe, with no significant airway obstruction, no complex pleural effusion, no cavities and no signs of miliary disease, or with peripheral lymph-node disease. The remaining children were considered to have severe TB. We estimated the prevalence of nonsevere TB and compared the clinical characteristics and outcomes between children with nonsevere and severe TB.

RESULTS

A total of 780 patients were included [46.9% males, median age 5.5 years (IQR: 2.6-11.1)], 477 (61.1%) of whom had nonsevere TB. Nonsevere TB was less frequent in children <1 year (33% vs 67%; P < 0.001), and >14 years of age (35% vs 65%; P = 0.002), mostly diagnosed in contact tracing studies (60.4% vs 29.2%; P < 0.001) and more frequently asymptomatic (38.3% vs 17.7%; P < 0.001). TB confirmation in nonsevere disease was less frequent by culture (27.0% vs 57.1%; P < 0.001) and by molecular tests (18.2% vs 48.8%; P < 0.001). Sequelae were less frequent in children with nonsevere disease (1.7 vs 5.4%; P < 0.001). No child with nonsevere disease died.

CONCLUSIONS

Two-thirds of children had nonsevere TB, mostly with benign clinical presentation and negative microbiologic results. In low-burden countries, most children with TB might benefit from short-course regimens.

Initiation and adherence to isoniazid preventive therapy in children under 5 years of age in Manhiça, Southern Mozambique

The WHO recommends preventive treatment for all pediatric contacts of a confirmed TB case, but coverage remains low in many high TB burden countries. We aimed to assess the coverage and adherence of the isoniazid preventive therapy (IPT) program among children under 5 years of age with household exposure to an adult pulmonary TB case in a rural district of Southern Mozambique. The estimated IPT coverage was 11.7%. A longer distance to the health center and lower age of the children hindered IPT initiation. Among patients who started IPT, 12/18 (69.9%) were adherent to the 6-month treatment.

Tuberculosis in Children Living With HIV: Ongoing Progress and Challenges

There has been much recent progress on control of the tuberculosis (TB) and human immunodeficiency virus (HIV) epidemics globally. However, advances in children have lagged behind, and TB-HIV coinfection continues to be a major driver of pediatric mortality in many settings. This review highlights recent research findings in the areas of prevention, diagnosis, and treatment of HIV-associated childhood TB. Key areas for future research are defined. Current prevention efforts such as vaccination, TB symptom screening, and TB preventive treatment are demonstrated as beneficial but need to be optimized for children living with HIV (CLHIV). Diagnosis of HIV-associated TB in children remains a major challenge, depending heavily on clinicians' ability to judge an array of signs, symptoms, and imaging findings, but there are a growing number of promising diagnostic tools with improved accuracy and feasibility. Treatment of TB-HIV coinfection has also seen recent progress with more evidence demonstrating the safety and effectiveness of shorter regimens for treatment of TB infection and disease and improved understanding of interactions between antiretrovirals and TB medications. However, several evidence gaps on drug-drug interactions persist, especially for young children and those with drug-resistant TB. Accelerated efforts are needed in these areas to build upon current progress and reduce the burden of TB on CLHIV.

Fine-grain population structure and transmission patterns of Mycobacterium tuberculosis in southern Mozambique, a high TB/HIV burden area

Genomic studies of the Mycobacterium tuberculosis complex (MTBC) might shed light on the dynamics of its transmission, especially in high-burden settings, where recent outbreaks are embedded in the complex natural history of the disease. To this end, we conducted a 1 year prospective surveillance-based study in Mozambique. We applied whole-genome sequencing (WGS) to 295 positive cultures. We fully characterized MTBC isolates by phylogenetics and dating evaluation, and carried out a molecular epidemiology analysis to investigate further associations with pre-defined transmission risk factors. The majority of strains (49.5%, 136/275) belonged to lineage (L) 4; 57.8 % of them (159/275) were in genomic transmission clusters (cut-off 5 SNPs), and a strikingly high proportion (45.5%) shared an identical genotype (0 SNP pairwise distance). We found two ‘likely endemic’ clades, comprising 67 strains, belonging to L1.2, which dated back to the late 19th century and were associated with recent spread among people living with human immunodeficiency virus (PLHIV). We describe for the first time the population structure of MTBC in our region, a high tuberculosis (TB)/HIV burden area. Clustering analysis revealed an unforeseen pattern of spread and high rates of progression to active TB, suggesting weaknesses in TB control activities. The long-term presence of local strains in Mozambique, which were responsible for large transmission among HIV/TB-coinfected patients, calls into question the role of HIV in TB transmission.

The intersecting pandemics of tuberculosis and COVID-19: population-level and patient-level impact, clinical presentation, and corrective interventions

The global tuberculosis burden remains substantial, with more than 10 million people newly ill per year. Nevertheless, tuberculosis incidence has slowly declined over the past decade, and mortality has decreased by almost a third in tandem. This positive trend was abruptly reversed by the COVID-19 pandemic, which in many parts of the world has resulted in a substantial reduction in tuberculosis testing and case notifications, with an associated increase in mortality, taking global tuberculosis control back by roughly 10 years. Here, we consider points of intersection between the tuberculosis and COVID-19 pandemics, identifying wide-ranging approaches that could be taken to reverse the devastating effects of COVID-19 on tuberculosis control. We review the impact of COVID-19 at the population level on tuberculosis case detection, morbidity and mortality, and the patient-level impact, including susceptibility to disease, clinical presentation, diagnosis, management, and prognosis. We propose strategies to reverse or mitigate the deleterious effects of COVID-19 and restore tuberculosis services. Finally, we highlight research priorities and major challenges and controversies that need to be addressed to restore and advance the global response to tuberculosis.

Accelerating research and development of new vaccines against tuberculosis: a global roadmap

To eliminate tuberculosis globally, a new, effective, and affordable vaccine is urgently needed, particularly for use in adults and adolescents in low-income and middle-income countries. We have created a roadmap that lists the actions needed to accelerate tuberculosis vaccine research and development using a participatory process. The vaccine pipeline needs more diverse immunological approaches, antigens, and platforms. Clinical development can be accelerated by validated preclinical models, agreed laboratory correlates of protection, efficient trial designs, and validated endpoints. Determining the public health impact of new tuberculosis vaccines requires understanding of a country's demand for a new tuberculosis vaccine, how to integrate vaccine implementation with ongoing tuberculosis prevention efforts, cost, and national and global demand to stimulate vaccine production. Investments in tuberculosis vaccine research and development need to be increased, with more diversity of funding sources and coordination between these funders. Open science is important to enhance the efficiency of tuberculosis vaccine research and development including early and freely available publication of study findings and effective mechanisms for sharing datasets and specimens. There is a need for increased engagement of industry vaccine developers, for increased political commitment for new tuberculosis vaccines, and to address stigma and vaccine hesitancy. The unprecedented speed by which COVID-19 vaccines have been developed and introduced provides important insight for tuberculosis vaccine research and development.

Causes of death in HIV-infected and HIV-uninfected children aged under-five years in western Kenya

OBJECTIVES

Describe the causes of death among infants and children less than 5 years stratified by HIV status.

DESIGN

Cross-sectional analysis of causes of death ascertained through minimally invasive tissue sampling (MITS) in the Kenya Child Health and Mortality Prevention Surveillance site.

METHODS

We included decedents aged 28 days to less than 5 years, whose death was reported within 36 h, underwent MITS, and had HIV test results and causes of death determined. MITS specimens were tested using Taqman Array Cards, culture, cytology, histopathology and immunohistochemistry and HIV PCR. A panel evaluated epidemiologic, clinical, verbal autopsy and laboratory data to assign causes of death using ICD-10 guidelines. Causes of death and etiological agents were stratified by HIV status.

RESULTS

Of 176 included decedents, 14% (n = 25) were HIV-infected, median viral load was 112 205 copies/ml [interquartile range (IQR) = 9349-2 670 143). HIV-disease (96%; n = 24) and malnutrition (23%; n = 34) were the leading underlying causes of death in HIV-infected and HIV-uninfected decedents, respectively. Malnutrition was more frequent in the causal chain of HIV-infected (56%; n = 14) than HIV-uninfected decedents (31%; n = 49) (P value = 0.03). Viral pneumonia was twice as common in HIV-infected (50%; n = 9) than HIV-uninfected decedents (22%; n = 7) (P value = 0.04).

CONCLUSION

Nearly all HIV-infected decedents' underlying cause of death was HIV disease, which was associated with malnutrition. Our findings underscore the need for strengthening early identification and management of HIV-infected children. Prevention, early diagnosis and treatment of malnutrition could be instrumental in improving the survival of HIV-infected and HIV-uninfected children.

Tuberculous Meningitis in Children: A Forgotten Public Health Emergency

Tuberculous meningitis (TBM) remains a major cause of morbidity and mortality in children with tuberculosis (TB), yet there are currently no estimates of the global burden of pediatric TBM. Due to frequent non-specific clinical presentation and limited and inadequate diagnostic tests, children with TBM are often diagnosed late or die undiagnosed. Even when diagnosed and treated, 20% of children with TBM die. Of survivors, the majority have substantial neurological disability with significant negative impact on children and their families. Surveillance data on this devastating form of TB can help to quantify the contribution of TBM to the overall burden, morbidity and mortality of TB in children and the epidemiology of TB more broadly. Pediatric TBM usually occurs shortly after primary infection with Mycobacterium tuberculosis and reflects ongoing TB transmission to children. In this article we explain the public health importance of pediatric TBM, discuss the epidemiology within the context of overall TB control and health system functioning and the limitations of current surveillance strategies. We provide a clear rationale for the benefit of improved surveillance of pediatric TBM using a TB care cascade framework to support monitoring and evaluation of pediatric TB, and TB control more broadly. Considering the public health implications of a diagnosis of TBM in children, we provide recommendations to strengthen pediatric TBM surveillance and outline how improved surveillance can help us identify opportunities for prevention, earlier diagnosis and improved care to minimize the impact of TBM on children globally.

Minimally Invasive Tissue Sampling as an Alternative to Complete Diagnostic Autopsies in the Context of Epidemic Outbreaks and Pandemics: The Example of Coronavirus Disease 2019 (COVID-19)

Background

Infectious diseases’ outbreak investigation requires, by definition, conducting a thorough epidemiological assessment while simultaneously obtaining biological samples for an adequate screening of potential responsible pathogens. Complete autopsies remain the gold-standard approach for cause-of-death evaluation and characterization of emerging diseases. However, for highly transmissible infections with a significant associated lethality, such as COVID-19, complete autopsies are seldom performed due to biosafety challenges, especially in low-resource settings. Minimally invasive tissue sampling (MITS) is a validated new approach based on obtaining postmortem samples from key organs and body fluids, a procedure that does not require advanced biosafety measures or a special autopsy room.

Methods

We aimed to review the use of MITS or similar procedures for outbreak investigation up to 27 March 2021 and their performance for evaluating COVID-19 deaths.

Results

After a literature review, we analyzed in detail the results of 20 studies conducted at international sites, whereby 216 COVID-19–related deaths were investigated. MITS provided a general and more granular understanding of the pathophysiological changes secondary to the infection and high-quality samples where the extent and degree of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–related damage could be evaluated.

Conclusions

MITS is a useful addition in the investigation and surveillance of infections occurring in outbreaks or epidemics. Its less invasive nature makes the tool more acceptable and feasible and reduces the risk of procedure-associated contagion, using basic biosafety measures. Standardized approaches protocolizing which samples should be collected—and under which exact biosafety measures—are necessary to facilitate and expand its use globally.

Minimally Invasive Tissue Sampling Findings in 12 Patients With Coronavirus Disease 2019

BACKGROUND

Minimally invasive tissue sampling (MITS), a postmortem procedure that uses core needle biopsy samples and does not require opening the body, may be a valid alternative to complete autopsy (CA) in highly infectious diseases such as coronavirus disease-19 (COVID-19). This study aimed to (1) compare the performance of MITS and CA in a series of COVID-19 deaths and (2) evaluate the safety of the procedure.

METHODS

From October 2020 to February 2021, MITS was conducted in 12 adults who tested positive before death for COVID-19, in a standard, well-ventilated autopsy room, where personnel used reinforced personal protective equipment. In 9 cases, a CA was performed after MITS. A thorough histological evaluation was conducted, and the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was evaluated by real-time reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

The diagnoses provided by MITS and CA matched almost perfectly. In 9 patients, COVID-19 was in the chain of events leading to death, being responsible for diffuse alveolar damage and mononuclear T-cell inflammatory response in the lungs. No specific COVID-19 features were identified. Three deaths were not related to COVID-19. All personnel involved in MITS repeatedly tested negative for COVID-19. SARS-CoV-2 was identified by RT-PCR and immunohistochemistry in the MITS samples, particularly in the lungs.

CONCLUSIONS

MITS is useful for evaluating COVID-19-related deaths in settings where a CA is not feasible. The results of this simplified and safer technique are comparable to those of CA.

Diagnostic performance of the Abbott RealTime MTB assay for tuberculosis diagnosis in people living with HIV

Strengthening tuberculosis diagnosis is an international priority and the advocacy for multi-disease testing devices raises the possibility of improving laboratory efficiency. However, the advantages of centralized platforms might not translate into real improvements under operational conditions. This study aimed to evaluate the field use of the Abbott RealTime MTB (RT-MTB) and Xpert MTB/RIF assays, in a large cohort of HIV-positive and TB presumptive cases in Southern Mozambique. Over a 6-month period, 255 HIV-positive TB presumptive cases were consecutively recruited in the high TB/HIV burden district of Manhiça. The diagnostic performance of both assays was evaluated against two different reference standards: a microbiological gold standard (MGS) and a composite reference standard (CRS). Results from the primary analysis (MGS) showed improved sensitivity (Se) and reduced specificity (Sp) for the Abbott RT-MTB assay compared to the Xpert MTB/RIF (RT-MTB Se: 0.92 (95% CI: 0.75;0.99) vs Xpert Se: 0.73 (95% CI: 0.52;0.88) p value = 0.06; RT-MTB Sp: 0.80 (0.72;0.86) vs Xpert Sp: 0.96 (0.92;0.99) p value < 0.001). The lower specificity may be due to cross-reactivity with non-tuberculous mycobacteria (NTMs), the detection of non-viable MTBC, or the identification of true TB cases missed by the gold standard.

Performance of Xpert MTB/RIF Ultra for tuberculosis diagnosis in the context of passive and active case finding

We present a field evaluation of the diagnostic accuracy of Xpert MTB/RIF (Xpert) and Xpert MTB/RIF Ultra (Ultra), using two cohorts in a high TB/HIV burden setting in Southern Mozambique. Single respiratory specimens from symptomatic adults accessing health care services (passive case finding (PCF) cohort), and from household and community close contacts (active case finding (ACF) cohort), were tested by smear microscopy, culture, Xpert and Ultra. Liquid and solid culture served as a composite reference standard. We explored trace results' impact on specificity via their recategorisation to negative (in all and just among those previously treated individuals) A total of 1419 and 252 participants were enrolled in the PCF and ACF cohorts, respectively. For the PCF cohort, Ultra showed higher sensitivity than Xpert overall (0.95 (95% CI: 0.90, 0.98) versus 0.88 (0.82, 0.93); p<0.001) and among smear negative patients (0.63 (0.48, 0.76) and 0.84 (0.71, 0.93). Ultra's specificity was lower than Xpert's (0.98 (0.97, 0.99) versus 0.96 (0.95, 0.97); p=0.008). For ACF, sensitivities were the same (0.67 (95% CI: 0.22,0.96) for both tests), although Ultra detected a higher number of microbiologically confirmed samples than Xpert (4.7% (12/252) versus 2.7% (7/252)). Conditional recategorisation of trace results among previously treated participants maintained differences in specificity in the PCF cohort. These results add evidence on the improved sensitivity of Ultra and support its use in different case finding scenarios.

High within-host diversity found from direct genotyping on post-mortem tuberculosis specimens in a high-burden setting

OBJECTIVES

To characterize the clonal complexity in Mycobacterium tuberculosis (MTB) infections considering factors that help maximize the detection of coexisting strains/variants.

METHODS

Genotypic analysis by Mycobacterial Interspersed Repetitive-Unit-Variable-Number Tandem-Repeats (MIRU-VNTR) was performed directly on 70 biopsy specimens from two or more different tissues involving 28 tuberculosis cases diagnosed post-mortem in Mozambique, a country with a high tuberculosis burden.

RESULTS

Genotypic data from isolates collected from two or more tissues were obtained for 23 of the 28 cases (82.1%), allowing the analysis of within-patient diversity. MIRU-VNTR analysis revealed clonal diversity in ten cases (35.7%). Five cases showed allelic differences in three or more loci, suggesting mixed infection with two different strains. In half of the cases showing within-host diversity, one of the specimens associated with clonal heterogeneity was brain tissue.

CONCLUSIONS

Direct MTB genotyping from post-mortem tissue samples revealed a frequent within-host Mycobacterium tuberculosis diversity, including mixed and polyclonal infections. Most of this diversity would have been overlooked if only standard analysis of respiratory specimens had been performed.

Xpert Ultra versus Xpert MTB/RIF for pulmonary tuberculosis and rifampicin resistance in adults with presumptive pulmonary tuberculosis

BACKGROUND

Xpert MTB/RIF and Xpert MTB/RIF Ultra (Xpert Ultra) are World Health Organization (WHO)-recommended rapid tests that simultaneously detect tuberculosis and rifampicin resistance in people with signs and symptoms of tuberculosis. This review builds on our recent extensive Cochrane Review of Xpert MTB/RIF accuracy.

OBJECTIVES

To compare the diagnostic accuracy of Xpert Ultra and Xpert MTB/RIF for the detection of pulmonary tuberculosis and detection of rifampicin resistance in adults with presumptive pulmonary tuberculosis. For pulmonary tuberculosis and rifampicin resistance, we also investigated potential sources of heterogeneity. We also summarized the frequency of Xpert Ultra trace-positive results, and estimated the accuracy of Xpert Ultra after repeat testing in those with trace-positive results.

SEARCH METHODS

We searched the Cochrane Infectious Diseases Group Specialized Register, MEDLINE, Embase, Science Citation Index, Web of Science, LILACS, Scopus, the WHO ICTRP, the ISRCTN registry, and ProQuest to 28 January 2020 with no language restriction.

SELECTION CRITERIA

We included diagnostic accuracy studies using respiratory specimens in adults with presumptive pulmonary tuberculosis that directly compared the index tests. For pulmonary tuberculosis detection, the reference standards were culture and a composite reference standard. For rifampicin resistance, the reference standards were culture-based drug susceptibility testing and line probe assays.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data using a standardized form, including data by smear and HIV status. We assessed risk of bias using QUADAS-2 and QUADAS-C. We performed meta-analyses comparing pooled sensitivities and specificities, separately for pulmonary tuberculosis detection and rifampicin resistance detection, and separately by reference standard. Most analyses used a bivariate random-effects model. For tuberculosis detection, we estimated accuracy in studies in participants who were not selected based on prior microscopy testing or history of tuberculosis. We performed subgroup analyses by smear status, HIV status, and history of tuberculosis. We summarized Xpert Ultra trace results.

MAIN RESULTS

We identified nine studies (3500 participants): seven had unselected participants (2834 participants). All compared Xpert Ultra and Xpert MTB/RIF for pulmonary tuberculosis detection; seven studies used a paired comparative accuracy design, and two studies used a randomized design. Five studies compared Xpert Ultra and Xpert MTB/RIF for rifampicin resistance detection; four studies used a paired design, and one study used a randomized design. Of the nine included studies, seven (78%) were mainly or exclusively in high tuberculosis burden countries. For pulmonary tuberculosis detection, most studies had low risk of bias in all domains. Pulmonary tuberculosis detection Xpert Ultra pooled sensitivity and specificity (95% credible interval) against culture were 90.9% (86.2 to 94.7) and 95.6% (93.0 to 97.4) (7 studies, 2834 participants; high-certainty evidence) versus Xpert MTB/RIF pooled sensitivity and specificity of 84.7% (78.6 to 89.9) and 98.4% (97.0 to 99.3) (7 studies, 2835 participants; high-certainty evidence). The difference in the accuracy of Xpert Ultra minus Xpert MTB/RIF was estimated at 6.3% (0.1 to 12.8) for sensitivity and -2.7% (-5.7 to -0.5) for specificity. If the point estimates for Xpert Ultra and Xpert MTB/RIF are applied to a hypothetical cohort of 1000 patients, where 10% of those presenting with symptoms have pulmonary tuberculosis, Xpert Ultra will miss 9 cases, and Xpert MTB/RIF will miss 15 cases. The number of people wrongly diagnosed with pulmonary tuberculosis would be 40 with Xpert Ultra and 14 with Xpert MTB/RIF. In smear-negative, culture-positive participants, pooled sensitivity was 77.5% (67.6 to 85.6) for Xpert Ultra versus 60.6% (48.4 to 71.7) for Xpert MTB/RIF; pooled specificity was 95.8% (92.9 to 97.7) for Xpert Ultra versus 98.8% (97.7 to 99.5) for Xpert MTB/RIF (6 studies). In people living with HIV, pooled sensitivity was 87.6% (75.4 to 94.1) for Xpert Ultra versus 74.9% (58.7 to 86.2) for Xpert MTB/RIF; pooled specificity was 92.8% (82.3 to 97.0) for Xpert Ultra versus 99.7% (98.6 to 100.0) for Xpert MTB/RIF (3 studies). In participants with a history of tuberculosis, pooled sensitivity was 84.2% (72.5 to 91.7) for Xpert Ultra versus 81.8% (68.7 to 90.0) for Xpert MTB/RIF; pooled specificity was 88.2% (70.5 to 96.6) for Xpert Ultra versus 97.4% (91.7 to 99.5) for Xpert MTB/RIF (4 studies). The proportion of Ultra trace-positive results ranged from 3.0% to 30.4%. Data were insufficient to estimate the accuracy of Xpert Ultra repeat testing in individuals with initial trace-positive results. Rifampicin resistance detection Pooled sensitivity and specificity were 94.9% (88.9 to 97.9) and 99.1% (97.7 to 99.8) (5 studies, 921 participants; high-certainty evidence) for Xpert Ultra versus 95.3% (90.0 to 98.1) and 98.8% (97.2 to 99.6) (5 studies, 930 participants; high-certainty evidence) for Xpert MTB/RIF. The difference in the accuracy of Xpert Ultra minus Xpert MTB/RIF was estimated at -0.3% (-6.9 to 5.7) for sensitivity and 0.3% (-1.2 to 2.0) for specificity. If the point estimates for Xpert Ultra and Xpert MTB/RIF are applied to a hypothetical cohort of 1000 patients, where 10% of those presenting with symptoms have rifampicin resistance, Xpert Ultra will miss 5 cases, and Xpert MTB/RIF will miss 5 cases. The number of people wrongly diagnosed with rifampicin resistance would be 8 with Xpert Ultra and 11 with Xpert MTB/RIF. We identified a higher number of rifampicin resistance indeterminate results with Xpert Ultra, pooled proportion 7.6% (2.4 to 21.0) compared to Xpert MTB/RIF pooled proportion 0.8% (0.2 to 2.4). The estimated difference in the pooled proportion of indeterminate rifampicin resistance results for Xpert Ultra versus Xpert MTB/RIF was 6.7% (1.4 to 20.1).

AUTHORS' CONCLUSIONS

Xpert Ultra has higher sensitivity and lower specificity than Xpert MTB/RIF for pulmonary tuberculosis, especially in smear-negative participants and people living with HIV. Xpert Ultra specificity was lower than that of Xpert MTB/RIF in participants with a history of tuberculosis. The sensitivity and specificity trade-off would be expected to vary by setting. For detection of rifampicin resistance, Xpert Ultra and Xpert MTB/RIF had similar sensitivity and specificity. Ultra trace-positive results were common. Xpert Ultra and Xpert MTB/RIF provide accurate results and can allow rapid initiation of treatment for rifampicin-resistant and multidrug-resistant tuberculosis.

Mortality and risk of tuberculosis among people living with HIV in whom TB was initially ruled out

Tuberculosis (TB) misdiagnosis remains a public health concern, especially among people living with HIV (PLHIV), given the high mortality associated with missed TB diagnoses. The main objective of this study was to describe the all-cause mortality, TB incidence rates and their associated risk factors in a cohort of PLHIV with presumptive TB in whom TB was initially ruled out. We retrospectively followed a cohort of PLHIV with presumptive TB over a 2 year-period in a rural district in Southern Mozambique. During the study period 382 PLHIV were followed-up. Mortality rate was 6.8/100 person-years (PYs) (95% CI 5.2-9.2) and TB incidence rate was 5.4/100 PYs (95% CI 3.9-7.5). Thirty-six percent of deaths and 43% of TB incident cases occurred in the first 12 months of the follow up. Mortality and TB incidence rates in the 2-year period after TB was initially ruled out was very high. The TB diagnostic work-up and linkage to HIV care should be strengthened to decrease TB burden and all-cause mortality among PLHIV with presumptive TB.

Low mortality rates at two years in HIV-infected individuals undergoing systematic tuberculosis testing with rapid assays at initiation of antiretroviral treatment in Mozambique

BACKGROUND

Few studies have evaluated the mortality rate in individuals with HIV initiating antiretroviral therapy (ART), undergoing screening with combined or repeated rapid tests for tuberculosis (TB).

METHODS

All individuals with HIV starting ART, irrespective of the presence of TB-related symptoms, received two consecutive Xpert tests plus a rapid test for the detection of mycobacterial lipoarabinomannan in urine (LAM). Mortality was evaluated by Kaplan-Meier analysis using the log-rank test in univariate analyses and Cox regression models with time-dependent covariates in multivariate analyses.

RESULTS

Among 972 individuals screened with combined tests, 98 (10.1%) tested positive for TB with Xpert, LAM, or both. At the end of the study, 780 (80.2%) had completed 2 years of follow-up, 39 (4.0%) had died, and 153 (15.7%) were lost to follow-up. In the multivariate analyses, the factors significantly associated with mortality were missed ART (hazard ratio (HR) 7.05, 95% confidence interval (CI) 2.33-21.35), symptomatic HIV disease (WHO-HIV stage >1) (HR 3.31, 95% CI 1.28-8.54), and low CD4 count (<200/mm³) (HR 2.72, 95% CI 1.21-6.13), with no significant effect of TB status. In the subgroup of the 98 TB-positive individuals, only missed ART (HR 4.12, 95% CI 1.03-16.46) and missed anti-TB treatment (HR 9.25, 95% CI 2.65-32.28) were significantly associated with mortality.

CONCLUSIONS

A low mortality rate was observed among individuals with HIV undergoing systematic testing for TB at initiation of ART. After adjusting for confounders, mortality was significantly associated with missed ART, advanced disease, and missed anti-TB treatment. These findings reinforce the need to promote early diagnosis of HIV and the adoption of screening strategies for TB that prevent presentation with severe disease.

Using community health workers for facility and community based TB case finding: An evaluation in central Mozambique

BACKGROUND

Mozambique has one of the highest incidence rates of both TB and HIV in the world and an estimated tuberculosis (TB) treatment coverage of only 57% in 2018. Numerous approaches are being tested to reduce existing gaps in coverage and the estimated number of missing cases.

METHODS

Thirty Community Healthcare Workers (CHWs) were tasked with increasing TB notifications by performing verbal facility-based TB screening of all people presenting for care and TB contact tracing in the community. Using routine National TB Program data, we analyzed trends in TB notifications in five intervention districts and seven control districts in Manica province the year before this project and during a one-year intervention period.

RESULTS

In the four quarters before the study, the intervention districts notified 5,219 individuals with all forms of TB, and the control districts notified 2,248 TB cases. During the study 5,982 all forms of people with TB were notified in the intervention area, an increase of 763 (14.6%) over the baseline, whereas the control districts notified 1,877 persons with TB, a decrease of -371 (-16.5%). The CHW screening activities yielded 1,502 notified and treated individuals with TB.

CONCLUSIONS

Employing CHWs to promote facility-based TB screening and household contact tracing may lead to an overall increase in TB notification.

PET/CT features of extrapulmonary tuberculosis at first clinical presentation: a cross-sectional observational 18F-FDG imaging study across six countries

Background

A large proportion of the huge global burden of extrapulmonary tuberculosis (EPTB) cases are treated empirically without accurate definition of disease sites and extent of multi-organ disease involvement. Positron emission tomography (PET) imaging using 2-deoxy-2-(fluorine-18) fluoro-d-glucose (18F-FDG) in tuberculosis could be a useful imaging technique for localising disease sites and extent of disease.

Methods

We conducted a study of HIV-negative adult patients with a new clinical diagnosis of EPTB across eight centres located in six countries: India, Pakistan, Thailand, South Africa, Serbia and Bangladesh, to assess the extent of disease and common sites involved at first presentation. 18F-FDG PET/computed tomography (CT) scans were performed within 2 weeks of presentation.

Findings

358 patients with EPTB (189 females; 169 males) were recruited over 45 months, with an age range of 18–83 years (females median 30 years; males median 38 years). 350 (98%) out of 358 patients (183 female, 167 male) had positive scans. 118 (33.7%) out of 350 had a single extrapulmonary site and 232 (66.3%) out of 350 had more than one site (organ) affected. Lymph nodes, skeleton, pleura and brain were common sites. 100 (28%) out of 358 EPTB patients had 18F-FDG PET/CT-positive sites in the lung. 110 patients were 18F-FDG PET/CT-positive in more body sites than were noted clinically at first presentation and 160 patients had the same number of positive body sites.

Interpretation

18F-FDG PET/CT scan has potential for further elucidating the spectrum of disease, pathogenesis of EPTB and monitoring the effects of treatment on active lesions over time, and requires longitudinal cohort studies, twinned with biopsy and molecular studies.