Chapter 5 - Public Health Surveillance

Surveillance is to observe with the purpose of giving in return direction. Surveillance is providing and interpreting observation to prevent and control disease. Everything in Public Health sprouts from surveillance data and the data inference. Public Health Surveillance needs to end with suggested direction supported by data and data inference.

Your surveillance project needs an objective, a purpose, a use for the data. Discover objectives by asking...
-What is the health event?
-What is the case definition for surveillance (this could be different than clinical and outbreak definitions)?
-What are the planned uses of this data?
-Where will this surveillance data overlap previous data?
-Who is the population?
-When should the data be acquired and how frequent?
-How will the data be gathered?
-How will the data be stored?
-How will analysis be done and by whom?
-How will the data be distributed once finished and to whom?

Major aspects of a Public Health Surveillance...
Acceptability. Will the target population participate in your data collection.
Flexibility. Changes happen, can the surveillance adapt without extra cost?
Predictive Value Positive. How many reported cases really are cases?
Quality. Data completeness/how many blanks do you have?
Representativeness. How well dose your sample depict the population?
Sensitivity. Can the surveillance account for those that are sick and hard to reach?
Simplicity. The easier the surveillance is to run the better.
Stability. How reliable and available resources are to conduct and finish surveillance.
Timelessness. Can the surveillance be completed fast enough for action to take place that will make a difference? (try a syndromic surveillance for faster disease findings)
Validity. Is the surveillance discovering the outbreaks and non-outbreaks it should? Like sensitivity and positive value.

TIP: Collecting data takes large time commitments and consumes large amounts of resources. Also the quality and representation of data will become the bottle neck of any surveillance so make sure the problem and objectives truly are significant. Things to consider when selecting surveillance projects include...
-incidence
-prevalence
-sequela
-severity (mortality)
-DALY's
-socioeconomic impact (burden of disease)
-communicability
-outbreak potential
-public concern
-international requirements
-prevent-ability
-control measures (including treatment)
-health system capacity to act speedily
-availability of resources to act
-economics
-ease of surveillance

NOTE: Communicable disease are the health events most under surveillance.

CDC and CSTE are U.S centers that determine how surveillance is done in the U.S government.