| dc.description.abstract |
Peste des petits ruminants (PPR) is a highly contagious viral disease that severely threatens the
livelihoods and food security of smallholder farmers across Africa, the Middle East, and Asia,
including Ethiopia, where persistent outbreaks undermine national eradication efforts. Despite
ongoing vaccination and surveillance campaigns, the continued prevalence of PPR highlights critical
gaps in understanding its transmission dynamics, particularly regarding the role of animal
movement, restocking practices, and spatial spread factors that have been insufficiently modelled
compared to other transboundary diseases. Furthermore, there is a notable lack of integrated
cost-effectiveness analyses of intervention strategies and optimal control frameworks tailored to
PPR. Addressing these gaps, this dissertation develops and analyses a suite of deterministic
mathematical models, incorporating novel components such as imperfect vaccination, restocked
subpopulations, spatial heterogeneity, and co-infection with Sheep and Goat Pox (SGP), using
epidemiological data from the Ethiopian Ministry of Agriculture and World orgnazation of
animal health (WOAH). Model parameters were carefully estimated despite data incompleteness,
employing nonlinear least squares and sensitivity analyses. Through rigorous qualitative
and quantitative analysis, including stability assessments, optimal control characterisation using
Pontryagin’s minimum principle, and comprehensive cost-effectiveness evaluations, this research
reveals that combining vaccination with targeted biosecurity and movement control measures is
the most effective and economically viable strategy for PPR eradication. Notably, the introduction
of infected, restocked animals is shown to facilitate disease persistence, underscoring the need
for integrated interventions beyond vaccination alone. The findings provide actionable recommendations
for policymakers: prioritizing coordinated vaccination, movement restrictions, and
enhanced biosecurity, supported by optimal allocation of limited veterinary resources. Overall,
this dissertation advances the understanding of PPR dynamics and provides practical recommendations
for improving disease control strategies in Ethiopia, thereby supporting national efforts
toward the eradication of PPR. |
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