Question

One of the most important things that an epidemiologist might do is called surveillance. Surveillance is about monitoring disease trends in order to understand how disease functions in populations. It also allows epidemiologists to recognize unusual trends and intervene. There are two major types of surveillance, which are active surveillance and passive surveillance. Please explain each type with an example of how it is used.

Answer 1

ACTIVE SURVEILLANCE:

In active surveillance a patient is closely monitored but treatment is not given in this unless the condition of the patient is ill or worse. Active surveillance is done in some types of cancers such as prostate cancer, urethral cancer etc.

For example if any person is having prostate cancer but doesn't want to undergo radiation therapy and surgery. Most of the prostate cancers are slow growing and doesn't need immediate treatment. In active surveillance the the treatment will be delayed and the patient will be monitored closely for the progression of the disease and the doctors regularly check them for any changes in the tumors. The main motive of active surveillance is to delay the surgery and radiation therapy of the slow growing tumor patients because these radiation therapy and surgery have side effects that can alter a person's quality of life. So they closely monitors the patient for any progression of tumors, a PSA blood test and DRE( digital rectal examination ) is done per year. For active surveillance the PSA level should be <10, group 1 or gleason 6.

PASSIVE SURVEILLANCE:

In this surveillance a group of health care professionals provide information or censes of any particaular disease or cases like in hospitals nurses report that they received 10 corona positive patients, in a nursing home they inform there are 5 cases of measeles. In this regular reporting of disease specifics by local members or staff.