Increasing incidence of candidaemia: long-term epidemiological trends, Queensland, Australia, 1999-2008

Given variability in the epidemiology of candidaemia and a relative paucity of contemporary longitudinal data, a passive laboratory-based surveillance study was performed to assess the epidemiology of candidaemia in all public healthcare facilities in Queensland, Australia over the period 1999-2008. Demographic and microbiological data on all candidaemia episodes, together with appropriate denominators (admissions and patient-days), were collected from laboratory and administrative information systems. From 1999 to 2008, 1137 episodes occurred (overall incidence-density: 0.45 per 10 000 patient-days) with a 3.5-fold increase in density (P<0.0001 for trend). Candidaemia episodes originating in traditional high-risk areas either decreased (haemato-oncology and paediatric wards) or remained stable (intensive care units). Episodes on adult medical/surgical wards increased significantly over time, accounting for 60% of the total by 2008. The relative proportion caused by Candida albicans decreased and Candida parapsilosis increased (both P<0.01). The proportion of fluconazole-resistant isolates did not change. The increasing occurrence of candidaemia outside traditional high-risk areas and the emergence of C. parapsilosis present new challenges for preventive and early intervention strategies.