Cost-effective eradication of an outbreak of methicillin-resistant Staphylococcus aureus in a community teaching hospital

During an eight-month period, 25 hospitalized patients became infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) in a 464-bed acute care, medical-surgical teaching hospital. There were only five cases during the eight months prior to the outbreak period (P less than 0.0001). Initial measures, including category-specific isolation and education, did not limit the spread of the outbreak of a strain of MRSA. This prompted institution of additional measures including (1) strict isolation of all infected and colonized cases; (2) prospective microbiological surveillance to detect additional cases; (3) multiple site cultures of identified cases to determine the extent of colonization; (4) employee and environment surveillance; (5) antibiotic decolonization of patients and employees; and (6) educational efforts. The highest number of personnel carriers were noted in one of the critical care units where most of the cases occurred. The decolonization protocol was 100% effective for personnel carriers. The incidence of nosocomial cases of MRSA fell to zero in the five months following the implementation of the strategy. The cost of the entire eradication process was approximately half that of treating a single MRSA bacteremia.     

A maternity hospital outbreak of methicillin-resistant Staphylococcus aureus.

A maternity hospital outbreak of methicillin-resistant Staphylococcus aureus with a strain other than EMRSA-1 is described. In contrast to previously documented outbreaks, which have usually centered on special care baby units, this outbreak mainly involved the routine ante-natal and postnatal wards. Thirty-seven mothers, 18 babies and nine staff were affected over a 6-week period. The high turnover of very mobile maternity patients and the open-plan design of the hospital influenced the course of the outbreak and adversely affected implementation of infection control measures. Significant environmental contamination and a very high rate of maternal perineal MRSA colonization were notable epidemiological features.     

Control of a hospital outbreak of methicillin-resistant Staphylococcus aureus infections: value of an isolation unit

An outbreak of methicillin- and gentamicin-resistant Staphylococcus aureus infections started in a university hospital after a patient, who was not known to be colonized, was admitted. During a 3-month period 15 surgical or geriatric patients and five staff were found to be infected or colonized by the epidemic strain in five surgical/orthopaedic wards, a geriatric ward, the intensive care unit and the isolation unit. Difficulties in controlling the outbreak arose when two patients who initially had negative bacteriological screening results were returned to general wards. Both patients were subsequently shown to be colonized and caused outbreaks which led to the further closure of two general wards. There was strong circumstantial evidence to suggest that physiotherapy staff were involved with the spread of the epidemic strain. Control of the outbreak was achieved by more strict isolation of 'negative' patient contacts as well as colonized/infected patients and increasing the level of staffing on the separate isolation unit.     

Ten years' experience with methicillin-resistant Staphylococcus aureus in a large Australian hospital.

The Royal Brisbane Hospital (RBH) is a 1200-bed teaching hospital with acute, general and specialist units for adult patients. Methicillin-resistant Staphylococcus aureus (MRSA) was first detected at the RBH in 1975 and the number of new patients colonized and infected increased from one in 1975 to 720 in 1989, with a peak of 811 in 1987. Virulence may be inferred from blood culture isolates. Between 1979 and 1989 the number of patients with S. aureus bacteraemia increased from 40 to 138 per year. The percentage of these isolates which were MRSA varied from a low of 4% in 1980 to a peak of 37% in 1984 with 28% in 1989. The control attempts, sensitivity patterns, sources of the isolates and their probable impact and importance will be discussed.     

An outbreak of catalase-negative methicillin-resistant Staphylococcus aureus

The wide dissemination of a major epidemic methicillin-resistant Staphylococcus aureus (MRSA) clone in Brazilian hospitals (Brazilian clone) limits the value of molecular typing techniques such as pulsed-field gel electrophoresis (PFGE) for outbreak investigation. We report the first outbreak of a catalase-negative strain of MRSA, which was initially detected by the unusual result of this phenotypical test. The outbreak occurred in the Hospital Sanatorinhos de Carapicuíba, a 237-bed secondary hospital located in S?o Paulo, Brazil. From May to August 2002, a total of 11 MRSA isolates were recovered from four patients in the intensive care unit. All the isolates were catalase negative and susceptible only to vancomycin and linezolid. Three of the four patients eventually died. Molecular typing demonstrated an indistinguishable PFGE pattern among the 11 isolates, with similarities to the Brazilian clone and the hospital's usual MRSA strain. This report emphasizes the importance of an uncommon phenotypical result as a marker for initiating an outbreak investigation and should encourage clinical laboratories to recognize and report such isolates.     

Effect of delayed infection control measures on a hospital outbreak of methicillin-resistant Staphylococcus aureus

All patients positive for methicillin-resistant Staphylococcus aureus (MRSA) at the University Hospitals of Geneva, Switzerland, between 1989 and 1997 (N = 1771) were included in a cohort study to evaluate the consequences of delayed containment of a hospital-wide outbreak occurring during a 4-year absence of MRSA control measures. The effects of efforts to control both the MRSA reservoir and the number of bacteraemic patients were assessed. Intensive infection control measures were initiated in 1993 and included patient screening, on-site surveillance, contact isolation, a computerized alert system, and hospital-wide promotion of hand hygiene. An increase in the rate of new MRSA-infected or -colonized patients was observed between 1989 and 1994 (from 0.05 to 0.60 cases per 100 admissions), which subsequently decreased to 0.24 cases in 1997 (P<0.001). However, the proportion of laboratory-documented methicillin-resistant isolates among all S. aureus showed little variation in the years from 1993 onwards (range, 19-24%), reflecting the result of an increase in the number of screening cultures. The annual number of patients with MRSA bacteraemia strongly correlated with the hospital-wide prevalence of MRSA patients (R(2)= 0.60; P = 0.01) and the rate of new MRSA patients (R(2)= 0.97; P<0.001). Consequently, the attack rate of nosocomial MRSA bacteraemia served as an excellent marker for the MRSA patient reservoir. In conclusion, despite delayed implementation, infection control measures had a substantial impact on both the reservoir of MRSA patients and the attack rate of MRSA bacteraemia.     

Methicillin-resistant Staphylococcus aureus in an Australian teaching hospital

A survey was undertaken of all isolations of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MRSA) at a large Australian teaching hospital over a 12 month period. All methicillin-resistant isolations obtained from the Casualty and Outpatient clinics were from staff members or patients with recent hospital contact. Twenty per cent of all methicillin-resistant isolations from in-patients were from specimens taken within 2 days of the patient's admission. Each of these patients had had hospital contact within the previous 4 months and it is assumed that the majority of them reintroduced the organism into the hospital. Such patients may provide an important means by which infection control procedures are bypassed. Patients who were relatively more likely to become infected or colonized with methicillin-resistant than with methicillin-sensitive strains included the elderly and those with postoperative wound infections (especially after orthopaedic or vascular surgery), spinal injuries, peripheral vascular disease, chronic skin ulcers or chronic diseases of the respiratory or urinary tracts. Eleven per cent of MRSA wound isolates and 15 per cent of sputum isolates were associated with serious infections requiring specific treatment, emphasizing the ability of these strains to produce serious illness. A small proportion of staff and asymptomatic patients were found to harbour MRSA and the importance of these individuals in facilitating cross-infection requires further investigation.     

Ultra-sonic nebulizers as a potential source of methicillin-resistant Staphylococcus aureus causing an outbreak in a university tertiary care hospital

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) occurred on a head and neck surgical (HNS) ward of a university hospital in Amsterdam. The outbreak lasted from May 2000 until November 2000, and MRSA spread to two intensive care units. Amplified fragment length polymorphism analysis indicated that a single clone was responsible for the outbreak. Phage-typing indicated that this clone was of a type that was uncommon in The Netherlands. Strict isolation of patients, according to the Dutch national guidelines, was instituted. During the outbreak, surveillance culture specimens, from patients, healthcare workers, and the environment, were obtained at regular intervals. MRSA was found in the dust filters of nebulizers through which air from the room was filtered and subsequently humidified. These nebulizers were used to humidify tracheostomies. The dust filters were not maintained according to the guidelines. Restricted use and cleaning and disinfection of all ultra-sonic nebulizers led to termination of the outbreak. The outbreak illustrates that to terminate transmission of outbreak strains of MRSA, meticulous measures are necessary, which not only include strict isolation precautions, but also decontamination of the environment. In addition, it demonstrates the necessity of adhering to cleaning and disinfection guidelines for all medical and nursing equipment used in the hospital.     

Spread and control of a methicillin-resistant Staphylococcus aureus in an academic hospital

Between December 1988 and March 1989 twelve patients in the Utrecht University Hospital developed an infection with a methicillin-resistant Staphylococcus aureus (MRSA). Twenty other patients and 39 personnel members became colonized with the same MRSA strain. In spite of early isolation measures, progression of this epidemic was probably caused by the extreme degree of contagiousness of the first patient, who had a drug-induced allergic skin eruption. It seems likely that spread occurred via personnel and via a computer tomographic scanner. To contain the epidemic it was necessary to institute a special isolation ward with dedicated personnel. Although several MRSA strains have been introduced in the University Hospital since 1986, the strain we describe here is the only one which spread epidemically.     

Control of a regional outbreak of vanA glycopeptide-resistant Enterococcus faecium, Eastern France, 2004-2009

At the end of 2004, an outbreak of glycopeptide-resistant enterococci (GRE) spread from the Nancy Teaching Hospital to more than 40 facilities in the Lorraine region. Because this outbreak appeared to be uninhibited, a regional task force was set up to organize and co-ordinate the management of the outbreak, visiting the affected facilities to publicize the existing recommendations and take stock of the problems encountered in the field. The task force then proposed control measures specific to the region. The proposed measures included promoting the use of alcohol-based hand-rub solutions, isolation measures, enhanced screening policies, cohorting GRE-colonized patients and contacts in special wards with dedicated staff where possible, or failing that, isolating them in single rooms with additional "contact" precautions, maintaining these precautions for GRE-colonized patients until a negative stool sample was obtained after antibiotic treatment (which is a more restrictive definition of "cleared" than usually employed), regional co-ordination of the follow-up of GRE-colonized patients with the weekly publication of a list of institutions that were or had been affected to allow isolation measures to be adopted as soon as known-GRE-colonized patient were readmitted. It was not possible to determine the efficacy of each individual measure on the course of the outbreak. Nevertheless, we observed that the number of new GRE-colonized patients started to decrease following their implementation. Ultimately, 1077 GRE colonizations were recorded in Lorraine, and the outbreak is now under control.     

Nosocomial outbreak of vancomycin-resistant Enterococcus faecium at a German university pediatric hospital

Nosocomial Infections caused by vancomycin-resistant enterococci (VRE) are an emerging threat to critically ill patients. At the University Hospital Eppendorf, VRE were isolated from 38 patients between August 1993 and April 1997, of whom 32 were hospitalized at the Department of Pediatrics. Pulsed-field gel electrophoresis revealed that 26 Enterococcus faecium isolates from patients of the Department of Pediatrics were identical or closely related, and that isolates from three additional patients of the same department were possibly related. All of these isolates were of vanA genotype. They were resistant to glycopeptides, ampicillin, ciprofloxacin, clindamycin, and erythromycin. Most isolates displayed high-level resistance to gentamicin, but all remained susceptible to quinupristin/dalfopristin. Implementation of stringent hand disinfection and environmental disinfection policies, as well as measures for patient isolation contained this first outbreak of VRE at a German Children's hospital, which emphasizes the importance of hygienic measures for the control of nosocomial spread of these organisms.     

Control of methicillin-resistant Staphylococcus aureus outbreak involving several hospitals

This population-based, retrospective, cohort study describes a large methicillin-resistant Staphylococcus aureus (MRSA) epidemic caused by one strain (E1) in the greater Helsinki region. The epidemic comprised 210 cases at several hospitals, but was finally controlled. The study period ranged from June 1991 to December 2000. The epidemic peaked in 1993-1995 with 143 cases (68% of total cases). From August 1993, all MRSA-positive cases at the eight municipal hospitals were isolated and barrier nursed. Contacts were cohorted and screened for MRSA colonization. Decolonization treatment was administered to some chronic carriers. MRSA cases and contacts were identified in the joint patient register of the municipal hospitals from August 1993. The annual incidence of MRSA E1 in Helsinki City area per 100,000 inhabitants rose from 0.2 in 1991 to 13.6 in 1994. It decreased from 1995, reaching 0.7 per 100,000 in 2000. A jointly agreed policy on MRSA and timely co-operation between all units were essential for control of this epidemic.     

The value of nasal mupirocin in containing an outbreak of methicillin-resistant Staphylococcus aureus in an orthopaedic unit

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) occurred in two adjacent orthopaedic wards following the admission of a known carrier. The outbreak was not contained by ward closure or by standard infection control measures. Eventually several nasal carriers were identified and treated with nasal mupirocin, following which the outbreak ended.     

Methicillin-resistant Staphylococcus aureus: report of an outbreak in a London teaching hospital

An outbreak with a strain of methicillin-resistant Staphylococcus aureus began in The London Hospital in 1982 and continues to be associated with significant morbidity and mortality. This particular strain, termed epidemic methicillin-resistant S. aureus, is recognized by its characteristic antibiogram, phage-type and plasmid profile. In this outbreak various means of control have been attempted. Sideroom isolation did not curtail spread of the organism and containment was only achieved with the combination of extended screening, mupirocin for treatment of carriage and the use of an isolation ward.     

Epidemiology of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus in a rural state.

BACKGROUND: Most data on methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE) isolates come from large tertiary care centers. Infection control personnel need to understand the epidemiology of MRSA and VRE across the continuum of care, including small rural hospitals, to develop effective control strategies. OBJECTIVE: To describe the epidemiology of MRSA and VRE in Iowa. SETTING: Fifteen hospitals in Iowa.Methods Between July 1998 and June 2001, a total of 1,968 S. aureus isolates and 1,845 Enterococcus isolates from patients infected with these pathogens were examined. Multivariate models were developed to evaluate patient and institutional risk factors for MRSA infection and VRE infection. RESULTS: The proportion of S. aureus isolates resistant to methicillin was 31%, and the proportion of Enterococcus isolates resistant to vancomycin was 6%. Independent risk factors for MRSA infection included residence in a long-term care facility, age of more than 60 years, hospitalization in a hospital with less than 200 short-term care beds, and acquiring the infection in the hospital. Independent risk factors for VRE infection included use of a central venous catheter, residence in a long-term care facility, acquisition of infection in the hospital, and hospitalization in a hospital with more than 200 short-term care beds. CONCLUSIONS: In Iowa, the epidemiology of MRSA differ from those of VRE. MRSA has become established in small rural hospitals. Effective MRSA control strategies may require inclusion of all hospitals in a state or region.     

Eradication of a large outbreak of a single strain of vanB vancomycin-resistant Enterococcus faecium at a major Australian teaching hospital.

OBJECTIVE: To demonstrate that nosocomial transmission of vancomycin-resistant enterococci (VRE) can be terminated and endemicity prevented despite widespread dissemination of an epidemic strain in a large tertiary-care referral hospital. INTERVENTIONS: Two months after the index case was detected in the intensive care unit, 68 patients became either infected or colonized with an epidemic strain of vanB vancomycin-resistant Enterococcus faecium despite standard infection control procedures. The following additional interventions were then introduced to control the outbreak: (1) formation of a VRE executive group; (2) rapid laboratory identification (30 to 48 hours) using culture and polymerase chain reaction detection of vanA and vanB resistance genes; (3) mass screening of all hospitalized patients with isolation of carriers and cohorting of contacts; (4) environmental screening and increased cleaning; (5) electronic flagging of medical records of contacts; and (6) antibiotic restrictions (third-generation cephalosporins and vancomycin). RESULTS: A total of 19,658 patient and 24,396 environmental swabs were processed between July and December 2001. One hundred sixty-nine patients in 23 wards were colonized with a single strain of vanB vancomycin-resistant E. faecium. Introducing additional control measures rapidly brought the outbreak under control. Hospital-wide screening found 39 previously unidentified colonized patients, with only 7 more nonsegregated patients being detected in the next 2 months. The outbreak was terminated within 3 months at a cost of dollar 2.7 million (Australian dollars). CONCLUSION: Despite widespread dissemination of VRE in a large acute care facility, eradication was achievable by a well-resourced, coordinated, multifaceted approach and was in accordance with good clinical governance.     

Epidemiology of methicillin-resistant Staphylococcus aureus at a children's hospital.

OBJECTIVE: To describe the relative contribution of and risk factors for both community-acquired and nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections. DESIGN: Retrospective cohort study. SETTING: 270-bed, tertiary-care children's hospital. PARTICIPANTS: All MRSA-infected children from whom MRSA was recovered between October 1, 1999, and September 30, 2001. METHODS: Demographic, clinical, and risk factor data were abstracted from medical records. Categorical variables were analyzed using the chi-square or Fisher's exact test and continuous variables were analyzed using the Mann-Whitney test. RESULTS: Of the 62 patients with new MRSA infection, 37 had community-acquired MRSA and 25 had nosocomial MRSA. Most community-acquired MRSA infections were of the skin and soft tissue, the middle ear, and the lower respiratory tract. Nosocomial MRSA infections occurred in the lower respiratory tract, the skin and soft tissue, and the blood. Risk factors for infection, including underlying medical illness, prior hospitalization, and prior surgery, were similar for patients with community-acquired MRSA and nosocomial MRSA. History of central venous catheterization and previous endotracheal intubation was more common in patients with nosocomial MRSA. Only 3 patients with community-acquired MRSA had no identifiable risk factor other than recent antibiotic use. Resistance for clindamycin, erythromycin, and levofloxacin was similar between strains of community-acquired MRSA and nosocomial MRSA. CONCLUSIONS: Similarities in patient risk factors and resistance patterns of isolates of both community-acquired and nosocomial MRSA suggest healthcare acquisition of most MRSA. Thus, classifying MRSA as either community acquired or nosocomial underestimates the amount of healthcare-associated MRSA.     

Outbreak of methicillin-resistant Staphylococcus aureus in a German tertiary-care hospital.

A biphasic outbreak of methicillin-resistant Staphylococcus aureus in intensive-care units of a German tertiary-care hospital afflicted 89 patients within 4 years. The spread of the outbreak most likely was facilitated by the contamination of mobile radiograph equipment. The outbreak was controlled by measures of hospital hygiene.