Engagement of private healthcare providers for case finding of tuberculosis and diabetes mellitus in Pakistan

Chronic hyperglycemia impairs anti-microbial function of macrophages in response to Mycobacterium tuberculosis infection

Diabetes mellitus (DM) is a major risk factor for tuberculosis (TB), though the underlying mechanisms linking DM and TB remain ambiguous. Macrophages are a key player in the innate immune response and their phagocytic ability is enhanced in response to microbial infections. Upon infection or inflammation, they also repel invading pathogens by generating; reactive oxygen species (ROS), reactive nitrogen species (RNS), pro-inflammatory cytokines (IL-1β and IL-6), and anti-inflammatory cytokines (IL-10). However, the robustness of these innate defensive capabilities of macrophages when exposed to hyperglycemia remains unclear. In our current work, we explored the production of these host defense molecules in response to challenge with Mycobacterium tuberculosis (Mtb) infection and lipopolysaccharide (LPS) stimulation. Utilizing peritoneal macrophages from high-fat diet + streptozotocin induced diabetic mice and hyperglycemic THP-1-derived macrophages as model systems; we found that LPS stimulation and Mtb infection were ineffective in stimulating the production of ROS, RNS, and pro-inflammatory cytokines in cells exposed to hyperglycemia. On the contrary, an increase in production of anti-inflammatory cytokines was observed. To confirm the mechanism of decreased anti-bacterial activity of the diabetic macrophage, we explored activation status of these compromised macrophages and found decreased surface expression of activation (TLR-4) and differentiation markers (CD11b and CD11c). We postulate that this could be the cause for higher susceptibility for Mtb infection among diabetic individuals.

A spatial analysis of TB cases and abnormal X-rays detected through active case-finding in Karachi, Pakistan

Tuberculosis (TB) is the leading cause of avoidable deaths from an infectious disease globally and a large of number of people who develop TB each year remain undiagnosed. Active case-finding has been recommended by the World Health Organization to bridge the case-detection gap for TB in high burden countries. However, concerns remain regarding their yield and cost-effectiveness. Data from mobile chest X-ray (CXR) supported active case-finding community camps conducted in Karachi, Pakistan from July 2018 to March 2020 was retrospectively analyzed. Frequency analysis was carried out at the camp-level and outcomes of interest for the spatial analyses were mycobacterium TB positivity (MTB+) and X-ray abnormality rates. The Global Moran's I statistic was used to test for spatial autocorrelation for MTB+ and abnormal X-rays within Union Councils (UCs) in Karachi. A total of 1161 (78.1%) camps yielded no MTB+ cases, 246 (16.5%) camps yielded 1 MTB+, 52 (3.5%) camps yielded 2 MTB+ and 27 (1.8%) yielded 3 or more MTB+. A total of 79 (5.3%) camps accounted for 193 (44.0%) of MTB+ cases detected. Statistically significant clustering for MTB positivity (Global Moran's I: 0.09) and abnormal chest X-rays (Global Moran's I: 0.36) rates was identified within UCs in Karachi. Clustering of UCs with high MTB positivity were identified in Karachi West district. Statistically significant spatial variation was identified in yield of bacteriologically positive TB cases and in abnormal CXR through active case-finding in Karachi. Cost-effectiveness of active case-finding programs can be improved by identifying and focusing interventions in hotspots and avoiding locations with no known TB cases reported through routine surveillance.

Tuberculosis treatment and resulting abnormal blood glucose: a scoping review of studies from 1981 - 2021

BACKGROUND

Hyperglycaemia is a risk factor for tuberculosis. Evidence of changes in blood glucose levels during and after tuberculosis treatment is unclear.

OBJECTIVE

To compile evidence of changes in blood glucose during and after tuberculosis treatment and the effects of elevated blood glucose changes on treatment outcomes in previously normoglycaemic patients.

METHODS

Original research studies (1980 to 2021) were identified in PubMed, Web of Science, CINAHL and Embase databases.

RESULTS

Of the 1,277 articles extracted, 14 were included in the final review. All the studies were observational and 50% were prospective. Fasting blood sugar was the most common clinical test (64%), followed by the glycated haemoglobin test and the oral glucose tolerance test (each 50%). Most tests were conducted at baseline and in the third month of treatment. Twelve studies showed that the prevalence of hyperglycaemia in previously normoglycaemic patients decreased from baseline to follow-up and end of treatment. Three studies showed successful treatment outcomes of 64%, 75% and 95%. Patients with hyperglycaemia at baseline were more likely to develop cavitary lung lesions and poor treatment outcomes and had higher post-treatment mortality. There was no difference in outcomes by human immunodeficiency virus (HIV) status.

CONCLUSION

Elevated blood glucose in normoglycaemic patients receiving treatment for tuberculosis decreased by the end of treatment. Positive HIV status did not affect glucose changes during treatment. Further research is needed to investigate post-treatment morbidity in patients with baseline hyperglycaemia and the effects of HIV on the association between blood glucose and tuberculosis.

Implementation of the WHO's collaborative framework for the management of tuberculosis and diabetes: a scoping review

OBJECTIVE

To map evidence on the implementation of the WHO's collaborative framework for the management of tuberculosis (TB) and diabetes mellitus (DM) comorbidity, globally.

DESIGN

Scoping review.

METHODS

Guided by Arksey and O'Malley's scoping review framework, this review mapped literature on the global implementation of the framework for the management of TB and DM comorbidity, globally. An extensive literature search for peer-reviewed studies, theses, studies in the press and a list of references from the selected studies was conducted to source-eligible studies. PubMed, Google Scholar, Web of Science, Science Direct, the EBSCOhost platform (academic search complete, health source: nursing/academic edition, CINAHL with full text), Scopus and the WHO library were used to source the literature. We performed title screening of articles using keywords in the databases, after which two independent reviewers (RS and PV) screened abstracts and full articles. Studies from August 2011 to May 2021 were included in this review and the screening was guided by the inclusion and exclusion criteria. Findings were analysed using the thematic content analysis approach and results presented in the form of a narrative report. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension was used as a checklist and for explaining the scoping review process.

RESULTS

This review found evidence of the WHO TB-DM collaborative framework's implementation in 35 countries across the globe. TB-DM comorbidity was identified in patients through bidirectional screening of both patients with TB and patients with DM in rural and urban settings.

CONCLUSION

Due to the paucity of evidence on mechanisms of collaboration, we recommend further research in other implementing countries to identify techniques used for diagnosis and integration of TB and DM services, in order to ensure that effective and joint management of TB-DM comorbidity in populations is achieved.