Surveillance of infection burden in residential aged care facilities

To explore the burden of illness associated with infectious syndromes and to measure the associated use of antimicrobials in residential aged care facilities (RACFs). Design, setting and subjects: Retrospective analysis of data for January 2006 to December 2010 from an infection surveillance system covering residents of four co-located RACFs, with a total of 150 residential care beds, in Melbourne, Victoria. Main outcome measures: Number of episodes and incidence of health careassociated infection (HCAI); rate of antimicrobial use; prescribing concordance with McGeer criteria for infection; frequency of clinical specimen collection. Results: There were 1114 episodes of an infectious syndrome over 267 684 occupied bed-days (OBD), affording an average HCAI rate of 4.16 episodes/ 1000 OBD annually over 5 years (95 CI, 3.92-4.41). The mean rate of antimicrobial use was 7.07 courses/1000 OBD (range, 6.71-7.84). Around 40 of antimicrobial prescribing was for episodes that did not fulfil the McGeer criteria for clinical infection; this included about half of suspected urinary tract and upper respiratory tract infections (URTI), and about one-third of suspected lower respiratory tract and skin infections. Antimicrobials were routinely prescribed for URTI and bronchitis. Of all episodes treated with antimicrobials, 36 had documentation that a clinical specimen was obtained. Conclusions: The HCAI rate remained relatively stable over time. Routine surveillance and feedback of infection rates to the facilities did not result in a noticeable decrease of infection burden over time. It is of immediate concern that antimicrobials were being prescribed for a large proportion of suspected infections that did not meet criteria for clinical infection. Opportunities exist to further improve the use of antimicrobials in the RACF setting.