This Thesis Has Been Submitted in Fulfilment of the Requirements for a Postgraduate Degree (E.G
Total Page:16
File Type:pdf, Size:1020Kb
This thesis has been submitted in fulfilment of the requirements for a postgraduate degree (e.g. PhD, MPhil, DClinPsychol) at the University of Edinburgh. Please note the following terms and conditions of use: • This work is protected by copyright and other intellectual property rights, which are retained by the thesis author, unless otherwise stated. • A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. • This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author. • The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author. • When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given. Pastoral Livelihoods and the Epidemiology of Emergent Trypanosomiasis on the Jos Plateau, Nigeria Ayodele Majekodunmi Submitted in fulfilment of the requirements of the degree of Doctor of Philosophy The University of Edinburgh 2011 Ph.D. – The University of Edinburgh - 2011 I Declaration I declare that the research described within this thesis is my own work and that this thesis is my own composition and certify that it has never been submitted for any other degree or professional qualification Ayodele Majekodunmi Edinburgh, 2011 Ph.D. – The University of Edinburgh - 2011 II I Contents Acknowledgements ................................................................................................... IV Chapter 1: General Introduction ............................................................................... I 1.1 Pastoralism ................................................................................................. 2 1.2 Agriculture and Trypanosomiasis ............................................................ 3 1.3 Rationale .................................................................................................... 5 1.4 Tsetse and Trypanosome Biology ............................................................. 8 1.4.1 The Parasite ....................................................................................... 8 1.4.2 The Vector........................................................................................... 9 1.5 Animal African trypanosomiasis .......................................................... 10 1.5.1 Diagnosis ........................................................................................... 10 1.5.2 Treatment............................................................................................. 13 1.6 Human African Trypanosomiasis ......................................................... 13 1.6.1 Diagnosis ........................................................................................... 15 1.6.2 Treatment.......................................................................................... 16 1.7 History of Tsetse and trypanosomiasis in Nigeria ................................. 17 1.7.1 Tsetse distribution and control ....................................................... 17 1.7.2 Animal African Trypanosomiasis ................................................... 21 1.7.3 Human African Trypanosomiasis ................................................... 23 1.8 Current Tsetse and Trypanosomiasis Situation in Nigeria ................. 27 1.9 Aims and objectives ............................................................................... 30 Chapter 2: Background ........................................................................................... 31 2.1 The Jos Plateau ......................................................................................... 32 2.1.2 People ................................................................................................ 34 2.1.3 Livestock ........................................................................................... 35 2.1.4 The Fulani Pastoral Group ............................................................. 37 2.2 Change in Tsetse & Trypanosomiasis status ......................................... 38 2.3.1 Factors contributing to the previous tsetse free status of the Jos plateau 40 2.3.2 Risk factors for tsetse and trypanosome introduction and establishment on the Jos plateau .................................................................... 40 2.4 Jos: conflict and civil strife ...................................................................... 42 2.5 Study Design ............................................................................................. 44 2.5.1 Cluster sampling surveys ................................................................. 44 2.5.2 Intracluster Homogeneity ................................................................ 46 2.5.3. Sample size estimation ..................................................................... 47 2.5.4 Study site selection ........................................................................... 49 2.6 AAT Prevalence Survey .......................................................................... 51 2.7 Participatory Rural Appraisal .............................................................. 51 2.8 Evaluation of FAMACHA cards as a pen-side test for Trypanosomiasis ................................................................................................... 52 Chapter 3: Longitudinal Study of Bovine Trypanosomiasis ................................ 54 3.1 Introduction .............................................................................................. 55 3.2 Aim and Objectives .................................................................................. 55 3.3 Materials and Methods ............................................................................ 56 3.3.1 Sample Frame ................................................................................... 56 Ph.D. – The University of Edinburgh - 2011 I 3.3.2 Sample Collection ............................................................................. 56 3.3.3 DNA Extraction ................................................................................ 57 3.3.4 T. brucei s.l. PCR .............................................................................. 58 3.3.5 T. congolense savannah PCR .............................................................. 59 3.3.6 T. vivax PCR ..................................................................................... 60 3.3.7 Gel electrophoresis .............................................................................. 62 3.3.8 Statistical analysis ............................................................................ 63 3.3 Results ....................................................................................................... 66 3.3.1 Prevalence of trypanosomiasis ............................................................ 66 3.3.2 Risk factors for trypanosomiasis .................................................... 73 3.3.3 T. b. brucei prevalence and risk factors.......................................... 74 3.3.4 T. congolense savannah prevalence and risk factors .................... 79 3.3.5 T. vivax prevalence and risk factors ............................................... 84 3.3.6 Seasonal variation ............................................................................ 89 3.3.7 Herd composition ............................................................................. 91 3.3.8 Prevalence by sex.............................................................................. 92 3.3.9 Prevalence by age ............................................................................. 92 3.3.10 Prevalence by breed ......................................................................... 93 3.3.11 Prevalence by condition score ......................................................... 93 3.4 Discussion .................................................................................................. 94 3.4.1 Trypanosomiasis prevalence ......................................................... 94 3.4.2 Risk factors for trypanosomiasis .................................................... 97 3.4.3 T. b. brucei prevalence & risk factors ........................................... 100 3.4.4 T. congolense prevalence & risk factors ....................................... 103 3.4.5 T. vivax prevalence & risk factors ................................................ 104 3.4.6 Seasonal variation patterns ........................................................... 105 3.5 Conclusions ............................................................................................. 111 Chapter 4: Pastoral Livelihoods, Herd Productivity and Knowledge, Attitude and Practices ........................................................................................................... 114 4.1 Introduction ........................................................................................... 115 4.1.1 Pastoralist Livelihoods ..................................................................... 115 4.1.2 Assets & Wealth Groups ............................................................... 116 4.1.2 Livelihood Risks ............................................................................. 118 4.2 Aims and Objectives .............................................................................. 130 4.3 Materials and Methods .......................................................................... 131 4.3.1 Participatory