Leon Worth 1
1 Infectious Diseases Physician, VICNISS Coordinating Centre, Melbourne, VIC, Australia
Background: Clostridium difficile poses a substantial and increasing healthcare burden internationally, and there is therefore a need for monitoring of infections in Australia. The objective of this study was to evaluate time trends and severity of illness for Clostridium difficile infection (CDI) events in Australian healthcare facilities.
Methods: All CDI events in patients admitted to Victorian public hospitals between 1st October 2010 and 31st December 2014 were reported to the Victorian Healthcare Associated Infection Surveillance System. Consistent with nationally-agreed case-definitions, CDI was defined as the isolation of a toxin-producing C. difficile organism in a diarrhoeal specimen. Events were classified as community-associated (CA-CDI) or healthcare-associated (HA-CDI), with severe disease defined as admission to an intensive care unit, requirement for surgery and/or death due to infection. Time trends were evaluated using a mixed-effects Poisson regression model.
Results: Overall, 6736 CDI events were reported across 89 healthcare facilities. Of these, 4826 (71.6%) were HA-CDI, a rate of 2.49/10,000 occupied bed days (OBDs). Incidence of HA-CDI was highest in the fifth quarter of surveillance (3.6/10,000 OBDs), followed by a reduction. Severe disease was reported in 1.66% of events, with the proportion being significantly higher for CA-CDI compared with HA-CDI (2.21 vs. 1.45%, p=0.03). Highest and lowest incidence of HA-CDI occurred in March and October, respectively.
Conclusions: A low incidence of HA-CDI was reported in Victoria compared with US/European surveillance reports. Seasonality was evident, together with diminishing HA-CDI rates in 2012-2014. Severe infections were more common in CA-CDI, supporting future enhanced surveillance in community settings.