Barriers to tuberculosis treatment adherence in high-burden tuberculosis settings in Ashanti region, Ghana: a qualitative study from patient's perspective

BACKGROUND

Despite having an effective community-based Directly Observed Therapy Short-course (DOTS) strategy for tuberculosis (TB) care, treatment adherence has been a major challenge in many developing countries including Ghana. Poor adherence results in discontinuity of treatment and leads to adverse treatment outcomes which pose an increased risk of drug resistance. This study explored barriers to TB treatment adherence and recommended potential patient-centered strategies to improve treatment adherence in two high-burden TB settings in the Ashanti region of Ghana.

METHODS

The study was conducted among TB patients who defaulted on treatment in the Obuasi Municipal and Obuasi East districts in the Ashanti region. A qualitative phenomenology approach was used to explore the barriers to TB treatment adherence. Purposive sampling was adopted to select study participants with different sociodemographic backgrounds and experiences with TB care. Eligible participants were selected by reviewing the medical records of patients from health facility TB registers (2019-2021). Sixty-one (61) TB patients met the eligibility criteria and were contacted via phone call. Out of the 61 patients, 20 were successfully reached and consented to participate. In-depth interviews were conducted with participants using a semi-structured interview guide. All interviews were audio recorded and transcribed verbatim. The transcripts were imported into Atlas.ti version 8.4 software and analyzed using thematic content analysis.

RESULTS

Food insecurity, cost of transportation to the treatment center, lack of family support, income insecurity, long distance to the treatment center, insufficient knowledge about TB, side effect of drugs, improvement in health after the intensive phase of the treatment regimen, and difficulty in accessing public transportation were the main co-occurring barriers to treatment adherence among the TB patients.

CONCLUSION

The main barriers to TB treatment adherence identified in this study reveal major implementation gaps in the TB programme including gaps related to social support, food security, income security, knowledge, and proximity to treatment centers. Hence, to improve treatment adherence there is a need for the government and the National Tuberculosis Programme (NTP) to collaborate with different sectors to provide comprehensive health education, social and financial support as well as food aid to TB patients.

Potential for the Development of a New Generation of Aminoglycoside Antibiotics

The present review summarizes recent publications devoted to aminoglycosides that study the main types of resistance to antibiotics of this class and the main directions of chemical modification aimed at overcoming the resistance or changing the spectrum of biological activity. Conjugates of aminoglycosides with various pharmacophores including amino acids, peptides, peptide nucleic acids, nucleic bases, and several other biologically active molecules and modifications resulting in other types of biological activity of this class of antibiotics are described. It is concluded that a promising research direction aimed at increasing the activity of antibiotics against resistant strains is the search for selective inhibitors of aminoglycoside-modifying enzymes. This would allow renewal of the use of antibiotics already meeting widespread resistance and would increase the potential of a new generation of antibiotics.

Trends of tuberculosis case detection, mortality and co-infection with HIV in Ghana: A retrospective cohort study

Background

In an era of renewed commitment to accelerate the declines in Tuberculosis (TB) incidence and mortality, there is the need for National Tuberculosis Programmes (NTPs) to monitor trends in key indicators across a geographical location and to provide reliable data for direct measurement of TB incidence and mortality. In this context, we explored the trends of TB case detection, mortality and HIV co-infection, and examined the predictors of TB deaths in Ten districts of the Volta region of Ghana.

Methods

We conducted a retrospective cohort study of all TB cases registered from 2013 to 2017 in 10 districts of the Volta Region of Ghana. Case detection rate (CDR) was computed as the ratio of the number of new and relapse TB case notified to NTP to the number of estimated incident TB cases in a given year. Case fatality rates were estimated using data from 2012–2016 cohort of TB patients. Simple and multiple logistic regression were used to identify predictors of TB deaths with odds ratios and 95% confidence intervals estimated.

Results

Overall, there were 3,735 new and relapse TB patients who commenced anti-TB treatment during the period, representing the case detection rate of 40.1% with district variations. The CDR remained stable during the 5 years. Of the total cases, HIV status was documented for 3,144 (84.2%), among whom, 712 (22.6%) were HIV positive. The TB/HIV co-infection was more prevalent among children under 15 years of age (30.1%), males (30.6%), treatment after lost to follow-up patients (33.3%), and smear-negative pulmonary TB patients (29.1%). The prevalence of TB/HIV co-infection did not significantly change over the years. The overall case fatality rate was 13% (n = 486), with considerable variation among HIV-positives and HIV-negative TB patients (21.8% and 11% respectively) (p<0.001) and among districts. TB/HIV co-infection, sputum smear-negative pulmonary TB and district of anti-TB treatment predicted TB mortality.

Conclusion

TB case detection rate was low and remained stable during the study period, whereas co-infection with HIV and mortality rates were quite high, indicating the need for feasible strategies such as active case finding to improve case detection, and improved case management to reduce mortality.

A four-year trend in pulmonary bacteriologically confirmed tuberculosis case detection in Kampala-Uganda

BACKGROUND

The management and control of pulmonary bacteriologically confirmed (PBC) tuberculosis (TB) also known as infectious TB is important not only to monitor for resistance but also to check for severity, treatment response and limit its spread.

METHOD

A retrospective analysis of diagnosis smear results of PBC TB patients in Kampala district registered between January 2012 and December 2015 at 65 TB diagnosis and treatment units (DTUs) was done.

RESULTS

Of the 10,404 records; 6551 (63.0%) belonged to PBC TB patients, 3734 (57.0%) of whom were male. Sputum smear microscopy was the diagnostic test most commonly used 4905 (74.9%) followed by GeneXpert testing, 1023 (15.6%). Majority, 1951 (39.8%), of the PBC TB patients had a smear positivity grading of 3+ (> 10 acid-fast bacillus (AFB)/Fields). Public facilities diagnosed more PBC TB patients compared to private facilities, 3983 (60.8%) vs 2566 (39.2%). From 2012 through 2015, there was a statistically significant increase in PBC TB patients enrolled on anti-TB treatment from 1389 to 2194 (p = 0.000). The percentage of HIV positive co-infected PBC TB patients diagnosed decreased from 597(43%) to 890(40.6%) (p = 0.000) within same period. Linkage to HIV care improved from 229 (34.4%) in 2012 to 464 (52.1%) in 2015 (p = 0.000). The treatment success rate (TSR) for PBC TB patients improved from 69% in 2012 to 75.5% by end of 2015 (p = 0.001) with an improvement in cure rate from 52.3% to 62% (p = 0.000). There was an observed significant decrease in TB related mortality from 8.9 to 6.4% (p = 0.013).

CONCLUSION

The proportion of diagnosed PBC TB patients increased from 2012 to 2015. PBC TB patients diagnosed with 3+ smear positivity grading results consistently contributed to the highest proportion of diagnosed PBC TB patients from 2012 to 2015. This could be due to the delay in diagnosis of TB patients because of late presentation of patients to clinics. A prospective study of PBC TB patients diagnosed with 3+ smear positivity grading may elucidate the reasons for the delay to diagnosis. Further, we propose a study of wider scope to estimate how many people a single PBC TB patient is likely to infect with TB before being diagnosed and treated.

Destination of aminoglycoside antibiotics in the 'post-antibiotic era'

Aminoglycoside antibiotics (AGAs) were developed at the dawn of the antibiotics era and have significantly aided in the treatment of infectious diseases. Aminoglycosides have become one of the four major types of antibiotics in use today and, fortunately, still have an important role in the clinical treatment of severe bacterial infections. In this review, the current usage, modes of action and side effects of AGAs, along with the most common bacterial resistance mechanisms, are outlined. Finally, the recent development situation and possibility of new AGAs in the 'post-antibiotic era' are considered.The Journal of Antibiotics advance online publication, 25 October 2017; doi:10.1038/ja.2017.117.

QSAR based therapeutic management of M. tuberculosis

Mycobacterium tuberculosis is responsible for severe mortality and morbidity worldwide but, under-developed and developing countries are more prone to infection. In search of effective and wide-spectrum anti-tubercular agents, interdisciplinary approaches are being explored. Of the several approaches used, computer based quantitative structure activity relationship (QSAR) have gained momentum. Structure-based drug design and discovery implies a combined knowledge of accurate prediction of ligand poses with the good prediction and interpretation of statistically validated models derived from the 3D-QSAR approach. The validated models are generally used to screen a small combinatorial library of potential synthetic candidates to identify hits which further subjected to docking to filter out compounds as novel potential emerging drug molecules to address multidrug-resistant tuberculosis. Several newer models are integrated to QSAR methods which include different types of chemical and biological data, and simultaneous prediction of pharmacological activities including toxicities and/or other safety profiles to get new compounds with desired activity. In the process, several newer molecules have been identified which are now being assessed for their clinical efficacy. Present review deals with the advances made in the field highlighting overall future prospects of the development of anti-tuberculosis drugs.

Extended spectrum β-lactamase producing Escherichia coli and Klebsiella pneumoniae: critical tools for antibiotic resistance pattern

Drug resistance is a phenomenon where by an organism becomes fully or partially resistant to drugs or antibiotics being used against it. Antibiotic resistance poses an exacting intimidation for people with underlying medical immune conditions or weakened immune systems. Infections caused by the enzyme extended spectrum β-lactamase (ESBL) producing multi drug resistance (MDR) Enterobacteriaceae especially Escherichia coli and Klebsiella pneumoniae are resistant to a broad range of beta lactams, including third generation cephalosporins. Among all the pathogens, these two MDR E. coli and K. pneumoniae have emerged as one of the world's greatest health threats in past two decades. The nosocomial infections caused by these ESBL producing MDR E. coli and K. pneumoniae complicated the therapy and limit treatment options.

Treatment Outcome of Tuberculosis Patients under Directly Observed Treatment Short Course and Factors Affecting Outcome in Southern Ethiopia: A Five-Year Retrospective Study

Tuberculosis (TB) is one of the major public health and socio-economic issues in the 21^st century globally. Assessment of TB treatment outcomes, and monitoring and evaluation of its risk factors in Directly Observed Treatment Short Course (DOTS) are among the major indicators of the performance of a national TB control program. Hence, this institution-based retrospective study was conducted to determine the treatment outcome of TB patients and investigate factors associated with unsuccessful outcome at Dilla University Referral Hospital, southern Ethiopia. Five years (2008 to 2013) TB record of TB clinic of the hospital was reviewed. A total 1537 registered TB patients with complete information were included. Of these, 942 (61.3%) were male, 1015 (66%) were from rural areas, 544 (35.4%) were smear positive pulmonary TB (PTB+), 816 (53.1%) were smear negative pulmonary TB (PTB-) and 177(11.5%) were extra pulmonary TB (EPTB) patients. Records of the 1537 TB patients showed that 181 (11.8%) were cured, 1129(73.5%) completed treatment, 171 (11.1%) defaulted, 52 (3.4%) died and 4 (0.3%) had treatment failure. The overall mean treatment success rate of the TB patients was 85.2%. The treatment success rate of the TB patients increased from 80.5% in September 2008-August 2009 to 84.8% in September 2012–May 2013. Tuberculosis type, age, residence and year of treatment were significantly associated with unsuccessful treatment outcome. The risk of unsuccessful outcome was significantly higher among TB patients from rural areas (AOR = 1.63, 95% CI: 1.21–2.20) compared to their urban counterparts. Unsuccessful treatment outcome was also observed in PTB- patients (AOR = 1.77, 95% CI: 1.26–2.50) and EPTB (AOR = 2.07, 95% CI: 1.28–3.37) compared to the PTB+ patients. In conclusion, it appears that DOTS have improved treatment success in the hospital during five years. Regular follow-up of patients with poor treatment outcome and provision of health information on TB treatment to patients from rural area is recommended.

Mechanisms of Resistance to Aminoglycoside Antibiotics: Overview and Perspectives

Aminoglycoside (AG) antibiotics are used to treat many Gram-negative and some Gram-positive infections and, importantly, multidrug-resistant tuberculosis. Among various bacterial species, resistance to AGs arises through a variety of intrinsic and acquired mechanisms. The bacterial cell wall serves as a natural barrier for small molecules such as AGs and may be further fortified via acquired mutations. Efflux pumps work to expel AGs from bacterial cells, and modifications here too may cause further resistance to AGs. Mutations in the ribosomal target of AGs, while rare, also contribute to resistance. Of growing clinical prominence is resistance caused by ribosome methyltransferases. By far the most widespread mechanism of resistance to AGs is the inactivation of these antibiotics by AG-modifying enzymes. We provide here an overview of these mechanisms by which bacteria become resistant to AGs and discuss their prevalence and potential for clinical relevance.

Study of mechanism of interaction of truncated isoniazid-nicotinamide adenine dinucleotide adduct against multiple enzymes of Mycobacterium tuberculosis by a computational approach

OBJECTIVE/BACKGROUND

Isoniazid (INH) is one of the effective antituberculosis (TB) drugs used for TB treatment. However, most of the drug-resistant Mycobacterium tuberculosis (MTB) clinical strains are resistant to INH, a first-line antituberculous drug. Certain metabolic enzymes such as adenosylhomocysteinase (Rv3248c), universal stress protein (Rv2623), nicotinamide adenine dinucleotide (reduced)-dependent enoyl-acyl carrier protein reductase (Rv1484), oxidoreductase (Rv2971), dihydrofolate reductase (Rv2763c), pyrroline-5-carboxylate dehydrogenase (Rv1187) have been identified to bind INH-nicotinamide adenine dinucleotide (INH-NAD) and INH-nicotinamide adenine dinucleotide phosphate adducts coupled to Sepharose resin. These enzymes are reported to be involved in many important biochemical processes of MTB, including cysteine and methionine metabolism, mycobacterial growth regulation, mycolic acid biosynthesis, detoxification of toxic metabolites, folate biosynthesis, etc. The truncated INH-nicotinamide adenine dinucleotide (oxidized) adduct, 4-isonicotinoylnicotinamide, isolated from urine samples of human TB patients treated with INH therapy is proposed to have antimycobacterial activity.

METHODS

To understand the mechanism of interaction of the truncated INH-NAD adduct, binding energy studies were carried out on the aforementioned six enzymes with known three-dimensional structures using AutoDock4.2.

RESULTS

In silico docking analysis of these MTB enzymes with the truncated INH-NAD adduct showed favorable binding interactions with docking energies ranging from -5.29 to -7.07 kcal/mol.

CONCLUSION

Thus, in silico docking study revealed that the INH-NAD adduct, which is generated in vivo after INH activation, may undergo spontaneous hydrolysis to form the truncated INH-NAD adduct and further binds and inhibits multiple enzymes of MTB, in addition to InhA, confirming that INH is an effective anti-TB drug acting at multiple enzymes. Further analysis of amino acid residues in the active site of INH-NAD-binding proteins showed the probable presence of catalytic triad in four enzymes possibly involved in INH binding to the enzyme.

Defining multidrug-resistant tuberculosis: correlating GenoType MTBDRplus assay results with minimum inhibitory concentrations

This study correlates MICs of rifampicin (RIF) and isoniazid (INH) with GenoType MTBDRplus assay results for drug-resistant Mycobacterium tuberculosis (MTB) clinical isolates. MICs of RIF and INH were established for 84 and 90 isolates, respectively, testing 7 concentrations of each drug. Genotypic resistance to each drug was determined by GenoType MTBDRplus assay with 50 representative mutations confirmed by pyrosequencing, with mutations in the rpoB gene associated with RIF resistance and mutations in the katG and/or inhA genes associated with INH resistance. Based upon the correlation of MICs with specific genetic profiles, relative resistance levels were established for each isolate. Results indicate that MTB phenotypic resistance, currently based upon the testing of isolate susceptibility to a single drug concentration, may be more accurately profiled via quantitative MICs, and therefore, the correlation of molecular diagnostic results with specific MICs may allow for more optimal treatment of infections.

Evaluation of pyrosequencing for detecting extensively drug-resistant Mycobacterium tuberculosis among clinical isolates from four high-burden countries

Reliable molecular diagnostics, which detect specific mutations associated with drug resistance, are promising technologies for the rapid identification and monitoring of drug resistance in Mycobacterium tuberculosis isolates. Pyrosequencing (PSQ) has the ability to detect mutations associated with first- and second-line anti-tuberculosis (TB) drugs, with the additional advantage of being rapidly adaptable for the identification of new mutations. The aim of this project was to evaluate the performance of PSQ in predicting phenotypic drug resistance in multidrug- and extensively drug-resistant tuberculosis (M/XDR-TB) clinical isolates from India, South Africa, Moldova, and the Philippines. A total of 187 archived isolates were run through a PSQ assay in order to identify M. tuberculosis (via the IS6110 marker), and to detect mutations associated with M/XDR-TB within small stretches of nucleotides in selected loci. The molecular targets included katG, the inhA promoter and the ahpC-oxyR intergenic region for isoniazid (INH) resistance; the rpoB core region for rifampin (RIF) resistance; gyrA for fluoroquinolone (FQ) resistance; and rrs for amikacin (AMK), capreomycin (CAP), and kanamycin (KAN) resistance. PSQ data were compared to phenotypic mycobacterial growth indicator tube (MGIT) 960 drug susceptibility testing results for performance analysis. The PSQ assay illustrated good sensitivity for the detection of resistance to INH (94%), RIF (96%), FQ (93%), AMK (84%), CAP (88%), and KAN (68%). The specificities of the assay were 96% for INH, 100% for RIF, FQ, AMK, and KAN, and 97% for CAP. PSQ is a highly efficient diagnostic tool that reveals specific nucleotide changes associated with resistance to the first- and second-line anti-TB drug medications. This methodology has the potential to be linked to mutation-specific clinical interpretation algorithms for rapid treatment decisions.

Stratifying low level Isoniazid resistance using additional intermediate drug concentration

Isoniazid (INH) susceptibility testing for 100 Mycobacterium tuberculosis performed by conventional minimum inhibitory concentration (MIC) method was stratified using additional drug concentrations. Introduction of additional drug concentrations did not greatly improve the discriminatory capacity, but can be used in specialized studies pertaining to cross resistance between structural analogues of INH.