Vector-borne diseases rely upon organisms, named vectors, such as mosquitoes,
ticks or sandflies that have an active role in the transmission of a pathogen
from one host to the other, and also, in a broader sense, upon animals such as
rodents, bats or pets, acting as reservoirs/carrier of pathogens of concern to
An emerging (or re-emerging) infectious disease generally is a disease (i)
that arises through evolution or change in existing pathogens, (ii) was
previously unrecognised or (iii) is already known but spreads to new
geographic areas, or new populations, or reappears after having been eradicated.
Many factors that may facilitate the introduction and establishment of
disease vectors, reservoirs or pathogens in new geographic areas could lead to
the emergence of a disease in the European Union (EU). These factors include
international travel and trade, e.g. legal and illegal trade in animals and
animal products, new agricultural practices and land-use patterns,
socio-demographic evolution and climatic changes.