Anne F. Voor in ’t holt

Withdrawal of a novel-design duodenoscope ends outbreak of a VIM-2-producing Pseudomonas aeruginosa

BACKGROUND AND STUDY AIMS Infections are a recognized risk of endoscopic retrograde cholangiopancreatography (ERCP). This paper reports on a large outbreak of VIM-2-producing Pseudomonas aeruginosa that was linked to the use of a recently introduced duodenoscope with a specific modified design (Olympus TJF-Q180V). METHODS Epidemiological investigations and molecular typing were executed in order to identify the source of the outbreak. Audits on implementation of infection control measures were performed. Additional infection control strategies were implemented to prevent further transmission. The design and the ability to clean and disinfect the duodenoscope were evaluated, and the distal tip was dismantled. RESULTS From January to April 2012, 30 patients with a VIM-2-positive P. aeruginosa were identified, of whom 22 had undergone an ERCP using a specific duodenoscope, the TJF-Q180V. This was a significant increase compared with the hospital-wide baseline level of 2 - 3 cases per month. Clonal relatedness of the VIM-2 P. aeruginosa was confirmed for all 22 cases and for the VIM-2 strain isolated from the recess under the forceps elevator of the duodenoscope. An investigational study of the new modified design, including the dismantling of the duodenoscope tip, revealed that the fixed distal cap hampered cleaning and disinfection, and that the O-ring might not seal the forceps elevator axis sufficiently. The high monthly number of cases decreased below the pre-existing baseline level following withdrawal of the TJF-Q180V device from clinical use. CONCLUSIONS Duodenoscope design modifications may compromise microbiological safety as illustrated by this outbreak. Extensive pre-marketing validation of the reprocessability of any new endoscope design and stringent post-marketing surveillance are therefore mandatory.

A systematic review and meta-Analyses show that carbapenem use and medical devices are the leading risk factors for carbapenem- resistant pseudomonas aeruginosa

ABSTRACT A systematic review and meta-analyses were performed to identify the risk factors associated with carbapenem-resistant Pseudomonas aeruginosa and to identify sources and reservoirs for the pathogen. A systematic search of PubMed and Embase databases from 1 January 1987 until 27 January 2012 identified 1,662 articles, 53 of which were included in a systematic review and 38 in a random-effects meta-analysis study. The use of carbapenem, use of fluoroquinolones, use of vancomycin, use of other antibiotics, having medical devices, intensive care unit (ICU) admission, having underlying diseases, patient characteristics, and length of hospital stay were significant risk factors in multivariate analyses. The meta-analyses showed that carbapenem use (odds ratio [OR] = 7.09; 95% confidence interval [CI] = 5.43 to 9.25) and medical devices (OR = 5.11; 95% CI = 3.55 to 7.37) generated the highest pooled estimates. Cumulative meta-analyses showed that the pooled estimate of carbapenem use was stable and that the pooled estimate of the risk factor “having medical devices” increased with time. We conclude that our results highlight the importance of antibiotic stewardship and the thoughtful use of medical devices in helping prevent outbreaks of carbapenem-resistant P. aeruginosa.

Clinical and Molecular Epidemiology of Extended-Spectrum Beta-Lactamase-Producing Klebsiella spp.: A Systematic Review and Meta-Analyses

Healthcare-related infections caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella spp. are of major concern. To control transmission, deep understanding of the transmission mechanisms is needed. This systematic review aimed to identify risk factors and sources, clonal relatedness using molecular techniques, and the most effective control strategies for ESBL-producing Klebsiella spp. A systematic search of PubMed, Embase, and Outbreak Database was performed. We identified 2771 articles from November 25th, 1960 until April 7th, 2014 of which 148 were included in the systematic review and 23 in a random-effects meta-analysis study. The random-effects meta-analyses showed that underlying disease or condition (odds ratio [OR] = 6.25; 95% confidence interval [CI] = 2.85 to 13.66) generated the highest pooled estimate. ESBL-producing Klebsiella spp. were spread through person-to-person contact and via sources in the environment; we identified both monoclonal and polyclonal presence. Multi-faceted interventions are needed to prevent transmission of ESBL-producing Klebsiella spp.

A systematic review and meta-analyses of the clinical epidemiology of carbapenem-resistant enterobacteriaceae

ABSTRACT Carbapenem-resistant Enterobacteriaceae (CRE) are major health care-associated pathogens and responsible for hospital outbreaks worldwide. To prevent a further increase in CRE infections and to improve infection prevention strategies, it is important to summarize the current knowledge about CRE infection prevention in hospital settings. This systematic review aimed to identify risk factors for CRE acquisition among hospitalized patients. In addition, we summarized the environmental sources/reservoirs and the most successful infection prevention strategies related to CRE. A total of 3,983 potentially relevant articles were identified and screened. Finally, we included 162 studies in the systematic review, of which 69 studies regarding risk factors for CRE acquisition were included in the random-effects meta-analysis studies. The meta-analyses regarding risk factors for CRE acquisition showed that the use of medical devices generated the highest pooled estimate (odds ratio [OR] = 5.09; 95% confidence interval [CI] = 3.38 to 7.67), followed by carbapenem use (OR = 4.71; 95% CI = 3.54 to 6.26). To control hospital outbreaks, bundled interventions, including the use of barrier/contact precautions for patients colonized or infected with CRE, are needed. In addition, it is necessary to optimize the therapeutic approach, which is an important message to infectious disease specialists, who need to be actively involved in a timely manner in the treatment of patients with known CRE infections or suspected carriers of CRE.

Antiseptic barrier cap effective in reducing central line-associated bloodstream infections: A systematic review and meta-analysis

BACKGROUND Microorganisms can intraluminally access a central venous catheter via the catheter hub. The catheter hub should be appropriately disinfected to prevent central line-associated bloodstream infections (CLABSIs). However, compliance with the time-consuming manual disinfection process is low. An alternative is the use of an antiseptic barrier cap, which cleans the catheter hub by continuous passive disinfection. OBJECTIVE To compare the effects of antiseptic barrier cap use and manual disinfection on the incidence of CLABSIs. DESIGN Systematic review and meta-analysis. METHODS We systematically searched Embase, Medline Ovid, Web-of-science, CINAHL EBSCO, Cochrane Library, PubMed Publisher and Google Scholar until May 10, 2016. The primary outcome, reduction in CLABSIs per 1000 catheter-days, expressed as an incidence rate ratio (IRR), was analyzed with a random effects meta-analysis. Studies were included if 1) conducted in a hospital setting, 2) used antiseptic barrier caps on hubs of central lines with access to the bloodstream and 3) reported the number of CLABSIs per 1000 catheter-days when using the barrier cap and when using manual disinfection. RESULTS A total of 1537 articles were identified as potentially relevant and after exclusion of duplicates, 953 articles were screened based on title and abstract; 18 articles were read full text. Eventually, nine studies were included in the systematic review, and seven of these nine in the random effects meta-analysis. The pooled IRR showed that use of the antiseptic barrier cap was effective in reducing CLABSIs (IRR=0.59, 95% CI=0.45-0.77, P<0.001). CONCLUSIONS Use of an antiseptic barrier cap is associated with a lower incidence CLABSIs and is an intervention worth adding to central-line maintenance bundles.

Urinary Tract Infections After Kidney Transplantation: A Risk Factor Analysis of 417 Patients

BACKGROUND The aim of this study was to evaluate the number of urinary tract infections (UTI) that occur after kidney transplantation (KT) and to identify possible risk factors for development of a UTI. MATERIAL AND METHODS We retrospectively analyzed all KTs performed between January 2012 and December 2013 in the Erasmus University Medical Center, Rotterdam. UTI was scored if: (1) a patient had a urine culture with no more than 2 species of microorganisms, (2) at least 1 of which was a bacterium of ≥10^5 CFU/mL, (3) which was treated with antibiotics, and (4) which occurred within 3 months after KT. RESULTS A total of 417 patients were transplanted from January 2012 until December 2013. A UTI developed in 115 (28%), after a median of 13 days from transplantation (range: 3-82 days). The most common causative agent was Escherichia coli, followed by Enterococcus faecalis, Enterococcus faecium, and Klebsiella pneumoniae. The variables that were independently related to a UTI were female gender (OR 3.58, 95%CI 2.16-5.91), recipients age >60 y (OR 2.12, 95%CI 1.28-3.48), percutaneous nephrostomy placements (OR 6.29, 95%CI 3.35-11.85), and surgical re-interventions (OR 2.12, 95%CI 1.04-4.32). Mean glomerular filtration rate was significantly lower in the group of patients with a UTI at 3, 6, 9, and 12 months postoperatively compared to those patients who did not have a UTI. CONCLUSIONS We conclude that a UTI after KT is a common problem. We identified independent risk factors for the development of a UTI. UTI is associated with a GFR decrease postoperatively.

Instant Typing Is Essential to Detect Transmission of Extended-Spectrum Beta- Lactamase-Producing Klebsiella Species

Background Infections with multidrug-resistant (MDR) microorganisms are an increasing threat to hospitalized patients. Although rapid typing of MDR microorganisms is required to apply targeted prevention measures, technical barriers often prevent this. We aimed to assess whether extended-spectrum beta-lactamase (ESBL)-producing Klebsiella species are transmitted between patients and whether routine, rapid typing is needed. Methods For 43 months, the clonality of all ESBL-producing Klebsiella isolates from patients admitted to Erasmus MC University Medical Center in Rotterdam, the Netherlands was assessed with Raman spectroscopy. A cluster was defined as n ≥2 patients who had identical isolates. Primary patients were the first patients in each cluster. Secondary patients were those identified with an isolate clonally related to the isolate of the primary patient. Results Isolates from 132 patients were analyzed. We identified 17 clusters, with 17 primary and 56 secondary patients. Fifty-nine patients had a unique isolate. Patients (n = 15) in four out of the 17 clusters were epidemiologically related. Ten of these 15 patients developed an infection. Conclusions Clonal outbreaks of ESBL-producing Klebsiella species were detected in our hospital. Theoretically, after Raman spectroscopy had detected a cluster of n ≥2, six infections in secondary patients could have been prevented. These findings demonstrate that spread of ESBL-producing Klebsiella species occurs, even in a non-outbreak setting, and underscore the need for routine rapid typing of these MDR bacteria.

Reply to Saliou et al.

We thank Saliou and Baron for their comments. They state that microbial surveillance of endoscopes by antegrade sampling with a sterile 0.9 % saline solution might be insufficient to reveal the microbial contamination. They also suggest the additional use of thiosulfate during sampling. Unfortunately, in the outbreak we described, the use of a thiosulfate-containing buffer would not have been able to detect the microbial contamination. As the manufacturer states, the elevator wire channel of the TJF-Q180V is sealed by an O-ring, which means that separate cleaning is no longer necessary. Moreover, this scope is also designed with a unique distal cap that is fixed, which impairs cleaning and disinfection in the spaces within this cap. Sampling of these spaces is only possible when using an ultrathin swab, as demonstrated in our study, which thereby revealed the VIM-2 producing Pseudomonas aeruginosa. However, we do agree with Saliou and Baron that the optimal sampling method for endoscopes is still under debate. At present, the use of sterile 0.9 % saline solution is recommended by the European Society of Gastrointestinal Endoscopy and the European Society of Gastroenterology and Endoscopy Nurses and Associates. Although the French guideline recommends the use of a tensioactive solution (e. g. Tween 80) to increase the detection of microorganisms, the use of sodium thiosulfate is not mentioned in this guideline. The combination of the narrow lumina of the endoscope and heavy contamination with blood, secretions, and microorganisms during its use, might promote the growth of biofilms in cases of insufficient (pre)cleaning. Once these biofilms occur, they are very resilient to physical removal by regular cleaning and are less susceptible to biocides. In a recent review, it was concluded that by ensuring prompt device cleaning and reprocessing, either by high-level disinfection or sterilization, and proper drying, biofilms will not have a chance to form [8]. Unfortunately, at present there is no evidence in the literature that a consensus on this matter has been reached. However, in light of recent reports of microbiological outbreaks after endoscopy, a reliable method of investigating microbial safety following high-level disinfection is urgently needed. The utility of sodium thiosulfate or another biofilm dissolver should be investigated in studies, led, ideally, by an international working group consisting of microbiologists and endoscopists. In addition, a consensus statement concerning the interpretation and action required from the data collected should become available and updated regularly. Saliou and Baron also stress the importance of endoscope drying in order to prevent bacterial proliferation. The importance of drying has been emphasized previously by Muscarella. As stated in our manuscript, at the Erasmus MC all endoscopes are dried and stored in a storage cabinet (WASSENBURG DRY 300; Wassenburg Medical Devices BV, Dodewaard, The Netherlands), unless immediate re-use (within 4 hours) is required. Therefore, bacterial proliferation during storage was not considered to be a possible cause of the VIM-2 producing P. aeruginosa outbreak.