Tuberculosis: a global health problem

Long-term trends of tuberculosis incidence and mortality in four central African countries

Tuberculosis (TB) incidence and mortality rates are still high in Sub-Saharan Africa, and the knowledge about the current patterns is valuable for policymaking to decrease the TB burden. Based on the Global Burden of Disease (GBD) study 2019, we used a Joinpoint regression analysis to examine the variations in the trends of TB incidence and mortality, and the age-period-cohort statistical model to evaluate their risks associated with age, period, and cohort in males and females from Cameroon (CAM), Central African Republic (CAR), Chad, and the Democratic Republic of the Congo (DRC). In the four countries, TB incidence and mortality rates displayed decreasing trends in men and women; except for the males from DRC that recorded an almost steady pattern in the trend of TB incidence between 1990 and 2019. TB incidence and mortality rates decreased according to the overall annual percentage changes over the adjusted age category in men and women of the four countries, and CAM registered the highest decrease. Although TB incidence and mortality rates increased with age between 1990 and 2019, the male gender was mainly associated with the upward behaviors of TB incidence rates, and the female gender association was with the upward behaviors of TB mortality rates. Males and females aged between 15–54 and 15–49 years old were evaluated as the population at high risks of TB incidence and mortality respectively in CAM, CAR, Chad, and DRC. The period and cohort relative risks (RRs) both declined in men and women of the four countries although there were some upward behaviors in their trends. Relatively to the period and cohort RRs, females and males from CAM recorded the most significant decrease compared to the rest of the countries. New public health approaches and policies towards young adults and adults, and a particular focus on elderlies’ health and life conditions should be adopted in CAM, CAR, DRC, and Chad to rapidly decrease TB incidence and mortality in both genders of the four countries.

A giant fourth-ventricular tuberculoma mimicking a primary posterior fossa tumor

Typically, an intracranial tuberculoma occurs within the brain parenchyma. Intraventricular tuberculomas are rare in the absence of systemic tuberculosis (TB), and the differential diagnosis between tuberculoma and other lesions, such as primary brain tumors, can be difficult. We report an extremely unusual case of solitary fourth-ventricular tuberculoma, which occurred in a 3-year-old female patient, with no indication of TB. This lesion appeared as a primary intraventricular tumor in the fourth ventricle in both clinical and radiological examinations. In this scenario, a surgical treatment option was pursued. Histopathological testing supported the diagnosis of tuberculoma. The patient was subsequently treated with 18 months' therapy for tuberculous, without adverse events.

In silico identification of novel chemical compounds with antituberculosis activity for the inhibition of InhA and EthR proteins from Mycobacterium tuberculosis

Tuberculosis (TB) continuously poses a major public health concern around the globe, with a mounting death toll of approximately 1.4 million in 2019. Reduced bioavailability, elevated toxicity, increased side effects, and resistance of multiple first-line and second-line TB medications, including isoniazid, ethionamide necessitate studies of new drugs. The method of computational biology and bioinformatics approach allows virtual screening of a large number of drugs, reduces growing side effects of medications, and predicts potential drug resistance over time. In this study, we have analyzed fifty small molecules with antituberculosis properties using in silico approach including molecular docking, drug-likeness assessment, ADMET (absorption, distribution, metabolism, excretion, toxicity) profile evaluation, P450 site of metabolism prediction, and molecular dynamics simulation. Among those fifty compounds, 3-[3-(4-Fluorophenyl)-1,2,4-oxadiazol-5-yl]-N-(2-methylphenyl) piperidine-1-carboxamide (C22) and 5-(4-Ethyl-phenyl)-2-(1H-tetrazol-5-ylmethyl)-2H-tetrazole (C29) were found to pass the two-step molecular docking, P450 site of metabolism prediction and pharmacokinetics analysis successfully. Their binding stability for target proteins has been evaluated through root mean square deviation and root mean square fluctuation, Radius of gyration analysis from 10 ns Molecular Dynamics Simulation (MDS). Our identified drugs (C22 and C29) performed better than the control drugs (Isoniazid, Ethionamide) regarding binding affinity and molecular stability with the regulatory proteins (InhA, EthR) of Mycobacterium tuberculosis. The study proposed these compounds as effective therapeutic agents for Tuberculosis drug discovery, but further in vitro and in vivo testing are needed to substantiate their potential as novel drugs and modes of action.

Mycobacterium bovis Bacillus Calmette-Guérin-Infected Dendritic Cells Induce TNF-α-Dependent Cell Cluster Formation That Promotes Bacterial Dissemination through an In Vitro Model of the Blood-Brain Barrier

CNS tuberculosis (CNSTB) is the most severe manifestation of extrapulmonary tuberculosis infection, but the mechanism of how mycobacteria cross the blood-brain barrier (BBB) is not well understood. In this study, we report a novel murine in vitro BBB model combining primary brain endothelial cells, Mycobacterium bovis bacillus Calmette-Guérin-infected dendritic cells (DCs), PBMCs, and bacterial Ag-specific CD4⁺ T cells. We show that mycobacterial infection limits DC mobility and also induces cellular cluster formation that has a similar composition to pulmonary mycobacterial granulomas. Within the clusters, infection from DCs disseminates to the recruited monocytes, promoting bacterial expansion. Mycobacterium-induced in vitro granulomas have been described previously, but this report shows that they can form on brain endothelial cell monolayers. Cellular cluster formation leads to cluster-associated damage of the endothelial cell monolayer defined by mitochondrial stress, disorganization of the tight junction proteins ZO-1 and claudin-5, upregulation of the adhesion molecules VCAM-1 and ICAM-1, and increased transmigration of bacteria-infected cells across the BBB. TNF-α inhibition reduces cluster formation on brain endothelial cells and mitigates cluster-associated damage. These data describe a model of bacterial dissemination across the BBB shedding light on a mechanism that might contribute to CNS tuberculosis infection and facilitate treatments.

Evaluation of patients admitted with musculoskeletal tuberculosis: sixteen years' experience from a single center in Turkey

Background

The aim of our study was to describe musculoskeletal system tuberculosis (TB) as a single-center experience.

Methods

This is a retrospective observational study conducted at a TB Dispensary in the east Mediterranean part of Turkey between 2004 and 2020. The clinical and demographic characteristics including age, gender, involvement location and duration of illness, presenting complaint, local examination findings, treatment outcome were retrieved and analyzed from the case files. Statistical analyses were performed using SPSS Statistics version 17.0 (IBM). The normality of data analysed by using Kolmogorov-Smirnov. The descriptive statistics were reported as mean ± standard deviation, medians, and ranges (min-max).

Results

Overall, 31 patients (3.2 % of all TB cases) with a mean age of 44.2 ± 16.7 years had musculoskeletal tuberculosis. The mean duration of treatment was 12.9 ± 5.5 months. Of the 31 patients, six (19.4 %) had concomitant pulmonary TB. One of the patients was in the pediatrics age group, and two of them were in the geriatric group. The most affected area was the vertebra. The most common complaint of the patients was back pain and seen in 22 patients (70.9 %).

Conclusions

The physicians should be suspicious about the diagnosis of musculoskeletal TB disease. If the diagnosis and treatment are delayed, spinal damage and other consequences might be incurable.

Prevalence and associated factors of psychological distress in tuberculosis patients in Northeast China: a cross-sectional study

Background

Psychological distress, a major comorbidities of tuberculosis (TB) patients, has posed a serious threat to the progress being made in global TB programs by affecting treatment adherence and health outcomes. However, the magnitude and associated factors of psychological distress have not been fully studied in China. The aim of the current study was to assess the prevalence of psychological distress in TB patients and to further determine the effects of socio-demographic characteristics, health-related variables, substance use status, social support, and experienced stigma on psychological distress.

Methods

A cross-sectional survey was conducted among TB patients attending three medical institutions in Dalian, Liaoning Province, Northeast China from November 2020 to March 2021. A structured questionnaire was developed to collect data on patients’ socio-demographic characteristics, health-related information, substance use status, psychological distress, family function, doctor-patient relationship, policy support, experienced stigma and so on. The binary logistics regression model was used to determine the associated factors of psychological distress.

Results

A total of 473 TB patients were enrolled in this study, and the prevalence of psychological distress was 64.1%. Binary logistic regression analysis revealed that patients with a middle school education level or above (OR: 0.521, 95%CI: 0.279–0.974), no adverse drug reactions (OR: 0.476, 95%CI: 0.268–0.846), and regular physical exercise (OR: 0.528, 95%CI: 0.281–0.993) were more likely to stay away from psychological distress. However, patients who had a high economic burden (OR: 1.697, 95%CI: 1.014–2.840), diabetes (OR: 2.165, 95%CI: 1.025–4.573), self-rated illness severe (OR: 3.169, 95%CI: 1.081–9.285), perceived poor resistance (OR: 2.065, 95%CI: 1.118–3.815), severe family dysfunction (OR: 4.001, 95%CI: 1.158–13.823), perceived need for strengthen psychological counseling (OR: 4.837, 95%CI: 2.833–8.258), and a high experienced stigma (OR: 3.253, 95%CI: 1.966–5.384) tended to have a psychological distress.

Conclusions

The study found that the proportion of psychological distress among TB patients was high in Northeast China, and it was influenced by a variety of factors. Effective interventions to reduce psychological distress in TB patients urgently need to be developed, and greater attention should be given to patients with risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06284-4.

Whole genome analysis of extensively drug resistant Mycobacterium tuberculosis strains in Peru

Peru has the highest burden of multidrug-resistant tuberculosis in the Americas region. Since 1999, the annual number of extensively drug-resistant tuberculosis (XDR-TB) Peruvian cases has been increasing, becoming a public health challenge. The objective of this study was to perform genomic characterization of Mycobacterium tuberculosis strains obtained from Peruvian patients with XDR-TB diagnosed from 2011 to 2015 in Peru. Whole genome sequencing (WGS) was performed on 68 XDR-TB strains from different regions of Peru. 58 (85.3%) strains came from the most populated districts of Lima and Callao. Concerning the lineages, 62 (91.2%) strains belonged to the Euro-American Lineage, while the remaining 6 (8.8%) strains belonged to the East-Asian Lineage. Most strains (90%) had high-confidence resistance mutations according to pre-established WHO-confident grading system. Discordant results between microbiological and molecular methodologies were caused by mutations outside the hotspot regions analysed by commercial molecular assays (rpoB I491F and inhA S94A). Cluster analysis using a cut-off ≤ 10 SNPs revealed that only 23 (34%) strains evidenced recent transmission links. This study highlights the relevance and utility of WGS as a high-resolution approach to predict drug resistance, analyse transmission of strains between groups, and determine evolutionary patterns of circulating XDR-TB strains in the country.

Zoonotic tuberculosis knowledge and practices among cattle handlers in selected districts of Bangladesh

We assessed zoonotic tuberculosis (zTB) knowledge and prevention and control practices of 404 cattle handlers via a survey in three dairy-intensive districts of Bangladesh. Most respondents were aged 30-49 (52%) and male (95%). Almost all (99%) recognized the important public health burden of tuberculosis in Bangladesh, however, most (58%) had inadequate knowledge about zTB transmission to humans. Inappropriate practices such as: not using protective equipment (98%); smoking, drinking or eating food whilst working with cattle (69%); and sharing the same premises with animals (83%) were identified. Cattle handlers educated at secondary or higher levels were 2.82- (95% CI: 1.59-5.10) and 5.15 times (95% CI: 1.74-15.20) more likely to have adequate knowledge of control and prevention activities compared to those with no formal education. Those who had reared animals for 1-5 years were 2.67 times (95% CI: 1.44-4.91) more likely to have adequate knowledge, compared to those who reared animals for >15 years. Cattle handlers with a monthly incomes of 10,000-20,000 taka were significantly (Odds Ratio = 0.36, 95% CI: 0.14-0.92) less likely to have adequate knowledge compared to those with monthly incomes <10,000 taka. Cattle handlers with high school or higher education were 6.98 times (95% CI: 2.47-19.71) more likely to use appropriate zTB control and prevention practices compared to those without formal education. Those who had reared animals for 1-5 years, 6-10 years and 11-15 years were 2.72- (95% CI: 1.42-5.24), 2.49- (95% CI: 1.29-4.77) and 2.86 times (95% CI: 1.13-7.23) more likely to apply appropriate practices compared to those who reared animals for >15 years. Overall, education, duration of cattle rearing and monthly income predicted zTB knowledge and practices. There is an urgent need to educate those at high-risk of zTB transmission on issues including the handling of infected animals, and general hygiene. A One Health approach, to support the Sustainable Development Goals and the End TB strategy, appears to be the way forward.

Effect of Disease State on the Pharmacokinetics of Bedaquiline in Renal-Impaired and Diabetic Rats

Bedaquiline (TMC-207) is a key anti-tubercular drug to fight against multidrug resistance tuberculosis. Little information is available till date on the impact of any disease state toward its pharmacokinetic behavior. The present research work aimed to investigate the effect of renal impairment and diabetes mellitus on the oral pharmacokinetics of bedaquiline in the rat model. Renal impairment and diabetes mellitus were induced in the Wistar rat model separately using cisplatin and streptozotocin, respectively, and thereafter, an oral pharmacokinetic study of bedaquiline was carried out in the individual disease models as well as in the normal rat model. Pharmacokinetic parameters of bedaquiline were not altered markedly in cisplatin-induced renal-impaired rats compared to normal rats except an area under the curve (AUC) for plasma concentration of bedaquiline in the experimental time frame (AUC_0-t ) reduced to 3477 ± 228 from 4984 ± 1174 ng h/mL, respectively. Maximum plasma concentrations of bedaquiline (259 ± 77 ng/mL), AUC_0-t (3112 ± 1046 ng h/mL), and AUC_0-∞ (3673 ± 1493 ng h/mL) were significantly reduced along with an increase in the clearance of bedaquiline (3.1 ± 1.1 L/h/kg) in the case of streptozotocin-induced diabetic rats compared to respective pharmacokinetic parameters of bedaquiline (482 ± 170 ng/mL, 4984 ± 1174 ng h/mL, and 6137 ± 1542 ng h/mL) in the normal rats. Preclinical findings suggest that dose adjustment of bedaquiline is required in the diabetes mellitus condition to prevent the therapeutic failure of bedaquiline treatment, but clinical exploration is needed to establish the fact. It is the first report for the consequence of renal impairment and diabetes mellitus on the pharmacokinetics of bedaquiline in the preclinical model.

Diagnosis of latent tuberculosis infection among pediatric household contacts of Iranian tuberculosis cases using tuberculin skin test, IFN- γ release assay and IFN-γ-induced protein-10

BACKGROUND

Although the World Health Organization has recommended the diagnosis and prophylactic treatment of latent tuberculous infection (LTBI) in child household contacts of tuberculosis (TB) cases, the national programs in high-burden TB regions rarely implement adequate screening of this high-risk group, mainly because of resource limitations. We aimed to evaluate the prevalence of LTBI among pediatric household contacts of TB cases in two high-burden provinces in Iran.

METHODS

We conducted a cohort study in children who had been in household contact with a TB index. All subjects were assessed for active TB disease. For LTBI diagnosis, tuberculin skin test (TST) and QuantiFERON®-TB Gold Plus (QFT-Plus) were performed at the time of the index TB case diagnosis, as well as, 3, 12, and 18 months, if the first results were negative. In addition, interferon-γ-induced protein-10(IP-10) concentrations were measured for all participants.

RESULTS

A total of 230 children were enrolled, who had contact with an index TB case. Three contacts were diagnosed with active TB. According to the TST/QFT-Plus results, 104 (45.2%) children were identified with LTBI during our study. Significantly increased IP-10 levels were found in LTBI patients compared to healthy contacts. Accordingly, more than 50% of LTBI contacts and about 10% of healthy contacts were considered as IP-10-positive.

CONCLUSION

This study alarmingly illustrates a high prevalence of LTBI among Iranian children exposed to TB cases. We, therefore, emphasize that the children living in close contact with an infectious TB case should be screened effectively and receive prophylactic therapy.

Therapeutic Potential of Mesenchymal Stem Cells and Their Products in Lung Diseases-Intravenous Administration versus Inhalation

The number of publications studying the therapeutic use of stem cells has steadily increased since 2000. Compared to other applications, there has been little interest in the evaluation of mesenchymal stem cells (MSCs) and MSC-derived products (mostly extracellular vesicles) for the treatment of respiratory diseases. Due to the lack of efficient treatments for acute respiratory distress syndrome caused by infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the action of MSCs has also been studied. This review describes mode of action and use of MSCs and MSC-derived products in the treatment of lung diseases including the respective advantages and limitations of the products. Further, issues related to standardized production are addressed. Administration by inhalation of MSCs, compared to intravenous injection, could decrease cell damage by shear stress, eliminate the barrier to reach target cells in the alveoli, prevent thrombus formation in the pulmonary vasculature and retention in filter for extracorporeal membrane oxygenation. There is more feasible to deliver extracellular vesicles than MSCs with inhalers, offering the advantage of non-invasive and repeated administration by the patient. Major obstacles for comparison of results are heterogeneity of the products, differences in the treatment protocols and small study cohorts.

Evolution of Drug-Resistant Mycobacterium tuberculosis Strains and Their Adaptation to the Human Lung Environment

In the last two decades, multi (MDR), extensively (XDR), extremely (XXDR) and total (TDR) drug-resistant Mycobacterium tuberculosis (M.tb) strains have emerged as a threat to public health worldwide, stressing the need to develop new tuberculosis (TB) prevention and treatment strategies. It is estimated that in the next 35 years, drug-resistant TB will kill around 75 million people and cost the global economy $16.7 trillion. Indeed, the COVID-19 pandemic alone may contribute with the development of 6.3 million new TB cases due to lack of resources and enforced confinement in TB endemic areas. Evolution of drug-resistant M.tb depends on numerous factors, such as bacterial fitness, strain's genetic background and its capacity to adapt to the surrounding environment, as well as host-specific and environmental factors. Whole-genome transcriptomics and genome-wide association studies in recent years have shed some insights into the complexity of M.tb drug resistance and have provided a better understanding of its underlying molecular mechanisms. In this review, we will discuss M.tb phenotypic and genotypic changes driving resistance, including changes in cell envelope components, as well as recently described intrinsic and extrinsic factors promoting resistance emergence and transmission. We will further explore how drug-resistant M.tb adapts differently than drug-susceptible strains to the lung environment at the cellular level, modulating M.tb-host interactions and disease outcome, and novel next generation sequencing (NGS) strategies to study drug-resistant TB.

Determinants of self-reported correct knowledge about tuberculosis transmission among men and women in Malawi: evidence from a nationwide household survey

BACKGROUND

Correct knowledge about transmission of tuberculosis (TB) can influence better health-seeking behaviors, and in turn, it can aid TB prevention in society. Therefore, this study aimed to examine the prevalence and predictors of self-reported correct knowledge about TB transmission among adults in Malawi.

METHODS

We conducted a secondary analysis of the data obtained from the Malawi Demographic and Health Survey, 2015/16 (MDHS 2015/16). Questions regarding self-reported TB transmission were computed to evaluate the correct knowledge about TB transmission. The factors associated with the correct knowledge about Tb were assessed using univariate and multivariable logistic regression.

RESULTS

Overall, the prevalence of correct knowledge about TB transmission in the general population of Malawian adults was 61.5%. Specifically, the prevalence of correct knowledge about TB transmission was 63.6 and 60.8% in men and women, respectively. Those aged 35-44 years, having secondary or high education, belonging to the richest household, being exposed to mass media, being in professional/technical/managerial, having knowledge that "TB can be cured", and those living in urban areas were significantly associated with correct knowledge about TB transmission.

CONCLUSIONS

The findings of this study show that if appropriate strategies for TB communication and education to address the rural masses, young individuals, poor individuals, and individuals in the agriculture sector are put it place, can enhance TB prevention in Malawi.

Mycobacteriophages as Potential Therapeutic Agents against Drug-Resistant Tuberculosis

The current emergence of multi-, extensively-, extremely-, and total-drug resistant strains of Mycobacterium tuberculosis poses a major health, social, and economic threat, and stresses the need to develop new therapeutic strategies. The notion of phage therapy against bacteria has been around for more than a century and, although its implementation was abandoned after the introduction of drugs, it is now making a comeback and gaining renewed interest in Western medicine as an alternative to treat drug-resistant pathogens. Mycobacteriophages are genetically diverse viruses that specifically infect mycobacterial hosts, including members of the M. tuberculosis complex. This review describes general features of mycobacteriophages and their mechanisms of killing M. tuberculosis, as well as their advantages and limitations as therapeutic and prophylactic agents against drug-resistant M. tuberculosis strains. This review also discusses the role of human lung micro-environments in shaping the availability of mycobacteriophage receptors on the M. tuberculosis cell envelope surface, the risk of potential development of bacterial resistance to mycobacteriophages, and the interactions with the mammalian host immune system. Finally, it summarizes the knowledge gaps and defines key questions to be addressed regarding the clinical application of phage therapy for the treatment of drug-resistant tuberculosis.

Effects of Curcumin and Its Analogues on Infectious Diseases

Infectious diseases (IDs) are life-threatening illnesses, which result from the spread of pathogenic microorganisms such as bacteria, viruses, fungi, and parasites. IDs are a major challenge for the healthcare systems around the world, leading to a wide variety of clinical manifestations and complications. Despite the capability of frontline-approved medications to partially prevent or mitigate the invasion and subsequent damage of IDs to host tissues and cells, problems such as drug resistance, insufficient efficacy, unpleasant side effects, and high expenses stand in the way of their beneficial applications. One strategy is to evaluate currently explored and available bioactive compounds as possible anti-microbial agents. The natural polyphenol curcumin has been postulated to possess various properties including anti-microbial activities. Studies have shown that it possess pleiotropic effects against bacterial- and parasitic-associating IDs including drug-resistant strains. Curcumin can also potentiate the efficacy of available anti-bacterial and anti-parasitic drugs in a synergistic fashion. In this review, we summarize the findings of these studies along with reported controversies of native curcumin and its analogues, alone and in combination, toward its application in future studies as a natural anti-bacterial and anti-parasitic agent.

Which Current and Novel Diagnostic Avenues for Bacterial Respiratory Diseases?

Bacterial acute pneumonia is responsible for an extremely large burden of death worldwide and diagnosis is paramount in the management of patients. While multidrug-resistant bacteria is one of the biggest health threats in the coming decades, clinicians urgently need access to novel diagnostic technologies. In this review, we will first present the already existing and largely used techniques that allow identifying pathogen-associated pneumonia. Then, we will discuss the latest and most promising technological advances that are based on connected technologies (artificial intelligence-based and Omics-based) or rapid tests, to improve the management of lung infections caused by pathogenic bacteria. We also aim to highlight the mutual benefits of fundamental and clinical studies for a better understanding of lung infections and their more efficient diagnostic management.

Pharmacodynamic Functions of Synthetic Derivatives for Treatment of Methicillin-Resistant Staphylococcus aureus (MRSA) and Mycobacterium tuberculosis

Drug resistant bacteria have emerged, so robust methods are needed to evaluate combined activities of known antibiotics as well as new synthetic compounds as novel antimicrobial agents to treatment efficacy in severe bacterial infections. Marine natural products (MNPs) have become new strong leads in the drug discovery endeavor and an effective alternative to control infections. Herein, we report the bioassay guided fractionation of marine extracts from the sponges Lendenfeldia, Ircinia, and Dysidea that led us to identify novel compounds with antimicrobial properties. Chemical synthesis of predicted compounds and their analogs has confirmed that the proposed structures may encode novel chemical structures with promising antimicrobial activity against the medically important pathogens. Several of the synthetic analogs exhibited potent and broad spectrum in vitro antibacterial activity, especially against the Methicillin-resistant Staphylococcus aureus (MRSA) (MICs to 12.5 μM), Mycobacterium tuberculosis (MICs to 0.02 μM), uropathogenic Escherichia coli (MIC o 6.2 μM), and Pseudomonas aeruginosa (MIC to 3.1 μM). Checkerboard assay (CA) and time-kill studies (TKS) experiments analyzed with the a pharmacodynamic model, have potentials for in vitro evaluation of new and existing antimicrobials. In this study, CA and TKS were used to identify the potential benefits of an antibiotic combination (i.e., synthetic compounds, vancomycin, and rifampicin) for the treatment of MRSA and M. tuberculosis infections. CA experiments indicated that the association of compounds 1a and 2a with vancomycin and compound 3 with rifampicin combination have a synergistic effect against a MRSA and M. tuberculosis infections, respectively. Furthermore, the analysis of TKS uncovered bactericidal and time-dependent properties of the synthetic compounds that may be due to variations in hydrophobicity and mechanisms of action of the molecules tested. The results of cross-referencing antimicrobial activity, and toxicity, CA, and Time-Kill experiments establish that these synthetic compounds are promising potential leads, with a favorable therapeutic index for antimicrobial drug development.

The practice of evaluating epidemic response in humanitarian and low-income settings: a systematic review

BACKGROUND

Epidemics of infectious disease occur frequently in low-income and humanitarian settings and pose a serious threat to populations. However, relatively little is known about responses to these epidemics. Robust evaluations can generate evidence on response efforts and inform future improvements. This systematic review aimed to (i) identify epidemics reported in low-income and crisis settings, (ii) determine the frequency with which evaluations of responses to these epidemics were conducted, (iii) describe the main typologies of evaluations undertaken and (iv) identify key gaps and strengths of recent evaluation practice.

METHODS

Reported epidemics were extracted from the following sources: World Health Organization Disease Outbreak News (WHO DON), UNICEF Cholera platform, Reliefweb, PROMED and Global Incidence Map. A systematic review for evaluation reports was conducted using the MEDLINE, EMBASE, Global Health, Web of Science, WPRIM, Reliefweb, PDQ Evidence and CINAHL Plus databases, complemented by grey literature searches using Google and Google Scholar. Evaluation records were quality-scored and linked to epidemics based on time and place. The time period for the review was 2010-2019.

RESULTS

A total of 429 epidemics were identified, primarily in sub-Saharan Africa, the Middle East and Central Asia. A total of 15,424 potential evaluations records were screened, 699 assessed for eligibility and 132 included for narrative synthesis. Only one tenth of epidemics had a corresponding response evaluation. Overall, there was wide variability in the quality, content as well as in the disease coverage of evaluation reports.

CONCLUSION

The current state of evaluations of responses to these epidemics reveals large gaps in coverage and quality and bears important implications for health equity and accountability to affected populations. The limited availability of epidemic response evaluations prevents improvements to future public health response. The diversity of emphasis and methods of available evaluations limits comparison across responses and time. In order to improve future response and save lives, there is a pressing need to develop a standardized and practical approach as well as governance arrangements to ensure the systematic conduct of epidemic response evaluations in low-income and crisis settings.

The case of pulmonary tuberculosis with COVID-19 in an Indian male-a first of its type case ever reported from South Asia

We report the first case of tuberculosis with COVID-19 from South Asia. The patient was a 43 years old Indian male. He reported to us in the outpatient department with chief complaints of cough with expectoration associated with fever, chest pain, and night sweats. The diagnosis of tuberculosis in the current pandemic of COVID-19 required a high degree of suspicion to rule out the SARS-CoV-2 infection along with the infection of Mycobacterium tuberculosis. The clinical presentations in the two diseases are quite similar and thus the present case will serve as a tool to help the clinicians handling cases of both the viral and bacterial infection across the globe.

Frequency of Codon 306 Mutations in embB Gene of Mycobacterium tuberculosis Resistant to Ethambutol: A Systematic Review and Meta-Analysis

BACKGROUND

Ethambutol (EMB) resistance is a major concern in patients with tuberculosis (TB). The aim of this study was to determine the frequency rate of mutations in the embB306 gene of Mycobacterium tuberculosis (M. tuberculosis) resistant to EMB, based on a systematic review and meta-analysis.

METHODS

Thirty-seven original articles (1997-2015) that have been published in valid databases were considered for this research. The articles were systematically reviewed for the prevalence and rate of mutations in embB306 in EMB-resistant M. tuberculosis. Data were analyzed using meta-analysis and random effects models (CI 95%, P < 0.10).

RESULTS

With a 6,931 sample size in 37 original articles, the lowest rate was related to EMB resistance that was observed in 2014 with 0.05 (95% CI: 0.04-0.07) and the highest prevalence rate was 0.84 (95% CI: 0.68-1.01), observed in 1997. Lowest and highest prevalence rates of embB306 gene mutation in M. tuberculosis were 0.03 (95% CI: 0.01-0.07) in 2014 and 0.78 (95% CI: 0.71-1.84) in 2005, in the USA, respectively.

CONCLUSIONS

The present study revealed the prevalence and association of mutations in the embB306 gene of M. tuberculosis with resistance to EMB. Detecting EMB-resistant M. tuberculosis can help in controlling and correcting the administration of drugs for patients with TB.

Effect of Global Fund financial support for patients with multidrug-resistant tuberculosis

SETTING: The Global Fund provides financial support for patients with multidrug-resistant tuberculosis (MDR-TB), patients' families and hospitals providing services for these patients in Thailand, but the impact of this support has not been evaluated.OBJECTIVE: To assess the impact of Global Fund financial support on drug adherence, out-of-pocket (OOP) payments, sputum culture conversion and the perception of the usefulness of this support.DESIGN: A retrospective cohort study was conducted in eight provincial hospitals with and without financial support in four regions of Thailand. MDR-TB patients aged ≥15 years registered in 2015-2016 who received treatment at these hospitals for at least 6 months were included.RESULTS: There was no significant difference in drug adherence rates. The OOP payments during treatment were significantly lower in patients who received financial support (P < 0.001). Although the supported group had higher positive culture rates at the beginning of treatment, sputum converted at a faster rate than for the unsupported group (P = 0.034). More than 80% of both groups perceived financial support as being useful, leading to faster diagnosis and improving follow-up compliance.CONCLUSION: Financial support for MDR-TB patients has a positive impact on treatment and should be continued.

Social franchising of community-based HIV counselling and testing services to increase HIV testing and linkage to care in Tshwane, South Africa: study protocol for a non-randomised implementation trial

BACKGROUND

Meeting the ambitious UN 90-90-90 HIV testing, treatment and viral load suppression targets requires innovative strategies and approaches in Sub-Saharan Africa. To date no known interventions have been tested with community health workers (counsellors) as social franchisees or owner-managed businesses in Community-based HIV counselling and testing (CBCT) work. The aim of this methods paper is to describe a Social franchise (SF) CBCT implementation trial to increase HIV testing and linkage to care for individuals at community levels in comparison with an existing CBCT programme methods.

METHODS/DESIGN

This is a two arm non-randomised community implementation trial with a once off round of post-test follow-up per HIV positive participant to assess linkage to care in low income communities. The intervention arm is a social franchise CBCT in which unemployed, self-employed or employed community members are recruited, contracted and incentivised to test at least 100 people per month, identifying at least 5 HIV positive tests and linking to care at least 4 of them. Social franchisees receive approximately $3.20 per HIV test and $8 per client linked to care. In the control arm, full-time employed HIV counsellors conduct CBCT on a fixed monthly salary. Primary study outcomes are HIV testing uptake rate, HIV positivity, Linkage to care and treatment rate and average counsellors' remuneration cost. Data collection will be conducted using both paper-based and electronic data applications by CBCT or SF counsellors. Data analysis will compare proportions of HIV testing, positivity, linkage to HIV care and treatment rates and counsellors' cost in the two study arms.

DISCUSSION

The study will provide important insight into whether the SF-delivered CBCT programme increases testing coverage and linkage to care as well as reducing CBCT cost per HIV test and per HIV positive person linked to care.

TRIAL REGISTRATION

Pan African Clinical Trial Registry PACTR201809873079121. The trial was retrospectively registered on 11 September 2018.

Improvement of Nutritional Status among Tuberculosis Patients by Channa striata Supplementation: A True Experimental Study in Indonesia

OBJECTIVE

To analyze the effect of Channa striata supplementation on body mass index among tuberculosis patients, in which their health status is also investigated.

METHODS

This study employed a true experiment. The study was designed randomized pretest-posttest with a control group, in which 200 respondents were enrolled. Body mass index (BMI), used as a nutritional status indicator, was measured every week for a month. Chi-square test was used to analyze the data with a significance level of 5% by STATA 13.

RESULTS

The mean BMI of all groups increases during the month, in which rapid alteration occurs in the treatment group. The mean BMI (kg/m2) in the treatment group at weeks 0-4 was reported to be 17.43, 17.65, 17.90, 18.04, and 18.22, respectively. Meanwhile, the mean BMI (kg/m2) at weeks 0-4 in the control group was reported to be 17.20, 17.36, 17.57, 17.71, and 17.96, respectively. Furthermore, the alteration from severe thinness to higher BMI level in the treatment group is the highest. Based on the statistical test, there were no differences in BMI between the treatment and control groups (p > 0.05). However, the alteration of nutritional status in the treatment group is faster than that in the control group. In addition, there is no difference in their health status between the treatment and control groups (p > 0.05), except vomiting (p < 0.05).

CONCLUSION

The BMI among tuberculosis patients with Channa striata supplementation is increasing faster than that in the control group within a month with a minimum potential negative effect.

Potential Genes Related to Levofloxacin Resistance in Mycobacterium tuberculosis Based on Transcriptome and Methylome Overlap Analysis

Drug-resistant Mycobacterium tuberculosis (M. tuberculosis) has become an increasingly serious public health problem and has complicated tuberculosis (TB) treatment. Levofloxacin (LOF) is an ideal anti-tuberculosis drug in clinical applications. However, the detailed molecular mechanisms of LOF-resistant M. tuberculosis in TB treatment have not been revealed. Our study performed transcriptome and methylome sequencing to investigate the potential biological characteristics of LOF resistance in M. tuberculosis H37Rv. In the transcriptome analysis, 953 differentially expressed genes (DEGs) were identified; 514 and 439 DEGs were significantly downregulated and upregulated in the LOF-resistant group and control group, respectively. The KEGG pathway analysis revealed that 97 pathways were enriched in this study. In the methylome analysis, 239 differentially methylated genes (DMGs) were identified; 150 and 89 DMGs were hypomethylated and hypermethylated in the LOF-resistant group and control group, respectively. The KEGG pathway analysis revealed that 74 pathways were enriched in this study. The overlap study suggested that 25 genes were obtained. It was notable that nine genes expressed downregulated mRNA and upregulated methylated levels, including pgi, fadE4, php, cyp132, pckA, rpmB1, pfkB, acg, and ctpF, especially cyp132, pckA, and pfkB, which were vital in LOF-resistant M. tuberculosis H37Rv. The overlapping genes between transcriptome and methylome could be essential for studying the molecular mechanisms of LOF-resistant M. tuberculosis H37Rv. These results may provide informative evidence for TB treatment with LOF.

Risk factors of tuberculosis infection among health care workers: A meta-analysis

BACKGROUNDS

Health care workers (HCWs) are globally known to have high risk of tuberculosis (TB) infection while risk factors of TB infections among HCWs are still inconclusive.

OBJECTIVES

To perform a meta-analysis in effort to identify risk factors of TB infection among HCWs.

METHODS

A meta-analysis was conducted between February and July 2019. Papers were searched in Pubmed, Embase, Cochrane, and Web of science and information of interest were extracted. The correlation and effect estimation were analyzed using random or fixed effect model.

RESULTS

A total of 12 studies consisting of 2871 cases and 15,673 controls were included and six risk factors were available for meta-analysis. Cumulative calculation found that age, working duration, and types of job were significant risk factor of TB infection while gender, active TB contact, and types of workplace were not associated significantly with TB infection among HCWs. Our pooled data revealed that decreased risk of TB infection was observed in age less than 30 years (age < 30 years vs. age ≥ 30 years) and working duration less than five years (working duration < 5 years vs. ≥5 years). Being more than 40 years, working more than 10 years, and being physicians increased the risk of TB infection significantly compared to age ≤40 years, working duration ≤10 years, and other job types, respectively.

CONCLUSIONS

Our meta-analysis has identified the significant risk factors of TB infection among HCWs. Our results may be useful for establishing future TB prevention program among HCWs.

Diagnosing Tuberculosis Using Deep Convolutional Neural Network

One of the global topmost causes of death is Tuberculosis (TB) which is caused by mycobacterium bacillus. The increase rate of infected people and the recorded deaths from TB disease is as a result of its transmissibility, lack of early diagnosis, and inadequate professional radiologist in developing regions where TB is more prevalent. Tuberculosis is unquestionably curable but needs to be detected early for necessary treatment to be effective. Many screening techniques are available, but chest radiograph has proven to be valuable for screening pulmonary diseases but hugely dependent on the interpretational skill of an expert radiologist. We propose a Computer-Aided Detection model using Deep Convolutional Neural Networks to automatically detect TB from Montgomery County (MC) Tuberculosis radiographs. Our proposed model performed at 87.1% validation accuracy and evaluated using confusion matrix and accuracy as metrics.

Time Interval for Diagnosis of Tuberculosis and Related Expenditure in Selected Health Centers in Addis Ababa, Ethiopia

Background. Tuberculosis (TB) has continued to be a major health problem globally, in spite of the efforts to improve the diagnosis, treatment, and prevention. It affects millions of people each year and stands as the second cause of death due to infectious disease in the world. Early case finding and timely initiation of treatment is essential to ensure effective control of the disease as late diagnosis and treatment can aggravate the disease and result in poor outcomes and increase chances of transmission. Although TB services are supposed to be provided free of charge, TB affected families incur different types of costs in the process of seeking care, which might include health and nonhealth related costs. TB programs need to identify the underlying factors for delay and related expenditure for TB related services, in order to devise an effective strategy to reduce them. Therefore, the study aimed to assess the time interval between developing TB symptom until patients start anti-TB treatment and associated cost incurred by patients and families. Methods. This cross-sectional study was conducted among pulmonary TB patients who are bacteriologically confirmed, whose age is above 15 years and diagnosed at health centres in Addis Ababa. Results. The median time interval between onset of symptom and commencement of treatment was 4 weeks (IQR: 3, 6). Most patients with TB symptoms visited several health facilities before the final diagnosis was confirmed, the median number of visits being two, and only 48.8% were diagnosed on their first visit. Hence, they spent a lot of their limited resource in search of getting the right diagnosis. The total combined expenditure for all the visits was estimated to be median (IQR) 172.65 birrs (12, 671). Two variables were found to show statistically significant association with higher expenditure. Respondents who have good level of knowledge about TB are less likely to spend more than the median expenditure almost by a fifth compared to those with limited knowledge on TB, (adjusted odds ratio (AOR) = 0.2, with 95% confidence interval (CI): 0.06, 0.84). Patients who visited public hospitals were almost three times and those who visited private health facilities almost four times more likely to pay more than the median total expenditure, compared to those who visited health centre, AOR (95% CI) = 2.8 (1.53, 5.19) and AOR (CI) of 3.86 (1.06, 14.03), respectively. Conclusion. Patients with TB symptoms visit several health facilities till they are diagnosed, the median duration from onset of symptom till commencement of TB treatment being 4 weeks. It was noted that they face major expenses in the process of navigation to the right care. Two variables had statistically significant association with high pre-diagnosis expenditure, where patients with good level of knowledge about TB are less likely to spend more than the median, while patients who visited public hospitals or private health facilities had very high expenses. Improved public awareness about TB, minimizing service charges and other related fees, and further improvement in increasing access to services could reduce the length of time and expense for TB patients and their families. It is recommended to build capacity of health service providers to update them on programmatic approaches and latest diagnostic algorithm. It is important to strengthen public private partnership for TB services.

Performance of Multidrug-Resistant Tuberculosis Surveillance in Yemen: Interview Study

BACKGROUND

Multidrug-resistant tuberculosis (MDR-TB) is a major challenge to ending TB occurrence by 2035. In Yemen, the 2011 survey showed an MDR-TB prevalence of 1.4% among new cases and 14.4% among previously treated cases. The National Tuberculosis Control Program (NTCP) established four MDR-TB sentinel surveillance sites in 2013 to monitor the MDR-TB situation. In Yemen, the 2011 survey showed an MDR-TB prevalence of 1.4% among new cases and 14.4% among previously treated cases. The NTCP established four MDR-TB sentinel surveillance sites in 2013 to monitor the MDR-TB situation.

OBJECTIVE

This study aimed to assess the performance of MDR-TB surveillance and determine its strengths and weaknesses.

METHODS

We used the updated Center for Diseases Control and Prevention guidelines for evaluating public health surveillance systems. Interviews were conducted with NTCP managers and Regional MDR-TB centers' staff using a semistructured questionnaire. We used a 5-point Likert scale to assess the usefulness and other attributes (eg, simplicity and flexibility). The mean percentage was calculated for each attribute and used for the final rank of the performance: poor (<60%), average (60%-80%), and good (>80%).

RESULTS

The MDR-TB surveillance system achieved good performance in usefulness (87%), acceptability (82%), and data quality (91%); average performance in flexibility (61%) and simplicity (72%); and poor performance in stability (55%). The overall performance score was average (74%). Although strong commitment, good monitoring, and well-trained staff are the main strengths, depending on an external fund is a major weakness along with unavailability of the MDR-TB unit at the governorate level.

CONCLUSIONS

Although the MDR-TB surveillance system has achieved an average overall performance, more efforts are required to improve its stability by ensuring constant power supply to enable laboratories to perform necessary diagnostic and follow-up tests. Gradual replacement of donors' funds by the government is recommended. Scaling up of MDR-TB services and removing access barriers are crucial.

Mucosal boosting of H56:CAF01 immunization promotes lung-localized T cells and an accelerated pulmonary response to Mycobacterium tuberculosis infection without enhancing vaccine protection

T cell-mediated protection against Mycobacterium tuberculosis (Mtb) is dependent upon the ability to localize within the site of pulmonary infection and directly interact with infected cells. In turn, vaccine strategies to improve rapid T cell targeting of Mtb-infected cells after pulmonary exposure are being actively pursued. Given parenterally, the subunit vaccine H56:CAF01 elicits polyfunctional CD4 T cells that localize to the lung parenchyma and confer durable protection. Here, we find that airway mucosal boosting of parenteral H56:CAF01 immunization greatly enhances the population of long-lived lung-resident T cells (Trm) and increases early vaccine T cell responses to pulmonary Mtb challenge in multiple mouse models. However, mucosal boosting does not alter the Th1/17 vaccine signature typical of H56:CAF01 and does not further improve durable control of pulmonary infection following aerosol Mtb-challenge. Additional mucosal boosting with H56:CAF01 further enhances the Trm response without further improving protection, while blocking the recruitment of non-Trm with FTY720-treatment failed to exposed Trm-mediated protection in mucosally boosting animals. These results demonstrate the limitations of maximizing lung-localized Trm in vaccine control of pulmonary Mtb infection, especially within an immunization protocol that is already optimized for the induction of mucosal-homing Th17 cells.

Channa striata (Ikan Gabus) Extract and the Acceleration of Tuberculosis Treatment: A True Experimental Study

Tuberculosis is international health problem, which is classified in Global Emergency disease since 1992. The objective of the study is to determine the effect of Channa striata extract toward the acceleration of tuberculosis treatment. The study used true experiment, in which the intervention of the study was Channa striata supplementation to respondent. In addition, Chi-square was used to analyze the data with SPSS version 22. The result is the proportion of respondent classified in negative category in intervention group within week 0, week 1, week 2, week 3, and week 4 being 10.7%, 35.9%, 56.3%, 70.9%, and 90.3%, respectively. Besides, the proportion of respondent classified in negative category in control group within week 0, week 1, week 2, week 3, and week 4 was 13.4%, 23.7%, 37.1%, 49.5%, and 68%, respectively. Based on Chi-square test, the P value of Channa striata supplementation toward the acceleration of tuberculosis treatment week 1, week 3, and week 4 is 0.045, 0.019, and 0.005 (P< α; α=0.05), respectively. It means that there were differences between Channa striata supplementation and acceleration of tuberculosis treatment among respondent. Therefore, Channa striata treatment was significantly related to the acceleration of tuberculosis recovery.

Depression and associated factors among patients with tuberculosis in Ethiopia: a cross-sectional study

PURPOSE

The study aimed to assess the magnitude of depression and associated factors among patients with tuberculosis (TB) visiting outpatient clinics in Ethiopia.

PATIENTS AND METHODS

A cross-sectional study was conducted among 415 TB patients. Study participants were selected through a systematic random sampling technique. Patient Health Questionnaire-9 (PHQ-9) was used to assess depression using face-to-face interviews. Data were analyzed using SPSS version 20. Bivariate and multivariate binary logistic analyses were done to identify associated factors with depression. P-values less than 0.05 were considered statistically significant, and the strength of the association was presented by adjusted OR (AOR) with 95% CI.

RESULTS

The magnitude of depression was found to be 31.1% with 95% CI (26.5-35.7). Extrapulmonary TB [AOR =1.8, 95% CI (1.02, 3.24)], poor social support [AOR =3.3, 95% CI (1.8, 6.03)] and perceived TB stigma [AOR =2.0, 95% CI (1.28, 3.18)] were variables found to be statistically significantly connected with depression.

CONCLUSION

The magnitude of depression was high compared to the general population and some other studies. Therefore, the current study area and other settings which provide TB screening and treatment need to assess patients for depression and provide intervention, giving more emphasis to patients with risk factors.

Social franchising of community-based HIV testing and linkage to HIV care and treatment services: an evaluation of a pilot study in Tshwane, South Africa

INTRODUCTION

Although HIV testing services (HTS) have been successfully task-shifted to lay counsellors, no model has tested the franchising of HTS to lay counsellors as independent small-scale business owners. This paper evaluates the effectiveness of a social franchisee (SF) HTS-managed pilot project compared to the Foundation for Professional Development (FPD) employee-managed HTS programme in testing and linking clients to care.

METHODS

Unemployed, formally employed or own business individuals were engaged as franchisees, trained and supported to deliver HTS services under a common brand in high HIV-prevalent communities in Tshwane district between 2016 and 2017. SFs were remunerated per-HIV test and received larger payments per-HIV-positive client linked to care. In the standard HTS, FPD employed counsellors received similar training and observed similar standards as in the SF HTS, but were remunerated through the normal payroll. We assessed the proportion of clients tested, HIV positivity, linkage to care and per-counsellor cost of HIV test and linkage to care in the two HTS groups.

RESULTS

The SF HTS had 19 HIV counsellors while FPD HTS employed 20. A combined total of 84,556 clients were tested by SFs (50.5%: 95% confidence interval (CI) 50.2 to 50.8)) and FPD (49.5%: 49.2 to 49.8). SFs tested more females than FPD (54.1%: 53.6 to 54.6 vs. 48%: 47.7 to 48.7). SFs identified more first-time testers than FPD (21.5%: 21.1 to 21.9 vs. 8.9%: 8.6 to 9.1). Overall, 8%: 7.9 to 8.2 tested positive with more clients testing positive in the SF (10.2%: 9.9 to 10.5) than FPD (5.9%: 5.6 to 6.1) group. The SFs identified more female HIV-positive clients (11.1%: 10.7 to 11.6) than FPD (6.5%: 6.2 to 6.9). The SFs linked fewer clients to HIV care and treatment (60.0%: 58.5 to 61.5) than FPD (80.3%: 78.7 to 81.9%). It cost four times less to conduct an HIV test using SFs ($3.90 per SF HIV test) than FPD ($13.98) and five times less to link a client to care with SFs ($62.74) than FPD ($303.13).

CONCLUSIONS

SF HTS was effective in identifying more clients, first-time HIV testers and more HIV-positive people, but less effective in linking clients to care than FPD HTS. The SF HTS model was cheaper than the FPD-employee model. We recommend strengthening SFs particularly their linkage to care activities.

Detection of Rifampicin- and Isoniazid-Resistant Mycobacterium tuberculosis Using the Quantamatrix Multiplexed Assay Platform System

Background

The increasing prevalence of drug-resistant tuberculosis (TB) infection represents a global public health emergency. We evaluated the usefulness of a newly developed multiplexed, bead-based bioassay (Quantamatrix Multiplexed Assay Platform [QMAP], QuantaMatrix, Seoul, Korea) to rapidly identify the Mycobacterium tuberculosis complex (MTBC) and detect rifampicin (RIF) and isoniazid (INH) resistance-associated mutations.

Methods

A total of 200 clinical isolates from respiratory samples were used. Phenotypic anti-TB drug susceptibility testing (DST) results were compared with those of the QMAP system, reverse blot hybridization (REBA) MTB-MDR assay, and gene sequencing analysis.

Results

Compared with the phenotypic DST results, the sensitivity and specificity of the QMAP system were 96.4% (106/110; 95% confidence interval [CI] 0.9072–0.9888) and 80.0% (72/90; 95% CI 0.7052–0.8705), respectively, for RIF resistance and 75.0% (108/144; 95% CI 0.6731–0.8139) and 96.4% (54/56; 95% CI 0.8718–0.9972), respectively, for INH resistance. The agreement rates between the QMAP system and REBA MTB-MDR assay for RIF and INH resistance detection were 97.6% (121/124; 95% CI 0.9282–0.9949) and 99.1% (109/110; 95% CI 0.9453–1.0000), respectively. Comparison between the QMAP system and gene sequencing analysis showed an overall agreement of 100% for RIF resistance (110/110; 95% CI 0.9711–1.0000) and INH resistance (124/124; 95% CI 0.9743–1.0000).

Conclusions

The QMAP system may serve as a useful screening method for identifying and accurately discriminating MTBC from non-tuberculous mycobacteria, as well as determining RIF- and INH-resistant MTB strains.

Direct Detection of Rifampin-Resistant Mycobacterium tuberculosis in Respiratory Specimens Using Quantamatrix Multiplexed Assay Platform (QMAP) System: A Multicenter Study in Korea

Rapid and accurate detection of rifampin-resistant Mycobacterium tuberculosis (MTB) is of primary importance for infection control and selection of anti-tuberculosis drugs. The aim of this study was to evaluate the usefulness of a newly developed multiplexed, bead-based bioassay (Quantamatrix Multiplexed Assay Platform, QMAP) for the direct detection of rifampin-resistant MTB in respiratory specimens. A total of 400 respiratory specimens collected from patients with clinically suspected tuberculosis or non-tuberculous mycobacteria (NTM) infections were tested with the culture-based conventional Mycobacterium species identification and QMAP system. Among 400 specimens, 154 samples were evaluated using phenotypic anti-tuberculosis drug susceptibility test (DST) and the QMAP system for the detection of rifampin resistance. Detection agreement rate between the culture-based conventional identification and QMAP system for MTB and NTM according to acid-fast bacillus smear positivity was as follows: 97.0% (131/135) and 93.6% (88/94) in 229 smear-positive samples and 69.4% (25/36) and 73.0% (65/89) in 171 smear-negative samples. Based on culture as the gold standard, the overall sensitivity and specificity of the QMAP system for Mycobacterium identification were 87.3 and 97.8%, respectively. The categorical agreement rate between phenotypic DST and QMAP system for rifampin was as follows: complete agreement, 92.9% (143/154); very major error, 0%; and major error, 0.6% (1/154). The overall sensitivity of the QMAP system for the detection of rifampin resistance was 97.1% (34/35). The QMAP system is a useful screening method for the early diagnosis of tuberculosis and selection of anti-tuberculosis drug, as it may detect rifampin-resistant MTB directly from respiratory specimens.

Polymer-augmented liposomes enhancing antibiotic delivery against intracellular infections

Pulmonary intracellular infections, such as tuberculosis, anthrax, and tularemia, have remained a significant challenge to conventional antibiotic therapy. Ineffective antibiotic treatment of these infections can lead not only to undesired side effects, but also to the emergence of antibiotic resistance. Aminoglycosides (e.g., streptomycin) have long been part of the therapeutic regiment for many pulmonary intracellular infections. Their bioavailability for intracellular bacterial pools, however, is limited by poor membrane permeability and rapid elimination. To address this challenge, polymer-augmented liposomes (PALs) were developed to provide improved cytosolic delivery of streptomycin to alveolar macrophages, an important host cell for intracellular pathogens. A multifunctional diblock copolymer was engineered to functionalize PALs with carbohydrate-mediated targeting, pH-responsive drug release, and endosomal release activity with a single functional polymer that replaces the pegylated lipid component to simplify the liposome formulation. The pH-sensing functionality enabled PALs to provide enhanced release of streptomycin under endosomal pH conditions (70% release in 6 hours) with limited release at physiological pH 7.4 (16%). The membrane-destabilizing activity connected to endosomal release was characterized in a hemolysis assay and PALs displayed a sharp pH profile across the endosomal pH development target range. The direct connection of this membrane-destabilizing pH profile to model drug release was demonstrated in an established pyranine/p-xylene bispyridinium dibromide (DPX) fluorescence dequenching assay. PALs displayed similar sharp pH-responsive release, whereas PEGylated control liposomes did not, and similar profiles were then shown for streptomycin release. The mannose-targeting capability of the PALs was also demonstrated with 2.5 times higher internalization compared to non-targeted PEGylated liposomes. Finally, the streptomycin-loaded PALs were shown to have a significantly improved intracellular antibacterial activity in a Francisella-macrophage co-culture model, compared with free streptomycin or streptomycin delivered by control PEGylated liposomes (13× and 16×, respectively). This study suggests the potential of PALs as a useful platform to deliver antibiotics for the treatment of intracellular macrophage infections.

Knowledge and practices about zoonotic tuberculosis prevention and associated determinants amongst livestock workers in Nigeria; 2015

Zoonotic tuberculosis (TB) is a significant public health disease, but has long been neglected. Information on knowledge and practices of its prevention and influencing factors amongst occupationally exposed individuals is required for designing all-inclusive, informed control programmes. We investigated knowledge and practices related to zoonotic TB prevention and associated determinants amongst herdsmen and abattoir workers in south-western, south-eastern and north-western Nigeria using semi-structured questionnaire. Data were analysed with STATA 12. A total of 510 respondents (196 herdsmen; 314 abattoir workers) participated in the survey, of which 58.6% and 46.9% respectively were knowledgeable and demonstrated good practices about zoonotic TB prevention. Almost 60% knew that zoonotic TB transmission was preventable and 49.8% knew transmission could be through consumption of infected animal products. However, only 16.7% knew the disease could be transmitted by aerosol. Just 49.4% sought medical check-up when ill, 37.8% used protective clothing and only 29.2% usually condemned TB infected cattle. Respondents with post-primary education were about three times more likely to be knowledgeable (OR = 2.70, 95%CI: 1.68-4.33) and two times more likely to demonstrate good practice (OR = 2.23, 95%CI: 1.45-3.42) than those without formal education. Similarly, abattoir workers were about 6.4 times more likely to be knowledgeable (OR: 6.39, 95%CI: 4.31-9.47) and two times more likely to demonstrate good practice (OR: 2.03, 95%CI: 1.40-2.92) than the herdsmen. There were important knowledge gaps with poor practices about zoonotic TB prevention amongst livestock workers in Nigeria. Strong predictors of knowledge and practice were being an abattoir worker and having post-primary education. Well-designed grassroots enlightenment programmes addressing modes of transmission, handling infected cattle and seeking medical check-up are urgently needed among high risk settings considering the recently launched Road Map for Zoonotic Tuberculosis which resonates that every tuberculosis case counts towards 2030 End-TB Strategy.

Incidence and Drug Resistance of Zoonotic Mycobacterium bovis Infection in Peshawar, Pakistan

Prevalence of zoonotic Mycobacterium bovis (bTB) disease in human population is underreported from the North of Pakistan. Here, we report on the proportion of human bTB disease among the overall TB patients, drug resistance pattern of bTB isolates, and knowledge, attitude, and practices (KAP)-based analysis of bTB disease. For this purpose, sputum samples from a total of 300 clinically diagnosed TB patients and 100 randomly selected school children suspected of pulmonary TB were processed by culture as well as polymerase chain reaction (PCR) for isolation, identification, and confirmation of Mycobacterium tuberculosis (mTB) and bTB species. Isolates of bTB were processed for drug susceptibility tests. Data on KAP regarding TB were obtained on a pretested questionnaire. Sputum-based PCR results indicated that 288/300 (96%) were confirmed as mTB, while 12/300 (4%) were found as bTB diseases. Interestingly, none of the school child was declared positive for either mTB or bTB. Notably, 274/300 (91.3%) positively cultured samples were identified as mTB, 13/300 (4.3%) as bTB, while 5/300 (1.7%) as mixed containing both. Importantly, except one, all of the bTB isolates were found resistant to pyrazinamide. Surprisingly, most of the bTB isolates (~70%) were found resistant to a broad range of first- and second-line anti-TB drugs. SplitsTree and recombination analysis indicated no evidence of intergenic recombination. Finally, residence, occupation, presence of animals at home, and sleeping alongside animals were found significantly associated with occurrence of bTB disease. To the best of our knowledge, we report for the first time on the high (4%) burden of bTB disease in human TB patients in Peshawar, Pakistan.

Oleanolic Acid and Its Derivatives: Biological Activities and Therapeutic Potential in Chronic Diseases

The increasing demand for natural products as an alternative therapy for chronic diseases has encouraged research into the pharmacological importance of bioactive compounds from plants. Recently, there has been a surge of interest in the therapeutic potential of oleanolic acid (OA) in the prevention and management of chronic diseases. Oleanolic acid is a pentacyclic triterpenoid widely found in plants, including fruits and vegetables with different techniques and chromatography platforms being employed in its extraction and isolation. Several studies have demonstrated the potential therapeutic effects of OA on different diseases and their symptoms. Furthermore, oleanolic acid also serves as a framework for the development of novel semi-synthetic triterpenoids that could prove vital in finding therapeutic modalities for various ailments. There are recent advances in the design and synthesis of chemical derivatives of OA to enhance its solubility, bioavailability and potency. Some of these derivatives have also been therapeutic candidates in a number of clinical trials. This review consolidates and expands on recent reports on the biological effects of oleanolic acid from different plant sources and its synthetic derivatives as well as their mechanisms of action in in vitro and in vivo study models. This review suggests that oleanolic acid and its derivatives are important candidates in the search for alternative therapy in the treatment and management of chronic diseases.

Prevalence and Associated Factors of Tuberculosis in Prisons Settings of East Gojjam Zone, Northwest Ethiopia

Background

Tuberculosis, mainly in prisoners, is a major public health problem in Ethiopia where there is no medical screening during prison admission. This creates scarcity of TB data in such settings.

Objective

To determine prevalence and associated factors of TB in prisons in East Gojjam Zone, Northwest Ethiopia.

Methods

A cross-sectional study was conducted from February to May 2016 among 265 prisoners in three prison sites. Sputum was processed using GeneXpert MTB/RIF. Data were analyzed using SPSS version 20.0. Multivariable logistic regression was used; p values = 0.05 were considered statistically significant.

Results

Of 265 prisoners, 9 (3.4%) were TB positive (males); 77.8%, 55.6%, and 55.6% of cases were rural dwellers, married, and farmers, respectively. Seven (2.6%) prisoners were HIV positive, and 3 (1.13%) had TB/HIV coinfection. One (0.4%) TB case was rifampicin resistant. Marriage (AOR = 1.5; 95% CI: 1.7, 13.03), HIV (AOR = 0.14; 95% CI: 0.001, 0.17), and sharing of rooms (AOR = 1.62; 95% CI: 2.6, 10.20) were predictors for TB.

Conclusion

Nine prisoners were TB positive. One case showed rifampicin resistance and three had TB/HIV coinfection. Marriage, HIV, and sharing of rooms were predictors for TB. Prevention/control and monitoring are mandatory in such settings.

Distribution of Mycobacterium tuberculosis in Korea in the preceding decade

BACKGROUND

Tuberculosis (TB) is an infectious disease caused by the bacillus Mycobacterium tuberculosis (MTB); it is transmitted among people through air. The aim of this study was to assess the prevalence of TB and its clinical trends by collecting and analyzing data on specimens in Korea.

METHODS

All clinical specimens referred to the Dankook University Hospital Laboratory in Cheonan, Korea, from September 2005 to June 2016 were tested to isolate MTB using solid and liquid cultures, acid-fast bacilli (AFB) smears, and polymerase chain reactions (PCR).

RESULTS

In total, 146 150 specimens were collected; the mean TB positivity rate was 7.8%. The highest positivity rate was observed among patients 30-39 years of age (12.6%), followed by those 20-29 years of age (12.2%). The mean positivity rate was highest in 2010 and lowest in 2016 (10.7% and 6.7%, respectively). When comparing 2015-2011, we saw a decrease in the number of TB-positive patients of 3.4%; this represented an annual decrease in 0.9%.

CONCLUSION

Our data revealed a trend for a decrease in TB prevalence over time. Moreover, TB positivity rates were highest among the younger age groups in our study. Therefore, rapid diagnosis and treatment of TB in younger individuals are crucial.

Performance of the Quantamatrix Multiplexed Assay Platform system for the differentiation and identification of Mycobacterium species

PURPOSE

The purpose of this study was to evaluate the usefulness of a new diagnostic multiplexed bead-based bioassay (Quantamatrix Multiplexed Assay Platform; QMAP) system with shape-encoded silica microparticles for the rapid and accurate detection and identification of 23 mycobacterial species/groups, including Mycobacterium tuberculosis complex (MTBC).

METHODOLOGY

A total of 295 mycobacterial clinical isolates cultured from respiratory specimens were used for identification of MTBC and non-tuberculous mycobacteria (NTM) using the QMAP system and the results were confirmed with PCR-restriction fragment length polymorphism (RFLP) analysis of the rpoB gene, rpoB sequence analysis and PCR-reverse blot hybridization assay (REBA).Results/Key findings. The Mycobacterium genus-specific probe of the QMAP system was positive for all 46 Mycobacterium reference strains and negative for 59 non-Mycobacterium strains. Based on 295 liquid culture-positive samples, both the culture-based conventional identification method and the QMAP system identified each 212 and 81 isolates as MTB and NTM species. The concordance rates for the identification of NTM species between the QMAP system and molecular assays were 92.8 % (77/83), 97.6 % (81/83) and 100 % (83/83) for PCR-RFLP, the rpoB sequence analysis and PCR-REBA, respectively.

CONCLUSION

The QMAP system yielded rapid, highly sensitive and specific results for the identification of MTBC and NTM and accurately discriminated between NTM species within 3 h.

Evaluation of the Quantamatrix Multiplexed Assay Platform system for simultaneous detection of Mycobacterium tuberculosis and the rifampicin resistance gene using cultured mycobacteria

BACKGROUND

The differentiation of Mycobacterium tuberculosis complex (MTBC) from non-tuberculous mycobacteria (NTM) is of primary importance for infection control and the selection of anti-tuberculosis drugs. Up to date data on rifampicin (RIF)-resistant tuberculosis (TB) is essential for the early management of multidrug-resistant TB. The aim of this study was to evaluate the usefulness of a newly developed multiplexed, bead-based bioassay (Quantamatrix Multiplexed Assay Platform, QMAP) for the rapid differentiation of 23 Mycobacterium species including MTBC and RIF-resistant strains.

METHODS

A total of 314 clinical Mycobacterium isolates cultured from respiratory specimens were used in this study.

RESULTS

The sensitivity and specificity of the QMAP system for Mycobacterium species were 100% (95% CI 99.15-100%, p<0.0001) and 97.8% (95% CI 91.86-99.87%, p<0.0001), respectively. The results of conventional drug susceptibility testing and the QMAP Dual-ID assay were completely concordant for all clinical isolates (100%, 95% CI 98.56-100%). Out of 223 M. tuberculosis (MTB) isolates, 196 were pan-susceptible and 27 were resistant to RIF according to QMAP results. All of the mutations in the RIF resistance-determining region detected by the QMAP system were confirmed by rpoB sequence analysis and a REBA MTB-Rifa reverse blot hybridization assay. The majority of the mutations (n=26, 96.3%), including those missing wild-type probe signals, were located in three codons (529-534, 524-529, and 514-520), and 17 (65.4%) of these mutations were detected by three mutation probes (531TTG, 526TAC, and 516GTC).

CONCLUSIONS

The entire QMAP system assay takes about 3h to complete, while results from the culture-based conventional method can take up to 48-72h. Although improvements to the QMAP system are needed for direct respiratory specimens, it may be useful for rapid screening, not only to identify and accurately discriminate MTBC from NTM, but also to identify RIF-resistant MTB strains in positive culture samples.

Patient attitudes towards community-based tuberculosis DOT and adherence to treatment in an urban setting; Kampala, Uganda

INTRODUCTION

High Tuberculosis treatment default rate (17%) and sub-optimal treatment completion rates (45%) has burdened Kampala. Nevertheless, there are observable increase in the number of patients on TB DOT; from 6% to 29% in two consecutive annual reports. The main objective was to determine the association of TB patient attitudes towards community-based observers on the TB drug adherence on directly observed treatment for TB in Kampala.

METHODS

A cross-sectional study was carried out in Lubaga division, Kampala. A total of 201 patients in continuation phase of treatment for Pulmonary TB (i.e. 8 to 20 weeks of TB treatment) were included in the study. Patient attitudes were measured using a 4-point Likert scale aggregated into a binary outcome with ''agree'' and ''disagree'' responses. Poisson regression model using a forward fitting approach in STATA v12 was used to determine the association between patient attitude towards CB-DOTs observers and adherence to TB treatment.

RESULTS

Among the 201 patients, 66% reported their treatment was being observed by someone. Relatives were the commonest (82%) treatment observers, 26% were non adherent to their TB treatment. Perceiving ''no need for a treatment observer'' and ''people rejecting TB patients'' were predictors of non-adherence to TB treatment (IRR=1.6,95%CI 1.00-2.57;p=0.048) and (IRR=0.6, 95%CI 0.35-0.95; p=0.019) respectively.

CONCLUSION

Patient's perceived attitude and stigma towards treatment observers contribute to non-adherence on TB treatment. For improved local TB control, more emphasis is needed to build a friendly environment between treatment supporters and patients during the course of TB treatment.

Policy and practice of programmatic management of latent tuberculosis infection in The Netherlands

Latent tuberculosis infection (LTBI) screening and preventive treatment is one of the components of the World Health Organization (WHO) End TB strategy, and particularly relevant for low tuberculosis (TB) incidence countries, i.e. less than 100 TB cases per million population. The Netherlands is such a low-incidence country with traditionally a strong emphasis on programmatic management of LTBI, e.g. examining contacts of infectious TB patients by the public health services. Increasingly, curative services are involved in LTBI management of clinical risk groups. The country recently adopted a five-year strategic national plan recommending LTBI screening of high-risk migrants populations. A monitoring and evaluation system is already in place to measure programme performance and guide policy. Research on LTBI screening of migrants is on-going and results should inform future decisions in scaling-up this intervention. Several challenges remain for programmatic LTBI management, such as securing financial resources and the right professional cadre for implementation; availability of screening tests and drugs; collecting additional data for monitoring and evaluation, in line with the WHO indicators for LTBI programmatic management; developing cultural-sensitive and client-centred education for migrants; reducing patient costs for LTBI screening and preventive treatment; and assessing cost-effectiveness and impact on TB epidemiology.

Heat shock protein70 is implicated in modulating NF-κB activation in alveolar macrophages of patients with active pulmonary tuberculosis

Heat shock proteins (HSPs) have been shown to modulate NF-κB activation. It is unknown whether HSP70 plays a role in modulating NF-κB-mediated pro-inflammatory cytokines released from alveolar macrophage (AM) of patients with active pulmonary tuberculosis (TB). Peripheral blood monocytes (PBMs) and AM were sampled from nineteen active TB patients and 14 healthy individuals. HSP70 expression was 3-fold higher in AMs of active TB patients than normal subjects, and declined after receiving 3-month anti-TB treatment. Overexpression of HSP70 by transfection with HSP70 plasmid decreased p-IκBα and p65 NF-κB activities. Inhibition of NF-κB activation using NF-κB or MAPK inhibitors increased HSP70 expression in AM of TB patients. Blocking p38- or ERK-MAPK decreased NF-κB and IκB activities, leading to up-regulated HSP70 expression. Overexpression of HSP70 alone or with p38 or ERK inhibitors decreased TNF-α (57%, 83% and 74%, respectively) and IL-6 (53%, 70%, and 67%, respectively) release from macrophages of TB patients. In conclusion, HSP70 modulates NF-κB activation in AM of TB patients, through inhibiting IκB-α phosphorylation or acting as a chaperon molecule to prevent NF-κB binding to the target genes by facilitating degradation. The upregulated HSP70 may suppress the release of pro-inflammatory cytokines during active PTB infection, and prevent overwhelming tissue damage.

Macrophage migration inhibitory factor -173 G > C polymorphism and risk of tuberculosis: A meta-analysis

The aim of the present meta-analysis was to find out the impact of MIF -173 G > C polymorphism on risk of tuberculosis (TB). We conducted a search of case-control studies on the associations of -173 G > C variant of MIF with susceptibility to tuberculosis in PubMed, ISI Web of Science, and Scopus. We extracted the data from eligible studies and achieved a meta-analysis to examine the relationship between MIF -173 G > C polymorphism and the risk of TB. Odds ratios (ORs) with the corresponding 95 % confidence intervals (CIs) were pooled to find out the impact of MIF -173G > C promoter polymorphism on TB risk. The pooled ORs were calculated for the codominant, dominant, recessive, and allelic model comparison. The findings revealed that MIF -173 G > C variant increased the risk of TB in codominant (OR = 1.54, 95 %CI = 1.26-1.88, p < 0.0001; CG vs GG), and dominant (OR = 1.62, 95 %CI = 1.33-1.96, p < 0.00001; GC+CC vs GG) inheritance models tested. The results suggested that the MIF -173 C allele significantly increased the risk of PTB (OR = 1.49, 95 %CI = 1.28-1.74, p < 0.00001). The findings of this meta-analysis propose that MIF -173 G > C variant is associated with the risk of TB. More case-control studies with well-designed in different ethnic groups and larger sample size are needed to confirm the findings.

Naïve Human Antibody Libraries for Infectious Diseases

Many countries are facing an uphill battle in combating the spread of infectious diseases. The constant evolution of microorganisms magnifies the problem as it facilitates the re-emergence of old infectious diseases as well as promote the introduction of new and more deadly variants. Evidently, infectious diseases have contributed to an alarming rate of mortality worldwide making it a growing concern. Historically, antibodies have been used successfully to prevent and treat infectious diseases since the nineteenth century using antisera collected from immunized animals. The inherent ability of antibodies to trigger effector mechanisms aids the immune system to fight off pathogens that invades the host. Immune libraries have always been an important source of antibodies for infectious diseases due to the skewed repertoire generated post infection. Even so, the role and ability of naïve antibody libraries should not be underestimated. The naïve repertoire has its own unique advantages in generating antibodies against target antigens. This chapter will highlight the concept, advantages and application of human naïve libraries as a source to isolate antibodies against infectious disease target antigens.