Part I: 5 Step Process of Surveillance & Types of Surveillance
The purpose of public health surveillance is to gain knowledge of the patterns of disease, injury, and other health problems in a community so that we can work towards their prevention and control.
Passive Surveillance Example:
A physician sees a patient, diagnoses measles, and then initiates a case report by contacting the local health department and providing the details as required for a case of measles. Here, the local health department relies on the physician to report the case.
Active Surveillance Example:
If a health department receives a case report for measles, a serious vaccine-preventable disease, active surveillance will be triggered. Public health practitioners will actively search for other cases, using a standard case definition: calling doctors' offices for any cases, following up to find additional cases among those exposed, checking laboratories.
Sentinel Surveillance Example:
A network of large hospitals might be used to collect high-quality data on various diseases and their causative organisms, such as invasive bacterial disease caused by Haemophilus influenza type b, pneumococcus or pneumococcus.
Syndromic Surveillance Example: INFLUENZA
Monitor data from school absenteeism logs, emergency call systems, hospitals' over-the-counter drug sale records, internet searches, and other data sources to detect unusual patterns. When a spike in activity is seen in any of the monitored systems disease epidemiologists and public health professionals are alerted that there may be an issue.