Thesis (MTech (Biomedical Technology))--Cape Peninsula University of Technology, 2010 / The World Health Organisation estimates that nine million people are infected with tuberculosis (TB) every year of which ninety-five percent live in developing countries. Africa has one of the highest incidences of TB in the world. but few of its countries are equipped to diagnose drug-resistant TB. This study aimed to develop a robust. yet simple and cost-effective assay. which would require minimal sophisticated instrumentation and specialised personnel that would make drug sensitivity screening for multi-drug resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) accessible to resource-poor high-burden settings. A four-quadrant colorimetric agar plate method was developed which showed good specificity (97.3%-100%) and sensitivity (77.8%-100%) compared to the polymerase chain reaction (PCR) method used as gold standard. Agreement between the methods. using Simple Kappa Coefficients. ranged between very good and excellent. all with high statistical significance (P < 0.0001). The currently used BACTEC MGIT SIREN sensitivity assay coupled with the E-test® strip method. as routinely used in the TB reference laboratory. was compared and showed excellent comparison with the newlydeveloped plate method. for each antibiotic tested. as well as the resultant monoresistant, MDR- or XDR-TB diagnoses. Moreover. the new method was found to be extremely cost-effective. priced at half the cost of a peR assay. These four quadrant plates. with a colorimetric indicator and selected antibiotics. can be considered as an economic altemative or a complimentary method for laboratories wishing to reduce the cost and complexity for TB drug sensitivity testing. Routine diagnostic testing would thus be made more accessible and affordable to laboratories that are not presently diagnosing drug resistant TB. therefore enhancing case detection and treatment in the resource-poor settings hardest hit by this curable disease.

Magister Artium - MA (Anthropology/Sociology) / Biomedicine positively maintains that tuberculosis transmission occurs due to close contact with a diseased individual (Coovadia and Benatar, 1991). Consequently, this refers to a direct mode of transmission where individuals are at direct risk of becoming infected. It is often taken for granted that when one speaks of contact within the context of tuberculosis, one is necessarily referring to contact or interactions among tuberculosis patients and people in the community with whom they have contact of any nature. It is then assumed that tuberculosis is transmitted in this manner. However, there are also indirect modes of transmission which are often neglected to be explored, but have an equally serious effect on transmission in high incidence areas. This paper also addresses other contact patterns that are also role-players in the tuberculosis epidemic.

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Tuberculosis transmission in free-ranging bison of northern Canada is of significant concern to wildlife managers because of its effects on condition and mortality in bison herds and the potential for transmission to local hunters and neighbouring cattle populations. The chronic nature of tuberculosis combined with the gregarious behaviours of bison permit its persistence in free-ranging herds even at low densities, which makes disease eradication difficult without whole herd depopulation. The protection of remaining non-infected free-ranging bison populations is thus of paramount importance to the conservation of specific disease-free wild bison in northern Canada and to the economic stability of cattle farms. Detection of movements and removal of dispersing animals between spatially separated free-ranging populations reduces the potential for contact between bison populations and minimizes the probability of tuberculosis transmission. In this thesis, a conceptual model was developed to assess the potential for tuberculosis transmission between two infected bison herds (Nyarling River and Garden River) in Wood Buffalo National Park and the spatially separated, Mackenzie Bison herd in the Northwest Territories. This conceptual model identifies gaps in knowledge and highlights areas where research is required to ensure accurate evaluation of tuberculosis transmission risk in freeranging bison. The main finding was that the bison cohort representing the highest risk for tuberculosis transmission between spatially separated free-ranging herds is mature males. The propensity of mature males to make long-distance movements is also not fully understood and research to predict these movements would make a significant contribution to risk assessment and management planning to reduce the probability of contact between infected and non-infected bison populations.

The disparity in tuberculosis rates between Indigenous and non-Indigenous people persists in Canada and New Zealand. The most common form of tuberculosis in humans is pulmonary tuberculosis so eliminating tuberculosis transmission is an important obstacle to decreasing the overall rates of the disease. In both Canada and New Zealand, social determinants of health such as housing conditions, access to health care and historical influences (including similar experiences with colonization) have been implicated in the high rates of tuberculosis. This thesis examines and compares the social determinants of tuberculosis transmission among Aboriginal people in the Canadian province of Alberta and Maori and Pacific people in New Zealand. In Alberta, ten Aboriginal individuals with smear-positive pulmonary tuberculosis participating in a larger prairie wide study were divided into two groups (transmitter and non-transmitter) based on transmission events identified through contact tracing and DNA fingerprinting. Interviews with the ten participants were analyzed and compared using an interpretive phenomenological perspective and informed by an Aboriginal framework of health. Survey data from the same individuals provided complementary descriptive statistics. In New Zealand, interviews with Maori and Pacific pulmonary TB participants that had been conducted as part of other studies were accessed and analyzed using an interpretive phenomenological perspective. Like in Canada, Indigenous frameworks of health specific to Maori and Pacific people informed the analysis. The Canadian analysis identified three factors of greater relevance within the transmission group: substance use, patient-delay-in-seeking-treatment, and number of contacts. These factors were also relevant for the Maori and Pacific experience of tuberculosis. The results of this cross-cultural comparative study highlight the complexity of the experience of tuberculosis for Indigenous people in both Canada and New Zealand. Future research and education and intervention programs must not only consider the proximal social determinants of health, such as poverty, unemployment, etc, but also the more distal social determinants of health and the causes of causes such as colonization and its multi-generational effects.

The disparity in tuberculosis rates between Indigenous and non-Indigenous people persists in Canada and New Zealand. The most common form of tuberculosis in humans is pulmonary tuberculosis so eliminating tuberculosis transmission is an important obstacle to decreasing the overall rates of the disease. In both Canada and New Zealand, social determinants of health such as housing conditions, access to health care and historical influences (including similar experiences with colonization) have been implicated in the high rates of tuberculosis. This thesis examines and compares the social determinants of tuberculosis transmission among Aboriginal people in the Canadian province of Alberta and Maori and Pacific people in New Zealand. In Alberta, ten Aboriginal individuals with smear-positive pulmonary tuberculosis participating in a larger prairie wide study were divided into two groups (transmitter and non-transmitter) based on transmission events identified through contact tracing and DNA fingerprinting. Interviews with the ten participants were analyzed and compared using an interpretive phenomenological perspective and informed by an Aboriginal framework of health. Survey data from the same individuals provided complementary descriptive statistics. In New Zealand, interviews with Maori and Pacific pulmonary TB participants that had been conducted as part of other studies were accessed and analyzed using an interpretive phenomenological perspective. Like in Canada, Indigenous frameworks of health specific to Maori and Pacific people informed the analysis. The Canadian analysis identified three factors of greater relevance within the transmission group: substance use, patient-delay-in-seeking-treatment, and number of contacts. These factors were also relevant for the Maori and Pacific experience of tuberculosis. The results of this cross-cultural comparative study highlight the complexity of the experience of tuberculosis for Indigenous people in both Canada and New Zealand. Future research and education and intervention programs must not only consider the proximal social determinants of health, such as poverty, unemployment, etc, but also the more distal social determinants of health and the causes of causes such as colonization and its multi-generational effects.

While the overall annual incidence of tuberculosis (TB) on the Island of Montreal has been stable at 10 per 100,000 in recent years, incidence varies tremendously by country of birth and by neighbourhood. It is not clear how much of this variation reflects population distribution, and how much reflects localized risk factors and/or local transmission. Precise mapping and spatial statistical analysis allowed for the identification of two types of TB concentrations: hotspots---raw concentrations of cases, and high-incidence zones---where TB incidence significantly exceeds the rate expected. The high-incidence zones were not fully explained by known risk factors for TB, such as high population densities or low incomes, when aggregated at the census tract level. The results were linked with Mycobacterium tuberculosis genotyping data to search for evidence of recent transmission. We found that there is substantial aggregation of TB in Montreal, beyond the concentration of the foreign-born as a group, and evidence of recent transmission contributing to high incidence was uncovered in one area of the city.

No description available.

Thesis (MScMedSc)--University of Stellenbosch, 2011. / Please refer to full text to view abstract.

Thesis (PhD)--Stellenbosch University, 2012. / Includes bibliography / ENGLISH ABSTRACT: Mycobacterium tuberculosis, the causative organism of tuberculosis (TB), is a major cause for mortality and morbidity world-wide with a death toll only second to HIV among infectious diseases. Drug resistance is widespread and cases of multiple drug resistant TB (MDR-TB) and extensively drug resistant TB (XDR-TB) have emerged in several countries. Drug treatment is problematic and new drugs are not developed rapidly enough to offset the rapid drug resistance mutation rate of M. tuberculosis. Simple and effective diagnostics are required to contain the spread of the disease as current routine diagnostics are not fulfilling this role. Additionally, current rapid TB diagnostics are out of reach to resource poor settings due to infrastructure, cost and skill requirements. Novel TB diagnostics are thus required that meet these requirements. Mycobacteriophages are phages that infect mycobacteria and could offer a viable and cost effective alternative rapid TB diagnostics. In this study, an affinity-tagged fluorescent reporter mycobacteriophage is described, which was engineered to act as a TB diagnostic. Its performance proved favourable and superior to current existing mycobacteriophage-based TB diagnostics. / AFRIKAANSE OPSOMMING: Mycobacterium tuberculosis, die organisme verantwoordelik vir tuberkulose (TB), is `n groot bron van mortaliteit en morbiditeit wêreldwyd en slegs HIV is verantwoordelik vir groter getalle sterftes as gevolg van n aansteeklike siekte. Middelweerstandigheid is algemeen en gevalle van meervoudigemiddelweerstandige tuberkulose (MDR-TB) en uiters weerstandige tuberkulose (XDR-TB) kom in verskeie lande voor. Antibiotika behandeling is problematies en nuwe anti-TB middels word nie vinnig genoeg ontwikkel om die antibiotika weerstandigheid mutasie spoed van M. tuberculosis te bekamp nie. Doeltreffende diagnostiese toetse word benodig om die verspreiding van die siekte te beheer en bestaande roetine diagnostiese toetse voldoen tans nie aan hierdie vereiste nie. Behalwe hiervoor, is huidige vinnige TB diagnostiese toetse buite bereik van arm instansies weens vereistes aan infrastruktuur, meegaande kostes en werknemervaardigheid. Nuwe TB diagnostiese toetse is dus nodig om aan hierdie vereistes te voldoen. Mikobacteriofaage is fage wat mikobacteria infekteer en kan moontlik 'n lewensvatbare en koste-effektiewe alternatief bied vir vinnige TB diagnostiese toetse. In hierdie studie word 'n affiniteitgekoppelde fluoreserende rapporteringsmikobakteriofaag beskryf wat ontwerp is om op te tree as `n nuwe vinnige TB diagnostiese toets. Die werking hiervan vertoon gunstige en beter resultate as die huidige, mikobacteriofaaggebaseerde TB-diagnostiese toetse.