health development versus medical relief not a turf battle卫生发展与医疗救助不是一个地盘的战斗.pdfVIP

Correspondence Air Travel and the Spread of Infl uenza: Important Caveats Cécile Viboud, Mark A. Miller, Bryan T. Grenfell, Ottar N. Bjørnstad, Lone Simonsen While air travel contributes to the spread of infl uenza epidemics, the magnitude of impact is not clear compared to other factors—a crucial issue when considering a fl ight ban in the context of pandemic planning. Recent modeling efforts simulating the spread of pandemic infl uenza have concluded that such an intervention would matter little relative to other interventions [1–3]. But this assessment has now been challenged by an observational study of infl uenza in the winter following the post-9/11/2001 depression in air traffi c. Brownstein and colleagues’ study published in the September issue of PLoS Medicine [4] correlates variations in air traffi c doi:10.1371/journal.pmed.0030503.g001 volume with patterns of timing and spread in infl uenza Figure 1. Patterns of Timing (A) and Spread (B) of 30 Infl uenza epidemics, based on United States mortality data from nine Epidemics in the US, Together with Trends in Air Travel Statistics epidemic seasons between 1996 and 2005. While we fi nd the Infl uenza patterns are based on weekly national vital statistics from study interesting, we have identifi ed several important caveats 1972 to 2002 [5]. Air travel statistics represent the annual number of and question the robustness of the conclusions. domestic and international passengers on US air carriers (scheduled fl ights, secondary y-axis) [7]. (A) Time series of timing of national peaks The core of this study’s results lies in the observation that of infl uenza mortality. The 2001–2002 epidemic following 9/11 peaked the 2001–2002 i