Fireblight is an incredibly devastating disease that is apparent worldwide. In many parts of the world, there are quarantine laws that try to prevent its spread.
It affects woody plants that are part of the Rose family and especially affects those that flower during the summer. Fireblight has been known to wipe out entire orchards in one growing season.
Part of its infectiousness is due to the number of vectors for the disease as it can be transmitted from any creature that touches it including pollinators, birds, pests and tools.
The rose family is also a largely used family for fruits grown and hedging in the UK which means that there are plenty of possible hosts for infection.
In the UK, if the disease is found then all susceptible plants within 100 square meters of the specimen must be destroyed and burned immediately.