13  Syndromic Surveillance

Syndromic surveillance refers to surveillance systems where the relevant event is not a diagnosed disease but rather cases from a group of illnesses. So threats can be detected if if there is no specific diagnosis yet. Syndromic surveillance can use many different events that indicate a syndrom.

Typical events:

• Physician office visits
• ICD-10 Codes of Hospitals
• Self assessment of people
• Information seeking
• Prescriptions
• Absenteeism

Advantages:

• can detect unkown or lesser-known diseases
• syndromic systems can be very fast
• can often be acquired automatically because it often works well with classification systems like ICD-10 codes

Disadvantages

• Syndromic surveillance is usually a sentinel system and not comprehensive
• Difficult to interpret during high activities of several similar diseases
• Calculating incidence and prevalence is usually biased because the denominator is not clear

Examples: For example, in syndromic surveillance, instead of tracking cases of SARS-CoV-2 infection, cases of acute respiratory illness are recorded. This approach makes the surveillance system more sensitive, capturing a broader spectrum of diseases. When a signal suggests a relevant event, such as an outbreak, further investigation can be conducted to identify the exact pathogen.