Concordance between epidemiological evaluation of probability of transmission and whole genome sequence relatedness among hospitalized patients acquiring Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae.

OBJECTIVES: We aimed to evaluate the concordance between epidemiologically determined transmission and genetic linkage of Klebsiella pneumoniae carbapenemase (KPC)-producing Klebsiella pneumoniae (KPC-Kp). METHODS: We included consecutive KPC-Kp carriers between December 2016 and April 2017 in a hospital endemic for KPC-Kp. We assessed epidemiological relatedness between patients by prospective investigations by the infection control team. The probability of epidemiological relatedness was classified into four groups: no suspected transmission, low, moderate and high probability of transmission. Whole-genome sequencing of isolates was performed. Genetic linkage between KPC-Kp isolates was expressed by distance between isolates in single nucleotide polymorphisms (SNPs). We established an SNP cut-off defining a different strain based on the reconstructed phylogenetic tree. We compared the epidemiological and genetic linkage of all isolates from all patients. RESULTS: The study included 25 KPC-Kp carriers with 49 isolates. SNP variance was available for 1129 crossed patient-isolate pairs. Genomic linkage, based on a cut-off of 80 SNPs to define related isolates, was found in 115/708 (16.2%) of isolates with no transmission suspected epidemiologically, 27/319 (8.5%) of low, 11/26 (42.3%) of moderate and 64/76 (84.2%) of high epidemiological transmission risk determination (p < 0.001 for trend). Similar results and significant trends were shown on sensitivity analyses using a lower SNP cut-off (six SNPs) and patient-isolate unique pairs, analysing the first isolate from each patient. CONCLUSIONS: While significant concordance between epidemiological and genomic transmission patterns was found, epidemiological investigations of transmission are limited by the possibility of unidentified transmissions or over-estimation of associations. Genetic linkage analysis is an important aid to epidemiological transmission assessment.

Correction to: Reducing surgical site infections following total hip and knee arthroplasty: an Israeli experience.

In the original article, one of the co-author's family name has been published incorrectly.

The association between infection control interventions and carbapenem-resistant Enterobacteriaceae incidence in an endemic hospital.

BACKGROUND: Israel experienced a national outbreak of carbapenem-resistant Enterobacteriaceae (CRE) starting in 2006. AIM: To assess the association between infection control (IC) interventions implemented in a referral hospital in Israel and CRE incidence. METHODS: Retrospective quasi-experimental study of prospectively collected data. CRE incidence, defined as the number of patients newly acquiring CRE in surveillance or clinical samples per 100,000 hospital-days, was plotted quarterly between 2005 and 2016. IC interventions were applied at different time-points throughout this period. Data were collected on IC staffing, number of rectal surveillance cultures, and carbapenem consumption. Autocorrelated segmented linear regression analysis was used to assess the time-points at which a significant change in the CRE incidence trend occurred, and the association between the timing of IC intervention implementation and observed CRE trends was assessed. Trends between time-points were expressed as quarterly percent change (QPC) with 95% confidence intervals (CIs). FINDINGS: Between 2005 and 2008, CRE incidence increased significantly (QPC: 19.7%; CI: 11.5-28.4), reaching a peak of 186.6 new acquisitions per 100,000 hospital-days. From mid-2011 until the end of follow-up, there was a significantly decreasing incidence trend (QPC: -4.5; CI: -6.4 to -2.5). Cohorting of patients, screening of contacts and high-risk patients on admission were insufficient to control the epidemic. Improved hand hygiene compliance, cohorting with dedicated nursing staff, addition of regular screening in high-risk departments, and carbapenem restriction were required. Decreasing CRE incidence was observed with an infectious diseases/IC staffing of 1.2-1.5 per 100 beds and 20,000-36,000 yearly CRE surveillance samples. CONCLUSION: A multi-faceted hospital-wide intervention programme is required to control CRE in hospital settings.

Reducing surgical site infections following total hip and knee arthroplasty: an Israeli experience.

PURPOSE: To assess the changes observed in surgical site infection (SSI) rates following total joint arthroplasty (TJA) after the introduction of an infection control programme and evaluate the risk factors for the development of these infections. DESIGN: Prospective cohort study. SETTING: Large tertiary medical centre in Israel. METHODS: Data about SSIs and potential prophylaxis-, patient-, and procedure-related risk factors were collected for all patients who underwent elective total hip and total knee arthroplasty during the study period. Multivariant analyses were conducted to determine which significant covariates affected the outcome. RESULTS: During the 76-month study period, SSIs (superficial and deep) occurred in 64 (4.4%) of 1554 patients. As compared with the 34 (7.7%) SSIs that occurred in the first 25 months, there were 23 (4.7%) SSIs in the following 25 months, and only 7 (1.3%) SSIs in the last third of the study (p = 0.058 and <0.001, respectively). A multiple logistic regression model indicated that risk factors for prosthetic joint infection were a National Nosocomial Infections Surveillance (NNIS) System surgical patient risk index score of 1 (OR 1.8; 95% CI 1.1-3.1) or 2 (OR 2.8; 95% CI 1.2-11.8). The incidence of SSI was not correlated with the timing, nor the duration of antibiotic prophylaxis. CONCLUSIONS: The introduction of preventive measures and surveillance coincided with a significant reduction in SSIs following TJA in our institution. The risk of infection correlated with higher scores in the NNIS System surgical patient risk.

Detection and characterization of carbapenemase-producing Enterobacteriaceae in wounded Syrian patients admitted to hospitals in northern Israel.

Since 2013, four hospitals in northern Israel have been providing care for Syrian nationals, primarily those wounded in the ongoing civil war. We analyzed carbapenemase-producing Enterobacteriaceae (CPE) isolates obtained from these patients. Isolate identification was performed using the VITEK 2 system. Polymerase chain reaction (PCR) was performed for the presence of bla KPC, bla NDM, and bla OXA-48. Susceptibility testing and genotyping were performed on selected isolates. During the study period, 595 Syrian patients were hospitalized, most of them young men. Thirty-two confirmed CPE isolates were grown from cultures taken from 30 patients. All but five isolates were identified as Klebsiella pneumoniae and Escherichia coli. Nineteen isolates produced NDM and 13 produced OXA-48. Among a further 29 isolates tested, multilocus sequence typing (MLST) showed that ST278 and ST38 were the major sequence types among the NDM-producing K. pneumoniae and OXA-48-producing E. coli isolates, respectively. Most were resistant to all three carbapenems in use in Israel and to gentamicin, but susceptible to colistin and fosfomycin. The source for bacterial acquisition could not be determined; however, some patients admitted to different medical centers were found to carry the same sequence type. CPE containing bla NDM and bla OXA-48 were prevalent among Syrian wounded hospitalized patients in northern Israel. The finding of the same sequence type among patients at different medical centers implies a common, prehospital source for these patients. These findings have implications for public health throughout the region.