Department of Epidemiology and Biostatistics, School of Public Health, Sichuan University, Chengdu, Sichuan, China.
Prevention and Health Section, Affiliated Hospital, Chengdu University, Chengdu, Sichuan, China.
PLoS One. 2019 Apr 19;14(4):e0215857. doi: 10.1371/journal.pone.0215857. eCollection 2019.
From 2013 to 2017, more than one thousand avian influenza A (H7N9) confirmed cases with hundreds of deaths were reported in mainland China. To identify priorities for epidemic prevention and control, a risk assessing framework for subnational variations is needed to define the epidemic potential of A (H7N9).
We established a consolidated two-stage framework that outlined the potential epidemic of H7N9 in humans: The Stage 1, index-case potential, used a Boosted Regression Trees model to assess population at risk due to spillover from poultry; the Stage 2, epidemic potential, synthesized the variables upon a framework of the Index for Risk Management to measure epidemic potential based on the probability of hazards and exposure, the vulnerability and coping capacity.
Provinces in southern and eastern China, especially Jiangsu, Zhejiang, Guangzhou, have high index-case potential of human infected with A (H7N9), while northern coastal provinces and municipalities with low morbidity, i.e. Tianjin and Liaoning, have an increasing risk of A (H7N9) infection. Provinces in central China are likely to have high potential of epidemic due to the high vulnerability and the lack of coping capacity.
This study provides a unified risk assessment of A (H7N9) to detect the two-stage heterogeneity of epidemic potential among different provinces in mainland China, allowing proactively evaluate health preparedness at subnational levels to improve surveillance, diagnostic capabilities, and health promotion.
从 2013 年到 2017 年，中国大陆报告了超过 1000 例确诊的甲型流感 H7N9 病例，其中数百人死亡。为了确定疫情防控的重点，需要建立一个针对亚省级变异的风险评估框架，以确定 A（H7N9）的流行潜力。
我们建立了一个综合的两阶段框架，概述了 H7N9 在人类中的潜在流行情况：第一阶段，指数病例潜力，使用 Boosted Regression Trees 模型评估因家禽溢出而处于风险中的人群；第二阶段，流行潜力，根据风险管理指数框架综合变量，根据危害和暴露的概率、脆弱性和应对能力来衡量流行潜力。
中国南方和东部的省份，特别是江苏、浙江和广东，具有较高的人感染 A（H7N9）的指数病例潜力，而发病率较低的北方沿海省份和直辖市，如天津和辽宁，感染 A（H7N9）的风险正在增加。中国中部省份由于脆弱性高和应对能力不足，可能具有较高的流行潜力。
本研究提供了对 A（H7N9）的统一风险评估，以检测中国大陆不同省份在流行潜力方面的两阶段异质性，从而能够主动评估亚省级的卫生准备情况，以改善监测、诊断能力和健康促进。
