HIV-Associated TB Syndemic: A Growing Clinical Challenge Worldwide

Exosomal microRNAs associated with tuberculosis among people living with human immunodeficiency virus

Objective

To investigate the diagnostic value of selected exosomal miRNAs for Tuberculosis (TB) among people living with human immunodeficiency virus (PLHIV).

Methods

A total of 43 adult HIV patients, including 20 diagnosed with TB and 23 controls, were enrolled. The levels of six exosomal miRNAs (miR-20a, miR-20b, miR-26a, miR-106a, miR-191, and miR-486) were measured using qRT-PCR.

Results

The levels of these six exosomal miRNAs (miR-20a, miR-20b, miR-26a, miR-106a, miR-191, and miR-486) were significantly higher in the plasma of TB patients compared to controls among PLHIV. The Receiver Operating Characteristic (ROC) curve of these six miRNAs showed a fair performance in distinguishing TB patients from controls, with Area Under Curve (AUC) values of 0.78 (95 %CI 0.63-0.93), 0.81 (95 %CI 0.67-0.95), 0.77 (95 %CI 0.61-0.93), 0.84 (95 %CI 0.70-0.98), 0.82 (95 %CI 0.68-0.95) and 0.79 (95 %CI 0.65-0.93), respectively. These miRNAs showed higher AUC values for extrapulmonary tuberculosis compared to pulmonary tuberculosis. An analysis of subgroups was performed based on CD4 + T cell count (＜200 and ≥ 200 cells·µL-1). In the high CD4 count group, all these six exosomal miRNAs appeared to have higher AUC values compared to the low CD4 count group.

Conclusions

These six exosomal miRNAs could serve as potential biomarkers for diagnosing TB among PLHIV.

Cystatin F Depletion in Mycobacterium tuberculosis-Infected Macrophages Improves Cathepsin C/Granzyme B-Driven Cytotoxic Effects on HIV-Infected Cells during Coinfection

Cystatin F (CstF) is a protease inhibitor of cysteine cathepsins, including those involved in activating the perforin/granzyme cytotoxic pathways. It is targeted at the endolysosomal pathway but can also be secreted to the extracellular milieu or endocytosed by bystander cells. CstF was shown to be significantly increased in tuberculous pleurisy, and during HIV coinfection, pleural fluids display high viral loads. In human macrophages, our previous results revealed a strong upregulation of CstF in phagocytes activated by interferon γ or after infection with Mycobacterium tuberculosis (Mtb). CstF manipulation using RNA silencing led to increased proteolytic activity of lysosomal cathepsins, improving Mtb intracellular killing. In the present work, we investigate the impact of CstF depletion in macrophages during the coinfection of Mtb-infected phagocytes with lymphocytes infected with HIV. The results indicate that decreasing the CstF released by phagocytes increases the major pro-granzyme convertase cathepsin C of cytotoxic immune cells from peripheral blood-derived lymphocytes. Consequently, an observed augmentation of the granzyme B cytolytic activity leads to a significant reduction in viral replication in HIV-infected CD4+ T-lymphocytes. Ultimately, this knowledge can be crucial for developing new therapeutic approaches to control both pathogens based on manipulating CstF.

The performance of tongue swabs for detection of pulmonary tuberculosis

Introduction

Oral and/or tongue swabs have demonstrated ability to detect Mycobacterium tuberculosis (Mtb) in adults with pulmonary tuberculosis (TB). Swabs provide useful alternative specimens for diagnosis of TB using molecular assays however, the diagnostic pickup by culture requires further improvement and development. Several studies identified the presence of differentially culturable tubercle bacilli (DCTB) populations in a variety of clinical specimens. These organisms do not grow in routine laboratory media and require growth factors in the form of culture filtrate (CF) from logarithmic phase cultures of Mtb H37Rv.

Methods

Herein, we compared the diagnostic performance of sputum and tongue swabs using Mycobacterial Growth Indicator Tube (MGIT) assays, Auramine smear, GeneXpert and DCTB assays supplemented with or without CF.

Results

From 89 eligible participants, 83 (93%), 66 (74%) and 79 (89%) were sputum positive by MGIT, smear and GeneXpert, respectively. The corresponding tongue swabs displayed a lower sensitivity with 39 (44%), 2 (2.0%) and 18 (20%) participants respectively for the same tests. We aimed to improve the diagnostic yield by utilizing DCTB assays. Sputum samples were associated with a higher positivity rate for CF-augmented DCTB at 82/89 (92%) relative to tongue swabs at 36/89 (40%). Similarly, sputum samples had a higher positivity rate for DCTB populations that were CF-independent at 64/89 (72%) relative to tongue swabs at 26/89 (29%). DCTB positivity increased significantly, relative to MGIT culture, for tongue swabs taken from HIV-positive participants. We next tested whether the use of an alternative smear stain, DMN-Trehalose, would improve diagnostic yield but noted no substantial increase.

Discussion

Collectively, our data show that while tongue swabs yield lower bacterial numbers for diagnostic testing, the use of growth supplementation may improve detection of TB particularly in HIV-positive people but this requires further interrogation in larger studies.

Unravelling the flexibility of Mycobacterium tuberculosis: an escape way for the bacilli

The persistence of Mycobacterium tuberculosis makes it difficult to eradicate the associated infection from the host. The flexible nature of mycobacteria and their ability to adapt to adverse host conditions give rise to different drug-tolerant phenotypes. Granuloma formation restricts nutrient supply, limits oxygen availability and exposes bacteria to a low pH environment, resulting in non-replicating bacteria. These non-replicating mycobacteria, which need high doses and long exposure to anti-tubercular drugs, are the root cause of lengthy chemotherapy. Novel strategies, which are effective against non-replicating mycobacteria, need to be adopted to shorten tuberculosis treatment. This not only will reduce the treatment time but also will help prevent the emergence of multi-drug-resistant strains of mycobacteria.

An Epidemic of Drug Resistance: Tuberculosis in the Twenty-First Century

With an estimated two billion people being carriers of latent tuberculosis infection (LTBI), the gains achieved by increasing access to diagnostics and treatment, although substantial, have had a modest impact on the global burden of tuberculosis (TB). At the same time, increased access to treatment has had the unintended consequence that drug-resistant TB (DR-TB) has increased dramatically. Earlier TB control strategies strongly emphasizing medical treatment have failed to address these issues effectively. The current strategy to eliminate TB by 2050 is accompanied by a call for a paradigm shift, emphasizing patient rights and equity more. Based on ethnographic fieldwork in Odisha, India, and global-level TB conferences, this paper contrasts the dynamics of global health policy and strategy-making with the lived realities of patients with DR-TB. A more thorough rethinking of the biosocial dynamics that impact the pathogenic disease is required to develop a comprehensive paradigm shift for TB control in the twenty-first century.

Difficulties in distinguishing silicosis and pulmonary tuberculosis in silica-exposed gold miners: A report of four cases

Silicosis and tuberculosis (TB) are both global health concerns, with high prevalence among miners from the South African gold mines. Although knowledge has accumulated about these two conditions as distinct diseases since the early 20th century, and despite progress in technology with multiple diagnostic tools and treatment options available for TB, the challenge of distinguishing and therefore efficiently managing these two conditions in this population remains as current as it was 100 years ago. To illustrate the diagnostic and health service problems of distinguishing TB and silicosis clinically and radiologically in former gold miners from the South African mines living in resource-poor areas, we discuss four cases reviewed for this report by a panel of experts. For each case, occupational history, past and current medical history, physical examination, radiological and laboratory findings are described. Common themes are: (1) poor agreement between radiological and clinical presentation; (2) poor agreement between radiology findings and detection of active TB on sputum Xpert MTB/RIF testing; and (3) difficulty in distinguishing the clinical and radiological presentations of silicosis and tuberculosis. Possible consequences at the population level are undertreatment or overtreatment of TB, and underdiagnosis or overdiagnosis of silicosis. There is a need for training of practitioners who are screening or attending to former gold miners in the clinical and radiological features of combined disease, using a curated database of miners' chest X-ray images. Investment in protocols for management of both acute and chronic silicotuberculosis in ex-miners is needed, as is clinical, epidemiologic, and operations research.

HIV/Mtb Co-Infection: From the Amplification of Disease Pathogenesis to an “Emerging Syndemic”

Human immunodeficiency virus (HIV) and Mycobacterium tuberculosis (Mtb) are pathogens responsible for millions of new infections each year; together, they cause high morbidity and mortality worldwide. In addition, late-stage HIV infection increases the risk of developing tuberculosis (TB) by a factor of 20 in latently infected people, and even patients with controlled HIV infection on antiretroviral therapy (ART) have a fourfold increased risk of developing TB. Conversely, Mtb infection exacerbates HIV pathogenesis and increases the rate of AIDS progression. In this review, we discuss this reciprocal amplification of HIV/Mtb coinfection and how they influence each other’s pathogenesis. Elucidating the infectious cofactors that impact on pathogenesis may open doors for the design of new potential therapeutic strategies to control disease progression, especially in contexts where vaccines or the sterile clearance of pathogens are not effectively available.

Pathogenesis, Diagnostic Challenges, and Risk Factors of Pott's Disease

Tuberculosis (TB) prevalence is increasing in developed nations and continuing to cause significant mortality in low- and middle-income countries. As a result of the uptick in cases, there also exists an increased prevalence of extrapulmonary TB. TB is caused by Mycobacterium tuberculosis (M. tb). When M. tb disseminates to the vertebral column, it is called Pott's disease or spinal TB. The frequency, symptoms, and severity of the disease range by the location of the spine and the region of the affected vertebrae. While the current literature shows that timely diagnosis is crucial to reduce the morbidity and mortality from Pott's disease, there is a lack of specific clinical diagnostic criteria for Pott's disease, and the symptoms may be very non-specific. Studies have shown that novel molecular diagnostic methods are effective and timely choices. Research has implicated the risk factors for the susceptibility and severity of Pott's disease, such as HIV and immunosuppression, poverty, and malnutrition. Based on the current literature available, our group aims to summarize the pathogenesis, clinical features, diagnostic challenges, as well as the known risk factors for Pott's disease within this literature review.

Proposing a New Conceptual Syndemic Framework for COVID-19 Vaccine Hesitancy: A Narrative Review

BACKGROUND

Discussions regarding syndemics have dominated research in recent years. Vaccine hesitancy has also been propelled to the forefront. In this narrative review, we aim to frame a novel syndemic framework to understand the interaction between vaccine hesitancy, COVID-19, and negative health outcomes.

METHODS

A non-systematic electronic search was conducted in PubMed and Google Scholar. Search criteria were limited to articles published between November 2019 and June 2022. Articles related to the COVID-19 syndemic and vaccine hesitancy were included.

RESULTS

Our review revealed that the adherence to COVID-19 regulations-although they were effective in preventing COVID-19 transmission, cases, and deaths-created a dynamically unstable 'vicious cycle' between undesirable health, economic, and social outcomes. The "accumulation" of complex stressors decreased individuals' cognitive flexibility and hindered them from making decisions and getting vaccinated. Furthermore, it increased individuals' risk of acquiring COVID-19, losing their employment, increasing poverty, and decreasing healthcare utilization. We illustrated how the amalgamation of sociodemographic and contextual factors associated with COVID-19 might impact people's vaccine decisions, making them more hesitant toward COVID-19 vaccination. Failing to receive vaccinations increases the chances of COVID-19 transmission, hospitalization, and other negative health outcomes.

CONCLUSIONS

Understanding the interaction between these factors is essential to provide policymakers with inspiration to set appropriate interventions for promoting COVID-19 vaccination acceptance to decrease the overall burden of pandemics.

A Scoping Review of Peer Navigation Programs for People Living with HIV: Form, Function and Effects

This scoping review maps recent research into peer navigation programs for people living with HIV. Four databases were systematically searched in June 2020. Results were screened according to defined criteria and were not restricted to any design, outcome or country. Six papers drew from randomised control trials, five from quasi-experimental or pragmatic trials, and four panel, eight qualitative, three mixed method and one cross-sectional designs were included for review. Programs incorporated health systems navigation and social support. Authors provided strong theoretical bases for peers to enhance program effects. Studies primarily reported program effects on continuum of care outcomes. Further research is required to capture the role HIV peer navigators play in preventing disease and promoting quality of life, mental health, and disease self-management in diverse settings and populations. Peer programs are complex, social interventions. Future work should evaluate detailed information about peer navigators, their activities, the quality of peer engagement as well as employee and community support structures to improve quality and impact.

Tuberculosis challenges: Resistance, co-infection, diagnosis, and treatment

Early diagnosis of tuberculosis (TB), followed by effective treatment, is the cornerstone of global TB control efforts. An estimated 3 million cases of TB remain undetected each year. Early detection and effective management of TB can prevent severe disease and reduce mortality and transmission. Intrinsic and acquired drug resistance of Mycobacterium tuberculosis (MTB) severely restricted the anti-TB therapeutic options, and public health policies are required to preserve the new medications to treat TB. In addition, TB and HIV frequently accelerate the progression of each other, and one disease can enhance the other effect. Overall, TB-HIV co-infections show an adverse bidirectional interaction. For HIV-infected patients, the risk of developing TB disease is approximately 22 times higher than for persons with a protective immune response. Analysis of the current TB challenges is critical to meet the goals of the end TB strategy and can go a long way in eradicating the disease. It provides opportunities for global TB control and demonstrates the efforts required to accelerate eliminating TB. This review will discuss the main challenges of the TB era, including resistance, co-infection, diagnosis, and treatment.

Tuberculosis and/or HIV Infection and Associated Socio-Behavioural Factors in Immigrants, in Portugal: A Cross-Sectional, Community-Based Descriptive Study

<b><i>Introduction:</i></b> Portugal is one of the countries in Western Europe with the highest prevalence of tuberculosis (TB) and human immunodeficiency virus (HIV). The prevalence among migrants is estimated to be higher than among non-migrants, which suggests a greater vulnerability of this population. <b><i>Aim:</i></b> To describe the distribution of TB, HIV and HIV-TB co-infection and socio-behavioural factors associated with immigrants that lived in the metropolitan area of Lisbon and used the services of a Non-Governmental Organization (NGO). <b><i>Methods:</i></b> Quantitative, cross-sectional and descriptive pilot study. An anonymous and structured questionnaire developed specifically for the study was applied by NGO employees duly trained for this purpose to a purposeful sample of 100 immigrants attending health services in an NGO in the metropolitan area of Lisbon, Portugal. <b><i>Results:</i></b> The prevalence of HIV-TB extrapulmonary coinfection and HIV infection was 1% (<i>n</i> = 1) and 17% (<i>n</i> = 17), respectively. Only 1 immigrant had 4 out of the 5 symptoms suggestive of TB. No cases of pulmonary TB were identified, although 3 of the immigrants reported having been treated for pulmonary TB in the past. The participants were young, mainly female and some were male-to-female transsexuals. Most were from the community of Portuguese-speaking countries, especially from Brazil, and almost half of them had not regularized their immigration status. Additionally, almost one-fifth of immigrants were unemployed (17%), and one-sixth performed sex work (14%). Most of the participants (71%) sometimes used or never used a condom during sexual intercourse. Additionally, 40% revealed using illicit drugs and 1% said that they had shared injection material in the last 12 months. <b><i>Discussion:</i></b> Being non-employed, with a low income and a lower level of education, consumption of illicit drugs and regular tobacco consumption were common characteristics in the immigrants studied, which points out social and economic disadvantages that could influence the risk of acquiring HIV and TB. Policies on latent TB infection and TB diagnosis are urgently needed, mainly aimed at vulnerable groups and culturally diverse populations.

Tuberculosis drug discovery: Progression and future interventions in the wake of emerging resistance

The emergence of drug resistance continues to afflict TB control where drug resistant strains have become a global health concern. Contrary to drug-sensitive TB, the treatment of MDR/XDR-TB is more complicated requiring the administration of second-line drugs that are inefficient than the first line drugs and are associated with greater side effects. The emergence of drug resistant Mtb strains had coincided with an innovation void in the field of drug discovery of anti-mycobacterials. However, the approval of bedaquiline and delamanid recently for use in MDR/XDR-TB has given an impetus to the TB drug discovery. The review discusses the drug discovery efforts in the field of tuberculosis with a focus on the strategies adopted and challenges confronted by TB research community. Here, we discuss the diverse clinical candidates in the current TB drug discovery pipeline. There is an urgent need to combat the current TB menace through multidisciplinary approaches and strategies making use of the recent advances in understanding the molecular biology and pathogenesis of Mtb. The review highlights the recent advances in drug discovery, with the host directed therapeutics and nanoparticles-drug delivery coming up as important tools to fight tuberculosis in the future.

Trends of HIV Mortality between 2001 and 2018: An Observational Analysis

Since the beginning of the epidemic in the early 1980s, HIV-related illnesses have led to the deaths of over 32.7 million individuals. The objective of this study was to describe current mortality rates for HIV through an observational analysis of HIV mortality data from 2001 to 2018 from the World Health Organization (WHO) Mortality Database. We computed age-standardized death rates (ASDRs) per 100,000 people using the World Standard Population. We plotted trends using locally weighted scatterplot smoothing (LOWESS). Data for females were available for 42 countries. In total, 31/48 (64.60%) and 25/42 (59.52%) countries showed decreases in mortality in males and females, respectively. South Africa had the highest ASDRs for both males (467.7/100,000) and females (391.1/100,000). The lowest mortalities were noted in Egypt for males (0.2/100,000) and in Japan for females (0.01/100,000). Kyrgyzstan had the greatest increase in mortality for males (+6998.6%). Estonia had the greatest increase in mortality for females (+5877.56%). The disparity between Egypt (the lowest) and South Africa (the highest) was 3042-fold for males. Between Japan and South Africa, the disparity was 43,454-fold for females. Although there was a decrease in mortality attributed to HIV among most of the countries studied, a rising trend remained in a number of developing countries.

New management approaches to tuberculosis in people living with HIV

PURPOSE OF REVIEW

People living with HIV (PLWH) are commonly coinfected with Mycobacterium tuberculosis, particularly in high-transmission resource-limited regions. Despite expanded access to antiretroviral therapy and tuberculosis (TB) treatment, TB remains the leading cause of death among PLWH. This review discusses recent advances in the management of TB in PLWH and examines emerging therapeutic approaches to improve outcomes of HIV-associated TB.

RECENT FINDINGS

Three recent key developments have transformed the management of HIV-associated TB. First, the scaling-up of rapid point-of-care urine-based tests for screening and diagnosis of TB in PLWH has facilitated early case detection and treatment. Second, increasing the availability of potent new and repurposed drugs to treat drug-resistant TB has generated optimism about the treatment and outcome of multidrug-resistant and extensively drug-resistant TB. Third, expanded access to the integrase inhibitor dolutegravir to treat HIV in resource-limited regions has simplified the management of TB/HIV coinfected patients and minimized serious adverse events.

SUMMARY

While it is unequivocal that substantial progress has been made in early detection and treatment of HIV-associated TB, significant therapeutic challenges persist. To optimize the management and outcomes of TB in HIV, therapeutic approaches that target the pathogen as well as enhance the host response should be explored.

Joint Modeling in Detecting Predictors of CD4 Cell Count and Status of Tuberculosis Among People Living with HIV/AIDS Under HAART at Felege Hiwot Teaching and Specialized Hospital, North-West Ethiopia

Background

Globally, for individuals infected with HIV, the presence of other infections including TB tends to increase the rate of HIV replication. Of the 8.8 million TB cases worldwide, an estimated 1.1 million (13%) were found to be co-infected with HIV. This research was conducted with the objective to identify potential predictors for the status of TB and CD4 cell count under PLWHIV at Felege Hiwot Specialized Hospital, North-west Ethiopia.

Methods

A retrospective repeated measurement was taken from a sample of 226 HIV patients. Separate and joint models were conducted for data analysis of CD4 cell count and TB status of people living with HIV.

Results

The descriptive statistics indicated that among the HIV patients receiving HAART, 26.6% had additional TB. AIDS clinical stage, weight, and hemoglobin level had a significant positive association with CD4 cell count, but a negative association with TB status. Weight and CD4 cell count have a negative relationship with the event of HIV/TB co-infection. Hence, the expected number of CD4 cell count of HIV patients who were co-infected with TB was decreased by 2.34 as compared to people living with HIV without TB. As visiting times of patients to hospitals for treatment increased by one unit, the odds of being co-infected with TB was decreased by 0.05, and the expected number of CD4 cell count was increased by 0.2. As patients’ age increased by one year, the expected number of CD4 cell count was decreased by 0.025 cells per/mm³.

Conclusion

Having lower CD4 cell count, lower weight, late WHO clinical stage, being non-adherent, having opportunistic infection, having lower hemoglobin, being ambulatory and bedridden were associated with a higher risk of co-infection of HIV/TB and were indicators of progression of the disease.

Accuracy of the tuberculosis point-of-care Alere determine lipoarabinomannan antigen diagnostic test using α-mannosidase treated and untreated urine in a cohort of people living with HIV in Guatemala

BACKGROUND

Improved point-of-care diagnostic tests for tuberculosis (TB) in severe immune suppressed people living with HIV (PLWH) are needed to decrease morbidity and mortality outcomes. The aim of the study is to evaluate the performance of the lipoarabinomannan antigen test (LAM-test) with and without α-mannosidase pre-treated urine in a cohort of PLWH in primary care clinics in Guatemala. We further determined TB incidence, and mortality rates and its risk factors in PLWH with TB symptoms.

METHODS

Prospective longitudinal study of PLWH with TB symptoms. Urine samples were collected at 2 HIV sites to test the sensitivity of the LAM-test in urine with and without α-mannosidase pre-treatment. A composite reference standard of either a positive Mycobacterium tuberculosis complex culture and/or GeneXpert^® MTB/RIF (Xpert, Cepheid, Sunnyvale, CA, USA) results was used in the LAM-test diagnostic accuracy studies. Cox proportional hazards regression was used to study mortality predictors.

RESULTS

The overall sensitivity of the LAM-test was of 56.1% with 95% CI of (43.3-68.3). There were no differences in the LAM-test sensitivity neither by hospital nor by CD4 T cell values. LAM-test sensitivity in PLWH with < 200 CD4 T cells/µl was of 62.2% (95% CI 46.5-76.2). There were no significant differences in sensitivity when comparing LAM-test results obtained from untreated vs. α-mannosidase treated urine [55.2% (95% CI 42.6-67.4) vs. 56.9% (95% CI 44-69.2), respectively]. TB incidence in our cohort was of 21.4/100 person years (PYs) (95% CI 16.6-27.6), and mortality rate was of 11.1/100 PYs (95% CI 8.2-15.0). Importantly, PLWH with a positive LAM-test result had an adjusted hazard ratio (aHR) of death of 1.98 (1.0-3.8) with a significant p value of 0.044 when compared to PLWH with a negative LAM-test result.

CONCLUSIONS

In this study, α-mannosidase treatment of urine did not significantly increase the LAM-test performance, however; this needs to be further evaluated in a large-scale study due to our study limitations. Importantly, high rates of TB incidence and mortality were found, and a positive LAM-test result predicted mortality in PLWH with TB clinical symptoms.

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.

Correlation Between Clinical Manifestation and Radiological Findings In Pulmonary Tuberculosis-Human Immunodeficiency Virus Coinfection Patients In Sanglah Hospital, Bali, Indonesia

BACKGROUND

Tuberculosis (TB) mono-infection has radiological features and typical clinical manifestations that are easily recognized by clinicians. These radiological features and clinical manifestations are often found to show atypical features in subjects coinfected with Tuberculosis- Human Immunodeficiency Virus (HIV), making TB diagnosis and early management challenging to establish.

OBJECTIVE

The aim of this study was to determine the relationship between the clinical and radiological presentation of pulmonary TB patients with HIV coinfection at the Central General Hospital Sanglah, Bali.

METHODS

This research was an observational analytic study with a cross-sectional method. A total of 54 TB-HIV coinfected patients were analyzed to their sociodemographic characteristics, clinical manifestations and chest radiographic features.

RESULTS

The majority of subjects were of productive age (26-61 years), male (64.8%) and belonged to the heterosexual group (90.7%). Weight loss (75.9%), cough (64.8%) and oral candidiasis (53.7%) are the most common clinical manifestations found in subjects, especially in subjects with CD4+ >200 cells/mm3. Atypical radiological features such as infiltration/consolidation (59.3%), fibrosis (16.7%) and hillar lymphadenopathy (14.8%) are the most commonly obtained radiological features of the subjects. From the results of the bivariate analysis, it was found that radiological features in the form of infiltration/consolidation were more commonly found in subjects with CD4+ <200 cells/mm3 (OR=1.254; 95% CI 1.059-1.568).

CONCLUSION

Based on the research that has been done, it can be concluded that there are no typical radiological features and clinical manifestations in patients with TB-HIV infection.

The social implications of participant choice on adherence to Isonaizid Preventive Therapy (IPT): A follow-up study to high completion rates in Eswatini

BACKGROUND

Eswatini (formerly Swaziland) has one of the highest rates of TB and HIV co-disease in the world. Despite national efforts to improve service delivery and prevent TB and HIV transmission, rates remain high. A recent prospective, observational study of integrated, patient-selected IPT delivery showed extraordinary improvements in IPT adherence, running counter to previous assumptions. This prompted the need to understand contextual and unseen study factors that contributed to high rates of adherence.

OBJECTIVE

To investigate high rates of IPT adherence rates among people living with HIV who participated in an observational study comparing modes of IPT delivery.

METHODS

Community-based participatory research guided the development of in-person administration of semi-structured questionnaires. Observational and field note data were analyzed. Qualitative data were analyzed using content analysis.

RESULTS

We interviewed 150 participants and analyzed responses from the 136 who remembered being given a choice of their IPT delivery method. Fifty-seven percent were female and the median age was 42. Nearly 67% of participants chose to receive facility-based IPT. High rates of self-reported IPT treatment adherence were linked to four key concepts: 1) adherence was positively impacted by community education; 2) disclosure of status served to empower participant completion; 3) mode of delivery perceptions positively impacted adherence; and 4) choice of treatment delivery seen as helpful but not essential for treatment completion.

DISCUSSION

Achieving higher rates of IPT adherence in Eswatini and similar rural areas requires community-engaged education and outreach in coordination with care delivery systems.

An Inflammatory Story: Antibodies in Tuberculosis Comorbidities

Mycobacterium tuberculosis (Mtb) resides in a quarter of the world's population and is the causative agent for tuberculosis (TB), the most common infectious reason of death in humans today. Although cellular immunity has been firmly established in the control of Mtb, there is growing evidence that antibodies may also modulate the infection. More specifically, certain antibody features are associated with inflammation and are divergent in different states of human infection and disease. Importantly, TB impacts not just the healthy but also those with chronic conditions. While HIV represents the quintessential comorbid condition for TB, recent epidemiological evidence shows that additional chronic conditions such as diabetes and kidney disease are rising. In fact, the prevalence of diabetes as a comorbid TB condition is now higher than that of HIV. These chronic diseases are themselves independently associated with pro-inflammatory immune states that encompass antibody profiles. This review discusses isotypes, subclasses, post-translational modifications and Fc-mediated functions of antibodies in TB infection and in the comorbid chronic conditions of HIV, diabetes, and kidney diseases. We propose that inflammatory antibody profiles, which are a marker of active TB, may be an important biomarker for detection of TB disease progression within comorbid individuals. We highlight the need for future studies to determine which inflammatory antibody profiles are the consequences of comorbidities and which may potentially contribute to TB reactivation.

Toxicity related to standard TB therapy for pulmonary tuberculosis and treatment outcomes in the REMoxTB study according to HIV status

BACKGROUND

The phase III REMoxTB study prospectively enrolled HIV-positive (with CD4+ count > 250 cells, not on anti-retroviral therapy) and HIV-negative patients. We investigated the incidence of adverse events and cure rates according to HIV status for patients receiving standard TB therapy in the trial.

METHODS

Forty-two HIV-positive cases were matched to 220 HIV-negative controls by age, gender, ethnicity, and trial site using coarsened exact matching. Grade 3 and 4 adverse events (AEs) were summarised by MedDRA System Organ Class. Kaplan-Meier curves for time to first grade 3 or 4 AE were constructed according to HIV status with hazard ratios calculated. Patients were considered cured if they were culture negative 18 months after commencing therapy with ≥2 consecutive negative culture results.

RESULTS

Twenty of 42 (47.6%) HIV-positive and 34 of 220 (15.5%) HIV-negative patients experienced ≥1 grade 3 or 4 AE, respectively. The majority of these were hepatobiliary disorders that accounted for 12 of 40 (30.0%) events occurring in 6 of 42 (14.3%) HIV-positive patients and for 15 of 60 (25.0%) events occurring in 9 of 220 (4.1%) HIV-negative patients. The median time to first grade 3 or 4 AE was 54 days (IQR 15.5-59.0) for HIV-positive and 29.5 days (IQR 9.0-119.0) for HIV-negative patients, respectively. The hazard ratio for experiencing a grade 3 or 4 AE among HIV-positive patients was 3.25 (95% CI 1.87-5.66, p < 0.01). Cure rates were similar, with 38 of 42 (90.5%) HIV-positive and 195 of 220 (88.6%) HIV-negative patients (p = 0.73) cured at 18 months.

CONCLUSIONS

HIV-positive patients receiving standard TB therapy in the REMoxTB study were at greater risk of adverse events during treatment but cure rates were similar when compared to a matched sample of HIV-negative patients.

DosR antigen Rv1737c induces activation of macrophages dependent on the TLR2 pathway

Latent Mycobacterium tuberculosis (Mtb) infection (LTBI) is the main clinical manifestation after Mtb exposure. During the latent phase, Mtb retards the attempts of eradication by the host immune system. The dormancy survival regulator (DosR) is held as essential for Mtb persistence. Rv1737c is predominantly expressed by the Mtb in latent infection. However, the role of Rv1737c in the immune evasion is still largely unknown. In this study, we have characterized the Rv1737c functions in the recruitment and activation of macrophages, which play a cardinal role in the innate and adaptive immunity. For the first time, we have revealed that Rv1737c induced the tolerogenic phenotype of macrophages by upregulating the expression of indoleamine 2,3-dioxygenase 1 (IDO1). Rv1737c-activated macrophages upregulated interleukin (IL)-4, IL-10, and Foxp3 T cells proliferation in vitro. Furthermore, the interaction of Rv1737c with macrophages was found to depend on the Toll-like receptor 2 (TLR2) pathway. It augmented nuclear factor κB (NF-κB) phosphorylation and co-stimulatory molecule expression. Thus, this study provides a crucial insight into a strategy adopted by Mtb to survive in the host by inducing tolerogenic macrophage expansion.

Impact of HIV on spontaneous spondylodiscitis

AIMS

HIV predisposes patients to opportunistic infections. However, with the establishment of Highly Active Anti-Retroviral Therapy (HAART), patients' CD4 counts are maintained, as is a near normal life expectancy. This study aimed to establish the impact of HIV on the bacteriology of spondylodiscitis in a region in which tuberculosis (TB) is endemic, and to identify factors that might distinguish between them.

PATIENTS AND METHODS

Between January 2014 and December 2015, 63 consecutive cases of spontaneous spondylodiscitis were identified from a single-centre, prospectively maintained database. Demographics, presenting symptoms, blood results, HIV status, bacteriology, imaging, and procedure undertaken were reviewed and comparisons made of TB, non-TB, and HIV groups. There were 63 patients (22 male, 41 female) with a mean age of 42.0 years (11 to 78; sd 15.0).

RESULTS

In total, 53 patients had tuberculous, nine bacterial, and one cryptococcal spondylodiscitis. There were 29 HIV-positive patients, 29 HIV-negative patients, and five patients with unknown HIV status. The local incidence of TB spondylodiscitis was 1.54/100 000 and that of non-TB spondylodiscitis was 0.29/100 000 per annum. TB patients were younger with similar clinical presentation and infective markers, but were more likely to have a paraspinal abscess. They were also less likely to have a hyperintense disc on MRI. There was no difference between the two HIV groups.

CONCLUSION

In areas of endemic TB and HIV, TB remains the most common cause of spondylodiscitis at five times the rate of non-tuberculous causes. HIV managed with HAART increases the rate of infection but does not influence the bacteriology unless there is a low CD4. There was little to differentiate the groups. TB /HIV co-infected patients were younger than non-TB and HIV-negative patients. Non-TB patients were more likely to have disc hyperintensity on MRI and TB patients were more likely to have abscess formation, but as both groups exhibited these features, neither was diagnostic. Culture confirmation remains necessary. Cite this article: Bone Joint J 2019;101-B:617-620.

The DosR antigen Rv1737c from Mycobacterium tuberculosis confers inflammation regulation in tuberculosis infection

There is an urgent need to identify the potential risk factors for activating latent Mycobacterium tuberculosis infection. In this study, we evaluated the immune function of Rv1737c, which is a latency-associated antigen of dormancy survival regulator (DosR) of M. tuberculosis in a mouse model. Our data showed that mice pretreated with recombinant Rv1737c (rRv1737c) exhibited higher levels of antigen-specific antibodies (IgG, IgM and IgA) than sham-treated mice. Following Bacilli Calmette-Guerin (BCG) challenge, rRv1737c adjuvanted with cholera toxin subunit B (CTB) induced diffuse lung inflammation and fibrosis compared to the control mice. The inflammatory pathogenesis due to rRv1737c pre-exposure was associated with a switch in the macrophage phenotype from M1 to activated M2 and was characterized by IL-10 production. Intracellular cytokine analysis further showed that the rRv1737c-pretreated mice exhibited an increased frequency of Th2 cells in the lungs, lymph nodes and spleen after BCG challenge. Furthermore, IFN-γ expression increased in the lungs after rRv1737c pretreatment compared to that in the sham mice. Accordingly, lung cells from rRv1737c-immunized mice stimulated with killed BCG produced higher levels of multiple cytokines, such as IFN-γ, IL-10 and IL-6. The results confirmed that the pathological features of rRv1737c promoted inflammation. Overall, our findings provide direct evidence of the pro-inflammatory function of rRv1737c in a murine model of BCG infection, indicating that Rv1737c is a pathogenic antigen of M. tuberculosis and may be key to the recurrence of latent infection.

"I attend at Vanguard and I attend here as well": barriers to accessing healthcare services among older South Africans with HIV and non-communicable diseases

Background

HIV and non-communicable disease (NCD) are syndemic within sub-Saharan Africa especially among older persons. The two epidemics interact with one another within a context of poverty, inequality and inequitable access to healthcare resulting in an increase in those aged 50 and older living with HIV and experiencing an NCD co-morbidity. We explore the challenges of navigating healthcare for older persons living with HIV and NCD co-morbidity.

Methods

In-depth semi-structured interviews were conducted with a small sample of older persons living with HIV (OPLWH). The perspectives of key informants were also sought to triangulate the evidence of OPLWH. The research took place in two communities on the outskirts of Cape Town, South Africa. All interviews were conducted by a trained interviewer and transcribed and translated for analysis. Thematic content analysis guided data analysis.

Results

OPLWH experienced an HIV-NCD syndemic. Our respondents sought care and accessed treatment for both HIV and other chronic (and acute) conditions, though these services were provided at different health facilities or by different health providers. Through the syndemic theory, it is possible to observe that OPLWH and NCDs face a number of physical and structural barriers to accessing the healthcare system. These barriers are compounded by separate appointments and spaces for each condition. These difficulties can exacerbate the impact of their ill-health and perpetuate structural vulnerabilities. Despite policy changes towards integrated care, this is not the experience of OPLWH in these communities.

Conclusions

The population living with HIV is aging increasing the likelihood that those living with HIV will also be living with other chronic conditions including NCDs. Thus, it is essential that health policy address this basic need to integrate HIV and NCD care.

Addressing diversity in tuberculosis using multidimensional approaches

Tuberculosis is a complex disease, which can affect many organs other than the lungs. Initial infection may be cleared without inducing immunological memory, or progress directly to primary disease. Alternatively, the infection may be controlled as latent TB infection, that may progress to active tuberculosis at a later stage. There is now a greater understanding that these infection states are part of a continuum, and studies using PET/CT imaging have shown that individual lung granulomas may respond to infection independently, in an un-synchronized manner. In addition, the Mycobacterium tuberculosis organisms themselves can exist in different states: as nonculturable forms, as 'persisters', as rapidly growing bacteria and a biofilm-forming cording phenotype. The 'omics' approaches of transcriptomics, metabolomics and proteomics can help reveal the mechanisms underlying these different infection states in the host, and identify biosignatures with diagnostic potential, that can predict the development of disease, in 'progressors' as early as 12-18 months before it can be detected clinically, or that can monitor the success of anti-TB therapy. Further insights can be obtained from studies of BCG vaccination and new TB vaccines. For example, epigenetic changes associated with trained immunity and a stronger immune responses following BCG vaccination can be identified. These omics approaches may be particularly valuable when linked to studies of mycobacterial growth inhibition, as a direct read-out of the ability to control mycobacterial growth. The second generation of omics studies is identifying much smaller signatures based on as few as 3 or 4 genes. Thus, narrowing down omics-derived biosignatures to a manageable set of markers now opens the way to field-friendly point of care assays.

High Turnover of Tissue Macrophages Contributes to Tuberculosis Reactivation in Simian Immunodeficiency Virus-Infected Rhesus Macaques

Background

Tuberculosis (TB) and human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS) profoundly affect the immune system and synergistically accelerate disease progression. It is believed that CD4+ T-cell depletion by HIV is the major cause of immunodeficiency and reactivation of latent TB. Previous studies demonstrated that blood monocyte turnover concurrent with tissue macrophage death from virus infection better predicted AIDS onset than CD4+ T-cell depletion in macaques infected with simian immunodeficiency virus (SIV).

Methods

In this study, we describe the contribution of macrophages to the pathogenesis of Mycobacterium tuberculosis (Mtb)/SIV coinfection in a rhesus macaque model using in vivo BrdU labeling, immunostaining, flow cytometry, and confocal microscopy.

Results

We found that increased monocyte and macrophage turnover and levels of SIV-infected lung macrophages correlated with TB reactivation. All Mtb/SIV-coinfected monkeys exhibited declines in CD4+ T cells regardless of reactivation or latency outcomes, negating lower CD4+ T-cell levels as a primary cause of Mtb reactivation.

Conclusions

Results suggest that SIV-related damage to macrophages contributes to Mtb reactivation during coinfection. This also supports strategies to target lung macrophages for the treatment of TB.

Spinal tuberculosis: review of current management

Tuberculosis (TB) remains endemic in many parts of the developing world and is increasingly seen in the developed world due to migration. A total of 1.3 million people die annually from the disease. Spinal TB is the most common musculoskeletal manifestation, affecting about 1 to 2% of all cases of TB. The coexistence of HIV, which is endemic in some regions, adds to the burden and the complexity of management. This review discusses the epidemiology, clinical presentation, diagnosis, impact of HIV and both the medical and surgical options in the management of spinal TB. Cite this article: Bone Joint J 2018;100-B:425-31.

High-fidelity DNA replication in Mycobacterium tuberculosis relies on a trinuclear zinc center

High-fidelity DNA replication depends on a proofreading 3′–5′ exonuclease that is associated with the replicative DNA polymerase. The replicative DNA polymerase DnaE1 from the major pathogen Mycobacterium tuberculosis (Mtb) uses its intrinsic PHP-exonuclease that is distinct from the canonical DEDD exonucleases found in the Escherichia coli and eukaryotic replisomes. The mechanism of the PHP-exonuclease is not known. Here, we present the crystal structure of the Mtb DnaE1 polymerase. The PHP-exonuclease has a trinuclear zinc center, coordinated by nine conserved residues. Cryo-EM analysis reveals the entry path of the primer strand in the PHP-exonuclease active site. Furthermore, the PHP-exonuclease shows a striking similarity to E. coli endonuclease IV, which provides clues regarding the mechanism of action. Altogether, this work provides important insights into the PHP-exonuclease and reveals unique properties that make it an attractive target for novel anti-mycobacterial drugs.

The polymerase and histidinol phosphatase (PHP) domain in the DNA polymerase DnaE1 is essential for mycobacterial high-fidelity DNA replication. Here, the authors determine the DnaE1 crystal structure, which reveals the PHP-exonuclease mechanism that can be exploited for antibiotic development.

HIV and tuberculosis co-infection among migrants in Europe: A systematic review on the prevalence, incidence and mortality

Background

International human migration has been rapidly growing. Migrants coming from low and middle income countries continue to be considerably vulnerable and at higher risk for infectious diseases, namely HIV (Human Immunodeficiency Virus) and tuberculosis (TB). In Europe, the number of patients with HIV-TB co-infection has been increasing and migration could be one of the potential driving forces.

Objective

This systematic review aims to improve the understanding on the burden of HIV-TB co-infection among migrants in Europe and to assess whether these populations are particularly vulnerable to this co-infection compared to nationals.

Design

MEDLINE^®, Web of Science^® and Scopus^® databases were searched from March to April 2016 using combinations of keywords. Titles and abstracts were screened and studies meeting the inclusion criteria proceeded for full-text revision. These articles were then selected for data extraction on the prevalence, incidence and mortality.

Results

The majority of HIV-TB prevalence data reported in the analysed studies, including extrapulmonary/disseminated TB forms, was higher among migrant vs. nationals, some of the studies even showing increasing trends over time. Additionally, while HIV-TB incidence rates have decreased among migrants and nationals, migrants are still at a higher risk for this co-infection. Migrants with HIV-TB co-infection were also more prone to unsuccessful treatment outcomes, death and drug resistant TB. However, contradicting results also showed lower mortality compared to nationals.

Conclusions

Overall, a disproportionate vulnerability of migrants to acquire the HIV-TB co-infection was observed across studies. Such vulnerability has been associated to low socioeconomic status, poor living conditions and limited access to healthcare. Adequate social support, early detection, appropriate treatment, and adequate access to healthcare are key improvements to tackle HIV-TB co-infection among these populations.

Rare presentation of intractable tuberculous panophthalmitis with intraocular and intraorbital abscesses: a case report

Background

We report a rare presentation of extrapulmonary tuberculosis.

Case presentation

A 29-year-old Burmese woman with human immunodeficiency virus infection and known pulmonary tuberculosis who had been treated for 5 months presented to our hospital with unilateral progressive painful visual loss of 1 month’s duration. She was diagnosed with tuberculous panophthalmitis with subretinal and intraorbital abscesses, conjunctival abscess, and extraocular muscle tuberculoma. The diagnosis was confirmed by a conjunctival pus swab with a positive result for acid-fast bacilli and a positive result for a mycobacterial culture. There was high suspicion of multidrug-resistant tuberculosis. Despite receiving ongoing aggressive treatment with conventional antituberculous medications, this patient required subtotal orbital exenteration to control her infection and prevent further progression. Second-line antituberculous medications were added to the first-line therapy, with satisfactory results achieved.

Conclusions

Tuberculous panophthalmitis with intraocular and intraorbital abscesses is a rare presentation of extrapulmonary tuberculosis. Patients who do not respond to first-line antituberculous therapy might be infected with either single-drug or multidrug-resistant Mycobacterium tuberculosis. Patient compliance is one of the key factors that can alter the course of treatment. Careful patient monitoring can improve disease progression, outcome, and prognosis.

Evaluation of a point of care ultrasound curriculum for Indonesian physicians taught by first-year medical students

BACKGROUND

The purpose of this study was to assess the short-term efficacy of a 4-week ultrasound curriculum taught by American first-year medical students to general practitioners working in public health care clinics, or puskesmas, in Bandung, Indonesia.

METHODS

We performed a prospective, observational study of Indonesian health care practitioners from public clinics in Bandung, Indonesia. These practitioners were enrolled in a 4-week ultrasound training course taught by first-year American medical students. A total of six sessions were held comprising of 38 ultrasound milestones. A pre-course and post-course written exam and practical exam was taken by each participant.

RESULTS

We enrolled 41 clinicians in the course. The average pre-course exam score was 35.2% with a 2.4% pass rate, whereas the average post-course exam score was 82.0% with a 92.7% pass rate. The average practical score at the completion of the course was 83.2% (SD=0.145) with 82.9% of the class passing (score above 75.0%).

CONCLUSION

Our data suggests that first-year medical students can effectively teach ultrasound to physicians in Indonesia using a 4-week intensive ultrasound training course. Future studies are needed to determine the amount of training required for proficiency and to evaluate the physicians' perceptions of the student-instructors' depth of knowledge and skill in point of care ultrasound.

Co-infections of tuberculosis, hepatitis B or C viruses in a cohort of people living with HIV/AIDS in China: predictors and sequelae

The co-infection of viral hepatitis and tuberculosis (TB) among people living with HIV/AIDS (PLWHA) makes the syndemic of HIV even worse as there is higher mortality and morbidity among PLWHA with co-infections compared to people with HIV mono-infection. In the current study, we explored predictors and sequelae among a group of Chinese PLWHA to guide future program strategies and enhance the repertoire of action for both preventative and clinical purposes. Between October 2012 and August 2013, we conducted a cross-sectional study in Guangxi Autonomous Region (Guangxi) of China. With an overall participation rate of 90%, we finally recruited 3002 patients with 2987 (99.5%) completed the survey and were included in the data analysis. We employed both predictive and explanatory modeling strategies to explore predictors and sequelae of co-infections among PLWHA. The overall prevalence of co-infection was 15.6% with 4.4% of HBV, 5.4% of HCV and 4.8% of TB, respectively. Predictors of co-infections included history of injecting drugs or drinking alcohol, sharing needles, having sex with sex workers or casual partners, higher viral loads and lower CD4 counts. Meanwhile, co-infections were associated with various physical and psychological problems among PLWHA. As an entangled phenomenon, co-infections among PLWHA produce continuous and shifting scenarios, which add complexity to clinic, epidemiological and political ways of dealing with health risks among PLWHA in China. Exploring predictors and sequelae can help to prevent and manage co-infection comorbidities among PLWHA.

Splenic tuberculosis in a patient with newly diagnosed advanced HIV infection

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Splenic tuberculosis (TB) is a rare clinical condition usually seen as a part of miliary TB.

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The presence of a splenic abscess without an active TB of the lung in an Italian HIV positive patient is very uncommon.

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Case reports of isolated splenic TB in which microbiological and molecular examinations have been carried out to confirm the diagnosis are rare especially in low TB prevalence areas as Italy.

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This case report may be useful when physicians are faced with differential diagnosis of splenic mass or abscess.

The extra-pulmonary tuberculosis (TB) constitutes to about 20% of all TB cases. Among extra-pulmonary form, splenic TB is very rare clinical condition especially as initial manifestation in a developed country. Diagnosis of splenic TB is challenging because it presents no specific symptoms or typical imaging findings and microbiological confirmation is not straight forward.

We describe the case of a 55 year old Italian female with advanced HIV infection whose first AIDS clinical manifestation was a TB splenic abscess.On CT, the lesion was multilocular, hypovascular, 34 mm large, and presented contrast enhancement and a spoke wheel pattern; it was initially considered a cystic formation of parasitic nature. In this patient clinical manifestations were nonspecific (nightly fever, weight loss, and fatigue); as diagnostic imaging could not pinpoint the underlying etiology, microbiological and molecular examinations of spleen abscess drainage proved pivotal for the diagnosis. The patient improved clinically with antitubercular therapy.

The rarityof splenic tuberculosis in an European patient coupled with the involvement of the spleen in isolation and outside the “miliary” setting prompted us to report this case.