Eichner Martin, Schwehm Markus, Wilson Nick, Baker Michael G
1Department of Medical Biometry, University of Tübingen, Germany.
BMC Infect Dis. 2009 Sep 29;9:160. doi: 10.1186/1471-2334-9-160.
Some island nations have explicit components of their influenza pandemic plans for providing travel warnings and restricting incoming travellers. But the potential value of such restrictions has not been quantified.
We developed a probabilistic model and used parameters from a published model (i.e., InfluSim) and travel data from Pacific Island Countries and Territories (PICTs).
The results indicate that of the 17 PICTs with travel data, only six would be likely to escape a major pandemic with a viral strain of relatively low contagiousness (i.e., for R0 = 1.5) even when imposing very tight travel volume reductions of 99% throughout the course of the pandemic. For a more contagious viral strain (R0 = 2.25) only five PICTs would have a probability of over 50% to escape. The total number of travellers during the pandemic must not exceed 115 (for R0 = 3.0) or 380 (for R0 = 1.5) if a PICT aims to keep the probability of pandemic arrival below 50%.
These results suggest that relatively few island nations could successfully rely on intensive travel volume restrictions alone to avoid the arrival of pandemic influenza (or subsequent waves). Therefore most island nations may need to plan for multiple additional interventions (e.g., screening and quarantine) to raise the probability of remaining pandemic free or achieving substantial delay in pandemic arrival.
一些岛国在其流感大流行计划中有明确的部分，用于发布旅行警告和限制入境旅客。但此类限制的潜在价值尚未得到量化。
我们开发了一个概率模型，并使用了已发表模型（即InfluSim）中的参数以及太平洋岛国和领地（PICTs）的旅行数据。
结果表明，在有旅行数据的17个PICTs中，即使在整个大流行期间将旅行量大幅减少99%，只有6个可能在面对传染性相对较低的病毒株（即R0 = 1.5）的大流行时幸免。对于传染性更强的病毒株（R0 = 2.25），只有5个PICTs有超过50%的概率幸免。如果一个PICT旨在将大流行到来的概率保持在50%以下，那么在大流行期间的旅客总数不得超过115人（对于R0 = 3.0）或380人（对于R0 = 1.5）。
这些结果表明，相对较少的岛国仅靠严格的旅行量限制就能成功避免大流行性流感（或后续浪潮）的到来。因此，大多数岛国可能需要规划多种额外的干预措施（如筛查和检疫），以提高保持无大流行状态或大幅延迟大流行到来的概率。
