Hospitalization costs for patients colonized with carbapenemase-producing Enterobacterales during an Australian outbreak

Carbapenem-producing Enterobacterales are an expanding group of Gram-negative bacteria that are resistant to carbapenems and cause over 9000 cases of hospital-associated infections in the USA. Efforts to quantify the economic and societal burden to healthcare are important to inform resource planning to implement infection control programmes. We estimated the healthcare costs during an outbreak of carbapenemase-producing Escherichia coli OXA-181 in Australia. We aimed to understand the economic burden to hospitals of patients who are asymptomatically colonized with high-risk bacteria. Hospital admissions data and associated costs were obtained from the State Health Department. Colonized patients were matched to non-colonized patients on age, sex, admission ward and diagnostic category. Mean healthcare costs and length of stay were examined using generalized linear models and accounted for time-dependent bias, patient age and ward location. On average, colonized patients had six times higher mean costs (AU$155,784; 95% confidence interval (CI): AU$77,892–285,604) than non-colonized patients (AU$25,964). Mean costs for those aged 75–79 years were 50% lower (P=0.02) compared with the youngest subgroup, 35–39 years of age. The mean extended length of stay was 12 days (95% CI: 3–21) for colonized patients. Nursing care was the main driver of overall costs for colonized (44%) and non-colonized (39%) patients. Patients colonized with carbapenem-producing Enterobacterales during an official hospital outbreak incurred higher costs than non-colonized patients. Although infected patients incur substantial economic burden to hospitals, the costs incurred by colonized patients is also high.