Association between Timing of Colonization and Risk of Developing Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae Infection in Hospitalized Patients.

Colonization by KPC-producing Klebsiella pneumoniae (KPC-Kp) is associated with the risk of developing KPC-Kp infection. The impact of the time elapsed since a patient becomes colonized on this risk is not well known. An observational, prospective, longitudinal cohort study of colonized patients undergoing active rectal culture screening to rule out KPC-Kp colonization (July 2012 to November 2017). Patients with a positive culture at inclusion (colonized at start of follow-up) and those with a negative culture at inclusion who became colonized within 90 days (colonized during follow-up) were included in the analysis. CART analysis was used to dichotomize variables according to their association with infection. Kaplan-Meier infection-free survival curves and the log-rank test were used for group comparisons. Logistic regression was used to identify variables associated with KPC-Kp infection. Among 1310 patients included, 166 were colonized at the end of follow-up. Forty-seven out of 118 patients colonized at start of follow-up developed infection (39.8%) versus 31 out of 48 patients colonized during follow-up (64.6%; P = 0.006). Variables associated with KPC-Kp infection in the logistic regression analysis were: colonization detection during follow-up (OR, 2.74; 95% CI, 1.07 to 7.04; P = 0.03), Giannella risk score (OR, 1.51; 95% CI, 1.32 to 1.73; P < 0.001), high-risk ward (OR, 4.77; 95% CI, 1.61 to 14.10; P = 0.005) and urological manipulation after admission (OR, 3.69; 95% CI, 1.08 to 12.60; P = 0.04). In 25 out of 31 patients (80.6%) colonized during follow-up who developed KPC-Kp infection, infection appeared within 15 days after colonization. The risk of KPC-Kp infection was higher when colonization is recently acquired during hospitalization. In this prospective study, we concluded that the timing of colonization was a factor to assess when considering empirical treatment for suspected KPC-Kp infection and prophylaxis or infection control. IMPORTANCE In this study, it was confirmed that patients who became colonized during hospitalization had a higher risk of developing KPC-Kp infection than hospitalized patients who were already colonized at the start of follow-up. Besides, the risk of infection in the group of patients who became colonized during follow-up was greater in the first weeks immediately after colonization was confirmed. Our findings support the need for designing preventive strategies for patients at the highest risk of infection development, including those admitted in high-risk hospital wards and those undergoing urological procedures.

Association between rectal colonisation by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae and mortality: a prospective, observational study.

OBJECTIVES: We evaluated the association of Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) rectal colonisation with crude mortality and whether this association is independent of the risk of KPC-Kp infection. METHODS: This was a prospective cohort study of patients followed-up 90 days after a study of rectal colonisation. Cox regression was used to study the variables associated with crude mortality. Sensitivity analyses for 90-day crude mortality in different subcohorts were performed. RESULTS: A total of 1244 patients (1078 non-colonised and 166 colonised) were included. None of the non-colonised patients and 78 (47.0%) of the colonised patients developed KPC-Kp infection. The 90-day crude mortality was 18.0% (194/1078) in non-colonised patients and 41.6% (69/166) in colonised patients. Rectal colonisation was not associated with crude mortality [hazard ratio (HR) = 1.03, 95% confidence interval (CI) 0.69-1.54; P = 0.85] when the model was adjusted for severe KPC-Kp infection [INCREMENT-CPE score (ICS) > 7]. KPC-Kp infection with ICS > 7 was associated with an increased risk of all-cause mortality (HR = 2.21, 95% CI 1.35-3.63; P = 0.002). In the sensitivity analyses, KPC-Kp colonisation was not associated with mortality in any of the analysed subcohorts, including patients who did not develop KPC-Kp infection (HR = 0.93, 95% CI 0.60-1.43; P = 0.74). CONCLUSION: KPC-Kp rectal colonisation was not associated with crude mortality. Mortality increased when colonised patients developed severe KPC-Kp infection (ICS > 7). Rectal colonisation was a necessary although insufficient condition to die from a KPC-Kp infection.

Risks of Infection and Mortality Among Patients Colonized With Klebsiella pneumoniae Carbapenemase-Producing K. pneumoniae: Validation of Scores and Proposal for Management.

Background: The management and indication of empiric treatment in Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp)-colonized patients should be improved. Methods: A prospective cohort of 94 patients colonized by KPC-Kp was followed for 90 days to validate (i) the Giannella risk score (GRS) to predict the development of any type of KPC-Kp infection and (ii) the INCREMENT-CPE score (ICS) to predict 30-day mortality in patients with infection. Both scores were combined to recommend appropriate empiric treatment. The predictive ability of the scores was measured by calculating the area under the receiver operating characteristic (AUROC) curve. Results: The GRS showed an AUROC curve for infection due to KPC-Kp of 0.92 (95% confidence interval [CI], .87-.98). The optimal cutoff point was fixed at <7 and ≥7 (92.9% sensitivity, 84.8% specificity); infection developed in 6.3% patients in the 0-6 GRS group and in 84.8% patient in the ≥7 GRS group. According to the ICS, the severity of the infection was also significantly higher in the ≥7 GRS group. The ICS showed an AUROC of 0.78 (95% CI, .65-.91) for 30-day all-cause mortality among patients with infection. A classification and regression tree analysis confirmed the GRS cutoff point at 7, and selected ≥12 points to predict a KPC-Kp infection with a high ICS. Conclusions: Our results validate the GRS and ICS for indicating empiric therapy in KPC-Kp-colonized patients.