Active search for disease in an apparently healthy individual is k/a -
Screening

Screening is the search for unrecognized disease by means of rapidly applied tests or examinations in an apparently healthy individuals.
In simple words, screening is the active search for disease among apparently healthy people.
The intention of screening is to identify disease in a community early, thus enabling earlier intervention and management in hope to reduce mortality and suffering from a disease.
Screening may be


Prescriptive screening: - people are screened for their own benefit. For example:- case detection by pap smear.
Prospective screening: - people are screened for other's benefit. For example:- screening of immigrant for the disease which is not present in that area.

Screening test
Screening test is a test for a particular disease given to asymptomatic people.
Monitoring
Case finding
Screening
Sentinel surveillance