ICU耐甲氧西林金黄色葡萄球菌感染暴发原因分析及对策

目的 分析ICU耐甲氧西林金黄色葡萄球菌(MRSA)感染暴发的原因,探讨预防控制的有效措施.方法 对ICU 2011年1月29日-2月10 日相继发生的4例MRSA肺部感染患者开展流行病学调查,并采取干顶措施控制感染流行.结果 入住ICU＜14 d相继有4例患者发生MRSA肺部感染,痰标本中分离到相同药敏谱的MRSA,是一起医院感染暴发;ICU环境取样检测,采集标本116份,其中阳性标本26份,阳性率22.4％;医务人员手、写字台、床间隔离布帘、床栏、床垫等标本分离到相同约敏谱MRSA;采取干预措施,将MRSA感染患者集中隔离,加强工作人员手卫生及医疗环境的清洁、消毒,有效地控制了感染流行.结论 在节假日期间 ICU管理存在疏漏,医疗环境污染严重及医护人员手卫生依从性较差,是造成感染暴发的主要原因.     

MRSA医院获得性肺部感染流行趋势

目的研究MRSA院内获得性肺部感染流行趋势和防治对策。方法对重症监护病房患者MRSA肺部感染及传播因素进行监测。结果金黄色葡萄球菌中MRSA占的比例逐年升高，尤其重症监护病房肺部感染的患者痰中MRSA检出率为75％；医护人员工作中手、呼吸机管道MRSA阳性率为40％～50％，水龙头、拖布MRSA阳性率为50％～100％；通过环境消毒，物表未检出MRSA。结论MRSA是医院获得性感染重要致病菌，在重症监护病房引起肺部感染流行，医务人员的手是感染的重要媒介。     

重症监护病房耐甲氧西林金黄色葡萄球菌感染调查

目的分析造成重症监护病房(ICU)耐甲氧西林金黄色葡萄球菌(MRSA)感染的原因,提出有效的预防与控制措施,进一步加强医院感染管理。方法对2005年12月-2006年2月初入住ICU患者,发生耐甲氧西林金黄色葡萄球菌感染进行前瞻性调查分析。结果9例患者发生下呼吸道医院感染,痰培养结果均为同一株MRSA所致;医护人员手、口咽、鼻腔培养出与患者同株MRSA。结论ICU为医院感染高发科室,患者病情危重、免疫低下、侵入性操作多、抗菌药物使用复杂且量大、耐药率高等都是导致医院感染的危险因素,所以提高医护人员医院感染控制理念,规范诊疗操作行为,树立合理使用抗菌药物的观念,是降低ICU发生MRSA感染的关键环节。     

耐甲氧西林金黄色葡萄球菌的定植与感染分析

目的 研究某院两个监护病房内耐甲氧西林金黄色葡萄球菌（MRSA）定植与感染状况,探讨MRSA定植与感染的危险因素及控制措施.方法 对两个监护病房内住院患者（18例）的体表及血液、医护人员（20例）的体表及其周围环境进行采样培养,并分析其定植感染的危险因素,从而制定干预措施.结果 7例MRSA定植感染者中5例的年龄大于60岁,3例进行过手术治疗,5例使用侵入性操作,6例使用抗菌药物时间超过5天;20份医护人员体表标本和80份环境标本中均分离到MRSA菌株,检出率分别为35％和3.75％.结论 侵入性操作及抗生素的大量使用等均为MRSA定植感染的危险因素,应适当减少;同时,应加强医务人员手卫生宣传教育,加强环境消毒,有效地预防和控制MRSA医院感染的发生.     

肾移植病房耐甲氧西林金黄色葡萄球菌随机扩增多态DNA分型研究

目的 研究医院肾移植病房耐甲氧西林金黄色葡萄球菌(MRSA)的分子流行病学特征,以确定病房内是否存在MRSA流行.方法 用头孢西丁纸片扩散法检测MRSA,用双重PCR方法检测金黄色葡萄球菌的femA,mecA基因,采用随机扩增多态DNA技术(RAPD),对肾移植病房一段时间内临床患者感染部位及环境和医务人员分离的MRSA作同源性分析.结果 16例患者中有5例感染MRSA;从57份医护人员鼻腔、手部、环境分离出1株MRSA;5株患者MRSA的RAPD分型具有较高的同源性;医护人员分离的MRSA与患者分型结果无同源性.结论我们医院肾移植病房存在严重的MRSA局部流行,应及时检测MRSA,防止医院感染菌株的播散.     

儿童医院及儿童监护所耐甲氧西林金葡菌感染与控制措施

耐甲氧西林金葡萄球菌(Methicillin-resistant Staphylococcus aureus,简称MRSA)是日益增长的院内感染致病菌。作者报告了美国肯塔基州Kosair儿童医院MRSA的爆发流行,并评价了控制感染措施。1987年11月～1989年8月,从儿童医院及儿童监护所(Pediatric long-term care facility,简称PLCF)转入儿童医院的患儿中,共有30例分离到MRSA。1987年11月培养出第1株MRSA,随后又发生6例MRSA院内感染。1988年8月对MRSA感染采取了控制措施(见下表)。实施措施后到1989年4月仅发生了1例MRSA     

一起蒸馏水污染引起鲍曼不动杆菌感染爆发的调查

2005年5月18～21日绍兴市某医院重症监护病房发生鲍曼不动杆菌感染爆发，该病房有13例患者住院，4d内有5例患者发生肺部鲍曼不动杆菌感染，罹患率为38．5％。后经对流行环节和暴露人群采取综合性防治措施，疫情很快被控制。     

某综合ICU耐碳青霉烯鲍曼不动杆菌下呼吸道医院感染暴发调查

目的调查某院综合重症监护病房（ICU）一起由耐碳青霉烯类鲍曼不动杆菌（CRAB）引起的疑似下呼吸道医院感染暴发流行的原因,为有效控制医院感染提供科学依据。方法对2014年3月4-23日该综合ICU CRAB感染病例进行流行病学调查和现场环境卫生学监测,并积极采取预防控制措施。结果共发生CRAB医院感染7例,流行期间总住院日数160 d,下呼吸道CRAB医院感染发病密度为43.75‰（7/160）,02床收治的5例患者中4例发生CRAB下呼吸道医院感染。单因素分析显示,使用常规吸痰是重要的危险因素;物体表面细菌菌落数合格率为31.75%(20/63)。02床吸引装置外架培养出CRAB,该菌与7例患者痰培养CRAB耐药谱相同。通过采取一系列控制措施,2014年3月24日后未再出现CRAB感染病例,此次CRAB暴发流行得到有效控制。结论此次疑似医院感染暴发可能原因为吸引装置外架污染CRAB后消毒不彻底,通过医务人员吸痰操作水平传播。ICU环境物体表面的清洁消毒对于预防医院感染至关重要。     

急诊科重症监护病房鲍氏不动杆菌分布调查

目的调查急诊重症监护病房中鲍氏不动杆菌流行情况及传播规律。方法采集患者体表、病房环境、医护人员标本分离鲍氏不动杆菌进行分析,用琼脂稀释法检测MIC值。结果50.0%的患者在入院后出现鲍氏不动杆菌的体表定植;入院7 d的患者80.0%出现体表定植;体表有定植的患者73.7%痰培养出鲍氏不动杆菌;体表定植菌与呼吸道分离菌100.0%为泛耐药株;环境及医护人员手中分离到鲍氏不动杆菌20.0%。结论鲍氏不动杆菌在患者体表、病房环境及医护人员手中大量存在,应加强环境消毒和医护人员手卫生的监督管理以减少由泛耐药鲍氏不动杆菌引起的医源性感染。     

耐甲氧西林金黄色葡萄球菌暴发流行菌株的基因分型研究

目的研究急诊重症监护病房(EICU)耐甲氧西林金黄色葡萄球菌(MRSA)暴发流行菌株的分子流行病学特征,以追踪传染源、了解传播途径,确定预防流行的策略。方法采用脉冲场凝胶电泳(PFGE)技术,对我院EICU在2004年12月临床患者感染部位分离的MRSA暴发流行株及暴发期间分离自环境和患者、医务人员携带的MRSA作同源性分析。结果17例患者中有6例感染MRSA,共分离出7株病原菌(其中有两株来自同一患者的不同部位);分别从一患者鼻腔、换药室台面、一护士的手、一病床床栏和病区的空气分离出5株MRSA;12株MRSA的PFGE分型结果显示共有4个型:所有患者感染部位分离的7个菌株和患者鼻腔及护士手上分离的两个菌株都是A型,为暴发菌株;换药室台面、病床床栏和空气中分离的菌株分别为B型、C型和D型。结论基因分型阐明了本次MRSA暴发流行的来源和传播途径,其可能是患者鼻腔携带的MRSA经由医护人员的手在病区中传播。     

Carriage of methicillin-resistant Staphylococcus aureus among hospital employees: prevalence, duration, and transmission to households.

OBJECTIVE: To assess the prevalence and duration of methicillin-resistant Staphylococcus aureus (MRSA) carriage among hospital employees and transmission to their households. DESIGN: A point-prevalence survey of MRSA carriage (nasal swabbing) of staff and patients throughout the hospital; a prevalence survey of MRSA carriage in 2 medical wards, with carriers observed to estimate carriage duration; and evaluation of transmission to MRSA-positive workers' families. All MRSA isolates were analyzed by pulsed-field gel electrophoresis. During the study, no MRSA outbreak was detected among hospitalized patients. SETTING: A 600-bed, public tertiary-care teaching hospital near Paris. RESULTS: Sixty MRSA carriers were identified among 965 healthcare providers (prevalence, 6.2%; CI95, 4.7%-7.7%). Prevalence was higher in staff from clinical wards than from elsewhere (9.0% vs 2.1%; P < .0001). Identity of isolates from employees and patients varied from 25% in medical wards to 100% in the long-term-care facility. MRSA carriage was identified in 14 employees from 2 medical wards (prevalence, 19.4%; CI95, 10.3%-28.5%). Prevalence depended on the length of service in these wards. Transmission to households was investigated in 10 MRSA-positive workers' families and was found in 4. All isolates from each family were identical. CONCLUSIONS: Few data are available concerning the prevalence of MRSA carriers among hospital employees in the absence of an outbreak among patients. MRSA transmission between patients and employees likely depends on the frequency and duration of exposure to MRSA-positive patients and infection control measures employed. Frequent transmission of MRSA from colonized healthcare workers to their households was documented.     

Nosocomial acquisition of methicillin-resistant Staphylococcus aureus during an outbreak of severe acute respiratory syndrome.

OBJECTIVE: The four hospitals assessed in this study use active surveillance cultures for methicillin-resistant Staphylococcus aureus (MRSA) and contact precautions for MRSA-positive patients as part of routine infection control practices. The objective of this study was to determine whether nosocomial acquisition of MRSA decreased in these hospitals during an outbreak of severe acute respiratory syndrome (SARS) when barrier precautions were routinely used for all patients. DESIGN: Retrospective cohort study. SETTING: Three tertiary-care hospitals (a 1100-bed hospital; a 500-bed hospital; and an 823-bed hospital) and a 430-bed community hospital, each located in Toronto, Ontario, Canada. PATIENTS: All admitted patients were included. RESULTS: The nosocomial rate of MRSA in all four hospitals combined during the SARS outbreak (3.7 per 10,000 patient-days) was not significantly different from that before (4.7 per 10,000 patient-days) or after (3.4 per 10,000 patient-days) the outbreak (P = .30 and P = .76, respectively). The nosocomial rate of MRSA after the outbreak was significantly lower than that before the outbreak (P = .003). Inappropriate reuse of gloves and gowns and failure to wash hands between patients on non-SARS wards were observed during the outbreak. Increased attention was paid to infection control education following the outbreak. CONCLUSIONS: Inappropriate reuse of gloves and gowns and failure to wash hands between patients may have contributed to transmission of MRSA during the SARS outbreak. Attention should be paid to training healthcare workers regarding the appropriate use of precautions as a means to protect themselves and patients.     

Outbreak of methicillin-resistant Staphylococcus aureus colonization and infection in a neonatal intensive care unit epidemiologically linked to a healthcare worker with chronic otitis.

OBJECTIVE: To describe the investigation and interventions necessary to contain an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection in a neonatal intensive care unit (NICU). DESIGN: Retrospective case finding that involved prospective performance of surveillance cultures for detection of MRSA and molecular typing of MRSA by repetitive-sequence polymerase chain reaction (rep-PCR). SETTING: Level III NICU in a tertiary care center. PARTICIPANTS: Three neonates in a NICU were identified with MRSA bloodstream infection on April 16, 2004. A point prevalence survey identified 6 additional colonized neonates (attack rate, 75% [9 of 12 neonates]). The outbreak strain was phenotypically unusual. INTERVENTIONS: Cohorting and mupirocin therapy were initiated for neonates who had acquired MRSA during the outbreak. Contact precautions were introduced in the NICU, and healthcare workers (HCWs) were retrained in cleaning and disinfection procedures and hand hygiene. Noncolonized neonates and newly admitted patients had surveillance cultures performed 3 times per week. RESULTS: Two new colonized neonates were identified 1 month later. HCW X, who had worked in the NICU since June 2003, was identified as having chronic otitis. MRSA was isolated from cultures of swab specimens from HCW X's ear canal and nares. HCW X was epidemiologically linked to the outbreak. Molecular typing (by rep-PCR) confirmed that the isolates from HCW X and from the neonates were more than 90% similar. Retrospective review of NICU isolates revealed that the outbreak strain was initially cultured from a neonate 2 months after HCW X began working on the unit. The epidemic strain was eradicated after removing HCW X from patient care in the NICU. CONCLUSION: An outbreak of MRSA colonization and infection in a NICU was epidemiologically linked to a HCW with chronic otitis externa and nasal colonization with MRSA. Eradication was not achieved until removal of HCW X from the NICU. Routine surveillance for MRSA may have allowed earlier recognition of the outbreak and is now standard practice in our NICU.     

The spread of a 'Dutch' methicillin-resistant Staphylococcus aureus strain

Following isolation of a methicillin-resistant Staphylococcus aureus (MRSA) in a patient subjected to amputation below the knee because of a vasculopathy, further investigations were carried out. Nose, throat and wound cultures were taken from staff and patients who had had contact with the index patient. After taking inventory cultures and cleansing of the two wards involved, these wards were quarantined. The bacterial strain was characterized using microbiological standard methods. The MRSA was encountered in a total of nine patients and two nurses. An infection due to this MRSA was found in two patients and one nurse. Eradication in the hospital was successful. MRSA with the same phage type was found in one nurse and one patient in two nearly hospitals and in one patient in a nearby city. Anamnestically, there had been no contact between them. Tracing this sort of outbreak in time is not possible with the current preventive MRSA policy because there are no demonstrable risk groups for a MRSA occurring in the Netherlands. Routine checking for MRSA carriership among nursing personnel and long-staying surgical patients is a possibility to detect spread of this MRSA. It appears advisable to take restrictive measures even against this S. aureus with restricted resistance, because neither penicillins nor cephalosporins are efficacious. In general, more attention should be given to prevention of nosocomial transmission of S. aureus.     

多耐药洋葱伯克霍尔德菌医院感染暴发调查

目的对某院多耐药洋葱伯克霍尔德菌医院感染暴发流行进行调查，查找传染源和传播途径，为预防和控制医院感染提供参考。方法采集患者标本和环境标本进行培养，根据医院感染诊断标准、区域分布、暴露时间判断是否为暴发。结果从感染患者痰标本分离出病原菌4株，均为多耐药洋葱伯克霍尔德菌。4例感染者均来自重症监护室同一病区，床位相邻；发病时间集中，为2011年1月16-22日。环境标本分离病原菌5株，分别分离自上述患者所在病区的床头柜、呼吸机管道、治疗车、被子、医务人员手，其他病房环境中未检出该菌。患者来源和环境来源的病原菌耐药谱基本一致。结论此次多耐药洋葱伯克霍尔德菌医院感染的暴发流行主要是重症监护室医疗用品被该菌污染所致。     

Effects on nursing workload of different methicillin-resistant Staphylococcus aureus (MRSA) control strategies

Nursing staff workload may influence hospital-acquired staphylococcal transmission. Closure of wards to new admissions is used in some institutions as part of methicillin-resistant Staphylococcus aureus (MRSA) outbreak control, and we postulated that it worked by reducing staff workload, allowing more time for good infection control practices. We have used the GRASPCopyright workload system to compare nursing workload during six MRSA outbreaks. Two outbreaks occurred while an aggressive control policy ('old'; 1994-1995) was in place, with a low threshold for ward closure. Control measures had been relaxed before the later four outbreaks, with wards remaining fully or partially open unless MRSA transmission proved intractable ('new'; 1995-1996). To standardize the analysis we compared GRASP and epidemiological data for periods while MRSA transmission was occurring on each ward ('during'), and four week periods 'before' and 'after'. Closing wards to admissions reduces staff workload towards a quality environment, although the nursing requirements of remaining patient rises. Workload pressures may rise during outbreaks if wards are not closed quickly and fully, and patients are not transferred to specialist isolation facilities. Changes in nursing workload need to be assessed during comparative studies of outbreak control measures and the GRASP(c) system appears to be a sensitive way to measure these.     

Antimicrobial therapy for methicillin-resistant Staphylococcus aureus colonization in residents and staff of a Veterans Affairs nursing home care unit.

OBJECTIVE: To evaluate the effect of antimicrobial therapy on patients and staff colonized with methicillin-resistant Staphylococcus aureus (MRSA) in a skilled nursing facility and to assess the role of the environment as a potential reservoir for MRSA in the nursing home setting. DESIGN: As part of a comprehensive program to control an MRSA outbreak in a nursing home, patients and staff colonized with MRSA received 1 of 3 antimicrobial decolonization regimens depending upon the site and extent of colonization. Followup cultures were performed during therapy and on days 2, 7, 14, and 30 following the completion of therapy. Cultures of the patients' inanimate environment (pajamas, sheet, and floor) were obtained during and after therapy. Antimicrobial susceptibility tests were performed on 54 MRSA isolates obtained before and 44 MRSA isolates recovered after therapy. SETTING: A 120-bed Veterans Affairs nursing home care unit. PARTICIPANTS: Thirty-six patients and 7 staff nurses colonized with MRSA at 1 or more sites. INTERVENTION: Decolonization therapy with rifampin, trimethoprim-sulfamethoxazole, and clindamycin used alone or in various combinations for 5 or 10 days in conjunction with other infection control measures employed to combat the MRSA outbreak. RESULTS: Twenty (56%) of the 36 NHCU patients were either persistently colonized or became recolonized with MRSA during the 30-day followup period. Positive cultures on day 3 during therapy frequently identified patients who subsequently exhibited persistent or recurrent colonization. Before therapy, 92% of MRSA isolates were susceptible to rifampin, whereas only 43% of the isolates obtained after therapy were susceptible. Sixteen (80%) of 20 patients with persistent or recurrent colonization had rifampin-resistant strains of MRSA isolated after therapy. Twenty-three (18%) of 125 environmental cultures obtained during and after therapy from patients who exhibited persistent or recurrent colonization were positive for MRSA, in contrast to 9 (8%) of 107 from patients who were successfully decolonized. CONCLUSIONS: The decolonization component of the outbreak control program was judged to be ineffective and potentially hazardous because colonization persisted or recurred in more than half of the patients, and substantial antimicrobial resistance was noted in MRSA stains isolated after therapy. Resistance, especially to rifampin, and possibly re-acquisition of MRSA from other human or environmental sources were 2 factors that appeared to impede the decolonization effort.     

The Dutch MRSA policy can and should be different

The methicillin-resistant Staphylococcus aureus (MRSA) infection rate in the Netherlands is low thanks to a nationwide 'search and destroy' MRSA policy. This policy is based on two factors: MRSA in the community was rare and all patients at risk for MRSA are isolated until culture results are negative. However, in 2005, livestock-associated MRSA emerged. This gave rise to an MRSA reservoir in the community. Yet the risk of livestock-associated MRSA being transmitted is low compared to that of other MRSA strains. Moreover, MRSA prevalence is lower in patients treated in a foreign hospital than had been assumed in the past. New tests (chromogenic media and PCR) have become available that allow rapid detection of MRSA carriage, resulting in a 48-60% decrease in isolation days. When rapid tests are performed, in addition to conventional cultures, patients at risk no longer need to be isolated and the closure of wards due to the risk of an outbreak is no longer necessary.     

2008-2010年金黄色葡萄球菌的分布调查

目的 了解2008年1月-2010年12月某院金黄色葡萄球菌(SAU)、耐甲氧西林金黄色葡萄球菌(MRSA)的分布,预防医院感染的暴发流行.方法 筛选某院各种临床标本中分离出的SAU224株,MRSA 67株,对其临床分布进行回顾性分析,对感染病例进行动态实时监测.结果 SAU标本多来源于分泌物标本,占31.3％,痰标本占22.8％,脓液标本占6.6％,全血标本占4.9％,MRSA标本主要分离自分泌物,占37.3％,痰标本占19.4％;以骨科、普外、ICU等外科手术科室为多见.结论 通过对菌株的临床分布进行分析,提示加强医院感染前瞻性监测,对感染患者进行动态实时追踪,及时采取消毒隔离等干预性措施,有助于减少医院感染的暴发流行.