Which sequence correctly lists the three stages of modern epidemiology in order?

• A. Sanitary statistics; Infectious disease epidemiology; Chronic disease epidemiology
• B. Infectious disease epidemiology; Sanitary statistics; Chronic disease epidemiology
• C. Sanitary statistics; Chronic disease epidemiology; Infectious disease epidemiology
• D. Infectious disease epidemiology; Chronic disease epidemiology; Sanitary statistics

Answer: (A)

The sequence tests how modern epidemiology developed over time, moving from describing populations to tackling infections to studying chronic diseases. The earliest phase, sanitary statistics, involved systematic collection of vital statistics—births, deaths, causes of death, life expectancy—to monitor population health and guide public health actions. The next phase focuses on infectious diseases, driven by germ theory, with an emphasis on identifying disease agents, transmission pathways, and methods to control outbreaks. The final phase centers on chronic diseases, which became the dominant health issue as infectious threats declined, using long-term cohort and analytic studies to uncover lifestyle and environmental risk factors and inform prevention.

This order best matches how the discipline evolved historically. Other sequences place chronic disease before infectious disease or reorder the foundational descriptive statistics, which doesn’t align with the historical progression of epidemiology.