Use of a Victorian statewide surveillance program to evaluate the burden of healthcare-associated Staphylococcus aureus bacteraemia and Clostridioides difficile infection in patients with cancer

Background: Patients with cancer are at high risk for infection, but the epidemiology of healthcare-associated Staphylococcus aureus bacteraemia (HA-SAB) and Clostridioides difficile infection (HA-CDI) in Australian cancer patients has not previously been reported. Aims: To compare the cumulative aggregate incidence and time trends of HA-SAB and HA-CDI in a predefined cancer cohort with a mixed statewide patient population in Victoria, Australia. Methods: All SAB and CDI events in patients admitted to Victorian healthcare facilities between 1 July 2010 and 31 December 2018 were submitted to the Victorian Healthcare Associated Infection Surveillance System Coordinating Centre. Descriptive analyses and multilevel mixed-effects Poisson regression modelling were applied to a standardised data extract. Results: In total, 10 608 and 13 118 SAB and CDI events were reported across 139 Victorian healthcare facilities, respectively. Of these, 89 (85%) and 279 (88%) were healthcare-associated in the cancer cohort compared with 34% (3561/10 503) and 66% (8403/12 802) in the statewide cohort. The aggregate incidence was more than twofold higher in the cancer cohort compared with the statewide cohort for HA-SAB (2.25 (95% confidence interval (CI): 1.74-2.77) vs 1.11 (95% CI: 1.07-1.15) HA-SAB/10 000 occupied bed-days) and threefold higher for HA-CDI (6.26 (95% CI: 5.12-7.41) vs 2.31 (95% CI: 2.21-2.42) HA-CDI/10 000 occupied bed-days). Higher quarterly diminishing rates were observed in the cancer cohort than the statewide data for both infections. Conclusions: Our findings demonstrate a higher burden of HA-SAB and HA-CDI in a cancer cohort when compared with state data and highlight the need for cancer-specific targets and benchmarks to meaningfully support quality improvement.