Patients with presumed tuberculosis in sub-Saharan Africa that are not diagnosed with tuberculosis: a systematic review and meta-analysis

Challenges and knowledge gaps in the management of non-tuberculous mycobacterial pulmonary disease in sub-Saharan African countries with a high tuberculosis burden: a scoping review

INTRODUCTION

In sub-Saharan African (SSA) countries endemic for tuberculosis (TB), previous TB is a significant risk factor for non-tuberculous mycobacterial pulmonary disease (NTM-PD). The deployment of GeneXpert MTB/RIF in pulmonary TB diagnostic work-up regularly identifies symptomatic patients with a positive smear microscopy but negative GeneXpert, indicative of NTM presence. This scoping review outlines recent evidence for NTM-PD diagnosis and management in SSA.

OBJECTIVE

The review's objective was to outline the risk factors, available diagnostics, management options and outcomes of NTM-PD in high-burden TB settings in SSA using the population-concept-context framework.

DESIGN AND DATA SOURCES

We searched existing literature from PubMed, Web of Science, African Journals Online, Google Scholar and grey literature. Studies published between January 2005 and December 2022 were retained. Data were extracted into Rayyan software and Mendeley and summarised using Excel.

RESULTS

We identified 785 potential articles, of which 105 were included in the full-text review, with 7 papers retained. Included articles used international criteria for diagnosing NTM-PD. Multiple papers were excluded due to non-application of the criteria, suggesting challenging application in the SSA setting. Identified risk factors include previous TB, smoking and mining. Most commonly, chest radiography and not CT was used for the radiological diagnosis of PD, which may miss early changes related to NTM-PD. Molecular methods for NTM species identification were employed in research settings, usually at referral centres, but were unavailable for routine care. Most studies did not report a standardised approach to treatment and they were not offered treatment for the specific disease, marking a lack of guidance in treatment decision-making. When treatment was provided, the outcome was often not reported due to the lack of implementation of standardised outcome definitions.

CONCLUSIONS

These outlined challenges present a unique opportunity for researchers to undertake further studies in NTM-PD and proffer solutions more applicable to SSA.

The Burden of Bacteriologically Negative TB Diagnosis: A Four-Year Review of Tuberculosis Cases at a Tertiary Facility

Aim

We aimed to investigate the demographic and clinical factors associated with TB mortality in patients managed at a tertiary TB referral center.

Methods

We conducted a retrospective review of the medical records of 1,933 TB patients seen between January 2017 and December 2020 at the Korle-Bu Teaching Hospital (KBTH) Chest Department in Accra, Ghana. TB mortality was defined as any TB patient who died for any reason during the course of treatment. Multivariable logistic regression was used to estimate adjusted odds ratios with 95% confidence intervals for factors associated with TB mortality.

Results

A total of 1,933 patients with TB were registered at the chest clinic over the study period. Males accounted for 1,227 (63.5%), and majority of participants were between 24 and 64 years old. Pulmonary TB (PTB) and extrapulmonary TB (EPTB) cases accounted for 51% and 48.4% of the total TB cases, respectively. A significant proportion (69%) of the patients managed for TB had no bacteriological confirmation of the disease. About 34% of tested TB patients were HIV positive. Mortality among patients was 33.6%. In a multivariable regression model, patients with HIV positive status had over 3-fold increased risk of mortality, compared to those with HIV negative status. TB patients diagnosed empirically had an increased risk of death compared to those with a confirmed diagnosis.

Conclusion

The proportion of clinically diagnosed TB was high among the patients seen at the chest clinic. Mortality was high among the patients with HIV/TB coinfection as well as in patients with empirical TB diagnosis.

Effect of multimodal diagnostic approach using deep learning-based automated detection algorithm for active pulmonary tuberculosis

In this study, we developed a model to predict culture test results for pulmonary tuberculosis (PTB) with a customized multimodal approach and evaluated its performance in different clinical settings. Moreover, we investigated potential performance improvements by combining this approach with deep learning-based automated detection algorithms (DLADs). This retrospective observational study enrolled patients over 18 years of age who consecutively visited the level 1 emergency department and underwent chest radiograph and sputum testing. The primary endpoint was positive sputum culture for PTB. We compared the performance of the diagnostic models by replacing radiologists' interpretations of chest radiographs with screening scores calculated through DLAD. The optimal diagnostic model had an area under the receiver operating characteristic curve of 0.924 (95% CI 0.871-0.976) and an area under precision recall curve of 0.403 (95% CI 0.195-0.580) while maintaining a specificity of 81.4% when sensitivity was fixed at 90%. Multicomponent models showed improved performance for detecting PTB when chest radiography interpretation was replaced by DLAD. Multicomponent diagnostic models with DLAD customized for different clinical settings are more practical than traditional methods for detecting patients with PTB. This novel diagnostic approach may help prevent the spread of PTB and optimize healthcare resource utilization in resource-limited clinical settings.

Etiologic Investigation of Patients Diagnosed with Bacteriologically Unconfirmed Tuberculosis in Tanzania

Globally, half of patients with pulmonary tuberculosis (PTB) are diagnosed clinically without bacteriologic confirmation. In clinically diagnosed PTB patients, we assessed both the proportion in whom PTB could be bacteriologically confirmed by reference standard diagnostic tests and the prevalence of diseases that mimic PTB. We recruited adult patients beginning treatment of bacteriologically unconfirmed PTB in Moshi, Tanzania, in 2019. We performed mycobacterial smear, Xpert MTB/RIF Ultra, and mycobacterial culture, fungal culture, and bacterial culture on two induced sputum samples: fungal serology and computed tomography chest scans. We followed participants for 2 months after enrollment. We enrolled 36 (63%) of 57 patients with bacteriologically unconfirmed PTB. The median (interquartile range) age was 55 (44-67) years. Six (17%) were HIV infected. We bacteriologically confirmed PTB in 2 (6%). We identified pneumonia in 11 of 23 (48%), bronchiectasis in 8 of 23 (35%), interstitial lung disease in 5 of 23 (22%), pleural collections in 5 of 23 (22%), lung malignancy in 1 of 23 (4%), and chronic pulmonary aspergillosis in 1 of 35 (3%). After 2 months, 4 (11%) were dead, 21 (58%) had persistent symptoms, 6 (17%) had recovered, and 5 (14%) were uncontactable. PTB could be bacteriologically confirmed in few patients with clinically diagnosed PTB and clinical outcomes were poor, suggesting that many did not have the disease. We identified a high prevalence of diseases other than tuberculosis that might be responsible for symptoms.

The gut microbiome: A line of defense against tuberculosis development

The tuberculosis (TB) burden remains a significant global public health concern, especially in less developed countries. While pulmonary tuberculosis (PTB) is the most common form of the disease, extrapulmonary tuberculosis, particularly intestinal TB (ITB), which is mostly secondary to PTB, is also a significant issue. With the development of sequencing technologies, recent studies have investigated the potential role of the gut microbiome in TB development. In this review, we summarized studies investigating the gut microbiome in both PTB and ITB patients (secondary to PTB) compared with healthy controls. Both PTB and ITB patients show reduced gut microbiome diversity characterized by reduced Firmicutes and elevated opportunistic pathogens colonization; Bacteroides and Prevotella were reported with opposite alteration in PTB and ITB patients. The alteration reported in TB patients may lead to a disequilibrium in metabolites such as short-chain fatty acid (SCFA) production, which may recast the lung microbiome and immunity via the "gut-lung axis". These findings may also shed light on the colonization of Mycobacterium tuberculosis in the gastrointestinal tract and the development of ITB in PTB patients. The findings highlight the crucial role of the gut microbiome in TB, particularly in ITB development, and suggest that probiotics and postbiotics might be useful supplements in shaping a balanced gut microbiome during TB treatment.

Sociodemographic Differences in Multimorbidity: A Closer Look from Indonesian Family and Life Survey

The prevalence of multimorbidity, the coexistence of two or more chronic diseases, is expected to increase, including in Indonesia. This phenomenon is associated with increased life expectancy and incidence of non-communicable diseases. Therefore, this study assesses the burden of multimorbidity in Indonesia by sociodemographic factors. The researchers analyzed cross-sectional data from the latest wave of IFLS conducted in 2014, the IFLS wave 5. The researchers included individuals aged 15 and above with blood pressure measurements (n= 32.256) from 13,536 households. Meanwhile, the researchers excluded individuals with missing data on BMI (183 individuals) or who had biologically implausible or extreme values (n=6). The analyses were then conducted on 32,067 individuals. The analyses comprised the ten most common self-reported chronic diseases diagnosis in IFLS-5. The findings revealed that the prevalence of self-reported multimorbidity in Indonesia was relatively high, at 9.32% (n= 2.989), with the highest proportion of multimorbidity reported among the elderly. Approximately 2.76% of the respondents (n- 885) reported having three or more chronic diseases. The most common combinations were hypertension and digestive problem (2.15%, n= 689), followed by hypertension and arthritis (1.79%, n= 574), and hypertension and high cholesterol (1.68%, n= 539). When stratified by sociodemographic factors, the researchers found a higher proportion of multimorbidity among females (11.01%, n= 3,530) compared to males (7.41%, n= 2.376), elderly (21.54%, n= 3.530) compared to younger adults, and previous smokers (20.90%, n= 6.072). People who were obese and overweight also reported a higher prevalence of multimorbidity (13.73%, n= 4.403 and 9.3%, n= 2.998, respectively). In addition, those living in urban areas had a higher proportion of multimorbidity (10.33%, n= 3.313) compared to rural areas (7.2%, n= 2.527). In conclusion, this study uncovered a relatively high prevalence of multimorbidity. People living in urban areas were overweight/obese and those who had low SES had a higher proportion of multimorbidity. With the nature of self-reported data and previously reported underdiagnosis of chronic diseases, screening to examine multimorbidity is needed.