Healthcare associated infection surveillance methodologies.

  • Active or passive:
    • active: trained personnel use various data sources to identify events;
    • passive: non-trained personnel identify and report events to infection prevention and control personnel.
  • Prospective or retrospective:
    • prospective: monitoring patients while still in the institution; includes post-discharge period for SSI:
      • visibility of infection control practitioner on wards (if active surveillance);
      • timely analysis and feedback;
      • labour intensive, costly;
    • retrospective: case-finding based solely on chart review after patient discharged.

  • Patient-based or laboratory-based:
    • patient-based: monitoring patients for events, risk factors, and procedures and practices related to patient care:
      • requires ward/unit rounds;
      • includes discussions with caregivers/ physicians;
    • laboratory-based: case-finding based solely on positive laboratory  findings:
      • events may be missed;
      • colonization.
  • Incidence or prevalence:
    • incidence: measure new events occurring during some defined time period;
    • prevalence: measure all events occurring at either a point in time or during some defined time period.
  • Priority-directed (targeted) or comprehensive:
    • priority-directed: Objectives for surveillance are defined and focused on specific events and/or patients:
      • usually less resource intensive/costly;
    • comprehensive: continuous monitoring of all patients for all events:
      • facility-wide;
      • usually more resource intensive/costly.
  • Risk-adjusted or crude:
    • risk-adjusted: Rates are controlled for variations the distribution of major risk factor(s) associated with an event’s occurrence:
      • comparison of rates possible;
    • crude: Rates assume equal distribution of risk factors for all events:
      • comparison of rates not possible.


Link to European IC/HH Core Competencies

Area 3. Surveillance and investigation of healthcare associated infection (HAI)


CDC Outline For Healthcare-Associated Infections Surveillance, 2006

Perl TM, Chaiwarit R. Surveillance: An Overview. In: Lautenbach E, Woeltje KF, Malani PN Eds. Practical Healthcare Epidemiology, Ed. Society for Healthcare Epidemiology of America, University of Chicago Press, Chicago, USA, 2010:111-142