[Semi-quantitative risk assessment on local transmission of Dengue fever caused by introduced cases]

To assess the risk of local transmission of Dengue caused by introduced cases with semi-quantitative method in 2015 in Zhejiang Province.

Risk indexes of local transmission of Dengue caused by introduced cases were reviewed. The weights of indexes were computed by analytic hierarchy process and further used to generate absolute risk values by multiplying indexes. Moreover, comprehensive indexes were computed to describe relative risk by combining analytic hierarchy process and TOPSIS methods.

Four primary indexes and 19 secondary indexes were identified for risk assessment of local transmission of Dengue. The indexes with maximum and minimum weight were the number of immigration from countries with Dengue patients (weight value: 0.0678) and density of population (weight value: 0.0371) respectively. All CR values, statistics for measuring consistency of score matrix, were less than 0.1 (minimum: 0.000, maximum: 0.0922, average: 0.0251). The absolute risk of Zhejiang Province was within the range of 0.397-0.504 (the full score was 1.0). The risk orders of 11 municipalities sorted by relative comprehensive indexes and absolute risk values methods were similar. The three highest municipalities were Hangzhou, Wenzhou and Ningbo and the ranges of absolute risk value were 0.387-0.494, 0.404-0.511 and 0.392-0.499 respectively.

The results provides scientific basis for preventing and controlling Dengue in Zhejiang Province. The indexes and weights may be used to assess risk of Dengue in future. In addition, the semi-quantitative method constructed in this study would be a significant reference for risk assessment of public health in emergencies.