Final answer:
The Public Health Service (PHS) is focused on the advancement of public health, including the enforcement of food and drug safety laws and early detection and prevention of disease. It has a historic role that evolved from the Marine Hospital Service and is now represented by entities such as the CDC, which oversees national disease surveillance systems and promotes health-related interventions like immunizations.
Step-by-step explanation:
The Public Health Service (PHS) is integral to promoting public health, offering essential human services, and enforcing laws related to the safety of food and drugs. Established originally in 1798 as the Marine Hospital Service (MHS), the PHS has evolved over time, now playing a crucial role in the detection and prevention of infectious diseases and epidemics by setting up strict protocols for medical checks on arriving ships. This evolution of responsibility marked the organization's transition towards its modern-day version, which includes the National Institutes of Health (NIH).
The main national public health organization in the United States today is the Centers for Disease Control and Prevention (CDC), which is a part of the Department of Health and Human Services. The CDC looks after the National Notifiable Disease Surveillance System (NNDSS), which is a cooperative effort with regional, state, and territorial health departments to monitor diseases of national public health importance. Public health efforts have historically been associated with positive externalities and public goods, such as the promotion of hygienic practices, funding of public sanitation systems, and backing medical research leading to discoveries that benefit the entire society. A classic example of such public health intervention is the requirement for immunizations, which protect not only the individual but also prevent the spread of illness to others.