Which intervention focuses on preventing a disease before it occurs?

The correct answer is centered on the concept of primary prevention, which is critical in public health. Primary prevention aims to reduce the incidence of disease by intervening before the onset of illness. It involves health education, immunizations, and lifestyle modifications to prevent diseases from occurring in the first place.

For instance, vaccination programs that immunize individuals against infectious diseases are a prime example of primary prevention. These initiatives target the vulnerable population groups before they are exposed to disease-causing agents, hence reducing the overall occurrence of disease in the community.

In contrast, tertiary prevention focuses on managing and reducing the impact of established diseases, while secondary prevention aims to detect diseases early to improve outcomes. Quaternary prevention is more about avoiding unnecessary medical interventions after diseases have already occurred. Understanding these distinctions reinforces the importance of primary prevention in maintaining public health and preventing diseases before they start.