Hu BiSong, Gong JianHua, Sun Jun, Zhou JiePing
15501Geography and Environment Department, Jiangxi Normal University, Nanchang, 330022 China.
35501Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, Jiangxi Normal University, Nanchang, 330022 China.
Chin Sci Bull. 2013;58(15):1818-1831. doi: 10.1007/s11434-012-5501-8. Epub 2012 Nov 8.
The changing spatiotemporal patterns of the individual susceptible-infected-symptomatic-treated-recovered epidemic process and the interactions of information/material flows between regions, along with the 2002-2003 Severe Acute Respiratory Syndrome (SARS) epidemiological investigation data in mainland China, including three typical locations of individuals (working unit/home address, onset location and reporting unit), are used to define the in-out flow of the SARS epidemic spread. Moreover, the input/output transmission networks of the SARS epidemic are built according to the definition of in-out flow. The spatiotemporal distribution of the SARS in-out flow, spatial distribution and temporal change of node characteristic parameters, and the structural characteristics of the SARS transmission networks are comprehensively and systematically explored. The results show that (1) Beijing and Guangdong had the highest risk of self-spread and output cases, and prevention/control measures directed toward self-spread cases in Beijing should have focused on the later period of the SARS epidemic; (2) the SARS transmission networks in mainland China had significant clustering characteristics, with two clustering areas of output cases centered in Beijing and Guangdong; (3) Guangdong was the original source of the SARS epidemic, and while the infected cases of most other provinces occurred mainly during the early period, there was no significant spread to the surrounding provinces; in contrast, although the input/output interactions between Beijing and the other provinces countrywide began during the mid-late epidemic period, SARS in Beijing showed a significant capacity for spatial spreading; (4) Guangdong had a significant range of spatial spreading throughout the entire epidemic period, while Beijing and its surrounding provinces formed a separate, significant range of high-risk spreading during the mid-late period; especially in late period, the influence range of Beijing's neighboring provinces, such as Hebei, was even slightly larger than that of Beijing; and (5) the input network had a low-intensity spread capacity and middle-level influence range, while the output network had an extensive high-intensity spread capacity and influence range that covered almost the entire country, and this spread and influence indicated that significant clustering characteristics increased gradually. This analysis of the epidemic in-out flow and its corresponding transmission network helps reveal the potential spatiotemporal characteristics and evolvement mechanism of the SARS epidemic and provides more effective theoretical support for prevention and control measures.
个体易感-感染-有症状-治疗-康复的疫情过程不断变化的时空模式以及区域间信息/物质流的相互作用，结合中国大陆2002-2003年严重急性呼吸综合征（SARS）流行病学调查数据，包括个体的三个典型地点（工作单位/家庭住址、发病地点和报告单位），用于定义SARS疫情传播的流入和流出。此外，根据流入和流出的定义构建了SARS疫情的输入/输出传播网络。全面系统地探究了SARS流入和流出的时空分布、节点特征参数的空间分布和时间变化以及SARS传播网络的结构特征。结果表明：（1）北京和广东的自我传播和输出病例风险最高，针对北京自我传播病例的防控措施应集中在SARS疫情后期；（2）中国大陆的SARS传播网络具有显著的聚集特征，有两个以北京和广东为中心的输出病例聚集区；（3）广东是SARS疫情的原发地，其他大多数省份的感染病例主要发生在早期，未向周边省份显著传播；相比之下，尽管北京与全国其他省份的输入/输出相互作用始于疫情中后期，但北京的SARS显示出显著的空间传播能力；（4）广东在整个疫情期间都有显著的空间传播范围，而北京及其周边省份在中后期形成了一个独立的、显著的高风险传播范围；特别是在后期，河北等北京周边省份的影响范围甚至略大于北京；（5）输入网络的传播能力强度低、影响范围中等，而输出网络具有广泛的高强度传播能力和几乎覆盖全国的影响范围，这种传播和影响表明显著的聚集特征逐渐增强。对疫情流入和流出及其相应传播网络的分析有助于揭示SARS疫情潜在的时空特征和演变机制，为防控措施提供更有效的理论支持。
