Mechanistic Models of Transmission Dynamics in Livestock: Quantifying Commercially Relevant Outcomes of Infectious Disease Prevention

Contagious mastitis in dairy animals often persists despite medication, fostering anti-microbial resistance. Outbreaks of Rift Valley Fever severely strain both medical and veterinary resources, yet vaccination is discouraged. In both systems, treating individual clinically infected livestock is insufficient to interrupt transmission, and widespread transmission threatens human health. I develop novel mechanistic models of outbreak dynamics in cattle for each of these zoonotic, agriculturally important pathogens to evaluate potential interventions. In Chapter 2, I use deterministic differential equations to represent vector-borne transmission of Rift Valley Fever. I find that there is a logistically feasible temporal window for mass live-attenuated vaccination that can avoid most coinfection with the wildtype virus. In Chapters 3 and 4, I model fomite transmission of contagious mastitis using stochastic discrete-time frameworks; one compartmental, and one which tracks individuals. Both quantify improvements that could be attained by systematically applying the Milk-Last intervention. My dissertation quantifies commercially relevant outcomes to inform stakeholders.