Laboratory Audits

To ensure that all cases of disease under surveillance are being reported, audits of the reporting laboratories are performed every January and July for the previous six month period. During laboratory audits, surveillance personnel compare the primary data source at every reporting site (usually a laboratory log book), which lists all isolates from normally sterile sites, to the list of cases reported prospectively to surveillance personnel. Case report forms are completed on all newly identified cases and isolates are collected when available. For laboratories routinely reporting all sterile site culture results via computer printouts, 100% sensitivity is assumed and a formal audit is not required.

Surveillance Indicators

The following surveillance indicators are used to assess ABCs: the percentage of isolates collected and sent to CDC, the percentage of cases enrolled in special studies nested within surveillance, the timeliness of the scheduled shipping of isolates, and the timeliness and sensitivities of completed audit data.

The timeliness and completeness of reporting in ABCs is evaluated using threshold percentages of isolate collection and enrollment into special studies.

Surveillance “fatigue” or operational problems are assessed using isolate shipping schedules, audit sensitivities, and the timeliness of the audit data being completed by set deadlines.