The focus of public health interventions is to prevent and manage diseases, injuries and other health conditions through surveillance of cases and the promotion of healthy behavior, communities, and (in aspects relevant to human health) environments. Its aim is to prevent health problems from happening or re-occurring by implementing educational programs, developing policies, administering services and conducting research. In many cases, treating a disease or controlling a pathogen can be vital to preventing it in others, such as during an outbreak. Vaccination programs and distribution of condoms to prevent the spread of communicable diseases are examples of common preventive public health measures, as are educational campaigns to promote vaccination and the use of condoms (including overcoming resistance to such).
Usage Note: Some people insist on maintaining a distinction between the words healthy and healthful. In this view, healthful means "conducive to good health" and is applied to things that promote health, while healthy means "possessing good health," and is applied solely to people and other organisms. Accordingly, healthy people have healthful habits. However, healthy has been used to mean "healthful" since the 1500s, as in this example from John Locke's Some Thoughts Concerning Education: "Gardening ... and working in wood, are fit and healthy recreations for a man of study or business." In fact, the word healthy is far more common than healthful when modifying words like diet, exercise, and foods, and healthy may strike many readers as more natural in many contexts. Certainly, both healthy and healthful must be considered standard in describing that which promotes health.