Spread and dynamics of the COVID-19 epidemic in Italy: Effects of emergency containment measures
Spread and dynamics of the COVID-19 epidemic in Italy: Effects of emergency containment measures
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DOI：
10.1073/pnas.2004978117
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发表时间：
2020-05-12
影响因子：
11.1
通讯作者：
Rinaldo, Andrea
中科院分区：
文献类型：
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作者：
Gatto, Marino;Bertuzzo, Enrico;Rinaldo, Andrea
2019冠状病毒病（COVID-19）在意大利的传播促使采取严厉措施遏制传播。我们研究这些干预措施的影响，基于正在展开的流行病的建模。我们测试建模选项的空间明确的类型，建议从最初的疫源地蔓延到意大利的其他地区的感染波。我们估计了一个类似于易感-暴露-暴露-传播（SEIR）的传播模型的参数，该模型包括一个由107个省组成的网络，该网络通过高分辨率的移动性连接，以及症状前和无症状传播的关键贡献。我们估计了一个广义再生数（R-0 = 3.60 [3.49至3.84]），这是一个合适的下一代矩阵的谱半径，该矩阵在没有遏制干预的情况下测量潜在的传播。该模式包括在意大利确诊首例病例（2020年2月21日）后实施渐进式限制，并持续到2020年3月25日。我们考虑到流行病学报告的不确定性，以及人类流动矩阵和意识依赖的暴露概率的时间依赖性。我们绘制了不同遏制措施及其影响的情景。结果表明，对流动性和人与人之间的相互作用的一系列限制使传播减少了45%（42%至49%）。避免住院是通过有选择地放宽限制获得的运行场景来衡量的，总计约20万人（截至2020年3月25日）。虽然一些假设需要重新审查，如年龄结构的社会混合模式和分布的流动性，住院治疗，和死亡率，我们的结论是，可核实的证据存在，以支持规划的应急措施。
The spread of coronavirus disease 2019 (COVID-19) in Italy prompted drastic measures for transmission containment. We examine the effects of these interventions, based on modeling of the unfolding epidemic. We test modeling options of the spatially explicit type, suggested by the wave of infections spreading from the initial foci to the rest of Italy. We estimate parameters of a metacommunity Susceptible-Exposed-Infected-Recovered (SEIR)-like transmission model that includes a network of 107 provinces connected by mobility at high resolution, and the critical contribution of presymptomatic and asymptomatic transmission. We estimate a generalized reproduction number (R-0 = 3.60 [3.49 to 3.84]), the spectral radius of a suitable next-generation matrix that measures the potential spread in the absence of containment interventions. The model includes the implementation of progressive restrictions after the first case confirmed in Italy (February 21, 2020) and runs until March 25, 2020. We account for uncertainty in epidemiological reporting, and time dependence of human mobility matrices and awareness-dependent exposure probabilities. We draw scenarios of different containment measures and their impact. Results suggest that the sequence of restrictions posed to mobility and human-to-human interactions have reduced transmission by 45% (42 to 49%). Averted hospitalizations are measured by running scenarios obtained by selectively relaxing the imposed restrictions and total about 200,000 individuals (as of March 25, 2020). Although a number of assumptions need to be reexamined, like age structure in social mixing patterns and in the distribution of mobility, hospitalization, and fatality, we conclude that verifiable evidence exists to support the planning of emergency measures.