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The clinical assessment of spirituality in palliative careCobb, Mark January 2013 (has links)
Background: The practice of palliative care and the specialty of palliative medicine emerged from the modern hospice movement and its foundational philosophy of treating the whole person. This holistic approach recognises that the needs of dying patients are complex and multifaceted. Spirituality is one of the dimensions of palliative care practice and it was assumed that there was sufficient robust primary data to support a synthesis of evidence. However, a critical examination of the published data found that many studies make use of unexamined assumptions and ambiguous constructs. The research in this field is therefore missing an important methodological step in the inductive cycle by failing to articulate explicit theory or identify critical concepts. Aim: To construct a conceptual model of spirituality that provides a systematic way of illustrating the essential properties, functions and relationships of how spirituality operates in the lives of palliative care patients that can be subject to empirical testing. Methods: Conceptual model building was used as a method of theoretical investigation to construct a minimal abstract and indirect representation of the way that spirituality potentially operates in the lives of patients. The model was then subject to empirical testing through generating quantitative and qualitative data from palliative care patients participating in a questionnaire and interview. Analysis: Quantitative data from the questionnaires was subject to descriptive statistics and exploratory data analysis using techniques of visual representation. Qualitative data was subject to deductive content analysis based upon categories derived from the conceptual model. Results: A Synoptic Model was developed whose theoretical claims were congruent with the findings from this sample with the exception of the disease construct. 19 patients participated in the questionnaire phase of the study and 10 participated in an interview. Patients discussed multiple aspects of spirituality including their beliefs, practices and experiences. For some patients spirituality provided an orientation to life and helped make sense of illness and its consequences. Spirituality was also a resource for some patients in helping them to face their current situation and their mortality. Discussion: The Synoptic Model provides empirically supported theoretical knowledge of spirituality that can be utilised in the context of palliative care and has implications for clinical practice in terms of patient care, education and development, and assessment. Further development and testing is required in different settings to refine the Synoptic Model’s content and specification.
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Recovery from community acquired pneumoniaWootton, Daniel January 2015 (has links)
Aims: To measure symptomatic recovery over a year among an adult cohort recruited from hospital with community acquired pneumonia (CAP). To measure the host recovery mechanism efferocytosis and the diversity of the bacterial microbiota in sputum and relate these to individual characteristics of subjects in the cohort. Methods: Patients with CAP were recruited from two hospitals in Liverpool, (UK) and were followed-up for one year. The CAP-sym questionnaire was completed at multiple time-points in order to create a statistical model of symptomatic recovery. DNA was extracted from acute sputum samples and 16S rRNA sequencing revealed the diversity of bacteria in sputum. At one month into recovery subjects volunteered for bronchoalveolar lavage and rates of efferocytosis were measured by co-culturing ex-vivo alveolar macrophages with apoptotic autologous neutrophils. Results: The 169 subjects recruited with CAP were found to have high levels of socio-economic deprivation, smoking and COPD and the median age was 64 years. A non-linear, longitudinal, statistical model of symptoms found that smoking impaired recovery but people tended to describe better recovery as they got older. Efferocytosis was impaired by smoking but improved by statins and these effects were modified by body mass index. Those with prior pulmonary disease had lower bacterial diversity in their sputum and in this cohort a species from the genus Haemophilus was dominant. Conclusion: This work proves the principal that modelling CAP-sym scores can be used to investigate factors associated with differential recovery from CAP. It highlights the detrimental effects of smoking on both recovery and efferocytosis. This is the first study to show that the bacterial diversity of CAP sputum is influenced by prior lung disease. The translational outcomes are the potential for trials of statins as pro-recovery agents and to study modified empirical antibiotics for those with CAP and prior-lung disease.
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Defining the neutrophil phenotype in systemic sclerosisBarnes, Theresa January 2010 (has links)
Background: Systemic sclerosis (SSc) is a disease characterised by a triad of immunological abnormalities, endothelial cell dysfunction and fibrosis. Neutrophils are the most abundant circulating leukocyte. They contain several mediators which when released can lead to modulation of the inflammatory response, cause endothelial cell activation and injury and eventually lead to fibrosis. The peri-endothelial cell environment in SSc has the potential to lead to neutrophil activation and indeed this has been previously described in the literature in terms of reactive oxygen species (ROS) generation. In this thesis I aim to explore the hypothesis that: “Neutrophils are activated in SSc and contribute to endothelial cell activation and damage”. Methods: The functional phenotype of SSc neutrophils was explored in vitro. Functions investigated included; ROS generation, chemotaxis, integrin expression, apoptosis and CD16 expression. The protein expression of ex vivo SSc neutrophils was compared to healthy control neutrophils. The DIGE technology was used to explore the pan-proteome and iTRAQ was used to focus in on the plasma membrane proteome. The role of neutrophil elastase was explored in SSc by examining the serum neutrophil elastase concentration and activity and correlating these to clinical manifestations of disease. The role of neutrophil: endothelial cell interactions was modelled in vitro using live cell imaging by confocal microscopy looking for evidence of endothelial cell activation (E-selectin expression) and apoptosis. Experiments examined the role of neutrophil derived mediators in these interactions. Results: Functional studies revealed that SSc neutrophils are hypofunctional in terms of spontaneous ROS generation and chemotaxis in vitro. This may reflect in vivo activation. SSc neutrophils are similar in terms of integrin expression and baseline apoptosis to control neutrophils. Pan-proteomic studies reveal neutrophil activation in SSc since changes in protein expression mirror those seen in response to neutrophil activators TNFα and LPS. Proteomic studies also point to neutrophil priming in vivo. Serum neutrophil elastase concentrations and activity were not elevated in SSc, however, discrepancies between concentration and activity suggest a functional deficiency in elastase inhibitors in SSc serum. Serum elastase activity and concentrations were found to be lower in RNP (ribonucleoprotein) positive patients indicating that different mechanisms maybe involved in different SSc subtypes. In vitro models demonstrate that SSc serum causes endothelial cell activation and apoptosis and that neutrophils are essential for this effect. Serine proteases seem to play an important role in inducing apoptosis and IL-6 trans signalling is involved in endothelial cell activation and apoptosis. Neutrophils do not express IL-6 but are dominant sources of the soluble IL-6R which is essential for trans signalling. Conclusions: There is evidence that neutrophils are activated in SSc though; no specific activating signature is identified. In co-cultures, neutrophils are essential for endothelial cell activation and apoptosis in response to SSc serum. Neutrophil mediators including serine proteases and IL6R are likely to play important roles in this effect. Therefore neutrophils may play an important part in the propagation of inflammation and endothelial cell activation which eventually leads to the fibrotic phenotype which is characteristic of this disease.
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Improving linkage into HIV care among adults in Blantyre, MalawiMacPherson, Peter January 2013 (has links)
This thesis is concerned with understanding the patient flow from diagnosis of HIV infection to initiation of antiretroviral therapy (ART). Untreated HIV-infected individuals have a high risk of progression to AIDS and death, and of transmitting infection to others. Interventions to ensure prompt linkage into HIV care and ART could have substantial individual and public health benefits. At the turn of the millennium, very few HIV-infected individuals in sub-Saharan Africa had access to lifesaving ART. Since then, national HIV care programmes, supported by international funding, have driven impressive achievements in scaling up ART delivery, with over 9 million people having initiated ART by the end of 2012. Despite these achievements, the majority of HIV infected adults in sub-Saharan Africa remain unaware of their HIV status, meaning that they do not have the opportunity to access ART. Additionally, concerning reports have arisen from a number of HIV care programmes about high rates of patient drop-out and death between diagnosis of HIV and ART initiation. Together, these factors could significantly hinder efforts to achieve universal knowledge of HIV status and coverage of ART. The uptake of HIV testing, and magnitude of and reasons for drop-out of care between HIV diagnosis and initiation of ART were investigated in a prospective cohort study and linked qualitative study at primary care level in Blantyre, Malawi. The main findings were of extremely low uptake of provider-initiated HIV testing and counselling (completed on only 13% of adult facility attendances) and high rates of patient loss to care before ART initiation. Difficulties in completing ART eligibility assessments (WHO clinical staging assessments and measurement of CD4 count) were the major barrier to successful initiation of ART, with over-busy clinics, rushed providers, as well as high patient care- seeking expenses being significant contributory factors. Other sub-Saharan African countries that have implemented the public health approaches to HIV care delivery are likely to face similar problems. To attempt to improve uptake of HTC and linkage into ART care, two novel interventions were investigated. A community-based cluster-randomised trial compared two approaches to improve linkage into HIV care: facility-based initiation of HIV care following home HIV self-testing (HIVST), or optional home initiation of HIV care following HIVST. Uptake of ART, completion of HIVST, reporting of positive HIVST results and retention on and adherence to ART were the outcomes of interest. Over 6-months of HIVST availability, there was a highly significant 3-fold increase in the proportion of the adult population initiating ART, and a doubling of the proportion of adults reporting positive HIVST results to community counsellors where home initiation of HIV care was available, indicating increased willingness to access home-based HIV care. Having identified substantial problems with the use of the WHO clinical staging system for identifying ART eligibility, the accuracy of a brief novel community health worker (CHW) ART eligibility assessment tool was compared against a gold standard of CD4 count. The CWH tool significantly outperformed the WHO clinical staging system in identifying CD4 count of <350 cells/mm3 in terms of sensitivity, positive predictive value, negative predictive value and area under the receiver operator characteristic curve. Nevertheless, overall performance of the CHW tool was still suboptimal with nearly half of ART eligible participants missed, and was worse when compared against the new WHO-recommended ART eligibility threshold of CD4<500 cell/mm3. In conclusion, suboptimal rates of facility-based HTC and subsequent linkage into care are potential major stumbling blocks in efforts to achieve universal access to ART. Current ART eligibility tools are either not widely available (CD4 count measurement), or are insensitive, overly-complex and time-consuming (WHO clinical staging system). Home initiation of HIV care following community-based HIVST overcomes these barriers, with high uptake of HIVST achieved over short time-frame and substantial and significantly increased population-level rates of ART initiation. In an era where “test-and- treat” is increasingly being seen as a strategy to impact upon the HIV epidemic, interventions that improve uptake of testing and linkage into care, such as home HIVST and initiation of HIV care, will be required.
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Challenges in the management of younger adults with type 1 diabetes in hospital outpatient and inpatient settingsSaunders, Simon January 2009 (has links)
This thesis examines the challenges of managing a population of patients with type 1 diabetes who initially attended a hospital outpatient clinic between 1991 and 1996. These 386 patients are subsequently reviewed in 2001 and 2006. The continued attendance at the clinic, level of glycaemic control and prevalence of microvascular and macrovascular complications are assessed. In demonstrating the outcomes of this cohort of patients they are compared to the patients within the landmark study The Diabetes Control and Complications Trial (DCCT). The DCCT showed conclusively that good glycaemic control decreased the risk of developing microvascular complications when compared to those patients with less tight glycaemic control. The findings of this study definitively demonstrated the benefits of good glycaemic control. What was also apparent, but a less publicised finding of this trial was the increase in episodes of hypoglycaemia and the weight gain seen in the group with intensive control arm. How do patients in the ‘real-world’ compare to those patients within the DCCT study, is such good control achievable outside the setting of a clinical trial? The outcomes of the patients attending the younger adult diabetes clinic are demonstrated to be similar to those patients in the DCCT who were controlled conventionally, despite encouragement to adopt an intensive insulin regime and offered regular clinical review from both diabetes specialist nurses and consultant. The potential causes for the differences in glycaemic control between an outpatient clinic and those patients in the DCCT are explored. The thesis also examines the difficulties in managing the small numbers of patients with type 1 diabetes who are hospital inpatients. In particular, a group of patients with diabetes who are also intravenous drug abusers are studied. This group are compared to other inpatients and the study clearly shows episodes of frequent admissions and very high mortality rates in the study group. In conclusion the thesis highlights the many problems which exist when trying to manage type 1 diabetes in the outpatient setting including clinic non-attendance, prevalence of other medical problems and limiting factors such as weight gain and hypoglycaemia. Discussion is also made of ways in which to address these issues and improve control for this group of patients.
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Coagulation and the endothelium in Malawian children with cerebral malariaMoxon, Chris January 2012 (has links)
Background: Cerebral malaria is a major cause of mortality and morbidity in African children. Pathology is related to interactions between malaria-infected red blood cells (iRBC) and the endothelium but the aetiology of the neurological compromise remains unclear. Methods: This thesis involved direct and downstream investigation of the endothelium in Malawian children with cerebral malaria and controls in post-mortem samples, plasma and through developing a novel ex vivo method to examine endothelium in subcutaneous tissue. Results: In post-mortem samples of brain in fatal cerebral malaria, there was thrombosis and loss of endothelial protein C receptor (EPCR) associated with iRBC sequestration. iRBC associated loss of EPCR and thrombomodulin was also demonstrated in post- mortem samples of gut and subcutaneous tissue but this was less marked than in the brain and rarely associated with thrombosis. Subcutaneous biopsies taken on admission with cerebral malaria demonstrated reduced EPCR and thrombomodulin ex vivo, showing that loss of these receptors is present at the time of presentation and are not just agonal events. Examination of coagulation in blood demonstrated activation of coagulation, as indicated by raised thrombin-anti-thrombin complexes and reduced protein C and antithrombin levels. However this was compensated as there was normal prothrombin fragment (F1+2)-to-activated protein C ratios and only mildly altered clotting times. Examination of markers of endothelial activation (soluble Intracellular Adhesion 2 Molecule-1 [sICAM-1] and Angiopoetin-2 [Ang-2]) and inflammation (C-reactive protein [CRP]) revealed endothelial activation and inflammation at presentation and during recovery and demonstrated that in cerebral malaria and in uncomplicated malaria there is persistent endothelial activation after parasites are cleared, up to a month after presentation. Complexes of very low density lipoprotein (VLDL) and CRP were also raised in cerebral and uncomplicated malaria. Conclusions: In cerebral malaria in Malawian children there is localised microvascular loss of endothelial anticoagulant receptors at sites of iRBC sequestration. In the brain, where constitutive expression of EPCR and thrombomodulin is low, this is accompanied by thrombosis; outside the brain, where constitutive EPCR and thrombomodulin expression is high, coagulation is compensated. This activation of coagulation and of the endothelium in response to acute infection leaves a residual imprint as detected by markers of endothelial activation and inflammation even in uncomplicated malaria several weeks after parasites are cleared. Since children in sub-Saharan African frequently suffer repeated infections these endothelial alterations may have important consequences both for subsequent infections and for long-term health. These mechanisms highlight potential targets for therapy.
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The role of redox balance in pulmonary innate immunityRylance, Jamie January 2013 (has links)
Introduction: Household air pollution (HAP) affects one half of the world population, comprises 90% of global particulate exposure, and is associated with mortality from respiratory infections. Particulates are known to alter cellular redox balance, including that of the alveolar macrophage (AM). We investigate redox balance as a mechanism to explain the link between particulate exposure and failure of innate immune function. Methods: Bronchoalveolar lavage was performed on healthy human volunteers in the UK (low HAP) and Malawi (high HAP). Antioxidant capacity was determined (concentrations of oxidised and reduced glutathione, and antioxidant capacities of glutathione peroxidase and superoxide dismutase). AM function was assessed by capacity to phagocytose, and to produce oxidative burst and proteolysis activity within the phagosome using reporter-fluorophore coated silica beads. AM cytokine responses to lipopolysaccharide and to respirable size wood smoke particles were measured before and after ex vivo treatment to reduce glutathione content. Personal exposure to particulates was estimated by the cytoplasmic content of black carbon within AM. Results: AM glutathione was similar in UK and Malawi non-smokers (of which 4.3% was in oxidised form). One quarter of Malawians exhibited a high oxidised glutathione phenotype (8.6% of total). Malawians exhibited higher levels of extracellular glutathione, and intracellular malondialdehyde and particulate content than UK volunteers. Nrf2 levels in Malawian AM were proportional to levels of particulate matter. We demonstrated no association between particulate matter content and AM cytokine responses to lipopolysaccharide or wood. Glutathione depletion did not consistently alter AM cytokine production. In vivo particulate exposure correlates with reduced AM phagosomal oxidative capacity, and increased cellular Nrf-2 concentration, but phagocytosis and phagosomal proteolysis are unaffected. Conclusion: Malawians have high levels of AM particulate exposure, as expected from HAP surveys. This is associated with evidence of oxidative stress (lipid peroxidation), antioxidant upregulation (raised extracellular glutathione, intracellular Nrf2) and a specific defect in AM function (reduced oxidative burst). Antibacterial function of the AM is key to preventing pulmonary infection: in a population subjected to high levels of household air pollution, particulate related defects in AM function could explain the high prevalence of infective respiratory illness.
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Characterization of the immune response in HIV-associated cryptococcal meningitisScriven, James January 2014 (has links)
Despite widespread roll out of anti-retroviral therapy (ART), cryptococcal meningitis (CM) remains a significant cause of morbidity and mortality among HIV-infected persons in sub-Saharan Africa. Host immune response is central to the pathogenesis, and not only influences susceptibility to infection, but clinical presentation and outcome. Animal studies suggest that macrophage activation is a crucial component of the host immune response but human studies are limited. This thesis aims to characterize the activation state of CSF macrophages and blood monocytes in persons with HIV-associated CM, assess the effect of ART on the immune response, and identify immune correlates of severe disease and poor outcome. A prospective cohort study was conducted in Cape Town, South Africa (Innate Immunity in Cryptococcal Disease (IICD)). Persons with HIV-associated CM were enrolled and the immune response in CSF and blood examined using flow cytometry and cytokine analysis. Soluble markers of macrophage activation (sCD14, sCD163) and the ex vivo responses of whole blood and monocytes to TLR ligands and cryptococcal preparations were also measured. Additional CSF and serum samples were obtained from the Cryptococcal Optimal ART timing (COAT) trial (South Africa and Uganda) to examine the immune consequences of earlier ART initiation in cryptococcal meningitis. In this trial, earlier ART was associated with increased mortality in CM compared with a deferred ART strategy (8 days vs. 5 weeks post CM diagnosis respectively). CSF flow cytometry showed that CD8 T cells were the most common cells in the CSF followed by neutrophils and CD4 T cells. Both CD14+ and CD14- CSF macrophages were identified and expressed a range of surface markers associated with different activation states. Cryptococci were identified using flow cytometry as CD45 negative cells; cryptococcal counts using flow cytometry showed a very strong correlation with quantitative culture. There was no suggestion that raised intracranial pressure occurred as a result of a pro-inflammatory response; instead, persons with high intracranial pressure had a greater CSF fungal burden, a significantly reduced CSF cellular infiltrate (particularly CD4 T cells, CD8 T cells and double negative T cells) and larger cryptococcal cells. Contrary to animal studies, there was no association between macrophage activation and fungal burden. ART appeared to have a more profound effect on the immune response at site of disease (CSF) compared to the blood. In the IICD study, ART was associated with an increased frequency of CD4 T cells and decreased frequency of CD8 T cells in the CSF, along with increased expression of CD206 and CD16 on the surface of CSF monocyte- macrophages, suggesting an alternatively activated (M2) phenotype. These changes were closely related to plasma HIV viral load, even in subjects not taking ART. In the COAT trial, participants who received earlier ART initiation were more likely to have a CSF cellular infiltrate by day 14 compared to those in the deferred ART arm (8 days vs. 5 weeks post CM diagnosis respectively). This primarily occurred among persons with an initial paucity of CSF cellular response, the same sub-group identified in the COAT trial to be at highest risk of mortality following early ART initiation, and the same group previous shown in cohort studies to be at increased risk of IRIS. Furthermore, participants in the Kampala earlier ART arm had increased sCD14 and sCD163 concentrations in their CSF at day 14 suggesting increased macrophage activation in the central nervous system (CNS). These findings are supportive of the hypothesis that the increased mortality associated with earlier ART initiation in the COAT trial was immunologically driven. Finally, immune correlates of fatal outcome were examined. Persons who died by week 12 in the IICD study were noted to have a lower proportion of double negative T cells and lower concentrations of IFN-γ in the CSF at baseline. Non-survivors also had evidence of increased immune activation in the blood, elevated IL-10, decreased monocyte HLA-DR expression, impaired monocyte TNF-α response to LPS, and decreased IFN-γ responses to LPS in whole blood. These features are consistent with those of monocyte anergy and the compensatory anti-inflammatory response syndrome. The cause for this immune signature among persons with HIV-associated cryptococcal meningitis was not clear and warrants further study; the downstream effects of HIV-1 induced immune activation or the immune modulatory effects of cryptococcal capsule are both possibilities.
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The assessment and characterisation of obstructive sleep apnoea in severe obesitySeetho, Ian January 2015 (has links)
Background: Obstructive Sleep Apnoea (OSA) is associated with cardiovascular disease. The current evidence regarding the effects of OSA in individuals with severe obesity is limited and has hitherto been largely unexplored. With the growing population of diabetes and obesity globally, the identification of severely obese individuals who have OSA is important given the risk of adverse outcomes associated with OSA. In this regard, the use of urinary proteomic (urinary peptide) profiling as a potential tool to characterise adult severely obese patients for the diagnostic assessment of OSA remains to be investigated. Aims: The aims of the studies described in this thesis were to (1) investigate the effects of OSA in severe obesity in relation to measures related to cardiovascular risk, specifically, arterial stiffness and serum urate; (2) assess current clinical practice of OSA assessment; and (3) explore the use of urinary proteomics in characterising subjects with severe obesity and OSA. Methods: In the arterial stiffness, urate and urinary proteomic studies, patients with severe obesity, were assessed at baseline and at follow-up. Anthropometric, respiratory and cardio-metabolic parameters were measured. All subjects had overnight polysomnography. Subjects with OSA were initially naive to OSA treatment at baseline were subsequently offered CPAP. For the arterial stiffness studies, pulse wave analysis (PWA) was performed. In the urate studies, serum urate measurements were taken to identify associations between OSA and urate at baseline; and CPAP with change in urate at follow-up. OSA assessment in diabetes clinical practice was explored by a national survey in relation to the International Diabetes Federation (IDF) guidance. In the urinary proteomics studies, urine samples were analysed by capillary electrophoresis-mass spectrometry (CE-MS) at baseline and at follow-up. Results: Severely obese patients with OSA had increased arterial stiffness. Although sleepiness and blood pressure improved with CPAP in severe obesity, CPAP alone was not sufficient to modify PWA measures to levels comparable with non-OSA patients. In the urate study, serum urate was associated with OSA in severely obese females and there was a trend for reduced urate levels in CPAP-treated patients. The questionnaire study revealed a disappointing low awareness of the IDF statements and of the perceived importance of assessing for OSA in type 2 diabetes. The urinary proteomic studies identified trends in the urinary peptide profiles suggesting that there may be inherent differences between OSA and non-OSA patients, even following a period of effective CPAP treatment. The identified peptide panel included collagens, cadherin and fibrinogen subtypes. Conclusions: The theme that links the studies in this thesis has been the importance of OSA in relation to cardiovascular risk. Severely obese patients with OSA have increased arterial stiffness that may increase cardiovascular risk. Likewise, in severely obese individuals with OSA who have hyperuricaemia or recurrent gout, there may be a need to consider OSA assessment as elevated urate levels are associated with increased cardiovascular risk. From the questionnaire study, it is clear that more work needs to be done to raise awareness about OSA assessment in diabetes teams as obesity is a risk factor for type 2 diabetes. Urinary proteomic CE-MS profiling has provided novel insights into the urinary proteome in OSA, with and without CPAP. Although there is insufficient evidence to support its use for OSA diagnosis, the urinary peptides identified may be linked with mechanisms underlying cardiovascular disease in OSA and may be associated with treatment effects of CPAP on OSA progression that influences expression of urinary peptides.
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Epidemiological characterization and control of Old World cutaneous leishmaniasis in the Kingdom of Saudi ArabiaAl Salem, Waleed January 2015 (has links)
A better understanding of cutaneous leishmaniasis (CL) epidemiology will lead to improved intervention methods to combat CL outbreaks and prevent disease re-emergence. CL is endemic throughout the Kingdom of Saudi Arabia (KSA), and new disease control tools are needed. In this thesis, I studied various aspects essential to the design of a new CL control strategy, including parasite species identification, patient response to anti-leishmanial drug treatment, sandfly species identification, assessment of sandfly biting exposure and risk of disease transmission, implementation of an integrated control strategy, and development of a potential new CL diagnostic tool for use in CL endemic setting. It was found that Leishmania major (responsible for zoonotic CL) and Leishmania tropica (responsible for anthroponotic CL) are the main causative agents of CL in KSA, with over 75% of all human cases caused by the former. The current national CL treatment regimen consists of application of topical clotrimazole/fucidine cream followed by 1-2 courses of intralesional sodium stibogluconate; however, treatment efficacy is highly variable and the reasons for this are not well understood. As part of this PhD study, tests to determine the efficacy of this standard CL treatment regime in several endemic regions of KSA were performed. Most L. major patients responded favourably to drug treatment, although treatment success varied greatly depending on geographical location. In contrast, 60% of L. tropica cases proved completely unresponsive to the same treatment protocol. Furthermore, the development of secondary infections (SI) around or within the CL lesion significantly favoured the treatment response of L. major patients, but had no effect on L. tropica cases. These findings indicate that there is an urgent need to implement alternative CL treatment protocols based on these parameters, and also indicate a possible increase in drug-resistant parasites. In this epidemiological study, the potential correlation between the type of immunity generated after exposure to sandfly bites and disease outcome was monitored by measuring anti-SP32 antibody levels. Constant exposure of the local residents to sandflies may help prevent development of severe CL disease outcomes. Notably, comparison of the levels of anti-saliva antibodies of local individuals with migrant labour indicated that the latter had significantly higher levels of anti-saliva marker and also developed a more severe pathology. This implies that the corresponding governmental sectors need to assess all transmission risk areas, as well as greatly improve housing conditions to minimize the risk of non-local construction workers contracting CL. This is essential as CL drug treatment is costly and currently non-local workers comprise around one third of the KSA population. Additionally, a disease control strategy based on a combination of vector and reservoir control methods was designed to combat zoonotic CL outbreaks. Construction sites at Al-Ahsa, known to be highly endemic for zoonotic CL, were monitored by a vector control team between 2012 and 2014. The control strategy was applied following the outbreak using mechanical, reservoir and vector control methods. No CL cases were reported after the control team’s intervention. This case study suggests that implementation of a health impact assessment should be carried out, as well as a control strategy, in areas that share a similar CL ecology and environment in order to minimize incidence cases. As part of my PhD, I developed a potential new diagnostic tool by using an ELISA assay method to measure the levels of anti-α-galactosyl antibodies in human sera using synthetic neoglycoproteins (NGPs). The assay sensitivity was 96% for L. major (95% CI 94%–98%) and 91% for L. tropica (95% CI 86%–98%). In addition, the assay had higher sensitivity than microscopy analysis, which only detected 68% and 45% of L. major and L. tropica infections, respectively. Furthermore, improvement of the selectivity in recognizing different α-galactosylated NGPs suggests that this assay could potentially be developed into a rapid diagnostic test for use in resource-poor settings. Overall, this thesis should help set a basis for designing a national strategy for CL elimination in KSA.
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