Which statement best distinguishes contact tracing from case investigation?

• A. Contact tracing identifies and assesses people exposed to a case; case investigation analyzes the confirmed case to determine transmission and implement controls.
• B. Contact tracing identifies and assesses the case's age group.
• C. Case investigation is identical to contact tracing.
• D. Only contact tracing is used after vaccine rollout.

Answer: (C)

The main idea is that case investigation and contact tracing serve different purposes but work together to control spread. Case investigation digs into the diagnosed patient: confirming the illness, documenting symptoms, onset date, severity, vaccination or exposure history, and possible sources or routes of transmission. The aim is to understand how the case fits into the bigger picture and to implement measures to protect the patient and prevent further transmission.

Contact tracing, starting from that identified case, focuses outward to people who may have been exposed. It involves identifying these exposed individuals, assessing their risk, advising on testing or quarantine, and monitoring them to stop onward spread.

The statement that best captures this distinction says contact tracing identifies and assesses those exposed to a case, while case investigation analyzes the confirmed case to determine transmission and implement controls. The other choices are incomplete or inaccurate because they either narrow the scope (focusing only on age groups), claim they’re identical, or misstate when these activities are used.