Marc Dangel

Highly Effective Regimen for Decolonization of Methicillin-Resistant Staphylococcus aureus Carriers

OBJECTIVE To evaluate the efficacy of a standardized regimen for decolonization of methicillin-resistant Staphylococcus aureus (MRSA) carriers and to identify factors influencing decolonization treatment failure. DESIGN Prospective cohort study from January 2002 to April 2007, with a mean follow-up period of 36 months. SETTING University hospital with 750 beds and 27,000 admissions/year. PATIENTS Of 94 consecutive hospitalized patients with MRSA colonization or infection, 32 were excluded because of spontaneous loss of MRSA, contraindications, death, or refusal to participate. In 62 patients, decolonization treatment was completed. At least 6 body sites were screened for MRSA (including by use of rectal swabs) before the start of treatment. INTERVENTIONS Standardized decolonization treatment consisted of mupirocin nasal ointment, chlorhexidine mouth rinse, and full-body wash with chlorhexidine soap for 5 days. Intestinal and urinary-tract colonization were treated with oral vancomycin and cotrimoxazole, respectively. Vaginal colonization was treated with povidone-iodine or, alternatively, with chlorhexidine ovula or octenidine solution. Other antibiotics were added to the regimen if treatment failed. Successful decolonization was considered to have been achieved if results were negative for 3 consecutive sets of cultures of more than 6 screening sites. RESULTS The mean age (+/- standard deviation [SD]) age of the 62 patients was 66.2 +/- 19 years. The most frequent locations of MRSA colonization were the nose (42 patients [68%]), the throat (33 [53%]), perianal area (33 [53%]), rectum (36 [58%]), and inguinal area (30 [49%]). Decolonization was completed in 87% of patients after a mean (+/-SD) of 2.1 +/- 1.8 decolonization cycles (range, 1-10 cycles). Sixty-five percent of patients ultimately required peroral antibiotic treatment (vancomycin, 52%; cotrimoxazole, 27%; rifampin and fusidic acid, 18%). Decolonization was successful in 54 (87%) of the patients in the intent-to-treat analysis and in 51 (98%) of 52 patients in the on-treatment analysis. CONCLUSION This standardized regimen for MRSA decolonization was highly effective in patients who completed the full decolonization treatment course.

Rate of Transmission of Extended-Spectrum Beta-Lactamase–Producing Enterobacteriaceae Without Contact Isolation

BACKGROUND Extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae are emerging worldwide. Contact isolation is recommended; however, little is known about the rate of transmission without contact isolation in the non-epidemic setting. Therefore, we aimed to estimate the rate of spread (R(0)) of ESBL-producing Enterobacteriaceae in a tertiary care center with 5 intensive care units. METHODS In this observational cohort study performed from June 1999 through April 2011, all patients at the University Hospital Basel, Switzerland, who were hospitalized in the same room as a patient colonized or infected with an ESBL-producing Enterobacteriaceae for at least 24 hours (index case) were screened for ESBL carriage by testing of rectal swab samples, swab samples from open wounds or drainages, and urine samples from patients with foley catheters. Strains with phenotypic evidence for ESBL were confirmed by polymerase chain reaction. Nosocomial transmission was assumed when the result of screening for ESBL carriage in a contact patient was positive and molecular typing by pulsed-field gel electrophoresis (PFGE) revealed clonal relatedness with the strain from the index patient. RESULTS Active screening for ESBL carriage could be performed in 133 consecutive contact patients. Transmission confirmed by PFGE occurred in 2 (1.5%) of 133 contact patients, after a mean exposure to the index case of 4.3 days. CONCLUSIONS The estimated rate of spread of ESBL-producing Enterobacteriaceae-in particular, Escherichia coli-was low in a tertiary care university-affiliated hospital with high levels of standard hygiene precautions. The low level of nosocomial transmission and the rapid emergence of community-acquired ESBL challenge the routine use of contact isolation in a non-epidemic setting, saving resources and potentially improving patient care.

ALCOHOL-BASED HANDRUB: EVALUATION OF TECHNIQUE AND MICROBIOLOGICAL EFFICACY WITH INTERNATIONAL INFECTION CONTROL PROFESSIONALS

BACKGROUND AND OBJECTIVE The Centers for Disease Control and Prevention has published a new guideline on hand hygiene promoting the use of the alcohol-based handrub, but the technique was not addressed. The goal of this study was to evaluate the influence of technique on the efficacy of the alcohol-based handrub. PARTICIPANTS Healthcare workers (HCWs) attending a course in hospital epidemiology. METHODS A fluorescent dye was added to a hand antiseptic, and hands were checked under ultraviolet light after antiseptic cleansing. Data regarding the numbers of predefined fluorescent areas on the skin were collected in addition to demographic data such as age, gender, job description, and job experience. Results of the visualization test were compared with the data from microbiological samples before and after the procedure by the hand plate technique. RESULTS Sixty HCWs were tested, 63% of whom had worked in infection control for more than 10 years. Sixty-six percent of all participants still had detectable bacteria after antisepsis. The mean log10 CFU reduction was 2.0 (range, 0-3.85). Twenty-five percent of all HCWs achieved less than 1.1 log10 CFU. Staphylococcus aureus was isolated from 13% (one of them being methicillin resistant) and gram-negative bacilli from 6.7%. After using the alcohol handrub, one subject still remained positive for S. aureus. Years of experience was the single most important factor predicting antimicrobial efficacy. CONCLUSIONS Technique is of crucial importance in hand antisepsis. Major deficiencies were detected among even highly trained HCWs. Training should be provided before switching from handwashing to the alcohol handrub

OCTENIDINE HYDROCHLORIDE FOR THE CARE OF CENTRAL VENOUS CATHETER INSERTION SITES IN SEVERELY IMMUNOCOMPROMISED PATIENTS

OBJECTIVE To determine the efficacy and tolerability of octenidine hydrochloride, a non-alcoholic skin antiseptic, for the care of central venous catheter (CVC) insertion sites. DESIGN Prospective, observational study. SETTING Bone marrow transplantation unit of a university hospital. PATIENTS All consecutive patients with a nontunneled CVC were enrolled prospectively after informed consent. METHODS Octenidine hydrochloride (0.1%) was applied for disinfection at the CVC insertion site during dressing changes. The following cultures were performed weekly as well as at the occurrence of any systemic inflammatory response syndrome criteria: cultures of the skin surrounding the CVC entry site, cultures of the three-way hub connected to the CVC, blood cultures, and cultures of the CVC tip on removal. Enhanced microbiological methods (skin swabs of a 24-cm2 standardized area, roll plate, and sonication of catheter tips) were applied. RESULTS One hundred thirty-five CVCs were inserted in 62 patients during the study period and remained for a mean period of 19.1 days, corresponding to 2,462 catheter-days. Bacterial density at the insertion site declined substantially over time, and most cultures became negative 2 weeks after insertion. Only 6 patients had a documented catheter-related bloodstream infection. The incidence density was 2.39 catheter infections per 1,000 catheter-days. No side effects were noted with application of the antiseptic. CONCLUSIONS Disinfection with a skin antiseptic that contains octenidine hydrochloride is highly active and well tolerated. It leads to a decrease in skin colonization over time and may be a new option for CVC care.

Distribution of spa types among meticillin-resistant Staphylococcus aureus isolates during a 6 year period at a low-prevalence University Hospital

This study describes the distribution and frequencies of strain types by protein A-encoding gene (spa) typing among a total of 200 meticillin-resistant Staphylococcus aureus (MRSA) single-patient isolates collected between 2000 and 2005 at the University Hospital Basel, Switzerland. Nine frequent spa types accounted for 49.5 % of MRSA isolates, whereas spa type t041 (15 % of all isolates) belonged to a local epidemic strain that is also a common strain type in southern Germany. Successful control of the outbreak strain was documented by epidemiological data and confirmed by spa typing results. The spa type t044 (3.5 %), corresponding to a widely disseminated European community-acquired MRSA (CA-MRSA), was first observed in 2002. The well-known CA-MRSA USA300 clone was detected in four patients (2 %). Sporadic strains occurring less than four times (32 different spa types) accounted for 23 % of isolates. No predominant spa type was seen, indicating a great genetic diversity. Only 34.5 % of patient isolates were acquired nosocomially. The presence of one or more of ten common virulence genes was shown in 79 % of strains. It was demonstrated that the sequence-based spa typing method allows analysis of local MRSA epidemiology in relation to other regions and countries over time.

Not All Patients with Vancomycin-Resistant Enterococci Need To Be Isolated

BACKGROUND Vancomycin-resistant enterococci (VRE) have triggered multiple outbreaks. However, VRE of genotype vanC appear not to be associated with outbreaks. The goal of this study was to estimate the risk of bloodstream infections in patients colonized with VRE of genotype vanC who received care from a bone marrow transplant unit for patients with leukemia, where only standard precautions were implemented for VRE of genotype vanC during the last 9 years. METHODS Since 2000, all patients in the bone marrow transplant unit underwent routine VRE rectal screening, data were prospectively entered in a database, and isolates were molecularly characterized. Infection control policy required contact isolation for patients infected with VRE of genotype vanA or vanB but only standard precautions for patients infected with VRE of genotype vanC. RESULTS From January 2000 to July 2008, 290 isolates of VRE of genotype vanC obtained from 273 different patients were identified, with an incidence of 25-43 isolates/year. Of 290 isolates, 285 (98%) were identified in rectal screening swabs, 5 were from other body sites, and none required specific treatment. During the entire study period, only 1 case of bloodstream infection was detected, reflecting an incidence of 1 (0.4%) of the 273 patients, or <0.2 cases per 1000 patient-days. No outbreaks were recorded. CONCLUSIONS These data provide strong evidence that carriers of VRE of genotype vanC do not require contact isolation, thereby saving resources and potentially improving patient care. The genotype should be routinely determined in areas with a high prevalence of VRE of genotype vanC.

No risk of surgical site infections from residual bacteria after disinfection with povidone-iodine-alcohol in 1014 cases: a prospective observational study.

Objective:We studied the impact of residual bacteria at the incision site after disinfection with polyvinylpyrrolidone (PVP or povidone)-iodine-alcohol and the correlation with postoperative surgical site infections (SSIs). Background:Chlorhexidine-based preparations are significantly more effective for catheter insertion care than povidone-iodine solutions to prevent catheter-associated infections, suggesting that the use of PVP-iodine should be reevaluated for disinfection of the surgical site. In the majority of European hospitals PVP-iodine-alcohol is still standard of care to prepare the preoperative site. Methods:We consecutively and prospectively enrolled 1005 patients from representative surgical disciplines. Skin cultures to determine skin microbial counts were taken after disinfection with PVP-iodine-alcohol, immediately before incision. Disinfection of the surgical site was performed using standardized procedure under supervision. Criteria for SSI were based on guidelines issued by the Centers for Disease Control including appropriate follow-up of 30 days and 1 year. Results:A total of 1014 skin cultures from surgical sites were analyzed from 1005 patients, of which 36 (3.6%) revealed significant colonization of the preoperative site, and 41 SSIs were detected, accounting for an SSI rate of 4.04%; residual bacteria before incision were completely unrelated to the incidence of SSI, even after adjustment for multiple potentially confounding variables. Conclusions:A low rate of SSIs of 4.04% was achieved when using PVP-iodine-alcohol for disinfection of the preoperative site. Remaining bacteria after standardized 3-step disinfection did not at all correlate with the development of an SSI. Our data provide clear evidence that PVP-iodine-alcohol is effective for preparation of the preoperative site.

Surgical Hand Antisepsis With Alcohol-Based Hand Rub: Comparison of Effectiveness After 1.5 and 3 Minutes of Application

OBJECTIVE Research has shown 1.5 minutes of surgical hand antisepsis with alcohol-based hand rub to be at least as effective under experimental conditions as the 3-minute reference disinfection recommended by European Norm 12791. The aim of the present study was to validate the effectiveness of 1.5 minutes of surgical hand antisepsis in a clinical setting by comparing the effectiveness of 1.5- and 3-minute applications of alcohol-based hand rub (45% vol/vol 2-propanol, 30% vol/vol 1-propanol, and 0.2% mecetronium ethylsulphate). DESIGN Prospective crossover trial in which each surgeon served as his or her own control, with individual randomization to the 1.5- or the 3-minute group during the first part of the trial. SETTING Basel University Hospital, Switzerland. PARTICIPANTS Thirty-two surgeons with different levels of postdoctoral training. METHODS We measured the bactericidal effectiveness of 1.5 minutes and 3 minutes of surgical hand antisepsis with alcohol-based hand rub by assessing the mean (+/-SD) log10 number of colony-forming units before the application of hand rub (baseline), after the application of hand rub (immediate effect), and after surgery (sustained effect) so as to follow European Norm 12791 as closely as possible. RESULTS The immediate mean (+/-SD) log10 reduction in colony-forming units (cfu) was 2.26 +/- 1.13 log10 cfu for the 1.5-minute group and 3.01 +/- 1.06 log10 cfu for the 3-minute group (P = .204). Similarly, there was no statistically significant difference between the 2 groups with respect to the sustained effect; the mean (+/-SD) log10 increase in bacterial density during surgery was 1.08 +/- 1.13 log10 cfu for the 1.5-minute group and 0.95 +/- 1.27 log10 cfu for the 3-minute group (P = .708). No adverse effects were recorded. CONCLUSION In this clinical trial, surgical hand antisepsis with alcohol-based hand rub resulted in a similar bacterial reduction, regardless of whether it was applied for 3 or 1.5 minutes, which confirms experimental data generated with healthy volunteers.

Methicillin-resistant Staphylococcus aureus (MRSA) among dental patients: a problem for infection control in dentistry?

We assessed the frequency of carriers of methicillin-resistant Staphylococcus aureus (MRSA) among 500 dental patients of a university clinic. From each participant, two specimens were taken from the anterior nares and the pharynx and analysed by culture. The participants completed a questionnaire on possible risk factors of MRSA infection. Two hundred ten individuals carried S. aureus, 90 in the nares only, 51 in the throat only and 69 in nares and throat. Isolates of 208 patients were methicillin-sensitive; two isolates were methicillin-resistant, both carried in the throat exclusively. In conclusion, the frequency of nasal and/or throat carriers of MRSA among dental patients was low and suggests few opportunities of exposure in the dental clinic assessed.

Sonication for diagnosis of catheter-related infection is not better than traditional roll-plate culture: a prospective cohort study with 975 central-venous catheters

This prospective randomized controlled study with 975 nontunneled central venous catheters (CVCs) showed that the semiquantitative roll-plate culture technique (SQC) was as accurate as the sonication method for diagnosis of catheter-related infections. Sonication is difficult to standardize, whereas SQC is simpler, faster, and as reliable as the sonication method for culturing CVCs.