疫学

1. Origins, structure, and basic meaning

• Structure: 疫学 (えきがく) is the discipline epidemiology, the study of disease occurrence and distribution.
• Basic usage: 感染症の疫学を研究する names a field of study; 疫学の調査 describes an investigation using that field's approach.

2. Common pitfalls and similar expressions

• Academic field and epidemiological investigation
  • The disease context fixes the term as epidemiology; の調査 applies the discipline's method to an investigation.