When is an epidemic an epidemic?
BACKGROUND
The large number of cases of West Nile fever diagnosed in Israel in 2000 once again brought into focus the confusion that frequently accompanies the use of the term "epidemic."


OBJECTIVE
To examine the different definitions of the term "epidemic" and to propose ways in which it can be used to both improve communication among professionals and provide the public with a better sense of the associated risks.


METHODS
The literature was reviewed for the various definitions of the terms "epidemic" and "outbreak." Sources included popular and medical dictionaries, ancient documents, epidemiology texts, legal texts, and the medical literature.


RESULTS
The term epidemic is variously defined. The broad definition given by epidemiologists--namely, more disease than is anticipated by previous experience--is less meaningful to the general public. In some ways it conflicts with the definitions found in the popular literature, which generally imply danger to the public and a very large number of victims.


CONCLUSIONS
The interpretation of the term epidemic may vary according to the context in which it is used. For risk communication, we suggest that every effort be made to add descriptive terms that characterize the epidemic.
Green
Manfred S
MS
Israel Center for Disease Control, Ministry of Health, Tel Hashomer, Israel. m.green@trendline.co.il
Swartz
Tiberio
T
Mayshar
Elana
E
Lev
Boaz
B
Leventhal
Alex
A
Slater
Paul E
PE
Shemer
Joshua
J
D003142:Communication; D004196:Disease Outbreaks / Q000145:classification*; D006801:Humans; D007557:Israel / Q000453:epidemiology; D010817:Physician-Patient Relations; D009626:Terminology as Topic; D014901:West Nile Fever / Q000453:epidemiology*