Burden of gastroenteritis outbreaks: specific epidemiology in a cohort of institutions caring for dependent people.

BACKGROUND: In institutions caring for dependent people, viral gastroenteritis occurs frequently and is highly contagious. In elderly persons, these episodes can lead to hospitalization and occasionally death. AIM: To study the impact of gastroenteritis outbreaks (GOs) in institutions caring for dependent people. METHODS: This study was conducted on 18 sites consisting of 35 units from four different disciplines (geriatric medicine and rehabilitation, psychogeriatrics, geriatric nursing homes, and specialized care homes for adults with physical and mental disabilities). Spatio-temporal analysis of GOs was performed during six winter seasons, and clinical and viral data were analysed with regard to structural parameters (size of the sites and dining-room organization), virus epidemiology and chronology of the outbreaks and type of activities. RESULTS: A total of 98 outbreaks were recorded in the 35 units. The risk of GO was high even outside national epidemic periods. Viruses were searched for in 86 outbreaks and were identified in 96.5% (83/86) of these outbreaks: norovirus genotype GII.4 (59.0%, 49/83), other viruses (41.0%, 34/83). There were variations between surveillance periods in terms of GO frequencies and attack rates and types of viruses. Dining-room organization could be a factor in cross-infection at a site. CONCLUSION: Specific surveillance that takes into account the precise epidemiology needs to be developed in institutions caring for dependent people in order to improve infectious disease control and information for healthcare workers.

Acquisition of carbapenem-resistant Gram-negative bacilli in intensive care unit: predictors and molecular epidemiology.

OBJECTIVES: We had for aim to determine the risk factors for acquiring carbapenem-intermediate or -resistant Gram-negative bacilli (CR-GNB) in an intensive care unit (ICU) and to identify the resistance mechanisms involved. PATIENTS AND METHODS: We conducted an observational prospective cohort study during 6 months in medical and surgical ICUs of the Besançon Teaching Hospital. Patients with acquired CR-GNB were patients whose cultures (screening or diagnosis) became positive more than 48h after admission to the ICU. The risk factors for ICU-acquired CR-GNB were determined by multivariate logistic regression. CR-GNB isolates were typed by pulsed-field gel electrophoresis (PFGE) and screened for resistance mechanisms with phenotypic and genotypic tests. RESULTS: Twenty-three of the 347 included patients had acquired a CR-GNB. The multivariate analysis revealed significant associations between this acquisition and the duration of previous treatments with piperacillin-tazobactam (adjusted odds ratio [aOR], 1.13, P=0.02) and aminoglycosides (aOR, 1.62; P=0.005), but not with carbapenems. The CR-GNB strains were identified as Pseudomonas aeruginosa (n=10), Stenotrophomonas maltophilia (n=7), and Enterobacter cloacae (n=6). No acquired carbapenemase-producing strain was identified. PFGE typing identified 1 multiple clone among P. aeruginosa isolates (4 patients), whereas for the other bacteria, all the strains were different. CONCLUSION: Our study results suggest that the strategy to prevent the emergence and spread of CR-GNB should not be limited to the sole restriction of carbapenem use in ICU settings.

Risk factors for Pseudomonas aeruginosa acquisition in intensive care units: a prospective multicentre study.

BACKGROUND: Pseudomonas aeruginosa is a major nosocomial pathogen in intensive care units (ICUs); however, endogenous versus exogenous origin of contamination remains unclear. AIM: To identify individual and environmental ICU risk factors for P. aeruginosa acquisition. METHODS: A five-month prospective multicentric study was performed in ten French ICUs. Adult patients hospitalized in ICU for ≥ 24 h were included and screened for P. aeruginosa colonization on admission, weekly and before discharge. P. aeruginosa acquisition was defined by a subsequent colonization or infection if screening swabs on admission were negative. Water samples were obtained weekly on water taps of the ICUs. Data on patient characteristics, invasive devices exposure, antimicrobial therapy, P. aeruginosa water and patient colonization pressures, and ICU characteristics were collected. Hazard ratios (HRs) were estimated using multivariate Cox model. FINDINGS: Among the 1314 patients without P. aeruginosa on admission, 201 (15%) acquired P. aeruginosa during their ICU stay. Individual characteristics significantly associated with P. aeruginosa acquisition were history of previous P. aeruginosa infection or colonization, cumulative duration of mechanical ventilation and cumulative days of antibiotics not active against P. aeruginosa. Environmental risk factors for P. aeruginosa acquisition were cumulative daily ward 'nine equivalents of nursing manpower use score' (NEMS) [hazard ratio (HR): 1.47 for ≥ 30 points; 95% confidence interval (CI): 1.06-2.03] and contaminated tap water in patient's room (HR: 1.76; CI: 1.09-2.84). CONCLUSION: Individual risk factors and environmental factors for which intervention is possible were identified for P. aeruginosa acquisition.

[Fungal and bacterial contamination of 30 general practitioners' consultation room in Franche-Comté (eastern France)]. / Contamination fongique et bactérienne de 30 salles de consultation de cabinets médicaux en Franche-Comté

OBJECTIVE: To evaluate the level of microbial contamination of general pratice environment. METHODS: Ten points, including air, water and surfaces were sampled in general practitioner's consultation room of 30 general practices in Franche-Comté region (eastern France). For each sample, a global microbial count was assessed as well as the presence of potential pathogen microorganisms: Aspergillus fumigatus, Staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacteriaceae. RESULTS: We note that 66.3% of the samples (n=202) were on the target level (<51 ufc/25 cm (2), <101 ufc/m(3), <100 ufc/mL in total bacteria, without pathogenic species and without A. fumigatus respectively on surfaces, air and water, without isolation of coliforme bacteria or P. aeruginosa for 100mL of water). A. fumigatus, S. aureus, P. aeruginosa and Enterobacteriaceae were recovered in 8.0%, 2.1%, 0.7%, 0% respectively. However, 66.7% of air sampling were positive to A. fumigatus with 2 to 12 cfu/m(3). CONCLUSION: This study shows a low level of bacterial contamination of general practitioner's consultation room. A. fumigatus frequency in air samples seems equivalent to that found in housing without air treatment.

Hospital cross-transmission of extended-spectrum ß-lactamase producing Escherichia coli and Klebsiella pneumoniae.

OBJECTIVES: We had for objective to measure the incidence and the clonal diversity of Escherichia coli and Klebsiella pneumoniae producing extended-spectrum ß-lactamases (ESBL) in order to assess the role of patient stay in amplification of the phenomenon, in our teaching hospital. MATERIAL AND METHODS: We measured the quarterly incidence rates of E. coli and K. pneumoniae producing or not producing ESBL in clinical samples between 1999 and 2010. The incidence of ESBL-producing isolates was season-adjusted. We determined the pulsotype of and identified the ESBL in all non-redundant strains isolated between 2009 and 2010. RESULTS: The incidence for 1000 hospitalization days increased from 0.00 to 0.44 for ESBL-producing E. coli, from 0.012 to 0.24 for ESBL-producing K. pneumoniae, from 1999 to 2010. Fifty-three different clones of E. coli were identified among the 61 genotyped isolates. The 28 K. pneumoniae isolates genotyped clustered into 11 different clones, among which one major epidemic clone that included 18 isolates. Respectively 66 and 75% of E. coli and K. pneumoniae isolates produced a CTX-M group 1 ESBL. CONCLUSION: The hospital seems to play a different role in the amplification of ESBL according to the producing species (K. pneumoniae or E. coli). ESBL-producing E. coli seem to have a limited cross-transmission within the hospital and seem to be added to non-producers. Conversely, ESBL-producing K. pneumoniae seem to be cross-transmitted within the hospital and to replace non-producers.

Antibiotic prescription in nursing homes for dependent elderly people: a cross-sectional study in Franche-Comté.

OBJECTIVES: We had for objective to determine the rate of patients treated with antibiotics and the determinants of antibiotic stewardship in nursing homes for dependent elderly people (French acronym EHPAD), of a French region (Franche-Comté). PATIENTS AND METHODS: A representative sample of EHPAD, in Franche-Comté, was included in a cross-sectional study made between April and June 2012. An external auditor and the EHPAD head physician collected data on the facility and on residents receiving antibiotics on the study day. An infectious diseases specialist and an infection control practitioner analyzed each prescription, a posteriori, to assess criteria of antimicrobial stewardship including re-assessment of the prescription between 48 and 72h after initiation of antibiotic treatment. RESULTS: Sixty-one (2.76%) of the 2210 residents in 18 nursing homes were under antibiotic treatment. This rate ranged from 0% to 7.5% among nursing homes. Sixty-two percent of prescriptions complied with recommendations regarding the choice of the drug, and 41.5% could not be improved by choosing an agent with a weaker ecological impact. Globally, 17.8% of prescriptions met all stewardship criteria including re-assessment of the prescription between 48 and 72h after initiation of antibiotic treatment. CONCLUSIONS: The study results differed. The rate of antibiotic prescription was low in Franche-Comté EHPAD compared to available European data, but antibiotic therapy could be greatly improved. This stresses the need to better train EHPAD physicians for antibiotic stewardship.

Alternatives to carbapenems in ESBL-producing Escherichia coli infections.

OBJECTIVES: The authors had for objective to assess the activity of a wide panel of antibiotics on extended-spectrum-ß-lactamase producing Escherichia coli isolates (ESBL-Ec), because of the sharp increase of their frequency, leading to an increased use of carbapenems. MATERIAL AND METHODS: We selected 100 ESBL-Ec in which ESBLs were identified by PCR and sequencing, between 2009 and 2010. We determined the MICs of amoxicillin-clavulanate, piperacillin-tazobactam, temocillin, mecillinam, cefoxitin, cefotaxime, ceftazidime, aztreonam, tigecycline, nitrofurantoin, and fosfomycin using reference methods. The susceptibility profiles were defined according to EUCAST 2012 recommendations. RESULTS: Fosfomycin, nitrofurantoin, and pivmecillinam were active against more than 90% of isolates and remain excellent choices for the oral treatment of urinary tract infections (UTIs). Temocillin and piperacillin-tazobactam are also good candidates for the treatment of pyelonephritis or bloodstream infections. Only 27, 23, and 8% of isolates were susceptible to ceftazidime, cefepime, and cefotaxime, respectively. CONCLUSION: Our study results prove that in many cases, there are non-carbapenem alternatives for the treatment of ESBL-Ec infections.

[Chronic wound care leads to the bacterial contamination of the environment]. / Les soins des plaies chroniques entraînent une contamination bactérienne de l'environnement.

AIM: The aim of this study was to determine levels of bacterial contamination of the environment during chronic wound dressing changes. METHODS: Sampling of chronic wounds and of the environment (air and surfaces) was performed during changing of chronic wound dressing. A series of samples was defined as the entire sample for a given day for a given patient. Five sequential samples of air and six samples of surfaces were taken for each series. Staphylococcus aureus, Pseudomonas aeruginosa and enterobacteria were specifically cultured. RESULTS: Thirty series of samples were taken for 26 different patients. Twenty-seven out of these 30 series were colonized with one or two of the target species. For 13 series of the latter samples (13/27, 48.1%), bacteria isolated from the wound were recovered in the environment, namely S. aureus and P. aeruginosa. The six enterobacteria isolated from wounds were not retrieved in the environment. Air samples were more often positive than surfaces samples. CONCLUSION: We demonstrated frequent contamination of the hospital environment with bacteria colonizing wounds during dressing changes. This indicates that wearing of masks and hand disinfection after contact with the environment constitute key measures in the control of bacterial cross-transmission.

Temporal effects of infection control practices and the use of antibiotics on the incidence of MRSA.

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) has spread throughout the world and has become highly endemic worldwide. The need for implementing MRSA control strategies is no longer a matter of debate. AIM: To determine the temporal association between various infection control practices, the use of antibiotics and the incidence of MRSA in a 1200-bed French university hospital. METHODS: A multi-variate time-series analysis, based on monthly data from a nine-year period (January 2000-December 2008), was performed in a 1200-bed French university hospital to determine the temporal association between different variables and the incidence of MRSA. MRSA colonization pressure, infection control practices and use of antibiotics were considered in the analysis. FINDINGS: Time-series analysis showed a positive significant relationship between the incidence of hospital-acquired MRSA (HA-MRSA) and MRSA colonization pressure, the use of antibiotics (fluoroquinolones, macrolides and aminoglycosides) and the use of gloves. Conversely, a global negative correlation was observed between the incidence of HA-MRSA and the use of alcohol-based hand rub. Overall, the model explained 40.5% of the variance in the monthly incidence of MRSA. CONCLUSION: This study showed that admission of patients with MRSA, the use of antibiotics and infection control practices contributed to the incidence of HA-MRSA. This suggests that efforts should be focused on high compliance with hand disinfection. These results also raise concerns about the use of gloves when caring for patients with MRSA.

Bacterial contamination of the hospital environment during wound dressing change.

INTRODUCTION: The hospital environment plays a role in the cross-transmission of multidrug-resistant bacteria. The aim of this study was to evaluate the bacterial contamination of the hospital environment during chronic wound dressing change. PATIENTS AND METHODS: This study was performed from July 2010 to May 2011. Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Enterobacteriaceae were counted in environmental samples (air and surfaces) that were obtained in the rooms of patients with wounds colonized (cases, n=9) or not (controls, n=15) during or not during wound dressing change. Bacterial contamination was compared to that found in the rooms of patients without colonized wounds. RESULTS: The environment was frequently contaminated during wound dressing change (38% of the sampled series were positive). In comparison, the contamination was less frequent in the environment of patients with colonized wounds when the wounds were not being dressed (14.3%) and in controls (3.8%). S. aureus was the most frequent species identified in positive samples. DISCUSSION: These results suggest that previously recommended measures such as hand hygiene after contact with the environment and wearing a mask are justified. Moreover, other measures should be suggested, in particular cleaning the room before and after dressing change of colonized wounds. LEVEL OF EVIDENCE: Level III: case control study.

Mupirocin resistance is not an inevitable consequence of mupirocin use.

The rate of mupirocin resistance in meticillin-resistant Staphylococcus aureus (MRSA) in Besançon University Hospital is low with a decreasing trend, from 10% in 2004 to 3% in 2009. This trend in resistance paralleled mupirocin consumption. Genotyping results showed that this decrease was not linked to a change in MRSA clones. It appears that the way in which the mupirocin is used, rather than the volume, plays a role in the emergence of resistance and that its cautious use is likely to maintain the mupirocin resistance at a low level, thus preserving its efficacy.

Relationship between prevalence of device-associated infections and alcohol-based hand-rub consumption: a multi-level approach.

Using a multi-level logistic regression model, we determined whether there was any relationship between alcohol-based hand-rub consumption and prevalence of device-associated infections (DAIs) in French healthcare facilities (HCFs). Two national databases were used: the 2006 French prevalence survey of nosocomial infections, and the 2006 French infection control indicator database which includes alcohol-based hand-rub consumption as an indicator (ICSHA: indicateur de consommation de solution hydro-alcoolique). Only patients with at least one medical device (urinary catheter, vascular catheter or tracheal tube) who were present in an HCF for at least two days were included in the analysis. A multi-level statistical analysis was performed to assess the joint effect of patient-level and hospital-level variables. In all, 814 HCFs, each with a minimum of 15 study patients, were included, giving a total of 53,459 patients. The overall prevalence of DAI was 6.7% (95% confidence interval: 6.4-6.9). The median value of ICSHA was 37.2%. There was no association between DAI prevalence and ICSHA, but all patient-level variables were associated with DAI prevalence. Patient-level variables explain 25% of the hospital-level variation in DAI prevalence, although 60% of this variation remains unexplained when both patient and hospital variables are included in the model. To further assess any association between DAI prevalence and hand hygiene, additional studies on hand hygiene practices specifically associated with invasive medical device manipulation are required.

Bacterial contamination of organ graft preservation solution and infection after transplantation.

Infectious complications represent a major cause of morbidity and mortality in patients with organ transplantation. Contamination of preservation solution (PS) can lead to life-threatening complications in the recipients. For a 3-year period, we investigated the bacterial contamination of both PSs and graft fragments, recipient infections, and explored the link between them. In total 137 organs were transplanted, and 131 organ and perfusate cultures out of 426 tested (30.8%) gave a positive bacterial culture, mainly with coagulase-negative staphylococci. Overall, 80 recipients out of 137 (58.4%) had at least 1 infection during the 4-month post-graft surveillance period. Twelve recipients had an infection with the same bacterial species that was recovered in the corresponding graft. However, based on pulsed-field gel electrophoresis typing results, only 1 case was very likely cross-transmitted via the transplantation.

[Clusters of respiratory tract infections and alert strategy in nursing homes]. / Cas groupés d'infections respiratoires aiguës et stratégie d'alerte en institutions de personnes âgées.

OBJECTIVE: Outbreaks of acute respiratory infections (ARI) are common in institutions for elderly people. We had for objective to investigate clusters of cases (lower respiratory tract infection and influenza-like illness [LRTI/ILI]) in order to improve and validate alert strategies in these institutions. METHODOLOGY: Prospective surveillance for LRTI/ILI was implemented in 11 institutions in Alsace, over five years. Clinical criteria were used to identify infected residents and clusters. Nasopharyngeal swabs were collected and rapid tests (Immunoassay) were performed to identify the influenza virus. RESULTS: The three week periods were analyzed if three cases or more were recorded during the first week. This analysis demonstrated an important risk of epidemic when this number of cases was reached in healthcare units. The influenza virus (10 clusters) and respiratory syncytial virus ([RSV], two clusters) were identified. CONCLUSION: The authors confirmed and emphasized the importance of adequate surveillance for clusters of respiratory tract infection cases. Early identification of an outbreak (three cases) is an important point to prevent transmission, especially during epidemic periods and if a virus is identified in the unit or institution.

Multilevel modelling of the prevalence of hospitalized patients infected with Pseudomonas aeruginosa.

Pseudomonas aeruginosa is one of the leading nosocomial pathogens. The question of the respective contribution of endogenous and exogenous sources remains controversial. In this study, we shed new light on this issue by means of a multilevel logistic regression analysis which allowed a simultaneous investigation of factors associated with prevalence of patients infected with P. aeruginosa at two levels: patient and healthcare facility (HCF) in the eastern regions of France. A total of 25 533 in-patients from 51 HCFs were included in the analysis. The overall prevalence was 0·37% (range 0-1·65%). Multilevel modelling estimated that <14% of total variability of the outcome variable was explained by differences between HCFs and that after adjusting for patient-level variables, which explained 52% of HCF-level variance, the latter became non-significantly different from zero. A compositional effect (patient factors), rather than a contextual effect (ecological factors), explains heterogeneity of the prevalence of patients infected with P. aeruginosa in the eastern HCFs of France.

[Regional audit on fluoroquinolones usage in the hospital and the community: are these antibiotics over-used?]. / Audit régional de l'usage des fluoroquinolones à l'hôpital et en ville : y a-t-il une surconsommation de ces antibiotiques ?

AIM OF THE STUDY: The ecological impact of an over-use or a mis-use of fluoroquinolones (FQs) appears of great importance according to published data. With the objective to set up a regional antibiotic stewardship program, we conducted a regional audit on FQs usage. MATERIAL AND METHODS: [corrected] Ninety general practionners and 15 health care facilities participated to this prospective study. Overall, 511 prescriptions were evaluated (276 from hospital physicians and 235 [46%] from general practionners). The compliance of FQs prescription with national recommendations and with a regional referential was assessed. This regional referential was established in order to preserve FQs. RESULTS: Only 14,3% of the prescriptions complied with the regional referential, even if the choice of FQs were in accordance with national recommendations in 56,8% of the prescriptions. Urinary tract infections (mostly non-complicated) were the most common indication for FQs prescription. CONCLUSION: Analysis of FQs prescriptions shows that there is a significant potential for FQs preservation in Franche-Comté.

Molecular epidemiology of multidrug-resistant Pseudomonas aeruginosa in a French university hospital.

The aim of this study was to assess the incidence and molecular epidemiology of multidrug-resistant (MDR) Pseudomonas aeruginosa in our university hospital. Analysis included antimicrobial susceptibility profiling, bla gene identification and pulsed-field gel electrophoresis (PFGE). During the one-year study, 654 patients had at least one sample that tested positive for P. aeruginosa, of whom 38 (5.8%) were colonised or infected with an MDR isolate, giving an incidence of 0.1 patient per 1000 patient-days. The 38 non-duplicate isolates yielded 12 different PFGE patterns, three of which included isolates from four patients and one of which included isolates from 15 patients. Two isolates produced acquired extended-spectrum ß-lactamase (one OXA-14 and one OXA-28). Genotyping showed that cross-transmission was responsible for about 70% of MDR P. aeruginosa cases although spatio-temporal analysis failed to demonstrate when this might have occurred for most cases. The major epidemic and the three main micro-epidemic clones were already present in our hospital with a more susceptible phenotype. It is likely that some P. aeruginosa clones are endemic in our hospital and that, within these clones, MDR isolates emerge under antibiotic pressure. Our results indicate that cross-transmission plays a major role in the spread of MDR P. aeruginosa and suggest that priority should be given to the improvement of standard hygienic precautions.

Use of mupirocin-chlorhexidine treatment to prevent Staphylococcus aureus surgical-site infections.

Evaluation of: Bode LGM, Kluytmans JAJW, Wertheim HFL et al.: Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. N. Engl. J. Med. 362, 9-17 (2010). Staphylococcus aureus is the main pathogen responsible for surgical-site infections and nasal carriage is a major risk factor for subsequent infection with this bacteria. Mupirocin is considered to be the topical antibacterial agent of choice for eradication of nasal S. aureus. The paper by Bode et al. provides strong evidence that the combination of a rapid identification of a S. aureus nasal carrier, mupirocin nasal ointment and chlorhexidine gluconate soap, significantly reduces the rate of S. aureus surgical-site infection by nearly 60%. In conclusion, mupirocin nasal ointment use in S. aureus carriers before surgery has numerous advantages with few side effects.