Risk factors for bacteriuria with carbapenem-resistant Klebsiella pneumoniae and its impact on mortality: a case-control study.

BACKGROUND: The objective of this study was to evaluate the mortality of and risk factors for bacteriuria due to carbapenem-resistant Klebsiella pneumoniae (CRKp) versus carbapenem-susceptible K. pneumoniae (CSKp) producing extended spectrum ß lactamase (ESBL). METHODS: This was a retrospective case-control study in which 135 case-patients with bacteriuria due to CRKp were compared with 127 control patients with CSKp producing ESBL. In a first step, multivariate Cox regression and Kaplan-Meier survival analysis models were used to determine the difference in mortality between the two groups and risk factors for mortality. In a second step, a univariate analysis was used to identify risk factors for CRKp colonization. RESULTS: There were no significant demographic or clinical differences between the groups. In-hospital mortality in the study and control groups was 29 and 25 %, respectively (non-significant difference). Multivariate analysis revealed that the most important risk factor for mortality in both groups was being bed ridden [hazard ratio 2.2, 95 % confidence interval (CI) 1.23-3.93; P = 0.008]. Patients with CRKp bacteriuria had a longer hospitalization time with a mean ± standard deviation of 28 ± 33 days compared to 22 ± 28 days in the control group (P < 0.05). Several univariate risk factors for acquiring CRKp bacteriuria were identified: antibiotic use [odds ratio (OR) 1.93, 95 % CI 1.18-3.17, p = 0.008], especially colistin (OR 2.04, 95 % CI 1.04-4.02; P = 0.036), presence of a urinary catheter (OR 2.09, 95 % CI 1.2-3.63; P = 0.008), surgery (OR 3.94, 95 % CI 1.85-8.37; P = 0.0002), invasive procedures (OR 3.06, 95 % CI 1.61-5.8; P = 0.0004), and intensive care unit admission (OR 2.49, 95 % CI 1.18-5.37; P = 0.015). CONCLUSION: Bacteriuria caused by CRKp as compared that caused by CSKp was not found to be a risk factor for death.

Improving implementation of infection control guidelines to reduce nosocomial infection rates: pioneering the report card.

BACKGROUND: Two detailed checklists were developed, based on published infection control guidelines, for daily use by infection control practitioners in departments and operating rooms. AIM: To assess the impact of the checklists on nosocomial infection rates in three hospitals over the course of one year. METHODS: The checklists included 20 subheadings (± 150 items). Project nurses conducted rounds in the study (but not control) departments; during each round, the nurses selected 15-20 items for observation, marked the checklists according to appropriateness of observed behaviour and provided on-the-spot corrective education. Rates of adherence to the checklist, antibiotic use, number of obtained and positive cultures, and positive staff hand and patient environment cultures were reported monthly as a report card to relevant personnel and administrators. The rate of nosocomial infections was determined in the first and last months. RESULTS: The baseline nosocomial infection rate was similar in the study and control departments: 37/345 (11%) and 26/270 (10%) respectively. In the last month, the rate in the study department decreased to 16/383 (4%) (P<0.01); in the control it decreased insignificantly to 21/248 (8%) (not significant). No significant trends were detected in the number of obtained cultures, positive cultures, or antibiotic use. Adherence to guidelines ranged from 75% to 94% between the hospitals (P<0.001): the overall rate increased from 80% to 91% (P<0.01). CONCLUSIONS: The use of checklists during the conduct of infection control rounds, combined with monthly reports, was associated with a significant decrease in nosocomial infections in study departments.

Carriage rate of carbapenem-resistant Klebsiella pneumoniae in hospitalised patients during a national outbreak.

During a national outbreak of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Israel, we conducted a point prevalence survey to determine the extent of asymptomatic carriage. Subsequently, a retrospective case-control study was done, comparing carriers of CRKP with non-carriers, in order to detect risk factors for carriage. Oral, perianal and rectal swabs were obtained from all hospitalised eligible and consenting patients. Selective media for carbapenem-resistant Gram-negative bacteria were used and pulsed-field gel electrophoresis (PFGE) helped to determine clonal source. Culture was obtained from 298 patients. Sixteen (5.4%) were carriers of CRKP, with a higher carriage rate in medical and surgical wards. Only 18% of carriers were treated with any carbapenem prior to the survey. Five of the 16 carriers had a positive clinical specimen for CRKP, hence a clinical infection versus asymptomatic carriage ratio of 1:3. The rectum was the most sensitive site sampled, detecting 15/16 carriers, and the overall sensitivity of the method was 94% with a negative predictive value of 99.6%. In a multivariate analysis of risk factors for CRKP carriage, three variables were significantly related to carriage state: diaper use, longer duration of hospital stay and vancomycin use. PFGE demonstrated that all 16 isolates were identical, confirming clonal origin. A point prevalence survey performed at a single medical centre during an outbreak of CRKP demonstrated a carriage rate of 5.4%. The clonal origin of these isolates suggests that strict adherence to isolation procedure may contain this outbreak.