Virus discovery in farm animals:Uncovering hidden viral threats and their role in disease

Abstract

As humanity has expanded, viral diseases have persistently accompanied both animals and humans. Especially, the current environmental challenges, biodiversity loss and habitat fragmentation, exhaustive agriculture practices and intensive livestock farming, have caused an excessive interference of human activities in natural ecosystems providing more chances of human–animal interactions and zoonotic spillover. In this thesis, the attention has been devoted to infectious diseases affecting livestock. In such an interconnected world, livestock is not only vital for maintaining food supplies, but can also be a reservoir of future pandemics. Today’s livestock industry faces a diverse number of viral diseases, presenting unprecedent diversity and complexity. While more prominent viral diseases are reportable to national and international agencies, newly emerged, non-reportable viruses have established themselves as significant economic and pathogenic threats. The challenge in monitoring novel and emerging livestock viruses is compounded by asymptomatic presentations, limitations in diagnostic capabilities, and the complexity of viral interactions. Moreover, many emerging diseases cannot be explained with the traditional postulates of virus causation, wherein only one pathogen should be the cause of only one disease. This thesis presents an analysis of these contemporary challenges drawing from real-world examples. In particular, four areas of virus research are explored: the discovery and analysis of novel viruses, understanding how these viruses spread, examining their evolutionary changes, and determining their role in disease causation