Prevalence and associations of Trypanosoma spp. and Sodalis glossinidius with intrinsic factors of tsetse flies

Trypanosomiasis has been identified as a neglected tropical disease in both humans and animals in many regions of sub-Saharan Africa. Whilst assessments of the biology of trypanosomes, vectors, vertebrate hosts and the environment have provided useful information about life cycles, transmission, and pathogenesis of the parasites that could be used for treatment and control, less information is available about the effects of interactions among multiple intrinsic factors on trypanosome presence in tsetse flies from different sites. It is known that multiple species of tsetse flies can transmit trypanosomes but differences in their vector competence has normally been studied in relation to individual factors in isolation, such as: intrinsic factors of the flies (e.g. age, sex); habitat characteristics; presence of endosymbionts (e.g. Wigglesworthia glossinidia, Sodalis glossinidius); feeding pattern; host communities that the flies feed on; and which species of trypanosomes are transmitted. The purpose of this study was to take a more integrated approach to investigate trypanosome prevalence in tsetse flies. In chapter 2, techniques were optimised for using the Polymerase Chain Reaction (PCR) to identify species of trypanosomes (Trypanosoma vivax, T. congolense, T. brucei, T. simiae, and T. godfreyi) present in four species of tsetse flies (Glossina austeni, G. brevipalpis, G. longipennis and G. pallidipes) from two regions of eastern Kenya (the Shimba Hills and Nguruman). Based on universal primers targeting the internal transcribed spacer 1 region (ITS-1), T. vivax was the predominant pathogenic species detected in flies, both singly and in combination with other species of trypanosomes. Using Generalised Linear Models (GLMs) and likelihood ratio tests to choose the best-fitting models, presence of T. vivax was significantly associated with an interaction between subpopulation (a combination between collection sites and species of Glossina) and sex of the flies (X2 = 7.52, df = 21, P-value = 0.0061); prevalence in females overall was higher than in males but this was not consistent across subpopulations. Similarly, T. congolense was significantly associated only with subpopulation (X2 = 18.77, df = 1, P-value = 0.0046); prevalence was higher overall in the Shimba Hills than in Nguruman but this pattern varied by species of tsetse fly. When associations were analysed in individual species of tsetse flies, there were no consistent associations between trypanosome prevalence and any single factor (site, sex, age) and different combinations of interactions were found to be significant for each. The results thus demonstrated complex interactions between vectors and trypanosome prevalence related to both the distribution and intrinsic factors of tsetse flies. The potential influence of the presence of S. glossinidius on trypanosome presence in tsetse flies was studied in chapter 3. A high number of Sodalis positive flies was found in the Shimba Hills, while there were only two positive flies from Nguruman. Presence or absence of Sodalis was significantly associated with subpopulation while trypanosome presence showed a significant association with age (X2 = 4.65, df = 14, P-value = 0.0310) and an interaction between subpopulation and sex (X2 = 18.94, df = 10, P-value = 0.0043). However, the specific associations that were significant varied across species of trypanosomes, with T. congolense and T. brucei but not T. vivax showing significant interactions involving Sodalis. Although it has previously been concluded that presence of Sodalis increases susceptibility to trypanosomes, the results presented here suggest a more complicated relationship, which may be biased by differences in the distribution and intrinsic factors of tsetse flies, as well as which trypanosome species are considered. In chapter 4 trypanosome status was studied in relation to blood meal sources, feeding status and feeding patterns of G. pallidipes (which was the predominant fly species collected for this study) as determined by sequencing the mitochondrial cytochrome B gene using DNA extracted from abdomen samples. African buffalo and African elephants were the main sources of blood meals but antelopes, warthogs, humans, giraffes and hyenas were also identified. Feeding on multiple hosts was common in flies sampled from the Shimba Hills but most flies from Nguruman had fed on single host species. Based on Multiple Correspondence Analysis (MCA), host-feeding patterns showed a correlation with site of sample collection and Sodalis status, while trypanosome status was correlated with sex and age of the flies, suggesting that recent host-feeding patterns from blood meal analysis cannot predict trypanosome status. In conclusion, the complexity of interactions found suggests that strategies of tsetse fly control should be specific to particular epidemic areas. Future studies should include laboratory experiments that use local colonies of tsetse flies, local strains of trypanosomes and local S. glossinidius under controlled environmental conditions to tease out the factors that affect vector competence and the relative influence of external environmental factors on the dynamics of these interactions.

Evangelical young women, contemporary Christianity, and an empowering self- understanding: a study into how contemporary women of faith understand themselves and God in relation to Dei, Holy Scripture and Christian mission

This thesis combines historical reflection with qualitative research to examine how Christian young women from Evangelical traditions are developing religious self- understanding in empowering ways. It seeks to establish connections between the ways in which historians and feminist theologians have responded to forces of restriction and limitation in Christian women’s past, and the strategies of self-empowerment adopted by Evangelical young women today. This study approaches Christian history and the present condition of female self-understanding through three central questions: How do young women understand themselves in relation to the imago Dei? How do young women understand themselves in relation to the Bible? How do young women understand themselves in relation to Christian mission? The first chapter addresses the ways in which young women are responding to historic denials of woman as the imago Dei and concepts of female inferiority or especial guilt by reclaiming possession of the divine image. The next section discusses how young women are relating to the Bible in empowering ways, both by adopting similar strategies to those utilised throughout Christianity’s past, and through the development of their own patterns of interpretation. Finally, this thesis draws attention to Christian mission as a space of empowerment, examining how young women develop life-enriching knowledge of God and self through involvement with mission. This thesis proposes that as young women continue to develop strategies that enable them to understand themselves and their faith in empowering ways, knowledge of their innate dignity and potential will inspire them — and those who come after them — to witness to God freely and fully in all contexts.

Re-imagining the theology of human sexuality in the Methodist Church: the use of narrative in theological methodology

This thesis proposes the development of a narrative methodology in the British Methodist Church. Such a methodology embraces and communicates both felt experience and critical theological thinking, thus producing and presenting a theology that might have a constructive transformative impact on wider society. In chapter one I explore the ways in which the Church speaks in public, identify some of the challenges it faces, and consider four models of engagement. If the Church is to engage in public discourses then I argue that its words need to be relevant and connect with people’s experiences. To ground the thinking I focus on the context of the British Methodist Church and explore how the Church engages in theological reflection through the lens of its thinking on issues of human sexuality. Chapter two reviews how theological reflection is undertaken in the British Methodist Church. I describe how the Methodist Quadrilateral of Scripture, tradition, reason and experience remains a foundational framework for theological reflection within the Methodist Church and consider the impact of institutional processes and the ways in which the Methodist people actually engage with theological thinking. The third and fourth chapters focus on how the British Methodist Church has produced its theology of human sexuality, giving particular attention to the use of personal and sexual stories in this process. I find that whilst there has been a desire to listen to the stories of the Methodist people, there has not been a corresponding interrogation or analysis of their stories so as to enable robust and constructive theological reflection on these experiences. Using resources from Foucauldian approaches to discourse analysis, I critique key statements and the processes involved in their production, offering an analysis of this body of theological thinking and indicating where possibilities for alternative ways of thinking and acting arise. The proposed methodology draws upon resources from social science methodologies, and in chapter five I look at the use of personal experience and relevant strategies of inquiry that prompt reflection on the hermeneutical process and employ narrative approaches in undertaking, analysing and presenting research. The exploration shows that qualitative research methodologies offer resources and methods of inquiry that could help the Church to engage with personal stories in its theological thinking in a robust, interrogative and imaginative way. In chapter six an examination of story and narrative is undertaken, to show how they have been understood as ways of knowing and how they relate to theological inquiry. Whilst acknowledging some of the limitations of narrative, I indicate how it offers constructive possibilities for theological reflection and could be a means for the British Methodist Church to engage in public discourse. This is explored further in chapter seven, which looks in more detail at how the British Methodist Church has used narrative in its theological thinking, and outlines areas requiring further attention in order for a narrative theological methodology to be developed, namely: attention to the question ‘whose experience?’; investigation of issues of power and the dynamics involved in the process of the production of theological thought; how personal stories and experiences are interrogated and how narrative is constructed; and how narrative might be employed within the Methodist Quadrilateral. The final chapter considers the advantages and limitations of such an approach, whether the development of such a method is possible in the Methodist Church today and its potential for helping the Church to engage in public discourse more effectively. I argue that this methodology can provoke new theological insights and enable new ways of being in the world