In the globalised environment, the interconnection and interdependence of economies enable pathogens to spread in unprecedented ways and extents. Human to human transmission (close encounters of the first kind) occur with pathogens that are well adapted to the human host, and spread between countries and continents. In a similar way, pathogens spreading between animals (close encounters of the second kind) spread not only within a farm, but also between different farms, due to trade, or live animals or vector movement, in a transboundary manner.