Colonization and infection with multiple nosocomial pathogens among patients colonized with vancomycin-resistant Enterococcus.

OBJECTIVE: To test the hypothesis that patients colonized with vancomycin-resistant Enterococcus (VRE) have a higher frequency of colonization or infection with other nosocomial pathogens than do patients who are not colonized with VRE. DESIGN: A rectal swab culture survey was conducted to determine the point-prevalence of stool colonization with ceftazidime-resistant gram-negative bacilli in hospitalized patients with or without VRE stool colonization. For a 6-month period, the frequency of Clostridium difficile diarrhea and isolation of antibiotic-resistant (ie, ceftazidime-, piperacillin/tazobactam-, levofloxacin-, or trimethoprim/sulfamethoxazole-resistant) gram-negative bacilli, methicillin-resistant Staphylococcus aureus (MRSA), and non-albicans Candida species from clinical specimens other than stool was examined. SETTING: A Department of Veterans Affairs medical center. PATIENTS: All patients hospitalized in the acute care facility and one nursing home unit during a 1-week period in February 2001. RESULTS: VRE-colonized patients had a higher point-prevalence of rectal colonization with ceftazidime-resistant gram-negative bacilli than did patients not colonized with VRE (17% vs 4%; P = .026). During a 6-month period,the VRE-colonized patients were more likely to have Clostridium difficile-associated diarrhea (26% vs 2%; P = .001), MRSA infection (17% vs 4%; P = .017), or colonization or infection with gram-negative bacilli resistant to 4 different antibiotics. CONCLUSION: VRE-colonized patients in our institution have a higher frequency of colonization or infection with other nosocomial pathogens than do patients who are not colonized with VRE. This suggests that isolation measures implemented to control VRE could help limit the dissemination of other, coexisting pathogens.     

Colonization with methicillin-resistant Staphylococcus aureus in ICU patients: morbidity, mortality, and glycopeptide use.

OBJECTIVE: To determine the impact of methicillin-resistant Staphylococcus aureus (MRSA) colonization on the occurrence of S. aureus infections (methicillin-resistant and methicillin-susceptible), the use of glycopeptides, and outcome among intensive care unit (CU) patients. DESIGN: Prospective observational cohort survey. SETTING: A medical-surgical ICU with 10 single-bed rooms in a 460-bed, tertiary-care, university-affiliated hospital. PATIENTS: A total of 1,044 ICU patients were followed for the detection of MRSA colonization from July 1, 1995, to July, 1 1998. METHODS: MRSA colonization was detected using nasal samples in all patients plus wound samples in surgical patients within 48 hours of admission or within the first 48 hours of ICU stay and weekly thereafter. MRSA infections were defined using Centers for Disease Control and Prevention standard definitions, except for ventilator-associated pneumonia and catheter-related infections, which were defined by quantitative distal culture samples. RESULTS: One thousand forty-four patients (70% medical patients) were included in the analysis. Mean age was 61+/-18 years; mean Simplified Acute Physiologic Score (SAPS) II was 36.4+/-20; and median ICU stay was 4 (range, 1-193) days. Two hundred thirty-one patients (22%) died in the ICU. Fifty-four patients (5.1%) were colonized with MRSA on admission, and 52 (4.9%) of 1,044 acquired MRSA colonization in the ICU. Thirty-five patients developed a total of 42 S. aureus infections (32 MRSA, 10 methicillin-susceptible). After factors associated with the development of an S. aureus infection were adjusted for in a multivariate Cox model (SAPS II >36: hazard ratio [HR], 1.64; P=.09; male gender: HR, 2.2; P=.05), MRSA colonization increased the risk of S. aureus infection (HR, 3.84; P=.0003). MRSA colonization did not influence ICU mortality (HR, 1.01; P=.94). Glycopeptides were used in 11.4% of the patients (119/1,044) for a median duration of 5 days. For patients with no colonization, MRSA colonization on admission, and ICU-acquired MRSA colonization, respectively, glycopeptide use per 1,000 hospital days was 37.7, 235.2, and 118.3 days. MRSA colonization per se increased by 3.3-fold the use of glycopeptides in MRSA-colonized patients, even when an MRSA infection was not demonstrated, compared to non-colonized patients. CONCLUSIONS: In our unit, MRSA colonization greatly increased the risk of S. aureus infection and of glycopeptide use in colonized and non-colonized patients, without influencing ICU mortality. MRSA colonization influenced glycopeptide use even if an MRSA infection was not demonstrated; thus, an MRSA control program is warranted to decrease vancomycin use and to limit glycopeptide resistance in gram-positive cocci.     

Selective use of intranasal mupirocin and chlorhexidine bathing and the incidence of methicillin-resistant Staphylococcus aureus colonization and infection among intensive care unit patients.

OBJECTIVE: To determine whether the use of chlorhexidine bathing and intranasal mupirocin therapy among patients colonized with methicillin-resistant Staphylococcus aureus (MRSA) would decrease the incidence of MRSA colonization and infection among intensive care unit (ICU) patients. METHODS: After a 9-month baseline period (January 13, 2003, through October 12, 2003) during which all incident cases of MRSA colonization or infection were identified through the use of active-surveillance cultures in a combined medical-coronary ICU, all patients colonized with MRSA were treated with intranasal mupirocin and underwent daily chlorhexidine bathing. RESULTS: After the intervention, incident cases of MRSA colonization or infection decreased 52% (incidence density, 8.45 vs 4.05 cases per 1,000 patient-days; P=.048). All MRSA isolates remained susceptible to chlorhexidine; the overall rate of mupirocin resistance was low (4.4%) among isolates identified by surveillance cultures and did not increase during the intervention period. CONCLUSIONS: We conclude that the selective use of intranasal mupirocin and daily chlorhexidine bathing for patients colonized with MRSA reduced the incidence of MRSA colonization and infection and contributed to reductions identified by active-surveillance cultures. This finding suggests that additional strategies to reduce the incidence of MRSA infection and colonization--beyond expanded surveillance--may be needed.     

Duration of colonization with methicillin-resistant Staphylococcus aureus among patients in the intensive care unit: implications for intervention.

OBJECTIVES: To determine the duration of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection before entry and during hospitalization in the intensive care unit (ICU) and the characteristics of patients who tested positive for MRSA. DESIGN: Prospective observational cohort survey. SETTING: A combined medical and coronary care ICU with 16 single-bed rooms in a 427-bed tertiary care Veteran Affairs Medical Center. PATIENTS: A total of 720 ICU patients associated with 845 ICU admissions were followed up for the detection of MRSA from January 13, 2003, to October 12, 2003. MRSA colonization was detected in patients by using active surveillance cultures (ASCs) of nasal swab specimens obtained within 48 hours of ICU entry and 3 times weekly thereafter. The duration of colonization during ICU stay and before ICU entry was calculated after a review of surveillance culture results, clinical culture results, and medical history. RESULTS: Ninety-three (11.0%) of 845 ICU admissions involved patients who were colonized with MRSA at the time of ICU entry, and 21 admissions (2.5%) involved patients who acquired MRSA during ICU stay. ASCs were positive for MRSA in 84 (73.6%) of the 114 admissions associated with MRSA positivity and were the sole means of identifying MRSA in 50 cases (43.8%). More than half of the MRSA-associated admissions involved patients who were transferred from hospital wards. The total bed-days of care for 38 admissions involving patients who tested positive for MRSA before ICU entry (1131 days) was nearly 20% higher than the total bed-days of care for all admissions associated with MRSA positivity (970 days). Admissions involving MRSA-positive patients were associated with a longer length of hospitalization before ICU entry (P < .001), longer length of ICU stay (P < .001), longer overall length of hospitalization (P < .001), and greater inpatient mortality than admissions involving MRSA-negative patients (P < .001). A total of 22.8% of all bed-care days were dedicated to MRSA-positive patients in the ICU, and 55 (48.2%) of 114 admissions associated with MRSA positivity involved patients who were colonized for the duration of their ICU stay. CONCLUSIONS: In our unit, ASCs were an effective means to identify MRSA colonization among patients admitted to the ICU. Unfortunately, the majority of identified patients had long durations of stay in our own hospital before ICU entry, with prolonged MRSA colonization. Enhanced efforts to control MRSA will have to account for the prevalence of MRSA within hospital wards and to direct control efforts at these patients in the future.     

Surveillance for vancomycin-resistant enterococci: type, rates, costs, and implications.

OBJECTIVE: To evaluate 2 active surveillance strategies for detection of enteric vancomycin-resistant enterococci (VRE) in an intensive care unit (ICU). DESIGN: Thirty-month prospective observational study. SETTING: ICU at a university-affiliated referral center. PATIENTS: All patients with an ICU stay of 24 hours or more were eligible for the study. INTERVENTION: Clinical active surveillance (CAS), involving culture of a rectal swab specimen for detection of VRE, was performed on admission, weekly while the patient was in the ICU, and at discharge. Laboratory-based active surveillance (LAS), involving culture of a stool specimen for detection of VRE, was performed on stool samples submitted for Clostridium difficile toxin detection. RESULTS: Enteric colonization with VRE was detected in 309 (17%) of 1,872 patients. The CAS method initially detected 280 (91%) of the 309 patients colonized with VRE, compared with 25 patients (8%) detected by LAS; colonization in 4 patients (1%) was initially detected by analysis of other clinical specimens. Most patients with colonization (76%) would have gone undetected by LAS alone, whereas use of the CAS method exclusively would have missed only 3 patients (1%) who were colonized. CAS cost Dollars 1,913 per month, or Dollars 57,395 for the 30-month study period. Cost savings of CAS from preventing cases of VRE colonization and bacteremia were estimated to range from Dollars 56,258 to Dollars 303,334 per month. CONCLUSIONS: A patient-based CAS strategy for detection of enteric colonization with VRE was superior to LAS. In this high-risk setting, CAS appeared to be the most efficient and cost-effective surveillance method. The modest costs of CAS were offset by the averted costs associated with the prevention of VRE colonization and bacteremia.     

Co-carriage rates of vancomycin-resistant Enterococcus and extended-spectrum beta-lactamase-producing bacteria among a cohort of intensive care unit patients: implications for an active surveillance program.

OBJECTIVE: To assess the co-colonization rates of extended-spectrum beta-lactamase (ESBL)-producing bacteria and vancomycin-resistant Enterococcus (VRE) obtained on active surveillance cultures. DESIGN: Prospective cohort study. SETTING: Medical and surgical intensive care units (ICUs) of a tertiary-care hospital. PATIENTS: Patients admitted between September 2001 and November 2002 to the medical and surgical ICUs at the University of Maryland Medical System had active surveillance perirectal cultures performed. Samples were concurrently processed for VRE and ESBL-producing bacteria. RESULTS: Of 1,362 patients who had active surveillance cultures on admission, 136 (10%) were colonized with VRE. Among these, 15 (positive predictive value, 11%) were co-colonized with ESBL. Among the 1,226 who were VRE negative, 1,209 were also ESBL negative (negative predictive value, 99%). Among the 1,362 who had active surveillance cultures on admission, 32 (2%) were colonized with ESBL. Among these, 15 (47%) were co-colonized with VRE. Of the 32 patients colonized with ESBL, 10 (31%) had positive clinical cultures for ESBL on the same hospital admission. For these 10 patients, the surveillance cultures were positive an average of 2.7 days earlier than the clinical cultures. CONCLUSIONS: Patients who are colonized with VRE can also be co-colonized with other antibiotic-resistant bacteria such as ESBL-producing bacteria. Our study is the first to measure co-colonization rates of VRE and ESBL-producing bacteria. Isolating VRE-colonized patients would isolate 47% of the ESBL-colonized patients without the need for further testing. Hence, active surveillance for VRE should also theoretically diminish the amount of patient-to-patient transmission of ESBL-producing bacteria.     

Methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci co-colonization

We assessed the prevalence, risk factors, and clinical outcomes of patients co-colonized with vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) upon admission to the medical and surgical intensive care units (ICUs) of a tertiary-care facility between January 1, 2002, and December 31, 2003. Co-colonization was defined as a VRE-positive perirectal surveillance culture with an MRSA-positive anterior nares surveillance culture collected concurrently. Among 2,440 patients, 65 (2.7%) were co-colonized. Independent risk factors included age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05), admission to the medical ICU (OR 4.38, 95% CI 2.46-7.81), male sex (OR 1.93, 95% CI 1.14-3.30), and receiving antimicrobial drugs on a previous admission within 1 year (OR 3.06, 95% CI 1.85-5.07). None of the co-colonized patients would have been identified with clinical cultures alone. We report a high prevalence of VRE/MRSA co-colonization upon admission to ICUs at a tertiary-care hospital.     

Epidemiology of multidrug-resistant bacteria in patients with long hospital stays.

OBJECTIVE: To determine rates of colonization with multidrug-resistant (MDR) bacteria (ie, methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant Enterococcus [VRE], extended-spectrum beta -lactamase [ESBL]-producing Enterobacteriaceae, and Acinetobacter baumannii) after prolonged hospitalization and to assess the yield of surveillance cultures and variables associated with colonization with MDR bacteria. DESIGN: Prospective observational cohort study conducted from February 6 to May 26, 2006. METHODS: All patients who spent more than 30 days in our university hospital (Paris, France) were included. Rectal and nasal swab samples obtained during day 30 screening were examined for MRSA, VRE, ESBL-producing Enterobacteriaceae, and A. baumannii. RESULTS: Of 470 eligible patients, 439 had surveillance culture samples available for analysis, including 51 patients (11.6%) with a history of colonization or infection due to 1 or more types of MDR bacteria (MRSA, recovered from 35 patients; ESBL-producing Enterobacteriaceae, from 16 patients; A. baumannii, from 6 patients; and VRE, from 0 patients) and 37 patients (9.5% of the 388 patients not known to have any of the 4 MDR bacteria before day 30 screening) newly identified as colonized by 1 or more MDR bacteria (MRSA, recovered from 20 patients; ESBL-producing Enterobacteriaceae, from 16 patients; A. baumannii, from 1 patient; and VRE, from 0 patients). A total of 87 (19.8%) of 439 patients were identified as colonized or infected with MDR bacteria at day 30. Factors that differed between patients with and without MRSA colonization included age, McCabe score, comorbidity score, receipt of surgery, and receipt of fluoroquinolone treatment. Patients with ESBL-producing Enterobacteriaceae colonization were younger than patients with MRSA colonization. CONCLUSIONS: Differences in the variables associated with MRSA colonization and ESBL-producing Enterobacteriaceae colonization suggest differences in the epidemiology of these 2 organisms. Day 30 screening resulted in a 72.5% increase in the number of patients identified as colonized with at least 1 type of MDR bacteria.     

重症监护病房多重耐药菌主动筛查及定植与感染状况调查分析

目的对某院4个重症监护病房患者多重耐药菌感染/定植状况进行调查分析,为预防和控制多重耐药菌在医院内传播,降低医院感染率提供依据。方法实时查阅病历,询问患者临床症状,主动收集患者肛拭子、咽拭子、鼻拭子、大便等标本,用显色培养基筛查(ESBLs)大肠埃希菌、(ESBLs)肺炎克雷伯菌、耐甲氧西林金黄色葡萄球菌(MRSA)、耐万古霉素肠球菌(VRE),结合临床微生物检验报告(2010年1月1日～2010年8月12日),对多重耐药菌的感染与定植状况、医院感染的危险因素等进行分析。结果患者入住ICU48h内、48h后均有多重耐药菌的感染与定植,而以(ESBLs)大肠埃希菌为主。(ESBLs)大肠埃希菌、耐甲氧西林金黄色葡萄球菌(MRSA)、(ESBLs)肺炎克雷伯菌、耐万古霉素肠球菌(VRE)的定植率(无感染症状)分别为42.86%、25.00%、42.86%、28.57%;感染率(有感染症状)分别为57.14%、75.00%、57.14%、71.43%。患者中有62.70%使用过抗菌药物,21.50%接受过气管插管,32.95%接受过呼吸机,2.27%接受过动静脉导管插管,4.00%接受过留置导尿管,12.40%使用过激素治疗。结论 ESBLs大肠埃希菌是ICU定植和感染的主要多重耐药菌。主动筛查多重耐药菌感染和定植状况,及时发现多重耐药菌,第一时间报告临床,采取消毒隔离措施,及时对患者进行治疗,切断多重耐药菌传播途径,降低或避免多重耐药菌医院感染。     

Active surveillance to determine the impact of methicillin-resistant Staphylococcus aureus colonization on patients in intensive care units of a Veterans Affairs Medical Center.

OBJECTIVE: The impact of methicillin-resistant Staphylococcus aureus (MRSA) colonization on mortality has not been well characterized. We sought to describe the impact of MRSA colonization on patients admitted to intensive care units (ICUs) in the Birmingham Veterans Affairs Medical Center (VAMC). METHODS: We conducted a retrospective cohort study of ICU patients at the Birmingham VAMC during 2005 to evaluate the predictors of MRSA colonization and determine its effect on clinical outcomes. Surveillance cultures for MRSA were performed on admission to the ICU and weekly thereafter. Clinical findings, the incidence of MRSA infection, and mortality within 3 months after ICU admission were recorded. Predictors of mortality and S. aureus colonization were determined using multivariable models. RESULTS: S. aureus colonization was present in 97 (23.3%) of 416 patients screened, of whom 67 (16.1%) were colonized with methicillin-susceptible S. aureus (MSSA) and 30 (7.2%) with MRSA. All-cause mortality at 3 months among MRSA-colonized patients was significantly greater than that among MSSA-colonized patients (46.7% vs 19.4%; P = .009). MRSA colonization was an independent predictor of death (adjusted odds ratio [OR], 3.7 [95% confidence interval [CI], 1.5-8.9]; P = .003) and onset of MRSA infection after hospital discharge (adjusted OR, 7.6 [95% CI, 2.48-23.2]; P < .001). Risk factors for MRSA colonization included recent antibiotic use (adjusted OR, 4.8 [95% CI, 1.9-12.2]; P = .001) and dialysis (adjusted OR, 18.9 [95% CI, 2.1-167.8]; P = .008). CONCLUSIONS: Among ICU patients, MRSA colonization is associated with subsequent MRSA infection and an all-cause mortality that is greater than that for MSSA colonization. Active surveillance for MRSA colonization may identify individuals at risk for these adverse outcomes. Prospective studies of outcomes in MRSA-colonized patients may better define the role of programs for active MRSA surveillance.     

Diminution des infections à Staphylococcus aureus résistant à la méticilline acquis en réanimation à Meaux,sous renforcement de l'isolement spécifique

Objectives – The authors wanted to assess the impact of an “isolation” reinforcement policy in a French general hospital intensive care unit (ICU), between 1994 and 1999.Design – In 1994, the number of methicillin-resistant Staphylococcus aureus (MRSA) strains responsible for infections and the incidence of imported or acquired MRSA colonized patients was simply observed. Later, specific interventions were successively performed: specific isolation of MRSA colonized patients, attempt to decontaminate these patients, and preventive specific isolation of an increasing number of hospitalized patients, before their colonization status was determined.Results – A significant decrease was observed in various rates: MRSA went from 54% to 13% (p<0.05, hospital rate stable at 32%); the rate of patients with acquired MRSA infections went from 8.6% to 0% (p<0.001); and the rate of patients with acquired colonization from 8.7% to 2.8% (NS for the overall 6 year analysis).Conclusions – This decrease was obtained through cooperation between ICU staff members, bacteriologists, and hospital nosocomial infection committee members. During the study, a particular attention was given to a strict application of the hand washing protocol. With a sustained effort, according to the Dutch model, these results may promote the possibility to control MRSA cross colonization in ICU patients in France, and the reduction of MRSA related infections.     

What to think if the results of the National Institutes of Health randomized trial of methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococcus control measures are negative (and other advice to young epidemiologists): a review and an au revoir.

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) infections continues to rise in National Nosocomial Infections Surveillance system hospitals, and these pathogens are reportedly causing more than 100,000 infections and many deaths each year in US healthcare facilities. This has led some to insist that control measures are now urgently needed, but several recent articles have suggested that isolation of patients does not work, is not needed, or is unsafe, or that a single cluster-randomized trial could be used to decide such matters. At least 101 studies have reported controlling MRSA infection and 38 have reported controlling VRE infection by means of active detection by surveillance culture and use of isolation for all colonized patients in healthcare settings where the pathogens are epidemic or endemic, in academic and nonacademic hospitals, and in acute care, intensive care, and long-term care settings. MRSA colonization and infection have been controlled to exceedingly low levels in multiple nations and in the state of Western Australia for decades by use of active detection and isolation. Studies suggesting problems with using such data to control MRSA colonization and infection have their own problems, which are discussed. Randomized trials are epidemiologic tools that can sometimes provide erroneous results, and they have not been considered necessary for studying isolation before it is used to control other important infections, such as tuberculosis, smallpox, and severe acute respiratory syndrome. No single epidemiologic study should be considered definitive. One should always weigh all available evidence. Infection with antibiotic-resistant pathogens such as MRSA and VRE is controllable to a low level by active detection and isolation of colonized and infected patients. Effective measures should be used to minimize the morbidity and mortality attributable to these largely preventable infections.     

MRSA in the critically ill.

MRSA colonization and infection rates were prospectively examined over an 18 month period in a general Intensive Care Unit. Of 642 admissions, 305 were in ICU for longer than 48 h and were hence included and a further three patients were already colonized at admission but stayed less than 48 h. Ninety-seven patients were colonized with MRSA including 19 who were already colonized at admission. There were 56 episodes of clinical infection in 43 patients. The mortality rates in the colonized and infected groups, were 14.8% and 16.2% respectively, while the rate in those not colonized was 23%. These figures were not statistically different. Those colonized or infected with MRSA had significantly longer ICU stays than those not colonized. Sputum colonization and infection was a major site for MRSA. There was diagnostic certainty of MRSA infection in 40% of cases emphasizing the difficulty in diagnosis of infection due to MRSA in the critically ill.Both colonization and infection with MRSA are associated with longer ICU stay but do not appear to influence mortality.     

The epidemiology of vancomycin-resistant Enterococcus colonization in a medical intensive care unit.

OBJECTIVE: To determine the epidemiology of colonization with vancomycin-resistant Enterococcus (VRE) among intensive care unit (ICU) patients. DESIGN: Ten-month prospective cohort study. SETTING: A 19-bed medical ICU of a 1,440-bed teaching hospital. METHODS: Patients admitted to the ICU had rectal swab cultures for VRE on admission and weekly thereafter. VRE-positive patients were cared for using contact precautions. Clinical data, including microbiology reports, were collected prospectively during the ICU stay. RESULTS: Of 519 patients who had admission stool cultures, 127 (25%) had cultures that were positive for VRE. Risk factors for VRE colonization identified by multiple logistic regression analysis were hospital stay greater than 3 days prior to ICU admission (adjusted odds ratio [AOR], 3.6; 95% confidence interval [CI95], 2.3 to 5.7), chronic dialysis (AOR, 2.4; CI95, 1.2 to 4.5), and having been admitted to the study hospital one to two times (AOR, 2.3; CI95, 1.4 to 3.8) or more than two times (AOR, 6.5; CI95, 3.7 to 11.6) within the past 12 months. Of the 352 VRE-negative patients who had one or more follow-up cultures, 74 (21%) became VRE positive during their ICU stay (27 cases per 1,000 patient-ICU days). CONCLUSION: The prevalence of VRE culture positivity on ICU admission was high and a sizable fraction of ICU patients became VRE positive during their ICU stay despite contact precautions for VRE-positive patients. This was likely due in large part to prior VRE exposures in the rest of the hospital where these control measures were not being used.     

ICU患者MRSA定植与感染的危险因素研究

目的比较重症监护室(ICU)、呼吸内科监护室(RICU)和神经外科监护室(NSICU)耐甲氧西林金黄色葡萄球菌(MRSA)定植与感染状况,探讨患者MRSA定植/感染的危险因素。方法采用前瞻性研究方法,连续收集2013年5月1日—7月31日入住某院3个ICU患者的临床资料,采集患者(医护人员)鼻拭子及其周围环境标本进行MRSA检测。结果 197例患者,检出MRSA22株,MRSA定植率为11.17%;ICU、RICU和NSICU定植率分别为4.00%、11.90%和15.87%,差别无统计学意义(χ2=4.04,P=0.133)。患者临床标本MRSA检出率为2.03%(4/197),医护人员MRSA鼻前庭定植率为1.72%(2/116)。MRSA定植患者周围环境中MRSA检出率为22.73%(5/22),高于非定植患者4.00%(7/175)(χ2=8.93,P=0.003)。多因素logistic回归分析结果显示,年龄≥60岁、侵入性操作、住ICU时间长和近期使用抗菌药物是MRSA定植/感染的独立危险因素。结论临床应主动对入住ICU的患者进行MRSA定植筛查,采取有效措施,防止MRSA在医院环境与患者间的双向传播;同时,尽量避免使用侵入性操作,减少患者住院日和合理使用抗菌药物,减少ICU患者MRSA定植与感染的发生。     

实施主动筛查防控重症监护病房多重耐药菌传播流行

目的对重症监护病房（ICU）住院患者采取主动筛查干预措施,早期发现多重耐药菌（MDRO）定植患者,并实施接触隔离措施,预防和控制MDRO交叉传播。 方法对2012年9月—2013年5月入住ICU的240例患者鼻前庭和直肠拭子进行培养筛查,并对耐甲氧西林金黄色葡萄球菌（MRSA）和产超广谱β 内酰胺酶（ESBLs）的大肠埃希菌、肺炎克雷伯菌定植患者实施接触隔离。收集主动筛查前后（2011年9月—2012年8月和2012年9月—2013年8月）ICU患者临床培养MDRO分离株并进行耐药性分析。结果240例患者中有56例鼻腔MRSA定植,定植率23.33%。其中入ICU时筛查MRSA已定植者22例,占39.29%;住ICU期间新增定植者34例,占60.71%。105例直肠拭子产ESBLs大肠埃希菌、肺炎克雷伯菌定植,定植率43.75%。其中入ICU时筛查已定植者72例,占68.57%;住ICU期间新增定植者33例,占31.43%。实施主动筛查前后ICU患者MDRO检出发病密度分别为28.56‰、13.71‰,差异有统计学意义［P＜0.05,RR及95%CI为2.08（1.582～2.743）］。结论ICU住院患者MDRO定植率较高,实施以主动筛查为基础的MDRO综合防控措施,可降低ICU MDRO传播流行。     

Clostridium difficile in the intensive care unit: epidemiology, costs, and colonization pressure.

OBJECTIVE: To evaluate the epidemiology, outcomes, and importance of Clostridium difficile colonization pressure (CCP) as a risk factor for C. difficile-associated disease (CDAD) acquisition in intensive care unit (ICU) patients. DESIGN: Secondary analysis of data from a 30-month retrospective cohort study. SETTING: A 19-bed medical ICU in a midwestern tertiary care referral center. PATIENTS: Consecutive sample of adult patients with a length of stay of 24 hours or more between July 1, 1997, and December 31, 1999. RESULTS: Seventy-six (4%) of 1,872 patients were identified with CDAD; 40 (53%) acquired CDAD in the ICU, for an incidence of 3.2 cases per 1,000 patient-days. Antimicrobial therapy, enteral feeding, mechanical ventilation, vancomycin-resistant enterococci (VRE) colonization or infection, and CCP (5.5 vs 2.0 CDAD case-days of exposure for patients with acquired CDAD vs no CDAD; P=.001) were associated with CDAD acquisition in the univariate analysis. Only VRE colonization or infection (45% of patients with acquired CDAD vs 16% of patients without CDAD; adjusted odds ratio, 2.76 [95% confidence interval, 1.36-5.59]) and a CCP of more than 30 case-days of exposure (20% with acquired CDAD vs 2% with no CDAD; adjusted odds ratio, 3.77 [95% confidence interval, 1.14-12.49]) remained statistically significant in the multivariable analysis. Lengths of stay (6.1 vs 3.0 days; P<.001 by univariate analysis) and ICU costs ($11,353 vs $6,028; P<.001 by univariate analysis) were higher for patients with any CDAD than for patients with no CDAD. CONCLUSIONS: In this nonoutbreak setting, the CCP was an independent risk factor for acquisition of CDAD in the ICU at the upper range of exposure duration. Having CDAD in the ICU was a marker of excess healthcare use.     

Reduction in hospitalwide incidence of infection or colonization with methicillin-resistant Staphylococcus aureus with use of antimicrobial hand-hygiene gel and statistical process control charts.

OBJECTIVE: To evaluate the impact of serial interventions on the incidence of methicillin-resistant Staphylococcus aureus (MRSA). DESIGN: Longitudinal observational study before and after interventions. SETTING: The Alfred Hospital is a 350-bed tertiary referral hospital with a 35-bed intensive care unit (ICU). INTERVENTIONS: A series of interventions including the introduction of an antimicrobial hand-hygiene gel to the intensive care unit and a hospitalwide MRSA surveillance feedback program that used statistical process control charts but not active surveillance cultures. METHODS: Serial interventions were introduced between January 2003 and May 2006. The incidence and rates of new patients colonized or infected with MRSA and episodes of MRSA bacteremia in the intensive care unit and hospitalwide were compared between the preintervention and intervention periods. Segmented regression analysis was used to calculate the percentage reduction in new patients with MRSA and in episodes of MRSA bacteremia hospitalwide in the intervention period. RESULTS: The rate of new patients with MRSA in the ICU was 6.7 cases per 100 patient admissions in the intervention period, compared with 9.3 cases per 100 patient admissions in the preintervention period (P=.047). The hospitalwide rate of new patients with MRSA was 1.7 cases per 100 patient admissions in the intervention period, compared with 3.0 cases per 100 patient admissions in the preintervention period (P<.001). By use of segmented regression analysis, the maximum and conservative estimates for percentage reduction in the rate of new patients with MRSA were 79.5% and 42.0%, respectively, and the maximum and conservative estimates for percentage reduction in the rate of episodes of MRSA bacteremia were 87.4% and 39.0%, respectively. CONCLUSION: A sustained reduction in the number of new patients with MRSA colonization or infection has been demonstrated using minimal resources and a limited number of interventions.