Point prevalence surveillance studies:

Correct Answer: D

Rationale: Point prevalence surveillance provides a snapshot of disease burden at a specific time, unlike continuous surveillance (A). It can be repeated periodically (B), and typically requires fewer resources than continuous surveillance (C), making it a practical tool for periodic assessment.

Correct Answer: B

Rationale: An epidemic refers to disease levels exceeding normal expectations and being more prolonged or widespread than localized outbreaks, distinct from endemic levels (A), pandemics (C), or the study of epidemiology (D).

Correct Answer: D

Rationale: The first step in outbreak investigation is to agree on a case definition to consistently identify cases, which guides subsequent steps like sample collection (B), meetings (C), and data organization (A).

Correct Answer: C

Rationale: After containment, preparing and distributing a report with findings and recommendations ensures lessons are documented and shared, more critical than celebration (A), basic notification (B), or sample disposal (D).