Which surveillance type involves proactive data collection to identify cases?

Which surveillance type involves proactive data collection to identify cases?

• A. Sentinel surveillance
• B. Passive surveillance
• C. Syndromic surveillance
• D. Active surveillance

Answer: (D)

Proactive case finding through regular outreach and systematic data collection is what active surveillance is designed to do. It involves health authorities actively seeking out cases—through routine contact with hospitals and clinics, active chart reviews, and targeted screening—to identify new infections as they occur. This approach yields more complete and timely data on who is affected, which is especially important during outbreaks or when trying to measure true incidence and monitor progress. In contrast, passive surveillance waits for providers or laboratories to report cases on their own, which can miss many cases and underestimate burden. Sentinel surveillance relies on data from select sites to infer trends rather than capturing every case. Syndromic surveillance focuses on early signals from symptoms or non-specific data to detect possible outbreaks, not necessarily confirming individual cases.

Proactive case finding through regular outreach and systematic data collection is what active surveillance is designed to do. It involves health authorities actively seeking out cases—through routine contact with hospitals and clinics, active chart reviews, and targeted screening—to identify new infections as they occur. This approach yields more complete and timely data on who is affected, which is especially important during outbreaks or when trying to measure true incidence and monitor progress.

In contrast, passive surveillance waits for providers or laboratories to report cases on their own, which can miss many cases and underestimate burden. Sentinel surveillance relies on data from select sites to infer trends rather than capturing every case. Syndromic surveillance focuses on early signals from symptoms or non-specific data to detect possible outbreaks, not necessarily confirming individual cases.