>In the Netherlands, seasonal influenza has ~1% mortality rate -- in the U.S. it's more like 0.1%.(I'm not a healthcare professional nor actuarian; the following is freehand speculation)
There are two key factors. Firstly, USA is much less densely populated, with various additional compounding aspects: social stratification, with many segments of society living mostly in their own areas, and lesser dependence on mass transport. Modern technology and abundance of land allows maintaining a degree of isolation when needed.
Secondly, the healthcare system in USA vs Netherlands is tale of semi-private vs nationalized system. The former has more incentives to be proactive and minimize costs, vs the later having incentives to make a good showing, with payments being assured anyway.