Box 1.

The historical developments in the definition of “zoonoses”. Note that modification(s) adopted if any have been italicized and highlighted.

Year	Zoonosis (Definition)	References
1950	Those diseases which are naturally transmitted between vertebrate animals and man.	(8)
1958	Those diseases and infections which are naturally transmitted between vertebrate animals and man.	(9)
1966	No modification(s) suggested.	(10)
1978	Those diseases and infections [the agents of] which are naturally transmitted between [other] vertebrate animals and man.	(11)