Epidemiology of and risk factors for mortality due to carbapenemase-producing organisms (CPO) in healthcare facilities

Abstract

SummaryBackgroundCarbapenemase-producing organisms (CPO) have been largely responsible for the extensive spread of carbapenem resistance, and their prevalence is increasing in many parts of the world.AimTo evaluate clinical and molecular epidemiology and mortality associated with CPO among patients.MethodsAll CPO from clinical and long-term healthcare surveillance cultures across Scotland in 2003–2017 were reviewed retrospectively. Polymerase chain reaction was used to detect genes coding for carbapenemases. A generalized linear mixed model was used to identify risk factors for mortality.FindingsIn total, 290 individuals with CPO were identified. The overall incidence increased over time (P<0.001) from 0.02 to 1.38 per 100,000 population between 2003 and 2017. A total of 243 distinct CPO isolates were obtained from 269 isolations in 214 individuals with available metadata. The majority of the isolates were Enterobacterales (206/243, 84.8%), and Klebsiella pneumoniae (65/206, 31.6%) and Enterobacter cloacae (52/206, 25.2%) were the most common species. VIM (75/243, 30.9%) and NDM (56/243, 23.0%) were the most common carbapenemases. The crude 30-day mortality rate was 11.8% (25/211), while the case fatality rate was 5.7% (12/211). Age >60 years [adjusted odds ratio (aOR) 3.36, 95% confidence interval (CI) 1.06–10.63; P=0.033], presence of non-fermenters (aOR 4.88, 95% CI 1.64–14.47; P=0.005), and systemic infection or organ failure (aOR 4.21, 95% CI 1.38–12.81; P=0.032) were independently associated with 30-day mortality.ConclusionThe incidence of CPO in Scotland is low but increasing. Awareness is required that inpatients aged >60 years, patients with systemic infection or organ failure, and patients presenting with non-fermenters are at higher risk of death from CPO.