title: Trends in the annual incidence of carbapenem-resistant Klebsiella pneumoniae bloodstream infections: a 8-year retrospective study in a large teaching hospital in northern Italy.
abstract: BACKGROUND
  Bloodstream infections (BSI) due to carbapenem-resistant (C-R) Klebsiella pneumoniae (Kp) are of global concern from both clinical and public health standpoints. This retrospective study aimed to describe C-R Kp BSI epidemiology in a large teaching hospital in northern Italy.
  
  
  METHODS
  Between 1 January 2007 and 31 December 2014, annual incidences both of C-R Kp BSI and of carbapenem-susceptible (C-S) Kp BSI were calculated as the number of events per 10,000 patient-days. A Chi square test for linear trend was used to assess the change in the incidence of C-R Kp BSI and C-S Kp BSI over the study period. Crude 30-day mortality rates were provided both for C-R Kp BSI and for C-S Kp BSI.
  
  
  RESULTS
  From 2007 to 2014, we observed 511 episodes of Kp BSI, 349 of which were caused by C-R Kp (68.3 %). The incidence of C-R Kp BSI considerably increased from 0.04/10,000 patient-days in 2007 to 1.77/10,000 patient-days in 2014 (Chi square for trend p < 0.001). The highest incidence of C-R Kp BSI was observed in intensive care units (ICUs), with a peak of 22.01 C-R Kp BSI/10,000 patient-days in 2012. A less marked but significant increase of C-S Kp BSI was also observed (Chi square for trend p = 0.004). Crude 30-day mortality was 36.1 % in patients with C-R Kp BSI and 23.5 % in those with C-S Kp BSI.
  
  
  CONCLUSIONS
  During the study period, we observed a dramatic increase in the incidence of C-R Kp BSI in our hospital. More concerted infection-control efforts are needed to contain this alarming C-R Kp diffusion.
authors.affiliation: Department of Health Sciences, University of Genoa and Hygiene and Infection Control Unit, IRCCS AOU San Martino-IST teaching Hospital, Genoa, Italy. cristiano.alicino@unige.it.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Alicino
authors.affiliation: Department of Health Sciences, University of Genoa and Infectious Diseases Unit, IRCCS AOU San Martino-IST teaching Hospital, L.go R. Benzi, 10-16132, Genoa, Italy. daniele.roberto.giacobbe@gmail.com.
authors.forename: Daniele Roberto
authors.initials: DR
authors.lastname: Giacobbe
authors.affiliation: Department of Health Sciences, University of Genoa and Hygiene and Infection Control Unit, IRCCS AOU San Martino-IST teaching Hospital, Genoa, Italy. andrea.orsi@unige.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Orsi
authors.affiliation: Department of Health Sciences, University of Genoa and Hygiene and Infection Control Unit, IRCCS AOU San Martino-IST teaching Hospital, Genoa, Italy. fedetassi@ymail.com.
authors.forename: Federico
authors.initials: F
authors.lastname: Tassinari
authors.affiliation: Department of Health Sciences, University of Genoa and Hygiene and Infection Control Unit, IRCCS AOU San Martino-IST teaching Hospital, Genoa, Italy. s2704638@studenti.unige.it.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Trucchi
authors.affiliation: Department of Health Sciences, University of Genoa and Infectious Diseases Unit, IRCCS AOU San Martino-IST teaching Hospital, L.go R. Benzi, 10-16132, Genoa, Italy. 3382907@studenti.unige.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Sarteschi
authors.affiliation: Occupational Medicine Unit, IRCCS AOU San Martino-IST teaching Hospital, Genoa, Italy. francesco.copello@hsanmartino.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Copello
authors.affiliation: Department of Health Sciences, University of Genoa and Infectious Diseases Unit, IRCCS AOU San Martino-IST teaching Hospital, L.go R. Benzi, 10-16132, Genoa, Italy. valerio.delbono@hsanmartino.it.
authors.forename: Valerio
authors.initials: V
authors.lastname: Del Bono
authors.affiliation: Department of Health Sciences, University of Genoa and Infectious Diseases Unit, IRCCS AOU San Martino-IST teaching Hospital, L.go R. Benzi, 10-16132, Genoa, Italy. claudio.viscoli@unige.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Viscoli
authors.affiliation: Department of Health Sciences, University of Genoa and Hygiene and Infection Control Unit, IRCCS AOU San Martino-IST teaching Hospital, Genoa, Italy. icardi@unige.it.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Icardi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D015780:Carbapenems / Q000494:pharmacology*; D005260:Female; D006784:Hospitals, Teaching / Q000706:statistics & numerical data; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007558:Italy / Q000453:epidemiology; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000472:pathogenicity; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D015780:Carbapenems