Microorganisms have inadvertently been spread via the global movement and trade of their substrates,
such as animals, plants, and soil. This intercontinental exchange in the current era of
globalisation has given rise to significant increases in the distribution of known pests and pathogens.
Importantly, it has also resulted in many novel, emerging, infectious diseases. Biosecurity
and quarantine, which aim to prevent the establishment of foreign or harmful organisms in a
non-native area, are under significant pressure due to the massive increases in travel and trade.
Traditionally, quarantine regulations have been implemented based on pathogens that
already cause significant disease problems on congener hosts in other parts of the world (e.g.,
Q-bank, available at http://www.q-bank.eu). Well-known pathogens are described, named, and
studied to determine their disease cycle, epidemiology, and impact. Their importance is
assessed based on their risk of infection, establishment, and economic or environmental consequences.
This then shapes phytosanitary practices.