Qualitative and quantitative assessment of risk of importation of Ebola virus disease to China

Objective To introduce the qualitative and quantitative methods in assessing the risk of importation of infectious diseases to China. Methods The quantitative assessment of the spread risk of Ebola virus disease (EVD) to China was conducted by calculating its infection probability, and the qualitative assessment of the severity of the EVD importation and the final risk level were conducted through expert counseling and risk matrix analysis. Results The assessment steps included transmission route estimation, importation and further spread estimation and importation severity, final risk and uncertainty estimations. Conclusion This quantitative assessment can estimate the likelihood of the importation of EVD to China, and this qualitative assessment can evaluate the severity and risk level of EVD's importation, but they are not suitable to be used in the rapid risk assessment of the outbreaks of other emerging infectious diseases and the diseases with unknown etiology.