A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in part fulfillment of the requirements for the degree of MSc (Med) (Pharmaceutical Affairs) Johannesburg, 25 March 2013 / The emergence of resistant forms of tuberculosis (TB) has not only caused continuous challenges on the world populations’ health, but has also attracted increased costs of primary health care for the infected and society at large. In 2005, when the South African public came to learn about another resistant form of TB other than multi-drug resistant (MDR), 53 patients had just died in a rural hospital in KwaZulu-Natal (KZN). The reports (SA DoH, 2006) came to announce this form of TB as extreme drug resistant tuberculosis (XDR-TB).

Over the last few years the World Health Organization (WHO) has endorsed several tests for the rapid detection of multidrug-resistant tuberculosis (MDR-TB) in resource-poor settings. The objective of this study was to compare the cost-effectiveness of a line probe assay test (less than one week for results) to conventional (bacterial culture) drug susceptibility testing (one month for results) for the detection of MDR-TB in an HIV-positive South African population by estimating the incremental cost-effectiveness ratio (ICER) per disability-adjusted life-year (DALY) averted. Costs of testing, drug treatment, hospitalization, as well as estimates for mortality, treatment success, and failure rates were obtained from literature sources, the South African Department of Health, the WHO, the Foundation of Innovative Diagnostics (FIND), and expert opinion. The willingness-to-pay threshold for a DALY averted was pre-set at 3 times the 2009 GDP per capita (about $17,400) for South Africa. In the base-case scenario for a prevalence of 30% of MDR-TB among HIV-positive patients, the average cost per person for the line probe assay testing strategy was $3,539/0.458 DALY averted and the conventional testing approach was $3,011/0.430 DALY averted. The base-line ICER was about $18,800 per DALY averted – about $1,400 above the pre-set threshold. In sensitivity analyses, the model was robust to changes in prevalence (+ 50%); costs (+ 10%), and probabilities of death, success and failure (+ 20%). However, when the treatment success rate for the line probe assay test was increased to 60% (one of the targets set by WHO in TB treatment) the ICER was below the willingness-to-pay level (i.e., cost-effective). The probabilistic sensitivity analysis showed there is a 70% chance that the additional cost of the line probe assay, compared with conventional testing, was less than $30,000 per DALY averted. However, the model may have underestimated the benefits of the line probe assay because it did not account for a decrease in the transmission of the disease due to earlier treatment nor did it measure any benefits more than a year after testing. / text

The study aimed to explore and describe the experiences of people treated for multidrug resistant tuberculosis (MDR-TB) in Omaheke region, Namibia in order to make relevant recommendations regarding their management. A descriptive qualitative design approach was used. Data was collected using in-depth individual interviews with six participants. The interview transcripts were analysed using thematic content analysis. Three themes emerged namely (1) Stressors related to MDR-TB diagnosis and treatment which involved nature of disease and compulsory hospitalisation (2) Impact of being treated for MDR-TB which related to emotional , social , spiritual and financial impact (3) Support structures for people treated for MDR-TB which included family members, health care professionals and friends. Systemic practical patient-centred, staff-centred and community-centred recommendations are suggested as well as recommendations for future research and an appraisal of the limitations of this study. / Health Studies / M.A. (Public Health)

Background: Pulmonary Tuberculosis (PTB) is considered a disease of the past but it remains a major cause of mortality among immune compromised patients and continues to be a significant threat to public health globally. Notably, the prevalence of diabetes mellitus (DM) has increased over the years. The biological link of TB and DM has been reported in numerous literature with DM attributed to three folds increase in the risk of TB and linked to Drug Resistant TB, especially amongst aged diabetic patients. The aim of the study was to examine the distribution of DM among TB patients and explore the risk of Drug resistant TB in Diabetics infected with TB Methods: The study employed a retrospective cross-sectional descriptive case based study involving 3638 patients diagnosed with pulmonary TB in the State of Florida, USA, 2009-2014. A comparative analysis of TB cases with DM and cases without DM adjusted for age was conducted. The risk of Drug resistant TB associated with DM was estimated through logistic regression analysis. Odds Ratios of TB/DM comorbidity were calculated and adjusted for Age using 5-year intervals from 40 years to above 70 years. Ninety-five percent (95%) confidence intervals were used and the accepted level of error was 0.05. Results: There were 3836 cases of Pulmonary TB in Florida for the period of 2009-2014. The majority of cases (65%) were males and likely unemployed (59.1%). The prevalence of DM was 12 % but when adjusted for age the prevalence of DM was 3.9% amongst patients aged below 40 years and 16.7 % in patients aged above 40 years. An estimated 469 cases had TB/DM comorbidity (12.2%). The majority of TB/DM cases were above 40 years amongst the patients with DM, 44/469 (9.4%) had drug resistant TB and a majority were resistant to Rifampin. Population density did not influence the distribution of TB in this study. Conclusion: Diabetes Mellitus, Aging, and low immunity are linked with increased rates of progressing from latent TB infection to active disease. To achieve the goal of TB elimination it is important to fully understand and identify known TB comorbidities for proper diagnosis and early initiation to care. There is a positive correlation between high DM burden and increased TB prevalence. Therefore, it is recommended that prevention of DM, hyperglycemia and comprehensive management of DM be intensified to prevent TB, improve TB treatment outcomes and reduce the risk of drug resistant TB in Florida, USA.

Magister Public Health - MPH / Namibia is currently coping with a dual burden of human immunodeficiency (HIV) and HIV-associated tuberculosis (TB). In 2010, HIV prevalence was 18.8%, the TB case notification rate was 634 per 100,000 population, while TB/HIV co-infection was 58% in 2009. There were 372 reported cases of drug-resistant TB (DR-TB) in 2009. This study assessed the prevalence, profile and outcome of adverse events (AEs) associated with the treatment of DR-TB, and risk factors for the adverse events. The researcher used a cross-sectional design. Data was collected from the treatment records of all patients treated for DR-TB (N = 59) at the study facility between January 2008 and February 2010. Descriptive statistics were used to describe the frequency of the adverse events and logistic regression to analyse the association between possible risk factors and (specific) adverse events, with stratification (sub-group analysis) and multivariate analysis to adjust for measured confounders. Results of logistic regression analysis are reported as odds ratio (OR), 95% confidence interval (CI) and p-value, where p<0.05 was considered to be statistically significant. A total of 141 adverse events were experienced by 90% (53/59) of patients in the sample. HIV-associated TB occurred in 31 (53%) of the sample. The prevalence of gastrointestinal tract (GIT) adverse events was 64%, tinnitus 45%, joint pain 28% and decreased hearing 25%. Abdominal pain, rash, nausea, decreased hearing and joint pain were found to be more common in people living with HIV than in HIV-negative patients. Moderate-to-severe adverse events were mostly experienced after four weeks of DR-TB treatment (OR 6.4; 95% CI 1.6 – 25.6, p= 0.01). Drug-resistant TB patients who were coinfected with HIV were more prone to experiencing three or more adverse events (OR 3.9; 95% CI 1.2 – 13.6, p= 0.03). Patients treated with zidovudine-based ART were at an increased risk of experiencing nausea (OR 7.5; 95% CI 1.1 -51.5, p=0.04). Females were associated with an increased risk of skin rash (OR 15.7; 95% CI 1.7 – 143.7, p=0.01). The use of cycloserine-based DR-TB regimens was associated with joint pain (OR 6.5; 95% CI 1.6 – 25.8, p=0.01), while the risk of ototoxicity was associated with the use of amikacin-containing regimens (OR 12.0; 95% CI 1.3 – 111.3, p=0.03). Adverse events were found to be more common among patients treated for DR-TB (90% prevalence), particularly during the intensive phase of TB therapy. Most of these adverse events were mild and tolerable. Some adverse events were more common among DR-TB patients who were co-infected with HIV than in HIV-negative patients. The characteristics and risk factors of the serious adverse events need further research. The use of cycloserine-based DR-TB regimens was associated with joint pain. Findings of the risk factor analysis are inconclusive because of the small sample size, which severely limited the power of the study. Clinicians should invest more time in the prevention and management of adverse events, and should pay greater attention to the needs of HIV co-infected DR-TB patients who are using second-line anti-TB medications, especially those who are concomitantly undergoing treatment using antiretroviral medicines.

Thesis (M. Sc. (Chemistry)) -- University of Limpopo, 2021 / Tuberculosis is one of the top 10 leading causes of death in the world. The development of drug resistant strains of Mycobacterium tuberculosis such as Multidrug resistant (MDR) and Extensively drug resistant (XDR) strains further complicate the TB control. Medicinal plants present a possible source for new potential antitubercular drugs. They have played an important role in drug discovery, with many pharmaceutical products originating from them. Isolation and characterisation of new antitubercular compounds from plant extracts is relevant today because of the development of resistant strains. The aim of the study was to evaluate the antimycobacterial activity of the leave extracts of Croton gratissimus and Leonotis leonorus. The first step was to extract fine powder leaves of the two plant species using four (dichloromethane, acetone, hexane and ethanol/water) different solvent systems. Isolation of the fractions was done using column chromatography and preparative thin layer chromatography. Minimum inhibitory concentrations were determined using the broth dilution method and the values were recorded in μg/mL. All the isolated fractions from both plant species were evaluated for preliminary in-vitro antimycobacterial activity. Some of the isolated fractions showed an increased activity against the pathogen as compared to the crude extracts. All the crude extracts of the two plants had activity with MIC90 values greater than 125 μg/mL. Seven fractions obtained from Croton gratissimus showed potential activity against the pathogen with MIC90 values ranging from 30.61 to 64.88 μg/mL. Leonotis leonurus had three fractions with promising activity with MICs ranging from 1.963 to 62.51 μg/mL. The crude extracts of the two plant species showed that the two plant species have antioxidant properties. The qualitative antioxidant assay showed that DCM crude extracts had more antioxidants than all other extracts because of more clear zones against the purple background colour on the TLC plates. These was confirmed by the qualitative antioxidant assay where DCM crude extracts was able to inhibit the highest percentage of DPPH at different concentrations than all other solvent extracts. The DCM crude extracts of L. leonurus and Croton gratissimus inhibited 87 and 93 % of DPPH respectively at 250 μg/mL. The structures of the compounds within the isolated fractions were elucidated using NMR and confirmed by MS and FTIR spectroscopies. The NMR data showed that the isolated fractions were not pure compounds but mixtures of closely related compounds. The compounds whose structures were elucidated included two labdane diterpenoids (Croton A and Croton B) and a Cembranolide ((5E,10E,13R)-4-isopropyl-7,11-dimethyl-15-oxo-14-oxa-bicyclo [11.2.1] hexadeca-5,10-dien-7-yl acetate) from Croton gratissimus and a phenol (4-(3,3,4,4-tetramethylheptyl) benzene-1,2-diol)) from Leonotis leonurus. / National Research Foundation (NRF) and Sasol Foundation

Master of Public Health - MPH / Decentralisation of multi-drug resistant tuberculosis (MDR-TB) services has resulted in improved access to care, with community-based treatment of MDR-TB shown to be more effective than centralised hospital-based care. Furthermore, increasing bed shortages resulted in the National Department of Health establishing MDR-TB policy guidelines in 2011. However, the extent to which this policy has been implemented by the decentralised MDR- TB sites and the factors influencing implementation of the policy from a management perspective were not well described. The aim of this study was therefore to explore and compare the actual and ascribed roles and responsibilities of key management-level role players at the decentralised MDR-TB sites, and to explore the factors influencing implementation of the MDR-TB decentralisation policy (2011).

Drug resistance is a serious problem in health care in general, and in malaria treatment in particular, rendering many of our previously considered ‘wonder drugs’ useless. Recently, large sums of money have been allocated for the continuous development of new drugs to replace the failing ones. We seem to be one step behind the evolution of antimalarial resistance; is it possible to get one step ahead? Are interventions which slow down the evolution and spread of drug-resistant malaria parasites achievable? In this thesis, I address these issues with experimental data, using the well-established rodent malaria model Plasmodium chabaudi to understand the selective advantages and disadvantages drug-resistant parasites endure within a vertebrate host and the selective pressures various drug treatment regimes exert on these parasites. Competitive interactions between drug-resistant and drug-sensitive parasites were observed within the host, with resistant parasites having a competitive disadvantage in the absence of drug treatment. The frequency of resistant parasites at the start of the infection was an important determinant of the strength of selection: the lower their frequency, the stronger the competitive suppression in non-treated hosts and the greater their competitive release following drug treatment. Genetically similar genotypes, one resistant and one sensitive, showed similar dynamics following drug treatment. Multiplicity of infection did not have an effect on the within-host dynamics: a larger number of co-infecting susceptible genotypes did not lead to greater competitive suppression or release of resistant parasites. Lastly, various drug treatment regimes were compared. Conventional drug treatment resulted in the greatest selective advantage for drug-resistant parasites, while less aggressive treatments were equally as effective, or even better, at improving host health and reducing overall infectiousness. These studies demonstrate that altering the within-host ecology of drug-resistant parasites by administering drugs and hence removing the drug-sensitive competitors has a large influence on the transmission potential of drug-resistant parasites. Furthermore, this thesis provides proof of principle that other drug treatment regimes different from those currently in use could better control drug-resistant parasites, without compromising other treatment goals. In the case of malaria, less drugs may mean extending the useful lifespan of that drug.

Magister Public Health - MPH / Ototoxic induced hearing loss is a common adverse event related to aminoglycosides used in Multi Drug Resistant -Tuberculosis treatment. Exposure to ototoxic drugs damages the structures of the inner ear. Symptomatic hearing loss presents as tinnitus, decreased hearing, a blocked sensation, difficulty understanding speech, and perception of fluctuating hearing, dizziness and hyperacusis/recruitment. The World Health Organization (1995) indicated that most cases of ototoxic hearing loss globally could be attributed to treatment with aminoglycosides. The aim of the study was to determine the proportion of DR-TB patients initiated on treatment at three decentralized sites during a defined period (1st October to 31st December 2015) who developed ototoxic induced hearing loss and the corresponding risk factors, whilst receiving audiological monitoring with an extended high frequency audiometer (KUDUwave). A retrospective cross-sectional study was conducted. Cumulatively across the three decentralized sites, 69 patient records were reviewed that met the inclusion criteria of the study. The mean age of the patients was 36.1, with a standard deviation (SD) of 10.7 years; more than half (37) were female. Ototoxicity , a threshold shift, placing patients at risk of developing a hearing loss was detected in 56.5% (n=39)of patients and not detected in 30.4%(n=21).The remaining 13,1% (n=9)is missing data. As a result, the regimen was adjusted in 36.2% of patients. . From the 53 patients who were tested for hearing loss post completion of the injectable phase of treatment, 22.6% (n=12) had normal hearing, 17.0 % (n=9) had unilateral hearing loss, and 60.4% (n=32) had bilateral hearing loss. Therefore, a total of 41 patients had a degree of hearing loss: over 30% (n=22)had mild to moderate hearing loss, and only about 15% (n=11)had severe to profound hearing loss. Analysis of risk factors showed that having ototoxicity detected and not adjusting regimen significantly increases the risk of patients developing a hearing loss. The key findings of the study have shown that a significant proportion of DR-TB patients receiving an aminoglycoside based regimen are at risk of developing ototoxic induced hearing loss, despite receiving audiological monitoring with an extended high frequency audiometer that allows for early detection of ototoxicity (threshold shift).

Doctor Pharmaceuticae - DPharm / Introduction: Drug-resistant tuberculosis remains a major world health problem and one of the leading cause of death worldwide. Despite adequate adherence to antituberculosis drugs by patients, the emergence of drug-resistance tuberculosis still occurs. This fact implies other factors leading to the emergence of resistant strains of Mycobacterium tuberculosis. A multidrug treatment regimen, which may consist of five to seven different drugs including terizidone, is used in the treatment of drugresistance tuberculosis. Terizidone is part of the multidrug regimen whose pharmacokinetics is scarce in literature and plasma concentration profile unknown. Two molecules of cycloserine joined by terephtalaldehyde moiety makes up a molecule of terizidone, which is thought to undergo complete metabolism into cycloserine in vivo. Additionally, the current literature report that terizidone and cycloserine can be used interchangeably as they are thought to be equivalent. The aim of this thesis was first to develop and validate bioanalytical methods for determination of terizidone and cycloserine in patients’ plasma samples. Secondly, to model population pharmacokinetics of terizidone and cycloserine. Thirdly, to determine the amount of cycloserine resulting from metabolism of terizidone.