摘要
Public health has been defined as“the science and art of preventing disease,prolonging life,and promoting health through the organized efforts and informed choices of society,organizations,public and private communities,and individuals”(1).Public health,and not medical care,has been responsible for most of the health gains in the world during the past century.Public health initiatives such as clean water and sanitation,vaccination,tobacco control,motor vehicle and workplace safety,and improved nutrition led to 80%of the gain in U.S.life expectancy in the 20th century(2).Globally,public health accomplishments such as smallpox(3)and polio eradication(4),and immunization(5)have saved millions of lives.
