What is the difference between active and passive surveillance?

Answer 1

Difference between active sensor and passive sensor

Answer:

Active transducers generate electric current or voltage directly in response to environmental stimulation. Examples of active transducers are thermocouples and piezoelectric accelerometers. Thermocouples produce a voltage related to a temperature of two metals and if the two junctions are at different temperatures, electricity is generated.

Passive transducers produce a change in some passive electrical quantity, such as capacitance, resistance, or inductance, as a result of stimulation. These usually require additional electrical energy for excitation. A simple example of a passive transducer is a device containing a length of wire and a moving contact touching the wire. The position of the contact determines the effective length of the wire, varying the resistance of the length of wire. Other examples of passive transducers are strain gauges, resistance temperature detectors (RTDs), and thermistors

Source:http://digital.ni.com/public.nsf/allkb/084702CE98679BB886256CA3006752D7

Answer 2

The major difference between passive surveillance and active surveillance is that passive surveillance relies on pre-existing data or data that is usually reported by public health officers or health care providers to health departments while active surveillance involves proactively collecting data from patients or participants from the general population.

Answer 3

Active surveillance involves actively searching for cases of a particular disease by conducting regular checks through surveys or screenings. Passive surveillance relies on healthcare providers and laboratories reporting cases as they encounter them. Active surveillance is more proactive and can provide more comprehensive data, while passive surveillance relies on existing healthcare systems for case reporting.