Healthcare-Associated Klebsiella pneumoniae carbapenemase Producing K. pneumoniae Bloodstream Infection: The Time Has Come

TO THE EDITOR—Klebsiella pneumoniae carbapenemase (KPC)–producing K. pneumoniae (KPC-Kp) has reached a worldwide diffusion, and the associated mortality rate of infected patients is ranging from 45% to 56% [1]. Several risk factors for mortality were identified in patients with KPC-Kp bloodstream infection (KPC-Kp BSI), such as the severity of the underlying disease or the delay in administration of appropriate therapy [2, 3]. Usually KPC-Kp infections arise in patients with prolonged hospital stay and have been previously treated with antibiotics [3]. We report on patients with KPC-Kp BSI diagnosed within 5 days after hospital admission [4]. The mortality was evaluated at 21 days after the first positive blood cultures, and appropriate treatment has been considered as the administration for ≥48 hours of an antibiotic with in vitro activity [5]. Eighteen patients with healthcareassociated KPC-Kp BSI were studied (Table 1). The majority of patients were men (11 [61%]), had a mean age of 63 years (standard deviation [SD], 14), had a previous admission in the 6 months before BSI onset (13 [72%]), or underwent surgery during the hospital stay (13 [72%]). Ten patients (56%) were in a medical ward at the time of diagnosis. The median time between hospital admission and KPC-Kp BSI was 3 days (SD, 1 day), and the mean Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 16 (range, 3–36). Five patients were colonized by KPC-Kp before KPC-Kp BSI. The comorbidities more frequently reported were malignancy (5 [36%]), chronic renal failure (4 [29%]), hepatopathy (3 [17%]), and cardiovascular disease (3 [17%]). After a median of 2 days (SD, 1 day), the empiric antibiotic treatment was changed and all patients were appropriately treated, mostly with combination therapy, according to the in vitro sensitivity. The overall mortality was 22% (4 patients). At univariate analysis the mortality was significantly associated with liver disease (P = .031), chronic renal failure (P = .047), and high APACHE II score (P = .01). The survival was associated with appropriate treatment administered for ≥48 hours. Usually, KPC-Kp BSI infections are diagnosed a median of 28–37 days after hospital admission [6–8]. In this study we report for the first time 18 patients with KPC-Kp BSI within 5 days after hospital admission, which had a very low crude mortality rate (22%) compared with 45% in the above-mentioned patients with nosocomial KPC-Kp BSI infections [6–8]. The pathogenesis of KPC-Kp BSI infection seems to be consistent with a multistep process where comorbidities, host factors, and prolonged antibiotic pressure contribute to the invasion of Table 1. Main Clinical Characteristics of Patients With Healthcare-Associated Klebsiella pneumoniae Carbapenemase Bloodstream Infection