Surveillance

Surveillance

• Surveillance:

Is the ongoing systematic collection and analysis of data and the
provision of information which leads to action being taken to prevent and control
a disease, usually one of an infectious nature

• Surveillance is of many types:

1. Passive Surveillance:

Data is itself reported to the health system - Example:

A patient with fever coming on his own to the PHC, CHC, Dispensary, Private Practitioner, Hospital
- Most of the national health programmes in India rely on Passive Surveillance for morbidity and mortality data collection

2. Active Surveillance:

Health system seeks out ‘actively’ the collection of data, i.e., goes out to community to collect data
- Example: Health worker goes house to house every fortnight to detect fever cases, collect blood slides (under malaria component of National Vector Borne Disease Control Program)

- Active Surveillance in National Health Programmes of India:

Is seen in NVBDCP (Health worker goes house to house every fortnight to detect fever cases, collect blood slides and provide presumptive treatment under malaria component) and National Leprosy Elimination Programme (Modified Leprosy Elimination Campaigns)

3. Sentinel Surveillance:

Monitoring of rate of occurrence of specific conditions to assess the stability or change in health levels of a population, It is also the study of disease rates in a specific population to estimate trends in larger population
- Example: Use of health practitioners to monitor trends of a health event in a population
- Helps in ‘identifying missing cases’ and ‘supplementing notified cases’
- Sentinel Surveillance is done in National AIDS Control Program wherein STD Clinics, ANC Clinics are sentinel sites to monitor trendsQ