| Sleeping sickness re-emerged in south-eastern Uganda in the 1970s, and remains a significant public health burden. Sleeping sickness has continued to spread northwards into new districts, and gaps remain in the understanding of the causes of its spread and distributions. This thesis presents a characterization and assessment of the historical patterns, processes, and predictors of sleeping sickness variation over space and time in south-eastern Uganda from 1970-2003 with the aim of improving the understanding of sleeping sickness transmission and guiding targeted prevention and control initiatives. Historical data and literature are used to characterize the multiple factors and processes affecting sleeping sickness over space and time in south-eastern Uganda. Sleeping sickness data were collected from records at the Ugandan Ministry of Health, individual sleeping sickness treatment centres, and through interviews with key informants to reconstruct an historical database of disease distributions and magnitude for 1970-2003. Remotely sensed imagery and Geographic Information Systems were used to extract a vegetation cover time-series for the region for four dates spanning the epidemic cycle. Data are used to conduct spatial and temporal analyses of sleeping sickness risk in south-eastern Uganda. Results show rapid propagation of sleeping sickness from its epicentre in southern Iganga District, followed by radial diffusion, and continued northwards spread into new districts and foci. Observed trends are consistent with the hypothesis of disease propagation due to changes in human-vector exposure and transport of the parasite to new areas via cattle reservoirs. Results indicate that rural areas with moderate-high vegetation cover, minimal tsetse habitat loss, high cattle infection, and civil conflict are at highest risk. Results support the probability of continued spread of sleeping sickness northwards into new regions in central Uganda. The central region is currently affected by high levels of civil conflict, which may accelerate disease spread. Central Uganda should be considered a high-priority area for emerging infection and targeted prevention and control initiatives. |
