In Italy, infections with carbapene
m-resistant
m>Klebsiella pneumoniaem> (CRKP) have increased
markedly since 2009, creating unprecedented proble
ms in healthcare settings and li
miting treat
ment options for infected patients.
Aim
To assess the attributable mortality due to CRKP in ten Italian hospitals and to describe the clinical characteristics of patients with an invasive CRKP and carbapenem-susceptible m>K. pneumoniaem> (CSKP) infection.
Methods
We conducted a matched cohort study, and calculated crude and attributable mortality for CRKP. The attributable mortality was calculated by subtracting the crude mortality rate of the patients with CSKP from the crude mortality rate of the patients with CRKP. We also described the clinical characteristics of CRKP and CSKP patients and analysed the determinants of mortality by using conditional Poisson regression.
Findings
The study included 98 patients, 49 with CRKP and 49 with CSKP. CRKP patients had undergone more invasive procedures and also tended to have more serious conditions, measured by higher Simplified Acute Physiology Score II. The attributable mortality of CRKP at 30 days was 41%. CRKP patients were three times more likely to die within 30 days [matched incidence rate ratio (mIRR): 3.0; 95% confidence interval (CI): 1.5–6.1]. Adjusting for potential confounders, the risk remained the same (adjusted mIRR: 3.0; 95% CI: 1.3–7.1).
Conclusion
CRKP infection had a marked effect on patient mortality, even after adjusting for other patient characteristics. To control the spread of CRKP we recommend prioritization of control measures in hospitals where CRKP is found.