About Rachel: I am excited that the ZELS-AS programme has given me the chance to be able to continue studying tsetse flies and the parasites which cause Rhodesian human African trypanosomiasis. I will be investigating a wide range of aspects of the disease, from quantifying the impact of trypanosome infection on the feeding behaviour of tsetse, to examining the visual and olfactory cues which tsetse may use to identify habitats. I will also be able to use previous experience from my MSc to examine genetic variation within and between tsetse populations and their rates of gene flow to determine the movement and distribution of flies in the Serengeti area. A great benefit of the ZELS-AS programme is being part of a community of international researchers and being able to learn and develop my skills in collaboration with several institutions. I cannot wait to return to Africa to begin the work which will hopefully lead to recommendations for improving the effectiveness of control methods.
Title: Tracking tsetse and trypanosomes: analysis of the transmission of trypanosomes between tsetse and their wild and domestic hosts
About the Project: This PhD studentship will be linked with the project investigating human African trypanosomiasis (sleeping sickness) in the Serengeti ecosystem of Tanzania (Co-PIs: Profs. Steve Torr, Liverpool School of Tropical Medicine; Dr. Liam Morrison, Roslin Institute; Dr Harriet Auty, Scotland’s Rural College; Prof. John Hargrove, University of Stellenbosch, South Africa; Dr Furaha Mramba, Tsetse and Trypanosomiasis Research Institute, Tanzania).
The inter-disciplinary supervisory team will be drawn from researchers in the ZELS consortium with expertise in parasitology, epidemiology, vector biology and mathematical modelling. This PhD will use various molecular methods to analyse the transmission dynamics of trypanosomes in wild populations of tsetse, livestock and hosts and laboratory-based studies of factors that are likely to affect transmission between tsetse and mammalian hosts. Studies will also be extended to include analyses of the population genetics of tsetse and Trypanosoma species to quantify sub-structuring of parasites related to geography, vector- and host-species. The student will gain experience of molecular techniques, entomology, parasitology and bioinformatics from Roslin and LSTM, as well as extensive experience of field work in Tanzania. Data generated by the PhD will improve estimation of key parameters involved in trypanosome transmission and hence make an important contribution to the development and application of epidemiological models of trypanosomiasis.
Outline: In sub-Saharan Africa, tsetse flies transmit trypanosomes which cause sleeping sickness in humans (Human African Trypanosomiasis, HAT) and animal trypanosomiasis in livestock. In East Africa, sleeping sickness is a zoonosis associated with wilderness area, with wild and domestic animals playing an important role as reservoir hosts. Our project is analysing the transmission dynamics of sleeping sickness associated with the Serengeti National Park of Tanzania and developing epidemiological models to guide interventions against the disease.
Important parameters in models of sleeping sickness include the duration of patent infection in vectors and hosts, and the probabilities that trypanosomes transfer between hosts and vectors when when a fly bites. Values for these parameters are based on surprisingly few empirical studies conducted largely before the advent of molecular tools.
The project will be based at the Liverpool School of Tropical Medicine, but will involve substantial periods of time spent in Tanzania. The student will gain experience of molecular techniques, entomology, parasitology and bioinformatics from Roslin and LSTM, as well as extensive experience of field work in Tanzania. Data generated by the PhD will improve estimation of key parameters involved in trypanosome transmission and hence make an important contribution to the development and application of epidemiological models of trypanosomiasis.