What is the primary contribution of contact tracing to disease control?

• A. It eliminates the need for laboratory testing.
• B. It identifies close contacts, monitors them for symptoms, and may prompt quarantine to interrupt transmission.
• C. It delays public health action.
• D. It only confirms the primary case's illness.

Answer: (B)

The main idea is that contact tracing follows the transmission chain by identifying people who had close contact with someone who is infected. By finding these exposed individuals, health workers can monitor them for symptoms during the incubation period and may recommend testing or quarantine. This helps interrupt transmission by removing potentially infectious people from the community or isolating new cases early, preventing further spread. It enables targeted actions for those at risk and supports faster, more precise interventions than broad measures.

Why the other statements don’t fit: laboratory testing remains essential to confirm infection and guide actions, so contact tracing doesn’t eliminate the need for tests. The goal is to speed up action, not delay it. And contact tracing isn’t limited to confirming the primary case’s illness; it extends to exposed contacts to prevent additional cases.