重磅：军科院曹务春教授PNAS发表埃博拉病毒的传播和干预手段有效性

2016年3月29日，国际著名学术期刊《美国国家科学院院刊》杂志在线发表了北京微生物流行病研究所曹务春研究员一项研究,研究指出在塞拉利昂实施的某些干预手段在遏制近来的埃博拉病毒暴发方面有效。方立群研究员为论文共同第一作者，曹务春研究员为论文共同通讯作者之一。

 

对于埃博拉病毒病(EVD)重新出现的担忧已经促使人们研究过去的暴发，从而改善对埃博拉病毒病(EVD)传播以及干预策略的有效性的理解。Wu-Chun Cao及其同事使用来自2014年5月到2015年9月塞拉利昂近来的埃博拉病毒病(EVD)暴发的数据，在多个层次上绘制了病例的空间和时间分布。这组作者估计，被定义为每个病人每周的次级感染的平均数量的传递率，在联合国埃博拉应急特派团(UNMEER)的策略方案于2014年10月启动之后，减少了43%，一旦在2014年12月实现100%的病例隔离与安全掩埋之后，传递率相对于2014年10月之前的水平减少了65%。埃博拉病毒病(EVD)的传播与人口密度高、接近埃博拉处理中心、农田覆盖率高以及温度高于或低于27 °C有关。这组作者还发现，在联合国埃博拉应急特派团(UNMEER)活动之后，一名病人感染一个家庭成员的可能性估计从9.3%下降到了1.7，下降了82%。这组作者说，这些结果可能有助于为未来的暴发制定有效的干预策略。

 

Transmission dynamics of Ebola virus disease and intervention effectiveness in Sierra Leone

 

Significance

 

Since the initial recognition of Ebola virus disease (EVD) in 1976, many epidemics have occurred in Africa. Serious concerns remain that the fatal disease may repeatedly reemerge. In this study, we used data from an unprecedented EVD outbreak in Sierra Leone to map spatiotemporal transmission patterns, identify influential factors, and assess the effects of interventions at the chiefdom level. Furthermore, we have quantified household transmissibility and the temporal association between interventions and household transmission. Our findings have deepened the understanding of the transmission dynamics of EVD and provided key information for future modeling efforts in forecasting future epidemics and establishing intervention strategies.

 

原文摘要：

 

Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014?2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission.