Zoonoses and Zoonotic Diseases: A Comprehensive Reference

Zoonotic Diseases - Human-Animal-Environment Nexus is a much needed, foundational reference on what is known of zoonotic disease, combining contemporary understanding of impactful zoonoses with factual, in-depth analysis of origins for ~700 other human pathogens, established or emergent, that are not ongoing zoonoses but are believed to have zoonotic origins. The work focusses on providing the context and importance of the subjects in contemporary science. Attention is given to the limitations of current data, and an attempt is made to progress ontologies in the light of modern genomic understanding and knowledge of disease processes. The state of knowledge on zoonosis and zoonotic origin human pathogens is weak, and disease narratives reflect this. The Global Burden of Disease project, for example, did not discriminate zoonosis or zoonotic origin disease in any meaningful way within its analysis. From available reviews, it is estimated that 99 percent of human zoonoses cases are derived directly or indirectly from domestic animals. This exposure may cause ~2.5 billion cases of human illness annually, 2.4 billion of which are caused by mostly thirteen diseases, of which nine also have a high impact on livestock and, therefore, human economy. Whilst some 60% of human infectious diseases (~900 pathogens) are suggested to have zoonotic origins, for most of them, animal source is no longer of any significance. Occasionally, spill overs still occur, resulting in new emergent human pathogens such as, apparently, the coronavirus causing COVID 19 which now circulates independently in the human population. Phylogenetics and genomics provide a new pathway for exploring relationships between organisms and their evolution, and this is enabling a more accurate examination of emergence of pathogens and their hosts. The frequency of emergence of infectious diseases has been reported to be increasing, posing new questions about disease pathogenesis and epidemiology in the modern world. If true, this heightens the urgency of understanding drivers, risk factors, pathways and mechanisms for emergence. Moving agendas forward requires careful analysis of the state of science in this field. This work is a first step and a point of reference for science and society in the field. It enables focus on key pathways and processes, future data needs from the nexus and the most appropriate interventions and actions supported by current evidence.