Jean-Christophe Lucet

High Rate of Acquisition but Short Duration of Carriage of Multidrug-Resistant Enterobacteriaceae After Travel to the Tropics

BACKGROUNDnMultidrug-resistant Enterobacteriaceae (MRE) are widespread in the community, especially in tropical regions. Travelers are at risk of acquiring MRE in these regions, but the precise extent of the problem is not known.nnnMETHODSnFrom February 2012 to April 2013, travelers attending 6 international vaccination centers in the Paris area prior to traveling to tropical regions were asked to provide a fecal sample before and after their trip. Those found to have acquired MRE were asked to send fecal samples 1, 2, 3, 6, and 12 months after their return, or until MRE was no longer detected. The fecal relative abundance of MRE among all Enterobacteriaceae was determined in each carrier.nnnRESULTSnAmong 824 participating travelers, 574 provided fecal samples before and after travel and were not MRE carriers before departure. Of these, 292 (50.9%) acquired an average of 1.8 MRE. Three travelers (0.5%) acquired carbapenemase-producing Enterobacteriaceae. The acquisition rate was higher in Asia (142/196 [72.4%]) than in sub-Saharan Africa (93/195 [47.7%]) or Latin America (57/183 [31.1%]). MRE acquisition was associated with the type of travel, diarrhea, and exposure to β-lactams during the travel. Three months after return, 4.7% of the travelers carried MRE. Carriage lasted longer in travelers returning from Asia and in travelers with a high relative abundance of MRE at return.nnnCONCLUSIONSnMRE acquisition is very frequent among travelers to tropical regions. Travel to these regions should be considered a risk factor of MRE carriage during the first 3 months after return, but not beyond.nnnCLINICAL TRIALS REGISTRATIONnNCT01526187.

Sternal wound infection after cardiac surgery: incidence and risk factors according to clinical presentation

The incidence of surgical site infection (SSI) after cardiac surgery depends on the definition used. A distinction is generally made between mediastinitis, as defined by the US Centers for Disease Control and Prevention (CDC), and superficial SSI. Our objective was to decipher these entities in terms of presentation and risk factors. We performed a 7-year single centre analysis of prospective surveillance of patients with cardiac surgery via median sternotomy. SSI was defined as the need for reoperation due to infection. Among 7170 patients, 292 (4.1%) developed SSI, including 145 CDC-defined mediastinitis (CDC-positive SSI, 2.0%) and 147 superficial SSI without associated bloodstream infection (CDC-negative SSI, 2.1%). Median time to reoperation for CDC-negative SSI was 18 days (interquartile range, 14-26) and 16 (interquartile range, 11-24) for CDC-positive SSI (p 0.02). Microorganisms associated with CDC-negative SSI were mainly skin commensals (62/147, 41%) or originated in the digestive tract (62/147, 42%); only six were due to Staphylococcus aureus (4%), while CDC-positive SSI were mostly due to S. aureus (52/145, 36%) and germs from the digestive tract (52/145, 36%). Risk factors for SSI were older age, obesity, chronic obstructive bronchopneumonia, diabetes mellitus, critical preoperative state, postoperative vasopressive support, transfusion or prolonged ventilation and coronary artery bypass grafting, especially if using both internal thoracic arteries in female patients. The number of internal thoracic arteries used and factors affecting wound healing were primarily associated with CDC-negative SSI, whereas comorbidities and perioperative complications were mainly associated with CDC-positive SSI. These 2 entities differed in time to revision surgery, bacteriology and risk factors, suggesting a differing pathophysiology.

Hand Hygiene, Cohorting, or Antibiotic Restriction to Control Outbreaks of Multidrug-Resistant Enterobacteriaceae

BACKGROUNDnThe best strategy for controlling extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) transmission in intensive care units (ICUs) remains elusive.nnnOBJECTIVEnWe developed a stochastic transmission model to quantify the effectiveness of interventions aimed at reducing the spread of ESBL-PE in an ICU.nnnMETHODSnWe modeled the evolution of an outbreak caused by the admission of a single carrier in a 10-bed ICU free of ESBL-PE. Using data obtained from recent muticenter studies, we studied 26 strategies combining different levels of the following 3 interventions: (1) increasing healthcare worker compliance with hand hygiene before and after contact with a patient; (2) cohorting; (3) reducing antibiotic prevalence at admission with or without reducing antibiotherapy duration.nnnRESULTSnImproving hand hygiene compliance from 55% before patient contact and 60% after patient contact to 80% before and 80% after patient contact reduced the nosocomial incidence rate of ESBL-PE colonization by 91% at 90 days. Adding cohorting to hand hygiene improvement intervention decreased the proportion of ESBL-PE acquisitions by an additional 7%. Antibiotic restriction had the lowest impact on the epidemic. When combined with other interventions, it only marginally improved effectiveness, despite strong hypotheses regarding antibiotic impact on transmission.nnnCONCLUSIONnOur results suggest that hand hygiene is the most effective intervention to control ESBL-PE transmission in an ICU.

Influence of Staff Behavior on Infectious Risk in Operating Rooms: What Is the Evidence?

SUMMARY A systematic literature review was performed to assess the impact of surgical-staff behaviors on the risk of surgical site infections. Published data are limited, heterogeneous, and weakened by several methodological flaws, underlying the need for more studies with accurate tools. OBJECTIVE To assess the current literature regarding the impact of surgical-staff behaviors on the risk of surgical-site infection (SSI). DESIGN Systematic literature review. METHODS We searched the Medline, EMBASE, Ovid, Web of Science, and Cochrane databases for original articles about the impact of intraoperative behaviors on the risk of SSI published in English before September 2013. RESULTS We retrieved 27 original articles reporting data on number of people in the operating room (n=14), door openings (n=14; number [n=6], frequency [n=7], reasons [n=4], or duration [n=3]), surgical-team discipline (evidence of distraction; n=4), compliance with traffic measures (n=6), or simulated behaviors (n=3). Most (59%) articles were published in 2009-2013. End points were the 30-day SSI rate (n=8), air-particle count (n=2), or microbiological air counts (n=6); 11 studies were only descriptive. Number of people in the operating room and SSI rate or airborne contaminants (particle/bacteria) were correlated in 2 studies. Door openings and airborne bacteria counts were correlated in 2 observational studies and 1 experimental study. Two cohort studies showed a significant association between surgeon interruptions/distraction or noise and SSI rate. The level of evidence was low in all studies. CONCLUSIONS Published data about the impact of operating-room behaviors on the risk of infection are limited and heterogeneous. All studies exhibit major methodological flaws. More studies with accurate tools should be performed to address the influence of operating room behaviors on the infectious risk.

Air contamination for predicting wound contamination in clean surgery: A large multicenter study

BACKGROUNDnThe best method to quantify air contamination in the operating room (OR) is debated, and studies in the field are controversial. We assessed the correlation between 2 types of air sampling and wound contaminations before closing and the factors affecting air contamination.nnnMETHODSnThis multicenter observational study included 13 ORs of cardiac and orthopedic surgery in 10 health care facilities. For each surgical procedure, 3 microbiologic air counts, 3 particles counts of 0.3, 0.5, and 5xa0μm particles, and 1 bacteriologic sample of the wound before skin closure were performed. We collected data on surgical procedures and environmental characteristics.nnnRESULTSnOf 180 particle counts during 60 procedures, the median log10 of 0.3, 0.5, and 5xa0μm particles was 7 (interquartile range [IQR], 6.2-7.9), 6.1 (IQR, 5.4-7), and 4.6 (IQR, 0-5.2), respectively. Of 180 air samples, 50 (28%) were sterile, 90 (50%) had 1-10xa0colony forming units (CFU)/m(3) and 40 (22%) >10xa0CFU/m(3). In orthopedic and cardiac surgery, wound cultures at closure were sterile for 24 and 9 patients, 10 and 11 had 1-10 CFU/100 cm(2), and 0 and 6 had >10 CFU/100 cm(2), respectively (P < .01). Particle sizes and a turbulent ventilation system were associated with an increased number of air microbial counts (Pxa0<xa0.001), but they were not associated with wound contamination (Pxa0=xa0.22).nnnCONCLUSIONSnThis study suggests that particle counting is a good surrogate of airborne microbiologic contamination in the OR.

Overcoming the obstacles of implementing infection prevention and control guidelines

Reasons for a successful or unsuccessful implementation of infection prevention and control (IPC) guidelines are often multiple and interconnected. This article reviews key elements from the national to the individual level that contribute to the success of the implementation of IPC measures and gives perspectives for improvement. Governance approaches, modes of communication and formats of guidelines are discussed with a view to improve collaboration and transparency among actors. The culture of IPC influences practices and varies according to countries, specialties and healthcare providers. We describe important contextual aspects, such as relationships between actors and resources and behavioural features including professional background or experience. Behaviour change techniques providing goal-setting, feedback and action planning have proved effective in mobilizing participants and may be key to trigger social movements of implementation. The leadership of international societies in coordinating actions at international, national and institutional levels using multidisciplinary approaches and fostering collaboration among clinical microbiology, infectious diseases and IPC will be essential for success.

Enterobacteriaceae bacteremia: risk factors for ESBLPE.

OBJECTIVESnThe increasing prevalence of extended spectrum beta-lactamase producing enterobacteriaceae (ESBLPE) requires defining the use of carbapenems in first intention. We analyzed the associations between enterobacteriaceae bacteremia (EbBact) and ESBLPE carriage during 10 years in a 950-bed teaching hospital.nnnMETHODSnWe analyzed a 10-year (July 2001 to June 2011) prospective collection of bacteremia cases including 2 databases: (1) EbBact and (2) a computerized database of patients carrying EBLSE. Only one episode of EbBact was analyzed per patient and hospital stay. Factors associated with ESBLPE bacteremia were assessed by univariate and multivariate logistic regression analysis.nnnRESULTSnOverall, 2355 cases of EbBact were identified, among which 135 (5.7%) were ESBLPE (2001-05: 1.4%, 2006-09: 7.6%, 2010-11: 14.2%). ESBLPE bacteremia was observed in 52 of the 88 (59%) patients carrying ESBLPE and in 83/2267 (3.7%) patients not known to be colonized with ESBLPE. Factors associated with ESBLPE bacteremia in patients not known to be colonized were: female gender (ORa=0.56, CI95% [0.34-0.91]), hospitalization in the ICU (ORa=2.51 [1.27-5.05]) or medical/surgical wards (ORa=1.83 [1.04-3.38]), the period (2006-09, ORa=4.08 [2.21-8.16]; 2010-11, ORa=8.17 [4.14-17.06] compared to 2001-05), and history of EbBact (ORa=2.29 [0.97-4.79]).nnnCONCLUSIONnIn case of EbBact, patients known to be colonized with ESBLPE present with ESBLPE bacteremia in more than half of the cases, requiring carbapenems as empirical antibiotic treatment. The global prevalence of ESBLPE among patients presenting with EbBact not known to be colonized with ESBLPE was 3.7%.

Reply to Collignon and Kennedy.

TO THE EDITOR—We read with interest the correspondence from Collignon and Kennedy [1] regarding the duration of carriage of resistant bacteria after travelers return from tropical regions. The authors discussed the divergence in duration using a study they published in 2010 [2] and the VOYAG-R study [3]. While the overall design of both studies is similar, some key points are not. Importantly, we considered multidrug-resistant Enterobacteriaceae (MRE) to be those that produced an extended-spectrumbeta-lactamase (ESBL), a plasmid-encoded cephalosporinase (pAmpC), and/or a carbapenemase [4]. In the Kennedy and Collignon study, an “antibiotic-resistant Escherichia coli” was defined as an E. coli resistant to 1 or more of the following antibiotics: gentamicin, third-generation cephalosporin (3GC), or ciprofloxacin [2]. Kennedy and Collignon found that 25.5% (26/102) of travelers acquired a 3GC-resistant E. coli (producing an ESBL or a pAmpC, thus fitting the definition of MRE that we chose). As mentioned by the authors, the clearance of those bacteria was fast, with only 1 traveler (1.0%, 1/102) still carrying a 3GC-resistant E. coli 3 months after return, which is close to the pretravel baseline prevalence they observed (2%, 2/102) [2] and even lower than what we found (4.7%, 24/515) [3]. Thus, when using the same definition for MRE, we believe that our results in terms of MRE carriage are similar. Furthermore, Collignon and Kennedy pointed at the follow-up of MRE carriage after return exclusively among the travelers who acquired an MRE (10.3% [24/233], 4.8% [11/230], and 2.2% [5/227] at 3, 6, and 12 months, respectively) [1], while we considered it more relevant to draw clinical conclusions based on all travelers (4.7% [24/515], 2.1% [11/512], and 1.0% [5/509] at 3, 6, and 12 months, respectively) [3]. We deemed it reasonable to assume that within 3 months after returning from a tropical region, one should be considered as a potential MRE carrier, but not beyond that time frame. This assumption is supported by the study of a large number of included travelers and by the use of sensitive microbiological methods. We are aware that the clearance of MRE varied in our study according to the area visited; 10.7% of travelers from Asia (18/168) were still carrying an MRE 3 months after return (and 4.8% [8/165] at 6 months). Nonetheless, we believe our message can be helpful to build a framework for the medical management of infected patients who return from tropical areas with no exposure to a healthcare institution abroad. As mentioned by Collignon and Kennedy, our conclusion may not be extended to specific situations such as carriage of fluoroquinolone-resistant Enterobacteriaceae and invasive procedures, but we are confident that our conclusion does apply to MRE.

O-03: Prise en charge des infections sternales après chirurgie cardiaque

Introduction – objectifs L’infection sternale (IS) est une complication severe en chirurgie cardiaque. Son traitement chirurgical en un temps par debridement avec drainage sur drains de Redon (DR) a montre son efficacite. Cependant, il n’existe pas de donnees sur la gestion des DR et de l’antibiotherapie (AB). L’objectif est de decrire ces IS et leur prise en charge. Materiels et methodes Nous avons realise une analyse retrospective monocentrique des patients reoperes entre 2009 et 2012 pour une suspicion d’IS post chirurgie cardiaque, confirmee lors de la reprise. Tous les patients ont eu un drainage par DR. Une analyse bacteriologique du liquide des DR etait realisee 2/semaine et les DR etaient mobilises apres au moins 3 cultures consecutives negatives et 2 semaines de drainage. Ont ete recueillis les donnees bacteriologiques, l’antibiotherapie, la gestion des DR et l’evolution. La severite etait par ailleurs evaluee selon les criteres CDC (CDC+ definissant une mediastinite, ou CDC-). Resultats Sur 160 patients avec IS, 143 patients non decedes precocement et sans endocardite ont ete inclus : 84 (59 %) CDC+, 59 (41 %) CDC–. Une documentation microbiologique a ete obtenue dans 137 cas (96 %) : 33 (23 %) polymicrobiens et 44 (31 %) responsables de bacteriemie. Les principaux germes (nxa0=xa0162) etaient : 70 (49 %) staphylocoques a coagulase negative, 46 (32 %) enterobacteries, 30 (20 %), S. aureus (parmi lesquels 23 (77 %) meti-S). L’AB et la gestion des DR sont illustrees dans le tableau. La duree mediane d’hospitalisation etait de 25 jours (IQR 20–35) dans les 2 groupes (CDC+ et CDC-). La mortalite hospitaliere etait de 8 % (11/143) : 11 % (9/84) pour les CDC+ et 3 % (2/59) pour les CDC- (pxa0=xa00,101). Conclusion La prise en charge des IS necessite d’etre mieux codifiee. La gestion des DR et AB entre CDC+ et CDC- est tres proche alors que leur physiopathologie et prise en charge chirurgicale sont differentes. La duree du drainage notamment etait similaire entre CDC+ et CDC-, souvent prolongee, et possiblement a l’origine de complications. Tableau : abstract O-03 Mediane (IQR) ou n (%) DC + (nxa0=xa084) DC – (nxa0=xa059) P Nombre de DR 5 (3–6) 3 (2–4) Delai de negativation des cultures de DR 6 (3–10) 7 (5–12) 0,25 Delai d’ablation des DR 20 (18–24) 20 (17–22) 0,50 Duree d’AB intraveineuse 20 (14–27) 16 (7–21) 0,07 Duree de bi-AB 28 (18–42) 20 (5–27) 0,002 Duree totale d’AB 40 (28–43) 31 (22–38) 0,06 Colonisation secondaire des DR 31 (37 %) 16 (27 %) 0,22 Surinfection (n, %) 11 (13 %) 5 (11 %) 0,39 2 e reprise pour surinfection 13 (15 %) 12 (20 %) 0,45