Key data for outbreak evaluation: building on the Ebola experience

Cori, Anne; Donnelly, Christl A.; Dorigatti, Ilaria; Ferguson, Neil M.; Fraser, Christophe; Garske, Tini; Jombart, Thibaut; Nedjati-Gilani, Gemma; Nouvellet, Pierre; Riley, Steven; Van Kerkhove, Maria D.; Mills, Harriet L.; Blake, Isobel M.

Cases in the line-list should be classified using standardized case definitions, which is sometimes difficult for outbreaks of new pathogens, or where different case definitions are provided by different organizations (e.g. World Health Organization (WHO) and US Centers for Disease Control and Prevention (CDC)) [78] . For the Ebola response, although the WHO released official case definitions of confirmed, probable and suspected Ebola cases [79] , different countries adopted different testing strategies, thereby limiting the opportunity for inter-country comparison. For example, in Guinea deceased individuals were not tested for Ebola, meaning these individuals were never classified as confirmed cases, unlike in Liberia and Sierra Leone. Encouraging use of a consistent testing protocol and case definition, and ensuring transparency in what is used where and when, would improve the validity of subsequent analyses.