Classifying infectious disease outbreaks to improve timeliness and efficiency of response.

Posid, Joseph M; Goodman, Richard A; Khan, Ali S

Following the intentional dissemination of B.anthracis through the U.S. Postal Service in 2001, use of the term "naturally occurring" to classify some infectious disease outbreaks has become more evident. However, this term is neither a scientific nor an epidemiologic classification that is helpful in describing either the source or the mode of transmission in outbreaks. In this paper, the authors provide examples of how and when the public health community has recognized potentially flawed or misleading taxonomy in the past and taken steps to improve the taxonomy's accuracy and usefulness. We also offer examples of alternative terms for classifying outbreaks since inaccurate descriptions of outbreaks could potentially lead to a flawed or incomplete set of underlying assumptions about the outbreak's causal factors. This, in turn, could lead to implementing a flawed or incomplete intervention or response strategy which could extend the duration of the outbreak, resulting in avoidable morbidity and mortality.