What are the three phases of public health frameworks?

• A. PH 1.0: infectious disease and sanitation, PH 2.0: chronic disease and prevention, PH 3.0: systems thinking and equity.
• B. PH 1.0 sanitation, PH 2.0 treatment, PH 3.0 governance.
• C. PH 1.0: digital health, PH 2.0: genomics, PH 3.0: nanotech.
• D. PH 1.0: climate health, PH 2.0: urban planning, PH 3.0: global health.

Answer: (A)

Public health evolves in three waves that build on each other. The first wave centers on stopping infectious disease and improving sanitation—things like clean water, proper sewage, vaccination, and outbreak control. The second wave shifts to preventing and managing chronic diseases, focusing on reducing risk factors, promoting healthy behaviors, and implementing population-wide prevention. The third wave adopts a systems approach, looking at how health is shaped by complex interactions across sectors, with emphasis on equity, social determinants of health, data-driven decision-making, and coordinated governance. This framing fits best because it captures the historical progression from infection control to chronic disease prevention to a holistic, equity-focused systems perspective. The other options mix in technology or different domains that aren’t described as the three successive public health phases.