3.3 Syndromic surveillance
Syndromic surveillance can be passive or active and involves gathering routinely collected data on signs, symptoms or clinical diagnoses of disease in human or animal health, when laboratory confirmation of disease is either unavailable or not timely. This methodology is employed in situations where an early warning system is needed, including to identify emerging syndromes and diseases; for example, it can be set up in busy Emergency Departments in hospitals across a country to rapidly detect spikes in seasonal influenza, based on number of people presenting to the Department with symptoms suggestive of possible influenza (for example, report of fever or measured high temperature). Information gleaned from this form of surveillance serves as an early warning flag for the health system, allowing for prompt interventions to mitigate disease spread and adjust health service capacity.
Syndromic surveillance also triggered the alarm bell which later led to the identification of BSE, when the number of neurological syndromes in cattle surged above the ‘usual’ incidence. This methodology is often cheap to implement, in part due to its lack of dependability on laboratory confirmation processes. The focus on signs and symptom data does make systems employing this methodology less accurate for pinpointing the cause of disease. For example, a ‘rash’ could be a sign of anything from dermatitis (i.e. skin inflammation) to a
Example:
3.2 Active surveillance