Methicillin-resistant Staphylococcus Aureus Control Research Articles

Control of Methicillin-Resistant Staphylococcus aureus in a Hospital and an Intensive Care Unit

To describe methicillin-resistant Staphylococcus aureus (MRSA) control in a hospital, including a surgical intensive care unit (SICU) outbreak. Prospective surveillance of newly identified patients with MRSA. Barrier isolation (disposable gloves for direct contact with patient or immediate environment) was used for the routine care of hospitalized MRSA patients as of October 1991. Beginning in 1992, MRSA isolates were typed by restriction endonuclease enzyme analysis of plasmid DNA (REAP) and/or pulsed-field gel electrophoresis of genomic DNA (PFGE). Surveillance information and MRSA typing were used concurrently to identify nosocomial case clustering, confirm cross-infection, and support a need for additional outbreak control interventions. University-affiliated public hospital. Patients with newly identified MRSA colonization or infection from 1991 through 1993 and epidemiologically associated staff providing care to eight SICU patients in an outbreak. Barrier isolation for affected and unaffected patients in and admitted to the SICU institution when the outbreak was identified and cross-infection confirmed. Anterior nares cultures of staff in contact with outbreak cases for detection of MRSA colonization. Fifty-six hospitalized patients with community-acquired MRSA and 80 patients with nosocomial MRSA colonization or infection were identified during the 3 years. After the introduction of barrier isolation, the annual frequency of new nosocomial MRSA cases decreased and only one outbreak (eight cases in the SICU) caused by type-related isolates occurred. The other 35 nosocomial cases of MRSA during 1992 and 1993 were not epidemiologically related or were caused by isolates with different types. The SICU outbreak ended after instituting barrier isolation for all patients (with and without MRSA) in and admitted to the unit. Six colonized SICU staff were identified. All outbreak cases had identical or related MRSA types by PFGE and REAP. Staff isolates were different from case isolates by typing, and staff were not restricted and not given treatment for colonization. After more than 6 months of follow up, no further outbreaks of MRSA in the SICU or elsewhere in the hospital occurred despite returning to barrier isolation for affected patients only. MRSA in hospitals and outbreaks of MRSA in ICUs can be controlled by surveillance and minimal barrier interventions. REAP or PFGE typing of MRSA can be used to support or refute the presence of cross-transmission. Typing also may be helpful when planning and assessing the effectiveness of interventions directed at endemic, as well as outbreak, MRSA control.

New threats to the control of methicillin-resistant Staphylococcus aureus

Several countries have achieved considerable success in the control of epidemic methicillin-resistant Staphylococcus aureus (MRSA). However, in several hospitals in the UK, MRSA strains of enhanced epidemicity, notably EMRSA-16, are becoming endemic. Our inability to eliminate the cause of a single-strain outbreak is unfamiliar and unnerving. Factors in ‘market-led’ health care delivery that hinder control of MRSA include a shortage of inpatient beds, patients moving from ward to ward, and more mixed-speciality wards. Increasing use of day treatments leaves an inpatient hospital population with more risk factors for infection. Early discharge of infected patients to convalescent homes, or to homes for the elderly, has created a new reservoir of infected and colonized patients. The emergence of high-level mupirocin resistance may soon also contribute to failure of control. The transfer of vancomycin resistance from Enterococcus faecium to a laboratory strain of S. aureus suggests that, especially in hospitals with both vancomycin-resistant enterococci and MRSA, there is the opportunity for the emergence of vancomycin-resistant MRSA for which there may be no effective antimicrobial prophylaxis or treatment. It is increasingly important to persuade hospital managers that even partial control of MRSA, whilst expensive, is still cost-effective and is a quality issue for individual hospitals. The control of EMRSA-16 in one hospital has recently been estimated to have saved more than £629 000 extra costs. MRSA continues to be at the forefront of those organisms that seriously challenge modern technological medicine and surgery.

A major outbreak of methicillin-resistant Staphylococcus aureus caused by a new phage-type (EMRSA-16)

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection caused by a novel phage-type (now designated EMRSA-16) occurred in three hospitals in East Northamptonshire over a 21-month period (April 1991—December 1992). Four hundred patients were colonized or infected. Seven patients died as a direct result of infection. Chest infections were significantly associated with the outbreak strain when compared with methicillin-sensitive S. aureus. Twenty-seven staff and two relatives who cared for patients were also colonized. A ‘search and destroy’ strategy, as advocated in the current UK guidelines for control of epidemic MRSA was implemented after detection of the first case. Despite extensive screening of staff and patients and isolation of colonized and infected patients, the outbreak strain spread to all wards of the three hospitals except paediatrics and maternity. A high incidence of throat colonization (51%) was observed. Failure to recognize the importance of this until late in the outbreak contributed to the delay in containing its spread. Key parts of the strategy which eventually contained the local outbreak were the establishment of isolation wards in two hospitals, treatment of all colonized patients and staff to eradicate carriage and screening of all patients upon discharge from wards where MRSA had ever been detected. EMRSA-16 spread to neighbouring hospitals by early 1992 and to London and the South of England by 1993. It is distinguished from other epidemic strains by its characteristic phage-type, antibiogram (susceptibility to tetracycline and resistance to ciprofloxacin), and in the pattern given on pulse field electrophoresis.

Control of naeethicillin-resistant Staphylococcus aureus in a pediatric burn unit

Background: Control of methicillin-resistant Staphylococcus aureus (MRSA) is particularly difficult in burn units, which are often cited as sources of hospital-wide MRSA outbreaks. We developed a successful MRSA control program and document here its apparent effectiveness in controlling MRSA transmission in a pediatric burn unit. Methods: An MRSA control program that included surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers was consistently applied in a pediatric burn unit through a 7-year period. Microbiology reports of MRSA isolates from patients and environmental surfaces and records of all patients from whom MRSA was isolated were reviewed. Results: During calendar years 1985 through 1991, a total of 991 acutely burned children were admitted to the Boston unit of the Shriners Burns Institute. Forty MRSA cases (4%) were identified. One patient both had MRSA at admission and met our criteria for nosocomial MRSA. Of the remaining 39 patients, 11 had MRSA at admission and 28 had nosocomial MRSA. There were 17 wound infections, two cases of pneumonia, and two bloodstream infections. No deaths were attributed to MRSA sepsis. Conclusion: An MRSA control program including surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers is associated with a low rate of nosocomial MRSA in a pediatric burn unit.

Methicillin-Resistant Staphylococcus aureus (MRSA): A Briefing for Acute Care Hospitals and Nursing Facilities

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) has increased in communities and in healthcare facilities in the United States since the mid-1970s. Although MRSA often is thought of as a nosocomial infection problem because it is encountered in facilities of all types and sizes, it also causes many community-acquired infections. Approaches to control of MRSA vary widely, and there is lack of agreement on the most appropriate measures to control MRSA in healthcare facilities. The wide variation in approaches is due, in part, to the lack of data establishing the efficacy of specific control measures. As a result, the approaches that have been advocated have resulted in confusing and often conflicting recommendations and control measures. In some settings, there also have been unreasonable barriers and administrative hurdles that delay or prevent the transfer of patients between acute care and nursing (extended care) facilities.

Control of methicillin-resistant Staphylococcus aureus bacteraemia in high-risk areas.

In a 3,000-bed tertiary care hospital, 88 cases of methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia were identified from 22,383 blood cultures (0.39%) submitted to the microbiology laboratory over a one-year period. Two high-risk areas were identified: the paediatric oncology unit, in which 12 cases of MRSA bacteraemia were identified from 924 blood cultures (1.3%), and the intensive care unit (ICU), in which 14 cases of MRSA bacteraemia were identified from 1,391 blood cultures (1.0%). In a one-year targeted intervention programme in which staff and patients were screened for MRSA carriage, patient carriers isolated, and mupirocin and chlorhexidine treatment administered, the number of MRSA bacteraemia cases decreased in these areas to 0 and 4, respectively (p = 0.000123 and 0.016), while the incidence of MRSA bacteraemia in non-targeted areas increased from 62 of 20,068 blood cultures (0.3%) to 82 of 18,784 blood cultures (0.44%) (p = 0.047). In the year post intervention the incidence of MRSA bacteraemia increased to 3 of 815 cultures (0.37%) in the paediatric oncology unit, 10 of 1,934 cultures (0.5%) in the ICU, and 112 of 18,977 cultures (0.59%) in the rest of the hospital (p = 0.00004 versus preintervention period). This study demonstrates the efficacy of targeted MRSA control measures in a hospital in which MRSA is endemic.

National survey of methicillin-resistantStaphylococcus aureus in Belgian hospitals: Detection methods, prevalence trends and infection control measures

A questionnaire survey of Belgian acute care hospitals was conducted to determine the methods used for detection of methicillin-resistant Staphylococcus aureus (MRSA), to estimate the prevalence of this organism during the period 1989-1991 and to describe the infection control measures used locally for limiting its spread. Questionnaires were returned by 144 acute care hospitals, with a coverage of 41 to 72% of hospitals by province. Methods used for detection of MRSA included disk diffusion (91%), microdilution panels (8%) and oxacillin agar screen (9%). Only 34% of laboratories performed disk diffusion testing under optimal conditions for detection of heterogenous resistance. Among 36 hospitals reporting complete susceptibility data of Staphylococcus aureus isolates tested during the study period (n = 24,153), a mean MRSA prevalence of 14% was found (range: 0-70%). The median prevalence increased from 9.5% in 1989 to 13.7% in 1991 and showed a significant linear increase during this period in 30% of these hospitals (p < 0.01). Precautions used for controlling spread of MRSA included hand decontamination using either soap and water or antimicrobial preparations (68% of hospitals), room decontamination (62%), patient isolation (55%) and various barrier precautions (24-49%). Carrier screening was performed in 37% of hospitals, but antibiotic decolonization was attempted in only 24%. This survey identified areas for improvement in MRSA detection methods and underscored the need for multicentric surveillance of MRSA prevalence and a reappraisal of MRSA control strategies in Belgian hospitals.

Postoperative complications due to methicillin-resistant staphylococcus aureus (MRSA) in an elderly patient: management and control of MRSA

An elderly lady was admitted to hospital for elective resection of an adenocarcinoma of the colon. Following an anastomotic leak she developed intra-abdominal sepsis and underwent abdominal drainage of pus. During recovery from her second operation, she developed pneumonia and a bacteraemia due to methicillin-resistant Staphylococcus aureus (MRSA). She was treated with vancomycin and co-trimoxazole and survived without further sequelae. Details of the development and treatment of this case are discussed. Procedures for the control and eradication of MRSA infections in hospitals are reviewed.

Methicillin resistant Staphylococcus aureus and its implications for nursing practice: a literature review.

The subject of methicillin-resistant Staphylococcus aureus (MRSA) and its implications for nursing practice are reviewed. Resistance of Staphylococcus aureus to antibiotics, and the emergence and incidence of MRSA both in the United Kingdom and abroad, are examined. Modes of transmission of MRSA by transfer of affected patients and, specifically, cross infection by staff are reviewed with methods to prevent cross infection, including screening of staff, handwashing techniques, barrier and cohort nursing, being examined. The costs of an MRSA outbreak, both financially and psychologically, to staff and patients are discussed. Guidelines for the control of epidemic MRSA are explained in the context of the above topics, and all areas are related to improving nursing practice.

Methicillin‐Resistant Staphylococcus aureus in Minnesota Nursing Homes

To assess the experience of Minnesota nursing homes with methicillin-resistant Staphylococcus aureus (MRSA) and the policies and procedures used for its control. A 12-question survey, with primarily categorical responses, was mailed to the Directors of Nursing of all Minnesota long-term-care facilities. A follow-up mailing was sent to non-responders 5 weeks later. The mailing included a cover letter, a description of the study and its purposes, and a stamped return envelope. Four weeks after the second mailing, all non-responding institutions were contacted by telephone and invited to participated by mail or by completing the survey by telephone. All long-term-care facilities in Minnesota licensed for skilled and intermediate care. The survey was directed to the Directors of Nursing of the long-term-care facilities with the request that, if another individual was better able to complete it, the survey be forwarded to them. Completed responses were obtained from 88% (395/445) of all long-term-care facilities in Minnesota. Forty-eight institutions (12%) had residents colonized or infected with MRSA. Only four (8%) of these facilities stated that MRSA was a problem; however, 33 (69%) of facilities with MRSA had sought outside help or consultation from a variety of sources for its control. Few facilities (7%) had cultured residents specifically for MRSA. Policies regarding the admission of colonized or infected persons were reported by 14% and 21% of facilities, respectively, and over 40% of these policies stated that persons with MRSA would not be accepted. Policies regarding the care of MRSA-colonized or -infected persons were not uniform. Both metropolitan and non-metropolitan facilities had residents with MRSA. Our results suggest that MRSA in long-term-care facilities may be a widespread and underrecognized problem. There is a need to develop uniform policies for the control of MRSA in nursing homes. These policies should consider the sources and objectives of long-term-care facilities.

Successful control of endemic MRSA in a cardiothoracic surgical unit

After a substantial increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the Cardiothoracic Surgical Unit at St. Vincent's Hospital, Sydney, a prospective study was undertaken in early 1986 to ascertain the carrier status of all patients entering the Unit. Of 84 patients, 27.4% were found to carry MRSA and the perineum was the major site of carriage, with 69.6% of MRSA positive cases carrying the organism in this site. As a result of these findings, the period of perioperative antibiotic cover was shortened, whole-body washing of patients with a 1% triclosan preparation was instituted and routine postoperative perineal swabs were taken. During the 18 months after implementation of these policies, a highly significant reduction in the number of MRSA carriers and infections was observed. The monitoring of perineal colonization proved to be a useful marker for increases in MRSA in the Unit.

Epidemiology of multi-resistant Staphylococcus aureus in Hong Kong

Methicillin-resistant Staphylococcus aureus (MRSA) are now common in Hong Kong, and account for 30% of all hospital Staph aureus (SA) isolates. All MRSA were analysed from a new teaching hospital between 1984 and 1986, and 12 hospitals in Hong Kong in October 1985. Over 600 non-duplicate Isolates of MRSA were analysed. 11 of the 12 hospitals were affected by MRSA, and between 8-537. of all isolates of SA were MRSA. MRSA were isolated from deep sites as well aB superficial, and about 30% of SA blood isolates were MRSA. More than 20 plasmid types of MRSA were identified, but two kinds pre-dominated and many of the types identified may be sub-types of these two. One of the common types was non-typable by phage, and the other reacted with phages 29, 77, 84 and 85. Isolates were usually multiply-resistant to several antlstaphylococcal agenta, especially gentamlcin, erythromycin, chloramphenicol and tetracycline. MRSA infection was widespread, but most common on Burns, ITU and SCBU wards. Plasmid type 2 was widely distributed in different medical specialtiea, but plasmid type 1 was most commonly Isolated from neonatal and paedlatric wards. There vas evidence that type 1 was being spread between hospitals by patient transfers within specialties. Owing to overcrowding, patient transfers, and lack of isolation facilities, the control of MRSA in Hong Kong hospitals will be difficult.

A descriptive survey of uncontrolled methicillin-resistant Staphylococcus aureus in a twin site general hospital.

Over a five year period beginning in 1981, during which control measures were applied intermittently, the incidence of methicillin-resistant Staphylococcus aureus (MRSA) isolates increased steadily within a twin site general hospital. A retrospective chart review of 154 patients identified in 1984-1985 showed that the MRSA 'definitely' contributed to three deaths (2%) and 'probably' contributed to a further 15 (10%). The prolonged median duration of hospital admission (22 days) before first isolation of MRSA, together with the clustering of cases in time on certain wards, suggested that most, if not all, affected patients acquired the MRSA in hospital. As the virulence of MRSA in our outbreak appeared the same as that reported from teaching hospitals, MRSA control measures need to be comprehensively applied in general hospitals.

Prospective microbiologic surveillance in control of nosocomial methicillin-resistant Staphylococcus aureus.

A prospective microbiological surveillance (PMS) program was developed in a comprehensive hospital-wide effort for control of nosocomial methicillin-resistant Staphylococcus aureus (MRSA). This PMS program entailed: active identification of colonized and infected patients; application of a screening microbiologic system for MRSA; isolation of colonized and infected patients; antibiotic decolonization of MRSA; and educational efforts. The PMS program was studied over three and one half years for its contribution to infection control of MRSA, early identification of nosocomial MRSA outbreaks, use of the highest yield surveillance culture sites, and cost effectiveness. Following initiation of the PMS program in December 1982, during an MRSA outbreak, the frequency of new MRSA cases declined from 14 to none by the end of a 3-month pilot study. The frequency of new MRSA cases stabilized at approximately 2 per month until October 1983, when the PMS system allowed prompt detection of a new outbreak of 11 cases. Following isolation and antibiotic decolonization, the frequency of cases again declined to 3 per month. A third outbreak in December 1985 again was promptly detected and controlled. Infection to colonization ratio decreased from a maximum of 1.5 during outbreaks to a minimum of 0.17 after outbreaks. Wounds and tracheostomy sites provided the greatest yield of detection of new cases of MRSA. During one 15-month period, 35 of the 43 new cases were detected initially at wounds and tracheostomy sites. No new MRSA cases were detected by a positive axillary or nares site alone. The estimated quarterly cost of outbreaks and infection paralleled the quarterly frequency of new MRSA cases.(ABSTRACT TRUNCATED AT 250 WORDS)