Tianna Brand, OIE: The literature and scientific studies reveal numerous factors - environmental, pathogen, host or vector adaptation, to name a few. The central and recurring theme in emergence and spread are the interactions between humans and animals. The opportunities for zoonotic pathogens to emerge are increasing. The growth of the human population and its consumption habits are the underlying factors - or root causes - for the emergence and spread of diseases. Ultimately a larger human population drives higher levels of intensive animal production, and furthermore drives the expansion of crop lands, human settlements and cities. All these factors contribute to the disruption of natural ecosystems and increased encroachment of humans into previously wild areas. Historically, the emergence of new human diseases from animal sources, such as the plague or Ebola, has been associated with major societal change. Mariana Marrana, OIE: New pathogenic agents appear all the time at the human-animal-environment interface. While, most often, the newly emerged diseases often only result in local transmission before fading away, human activities provide the pathway for local disease events to become regional or global. Therefore, a disease outbreak that could be inconsequential from a global perspective can take pandemic proportions in a matter of weeks, as we saw at the start of the COVID-19 pandemic.