Risk factors and costs associated with methicillin-resistant Staphylococcus aureus bloodstream infections.

OBJECTIVES: To compare the cost of hospitalization of patients with methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) versus patients with methicillin-sensitive S. aureus (MSSA) BSI, controlling for severity of underlying illness; and to identify risk factors associated with MRSA BSI. DESIGN: Retrospective case-control study based on medical chart review. SETTING: A 640-bed, tertiary-care hospital in Seattle, Washington. PATIENTS: All patients admitted to the hospital between January 1, 1997, and December 31, 1999, with S. aureus BSI confirmed by culture. RESULTS: Twenty patients with MRSA BSI were compared with 40 patients with MSSA BSI. Univariate analysis identified 5 risk factors associated with MRSA BSI. Recent hospital admission (P = .006) and assisted living (P = .004) remained significant in a multivariate model. Costs were significantly higher per patient-day of hospitalization for MRSA BSI than for MSSA BSI (dollar 5,878 vs dollar 2,073; P = .003). When patients were stratified according to severity of illness as measured by the case mix index, a difference of dollar 5,302 per patient-day was found between the two groups for all patients with a case mix index greater than 2 (P < .001). CONCLUSION: These observations suggest that MRSA BSI significantly increases hospitalization costs compared with MSSA BSI, even when controlling for the severity of the patient's underlying illness. As MRSA BSI was also found to be significantly associated with a group of patients who have repeated hospitalizations, such infections contribute substantially to the increasing cost of medical care.     

肿瘤患者耐甲氧西林金黄色葡萄球菌医院感染耐药性分析

目的研究肿瘤患者耐甲氧西林金黄色葡萄球菌(MRSA)医院感染现状及耐药性,以指导临床合理选用抗菌药物并为预防与控制医院感染提供科学依据。方法严格按照《全国临床检验操作规程》进行MRSA分离、鉴定,采用K-B法进行药敏试验,依据CLSI最新拆点判读结果。结果 67株葡萄球菌属中金黄色葡萄球菌18株,占26.87%,其中MRSA12株,MRSA分离率66.67%;MRSA主要分离自痰标本5株,占41.67%,其次是腹水标本3株,占25.00%;科室来源主要为肿瘤内科及肿瘤外科,分别占50.50%、41.67%;MRSA除对替考拉宁、夫西地酸、万古霉素等100.00%敏感外,对常用抗菌药物均存在较高的耐药性,MRSA对苯唑西林和青霉素耐药率100.00%,对氨基糖苷类、大环内酯类等抗菌药物耐药率>80.00%,未发现耐万古霉素菌株。结论了解MRSA感染的分布与特征、监测其耐药性,有助于临床及时采取合理的防治措施,有效预防与控制MRSA医院感染的暴发流行。     

Incidence of methicillin-resistant Staphylococcus aureus nosocomial infections in intensive care units in Lyon University hospitals, France, 2003-2006.

We describe the trends in the incidence of methicillin-resistant Staphylococcus aureus nosocomial infection in intensive care units in Lyon hospitals from January 1, 2003, through December 31, 2006. The incidence rate decreased from 1.77 cases per 100 ICU patients in 2003 to 1.16 cases per 100 ICU patients in 2006, a reduction of 38.0% (P = .05).     

Cryptococcosis in the University Hospital,Kuala Lumpur and review of published cases

Between January 1974 and June 1980, 85 cases of cryptococcosis were diagnosed in the University Hospital, Kuala Lumpur, Malaysia. The diagnosis was based on positive culture of the organism in 81 cases; the remaining four were diagnosed on histopathological findings. Cerebral cryptococcosis was the most common presentation and Chinese are particularly susceptible (72% of cases). The incidence of the disease is shown to be far greater than previously suspected. Association with compromised host status is uncommon (14%). The local literature is briefly reviewed and the findings discussed.     

First report of methicillin-resistant Staphylococcus aureus Cordobes/Chilean clone involved in nosocomial infections in Brazil

SUMMARY Methicillin-resistant Staphylococcus aureus (MRSA) commonly causes infection in hospitalized patients. Resistance is due to the acquisition of mecA gene located on the chromosomal element SCCmec and to date 12 types have been identified. Specific epidemic clones of MRSA have emerged with enhanced ability to spread within and among hospitals and to cross national boundaries. We studied 30 isolates from patients with MRSA infections at two hospitals in Porto Alegre city from April to December, 2008 and determined their SCCmec type by PCR. Representative strains were typed by PFGE. Eighteen (60%) isolates carried SCCmec type III and had PFGE profiles clonally related to the previously characterized Brazilian epidemic clone, and 11 (36·7%) isolates with pulsotypes closely related to the Cordobes/Chilean clone harboured SCCmec type I. To the best of our knowledge, this is the first report of the appearance of Cordobes/Chilean clone involved in nosocomial infection in Brazil.     

Risk factors for nosocomial infective endocarditis in patients with methicillin-resistant Staphylococcus aureus bacteremia.

BACKGROUND AND OBJECTIVE: Nosocomial infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are increasing. Only a few studies of MRSA infective endocarditis have been conducted, and none have reported its risk factors. We sought to determine the host-related risk factors for infective endocarditis in patients with nosocomial MRSA bacteremia. SETTING: A 2,000-bed, university-affiliated, tertiary-care hospital. PATIENTS: Thirty-one patients with nosocomial MRSA infective endocarditis between October 1996 and May 2003. DESIGN: A retrospective chart review was conducted. Data were compared with those from a control group of patients with nosocomial MRSA bacteremia. Logistic regression was used to identify independent risk factors for nosocomial infective endocarditis. RESULTS: Compared with patients who had nosocomial MRSA bacteremia and no infective endocarditis, patients who had infective endocarditis had a higher incidence of chronic liver disease and a lower incidence of immunodeficiency. The risk of developing infective endocarditis was approximately 10% for patients with nosocomial MRSA bacteremia. CONCLUSION: Patients with MRSA bacteremia and underlying chronic liver disease were prone to infective endocarditis.     

住院患儿耐甲氧西林金黄色葡萄球菌医院感染分析

目的 分析感染耐甲氧西林金黄色葡萄球菌( MRSA)患儿医院感染的分布特点及其影响因素,为预防、控制MRSA医院感染提供科学依据.方法 采取流行病学现状研究方法,对2009年1月-2010年12月127例患儿的临床资料进行回顾性调查分析.结果 127例患儿的各种临床标本中共分离出金黄色葡萄球菌127株,MRSA 47株,MRSA分离率为37.01％；47例儿童MRSA医院感染的性别分布为男35例,女12例,其MRSA感染率分别为38.04％、34.29％,男女组间MRSA感染率比较,差异无统计学意义；年龄分布为＜3岁17例,3～7岁23例,7～11岁7例,MRSA感染率分别为35.42％、37.70％、38.89％,年龄组间MRSA感染率比较,差异无统计学意义.结论 针对患儿的疾病特点强化培训和指导,强化消毒隔离观、科学合理地使用抗菌药物、缩短住院时间、及时隔离MRSA感染者等,均为预防和控制MRSA感染的有效措施.     

肺癌患者耐甲氧西林金黄色葡萄球菌医院感染危险因素分析

目的 分析肺癌患者医院感染耐甲氧西林葡萄球菌(MRSA)的危险因素.方法 收集2004年1月-2010年10月台州市博爱医院肿瘤科90例肺癌患者资料,其中诊断为MRSA感染病例56例为感染组,对照组为同时期同病区未感染MRSA肺癌患者34例;采用纸片扩散(K-B)法进行药敏试验;MRSA的鉴定采用CLSI 2004年指定的头孢西丁法;感染组与对照组之间比较计数资料采用t检验、卡方检验及多因素logistic回归进行分析.结果 t检验、卡方检验结果提示,年龄、混合真菌感染、机械通气、使用糖皮质激素、抗菌药物联合使用为肺癌患者医院感染MRSA的相关因素;多因素logistic回归分析结果表明,混合真菌感染(OR=12.22)、机械通气(OR=8.13)、使用糖皮质激素(OR=6.98)、抗菌药物联合使用(OR=5.18)进入回归方程.结论 混合真菌感染、机械通气、使用糖皮质激素、抗菌药物联合使用为肺癌患者医院感染MRSA的独立危险因素.     

Biofilm formation by and accessory gene regulator typing of methicillin-resistant Staphylococcus aureus strains recovered from patients with nosocomial infections.

The association between biofilm formation and the accessory gene regulator (agr) types of methicillin-resistant Staphylococcus aureus (MRSA) strains in our hospital were investigated. The biofilm index and the incidence of MRSA strains carrying agr-2 in the infection group (n=91) were significantly higher than were those in the carrier group (n=225), suggesting that biofilm formation and agr type are associated with nosocomial MRSA infections.     

Recurring methicillin-resistant Staphylococcus aureus infections in a football team

An outbreak of community-associated methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) occurred in a college football team from August to September 2003. Eleven case-players were identified, and boils were the most common sign. Linemen had the highest attack rate (18%). Among 99 (93% of team) players with cultured specimens, 8 (8%) had positive MRSA nasal cultures. All available case-players' MRSA isolates characterized had the community-associated pulsed-field type USA300. A case-control study found that sharing bars of soap and having preexisting cuts or abrasions were associated with infection. A carrier-control study found that having a locker near a teammate with an SSTI, sharing towels, and living on campus were associated with nasal carriage. Successful outbreak control measures included daily hexachlorophene showers and hygiene education.     

Descriptive analysis of patients with community-onset and hospital-onset methicillin-resistant Staphylococcus aureus infections.

Three hundred sixty-seven hospital- and community-onset methicillin-resistant Staphylococcus aureus (MRSA) infections diagnosed in a Dallas-Fort Worth Metroplex community hospital are described. Differences in age, gender, ethnicity, and susceptibility to four antibiotics between the two groups of patients are explored.     

Surveillance and control of methicillin-resistant Staphylococcus aureus infections in French hospitals.

OBJECTIVE: To assess the way French hospitals conduct surveillance for, and control infections caused by, methicillin-resistant Staphylococcus aureus (MRSA), and to evaluate the incidence of these infections. DESIGN: Retrospective analysis of sample surveillance data. SETTING: Representative sample of French hospitals. PARTICIPANTS: Representative sample of 38 French public hospitals. METHODS: Hospitals were selected randomly in 1996, taking into account their location and number of beds. Administrative data, surveillance denominators used, antimicrobial resistance rates, and infection control practices were analyzed for the period 1990 to 1995. The same 38 centers were contacted 3 years later, in 1998, to reassess their surveillance and control activities. RESULTS: French hospitals were slow to implement MRSA surveillance programs; only 5% had such programs in 1990, when the median incidence per admission (0.37%) and per patient-days (0.04%) of MRSA infections was already high. Despite the implementation of surveillance programs in 66% of French hospitals in 1995 and 87% in 1998, the MRSA infection rates remained stable from 1990 to 1995 and increased from 1995 to 1998. The proportion of French hospitals having a policy for the transfer of MRSA-infected patients to other hospitals increased from 47% in 1995 to 61% in 1998, whereas screening for MRSA colonization (42%-53%) and isolation for colonized or infected patients (87%-89%) remained stable. CONCLUSIONS: This first national survey showed that French hospitals probably were not optimally prepared to control and prevent MRSA infections, since they were slow to respond to the growing problem.     

耐甲氧西林金黄色葡萄球菌的感染分布及耐药分析

目的 了解临床分离的耐甲氧西林金黄色葡萄球菌(MRSA)感染分布及耐药性特点,为合理使用抗菌药物提供依据.方法 对医院2010年各类标本中分离的金黄色葡萄球菌进行回顾性分析,用PCR检测mecA基因确证MRSA.结果 2010年共分离出金黄色葡萄球菌122株,其中MRSA 79株,占64.75％,主要分布于ICU、骨科、老年病科,主要来源于痰和创面分泌物,分别占70.98％和22.78％;79株MRSA对万古霉素、利奈唑烷、呋喃妥因和磺胺甲嗯唑/甲氧苄啶的耐药率分别为0、0、17.72％和18.99％,对其他种类抗菌药物耐药率均＞75.00 ％,且耐药率均高于甲氧西林敏感金黄色葡萄球菌(MSSA).结论 临床分离的金黄色葡萄球菌中MRSA检出率较高,对多种抗菌药物耐药率高,且多为多药耐药,临床应根据药敏结果合理选择抗菌药物,减低耐药菌株的产生.     

Characteristics of Staphylococcus aureus infections, Chicago Pediatric Hospital

Invasive and skin community-associated (CA)-methicillin-resistant Staphylococcus aureus isolates from children were matched with invasive CA-methicillin-sensitive S. aureus strains during 2000-2004. Isolates were analyzed for presence of Panton-Valentine leukocidin. A USA400 lineage clone (n = 6) and the predominant USA300 lineage clone emerged.     

Invasive methicillin-resistant Staphylococcus aureus infections among dialysis patients--United States, 2005

Staphylococcus aureus is a leading cause of bloodstream and other invasive infections in the United States. S. aureus has become increasingly resistant to first-line antimicrobial agents in health-care settings. Dialysis patients are especially vulnerable to infections, frequently those caused by antimicrobial-resistant organisms, including methicillin-resistant Staphylococcus aureus (MRSA). To assess the incidence of invasive MRSA infection among dialysis patients in the United States during 2005, surveillance data were analyzed from the Active Bacterial Core surveillance (ABCs) system. This report summarizes the results of that analysis, which estimated that, in 2005, the incidence of invasive MRSA infection among dialysis patients was 45.2 cases per 1,000 population. Persons receiving dialysis are at high risk for infection with invasive MRSA compared with the general population, in which rates of invasive MRSA have ranged from 0.2 to 0.4 infections per 1,000 population. The findings in this report underscore the need for continued surveillance and infection-control strategies aimed at reducing infection rates and preventing additional antimicrobial resistance among persons receiving dialysis.     

耐甲氧西林金黄色葡萄球菌PFGE分型与医院感染暴发的分子流行病学研究

目的了解医院感染耐甲氧西林金黄色葡萄球菌(MRSA)的同源性及院内流行特征,为临床控制MRSA感染、制定合适的预防控制措施提供依据。方法收集2011年6-7月全院患者各类标本中分离出的MRSA 36株,金黄色葡萄球菌鉴定采用法国生物梅里埃公司的VITEK-2全自动微生物分析系统,根据美国CLSI标准用头孢西丁K-B法确认MRSA;运用脉冲场凝胶电泳(PFGE)对医院感染MRSA进行基因分型,并进行流行病学分析。结果临床分离的36株MRSA,PFGE分型为6型8个亚型,其中以A型为主;在研究期间,NICU及ICU发生两次MRSA感染暴发。结论 MRSA在NICU及ICU易发生交叉感染;PFGE是医院感染暴发及流行病学的较好的研究手段。