Definition: A worry that tends to persist over time and has as its subject a state or process. The subject of the worry has the potential to require intervention or management.

Examples: an observation result, procedure, substance administration, equipment repair status, device recall status, a health risk, a financial risk, public health risk, pregnancy, health maintenance, allergy, and acute or chronic illness.

A public health case is a Concern about an observation or event that has a specific significance for public health. The creation of a PublicHealthCase initiates the tracking of the object of concern. The decision to track is related to but somewhat independent of the underlying event or observation.

UsageNotes: Typically a Public Health Case involves an instance or instances of a reportable infectious disease or other condition. The public health case can include a health-related event concerning a single individual or it may refer to multiple health-related events that are occurrences of the same disease or condition of interest to public health.

A public health case definition (Act.moodCode = "definition") includes the description of the clinical, laboratory, and epidemiologic indicators associated with a disease or condition of interest to public health. There are case definitions for conditions that are reportable, as well as for those that are not. A public health case definition is a construct used by public health for the purpose of counting cases, and should not be used as clinical indications for treatment. Examples include AIDS, toxic-shock syndrome, and salmonellosis and their associated indicators that are used to define a case.

An Outbreak is a concern resulting from a series of public health cases.

UsageNotes: The date on which an outbreak starts is the earliest date of onset among the cases assigned to the outbreak and its ending date is the last date of onset among the cases assigned to the outbreak. The effectiveTime attribute is used to convey the relevant dates for the case. An outbreak definition (Act.moodCode = "definition" includes the criteria for the number, types and occurrence pattern of cases necessary to declare an outbreak and to judge the severity of an outbreak.