The Kurath research laboratory is focused on the molecular biology, pathogenesis, genetic diversity, evolution, and control of RNA viruses. The experimental system is an acute rhabdovirus pathogen in fish hosts that represent naturally co-evolved host-pathogen associations. These are tested experimentally in controlled laboratory virus challenges to investigate the molecular basis of pathogenesis, host-specificity, and host-specific viral virulence. Her laboratory has also developed in vivo assays to investigate viral fitness and competition during infections in living hosts, using virus strains of equal or unequal virulence, in both co-infections and superinfections. These assays are used to address a wide range of questions including how viral fitness impacts the evolution of critical factors such as virulence. The overall goal is to understand the basic science of how viruses function in natural host populations, including factors that influence the viral infection processes, and selection pressures that lead to viral co-circulation, emergence and displacement events in the field. Trainees in the laboratory conduct investigations of viral infection dynamics and fitness, with ultimate applications to improving our abilities to predict and manage acute disease.