The science of public health has evolved since the 18th century, when it focused on isolating the ill and quarantining those exposed to diseases to prevent transmission of infection. In the 19th century, the focus was on sanitation, especially separating fecal contamination from food and water. Living conditions improved tremendously as a result. With the understanding of infectious disease transmission in the early part of the 20th century, the focus shifted to immunizations and infection control.

Talk of the end of American exceptionalism seems to be everywhere lately, but in at least one area, the United States inarguably reigns supreme.  Currently, per capita health care expenditures in the U.S. are approaching $8,000 a year, far more than anywhere else in the world.  The nation with the second-highest per capita cost, Norway, spends  $2,500 less per person per year.  What do Americans get for their money?  A life expectancy of 78.2 years, slightly ahead of Panama and Libya.