To describe the control of an outbreak of infection and colonization with the New York/Japan methicillin-resistant Staphylococcus aureus (MRSA) clone in multiple healthcare facilities, and to demonstrate the importance of making an MRSA management policy involving molecular typing of MRSA into a statewide public health responsibility.

A range of healthcare facilities, including 2 metropolitan teaching hospitals and a regional hospital, as well as several community hospitals and long-term care facilities in a nonmetropolitan healthcare region.

A comprehensive, statewide MRSA epidemiological investigation and management policy.

In May 2005, there were 3 isolates referred to the Western Australian Gram-Positive Bacteria Typing and Research Unit that were identified as the New York/Japan MRSA clone, a pandemic MRSA clone with the ability to spread and replace existing clones in a region. Subsequent investigation identified 28 additional cases of infection and/or colonization dating from 2002 onward, including 1 involving a colonized healthcare worker (HCW) who had previously been hospitalized overseas. Of the 31 isolates detected, 25 were linked epidemiologically and via molecular typing to the isolate recovered from the colonized HCW. Four isolates appeared to have been introduced separately from overseas. Although the isolate from the single remaining case patient was genetically indistinct from the isolates that spread within Western Australia, no specific epidemiological link could be established. The application of standard outbreak management strategies reduced further spread.

The elimination of the New/York Japan MRSA clone in a healthcare region demonstrates the importance of incorporating MRSA management policy into statewide public health programs. The mainstays of such programs should include a comprehensive and effective outbreak identification and management policy (including pre-employment screening of HCWs, where applicable) and MRSA clone identification by multilocus sequence typing.

To evaluate the prevalence of colonization among patients with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection and their household contacts.

Prospective, observational laboratory study of nasal colonization among patients and their household members from September 15, 2004, to February 20, 2006.

A 600-bed, urban, academic medical center.

Fifty-one patients who presented with CA-MRSA infections and 49 household members had cultures of nasal swab specimens performed.

Skin and soft-tissue infections were seen in 50 patients (98%) and 2 household members. Twenty-one (41%) of 51 patients and 10 (20%) of 49 household members were colonized with MRSA. An additional 5 patients (10%) and 12 household members (24%) were colonized with methicillin-susceptible Staphylococcus aureus. Most MRSA isolates (95%; infective and colonizing) carried the staphylococcal cassette chromosome mec type IV complex, and 67% represented a single clone, identical to USA 300. Of the colonized household members, 5 had isolates related to the patients' infective isolate.

The frequency of CA-MRSA colonization among household members of patients with CA-MRSA infections is higher than rates reported among the general population. Among colonized household members, only half of the MRSA strains were related to the patients' infective isolate. Within the same household, multiple strains of CA-MRSA may be present.

To identify factors contributing to a cluster of deaths from invasive group A streptococcus (GAS) infection in a nursing home facility and to prevent additional cases.

Outbreak investigation.

A 146-bed nursing home facility in northern Nevada.

We defined a case as the isolation of GAS from a normally sterile site in a resident of nursing home A. To identify case patients, we reviewed resident records from nursing home A, the local hospital, and the hospital laboratory. We obtained oropharyngeal and skin lesion swabs from staff and residents to assess GAS colonization and performed emm typing on available isolates. To identify potential risk factors for transmission, we performed a cohort study and investigated concurrent illness among residents and surveyed staff regarding infection control practices.

Six residents met the case patient definition; 3 (50%) of them died. Among invasive GAS isolates available for analysis, 2 distinct strains were identified: emm11 (3 isolates) and emm89 (2 isolates). The rate of GAS carriage was 6% among residents and 4% among staff; carriage isolates were emm89 (8 isolates), emm11 (2 isolates), and emm1 (1 isolate). Concurrently, 35 (24%) of the residents developed a respiratory illness of unknown etiology; 41% of these persons died. Twenty-one (30%) of the surveyed employees did not always wash their hands before patient contacts, and 27 (38%) did not always wash their hands between patient contacts.

Concurrent respiratory illness likely contributed to an outbreak of invasive GAS infection from 2 strains in a highly susceptible population. This outbreak highlights the importance of appropriate infection control measures, including respiratory hygiene practices, in nursing home facilities.

To estimate the incidence rate of reported occupational blood and body fluid exposures among French healthcare workers (HCWs).

Prospective national follow-up of HCWs from January 1 to December 31, 2004.

University hospitals, hospitals, clinics, local medical centers, and specialized psychiatric centers were included in the study on a voluntary basis.

At participating medical centers, every reported blood and body fluid exposure was documented by the occupational practitioner in charge of the exposed HCW by use of an anonymous, standardized questionnaire.

A total of 375 medical centers (15% of French medical centers, accounting for 29% of hospital beds) reported 13,041 blood and body fluid exposures; of these, 9,396 (72.0%) were needlestick injuries. Blood and body fluid exposures were avoidable in 39.1% of cases (5,091 of 13,020), and 52.2% of percutaneous injuries (4,986 of 9,552) were avoidable (5.9% due to needle recapping). Of 10,656 percutaneous injuries, 22.6% occurred during an injection, 17.9% during blood sampling, and 16.6% during surgery. Of 2,065 splashes, 22.6% occurred during nursing activities, 19.1% during surgery, 14.1% during placement or removal of an intravenous line, and 12.0% during manipulation of a tracheotomy tube. The incidence rates of exposures were 8.9 per 100 hospital beds (95% confidence interval [CI], 8.7-9.0 exposures), 2.2 per 100 full-time—equivalent physicians (95% CI, 2.4-2.6 exposures), and 7.0 per 100 full-time—equivalent nurses (95% CI, 6.8-7.2 exposures). Human immunodeficiency virus serological status was unknown for 2,789 (21.4%) of 13,041 patients who were the source of the blood and body fluid exposures.

National surveillance networks for blood and body fluid exposures help to better document their characteristics and risk factors and can enhance prevention at participating medical centers.

Modified contact precautions (MCP), defined as routine donning of isolation gowns (along with routine gloving) on entry into the rooms of patients under contact precautions, regardless of the likelihood of direct exposure to the patient or their immediate environment, were instituted at our medical center to reduce nosocomial transmission of common hospital pathogens.

To study compliance with MCP policy regarding routine gowning in intensive care units (ICUs) and general wards and to determine the relationship between gown and glove use in the care of patients under MCP in ICUs.

Prospective observational study from February 20, 2004, through January 8, 2005, involving 2,110 persons (1,504 healthcare workers [HCWs] and 606 non-HCW visitors).

A 900-bed tertiary care teaching community hospital.

Overall compliance with routine gown use was observed for 1,542 persons (73%), including 1,150 HCWs (76%) and 392 visitors (65%) (odds ratio [OR], 1.8 [95% confidence interval {CI}, 1.4-2.2]; P < .001). Visitors in the ICUs (186 [91%] of 204) were more likely than visitors in the general wards (202 [51%] of 398) to comply with gown use (OR, 10 [95% CI, 6.0-17.0]; P < .001). In logistic regression analysis, independent predictors of gown compliance among HCWs were female sex (OR, 2.3 [95% CI, 1.8-3.0]; P < .001) and ICU setting (OR, 2.2 [95% CI, 1.7-2.9]; P < .001). In the ICUs, gown use was highly predictive of glove use among HCWs (positive predictive value, 95%).

Improvement in compliance with gown use at our medical center will require more-intensive educational efforts targeted at male HCWs and at HCWs and visitors on general wards. In the care of ICU patients under MCP, HCW compliance with gown use may be used as a proxy for their compliance with glove use.

To determine the appropriate method to calculate the rate of methicillin-resistant Staphylococcus aureus (MRSA) infection and colonization (hereafter, MRSA rates) for interhospital comparisons, such that the large number of patients who are already MRSA positive on admission is taken into account.

A prospective, multicenter, hospital-based surveillance of MRSA-positive case patients from January through December 2004.

Data from 31 hospitals participating in the German national nosocomial infections surveillance system (KISS) were recorded during routine surveillance by the infection control team at each hospital.

Data for 4,215 MRSA-positive case patients were evaluated. From this data, the following values were calculated. The median incidence density was 0.71 MRSA-positive case patients per 1,000 patient-days, and the median nosocomial incidence density was 0.27 patients with nosocomial MRSA infection or colonization per 1,000 patient-days (95% CI, 0.18-0.34). The median average daily MRSA burden was 1.13 MRSA patient-days per 100 patient-days (95% CI, 0.86-1.51), with the average daily MRSA burden defined as the total number of MRSA patient-days divided by the total number of patient-days times 100. The median MRSA-days–associated nosocomial MRSA infection and colonization rate, which describes the MRSA infection risk for other patients in hospitals housing large numbers of MRSA-positive patients and/or many patients who were MRSA positive on admission, was 23.1 cases of nosocomial MRSA infection and colonization per 1,000 MRSA patient-days (95% CI, 17.4-28.6). The values were also calculated for various MRSA screening levels.

The MRSA-days–associated nosocomial MRSA rate allows investigators to assess the extent of MRSA colonization and infection at each hospital, taking into account cases that have been imported from other hospitals, as well as from the community. This information provides an appropriate incentive for hospitals to introduce further infection control measures.

To investigate the impact of antimicrobial resistance on clinical and economic outcomes among hospitalized patients with multidrug-resistant (MDR) Acinetobacter baumannii bacteremia.

A retrospective, matched-cohort study.

A tertiary care university teaching hospital

A matched case-control (1:1) study was conducted to compare the differences in clinical and economic outcomes of patients with MDR A. baumannii bacteremia and patients with non-MDR A. baumannii bacteremia. Case patients were matched to control patients on the basis of sex, age, severity of underlying and acute illness, and length of hospital stay before onset of bacteremia.

Forty-six (95.8%) of 48 cases with MDR A. baumannii bacteremia were eligible for the study and matched with appropriate controls. The sepsis-related mortality rate was 34.8% among cases and 13.0% among controls, for an attributable mortality rate of 21.8% (adjusted odds ratio, 4.1 [95% confidence interval, 1.1-15.7]; P = .036). After the onset of bacteremia, cases and controls had a significantly different length of hospital stay (54.2 vs 34.1 days; P = .006), hospitalization cost (US$9,349 vs US$4,865; P = .001 ), and antibiotic therapy cost (US$2,257 vs US$1,610; P = .014). Thus, bacteremia due to MDR A. baumannii resulted in 13.4 days of additional hospitalization and US$3,758 of additional costs, compared with bacteremia due to non-MDR A. baumannii.

Patients with MDR A. baumannii bacteremia had a higher mortality rate and incurred greater medical costs than patients with non-MDR A. baumannii bacteremia.

In 2000, the rate of surgical site infections (SSIs) associated with pacemaker and implantable cardioverter-defibrillator (ICD) procedures performed in the cardiothoracic operating rooms of hospital A was 16% (19 of 116 procedures resulted in infections). This study investigates risks for SSI associated with these procedures in the cardiothoracic operating room.

Unmatched 1: 3 case-control study performed over a 12-month period among patients who had undergone implantation of a pacemaker and/or ICD. A standardized observation scrutinized infection control practices in the area where the procedures were performed.

The cardiothoracic operating rooms of hospital A, which belongs to a hospital consortium in the midwestern United States.

Patients with SSI were identified as case patients. Control patients were chosen from the group of uninfected patients who had procedures performed during the same period as case patients.

A total of 19 SSIs associated with pacemaker and ICD procedures were retrospectively identified among the patients who underwent procedures in these cardiothoracic operating rooms. Culture samples were obtained from 7 patients; 2 yielded coagulase-negative Staphylococcus on culture, 2 yielded Staphylococcus aureus, 1 yielded Serratia marcescens, and 2 showed no growth. In the case-control study, age, race, sex, diabetes mellitus, smoking history, timing of antibiotic therapy, and hair removal did not differ significantly between case patients and control patients. Case patients were more likely to have an abdominal device in place (odds ratio [OR], 5.5 [95% confidence interval {CI}, 1.6-19.3]; P = .006) and less likely to have received a new implant (OR 0.3 [95% CI, 0.1-0.8]; P = .02) or to have had new leads placed (OR, 0.2 [95% CI, 0.1-0.6]; P = .003).

Abdominal placement of implanted devices was associated with occurrence of an SSI after pacemaker and/or ICD procedures.

To investigate relationships between rates of antimicrobial consumption and the incidence of antimicrobial resistance in Staphylococcus aureus and Pseudomonas aeruginosa isolates from hospitals.

We conducted an observational study that used retrospective data from 2002 and linear regression to model relationships. Hospitals were asked to collect data on consecutive S. aureus and P. aeruginosa isolates, consumption rates for antibiotics (ie, anti-infectives for systemic use as defined by Anatomical Therapeutic Chemical class J01), and hospital characteristics, including infection control policies. Rates of methicillin resistance in S. aureus and rates of ceftazidime and ciprofloxacin resistance in P. aeruginosa were expressed as the percentage of isolates that were nonsusceptible (ie, either resistant or intermediately susceptible) and as the incidence of nonsuceptible isolates (ie, the number of nonsuceptible isolates recovered per 1,000 patient-days). The rate of antimicrobial consumption was expressed as the number of defined daily doses per 1,000 patient-days.

Data were obtained from 47 French hospitals, and a total of 12,188 S. aureus isolates and 6,370 P. aeruginosa isolates were tested.

In the multivariate analysis, fewer antimicrobials showed a significant association between the consumption rate and the percentage of isolates that were resistant than an association between the consumption rate and the incidence of resistance. The overall rate of antibiotic consumption, not including the antibiotics used to treat methicillin-resistant S. aureus infection, explained 13% of the variance between hospitals in the incidence of methicillin resistance among S. aureus isolates. The incidence of methicillin resistance in S. aureus isolates increased with the use of ciprofloxacin and levofloxacin and with the percentage of the hospital's beds located in intensive care units (adjusted multivariate coefficient of determination [aR2], 0.30). For P. aeruginosa, the incidence of ceftazidime resistance was greater in hospitals with higher consumption rates for ceftazidime, levofloxacin, and gentamicin (aR2, 0.37). The incidence of ciprofloxacin resistance increased with the use of fluoroquinolones and with the percentage of a hospital's beds located in intensive care (aR2, 0.28).

A statistically significant relationship existed between the rate of fluoroquinolone use and the rate of antimicrobial resistance among S. aureus and P. aeruginosa isolates. The incidence of resistant isolates showed a stronger association with the rate of antimicrobial use than did the percentage of isolates with resistance.

The low prevalence of infection and colonization with methicillin-resistant Staphylococcus aureus (MRSA) in The Netherlands is ascribed to a national “search-and-destroy” policy. We describe the measures that were implemented to control widespread MRSA colonization and infection in a Dutch hospital.

Descriptive intervention study.

Teaching medical center with a capacity of 679 beds, including 16 intensive care beds.

MRSA colonization and infection were identified using conventional culture with a selective broth. Isolates were typed using pulsed-field gel electrophoresis. Measures to control the epidemic included screening of contacts (patients and hospital staff), screening of patients at readmission or discharge, strict isolation of MRSA-positive patients, decolonization of colonized staff and patients, the development of an electronic signal identifying MRSA-positive patients, and the development of a culture information-system for hospital personnel.

Awareness of uncontrolled dissemination of MRSA began in November 2001. Because the clone involved had a low minimum inhibitory concentration for oxacillin, at first it was not recognized as MRSA. In February 2002, when major screening efforts started, it appeared that MRSA had spread all over the hospital and that many staff members were colonized. By the end of December 2005, a total of 600 patients and 135 staff members were found to be newly colonized. The yearly incidence of cases of MRSA colonization and infection decreased from 351 in 2002 to 56 in 2005. Typing of the isolates showed that 3 MRSA clones were predominant. Outbreaks of colonization involving these clones did not occur after 2003.

Our observations show that strict application of “search-and-destroy” measures can effectively control a huge epidemic of MRSA colonization and infection.

To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among older residents of care homes in Leeds, United Kingdom, and to identify resident and care home risk factors for carriage.

We conducted a cross-sectional prevalence survey of 715 residents from 39 care homes. All participants were tested for nasal colonization with S. aureus, including MRSA. A short questionnaire was completed about each participant and each care home. A multivariable model was used to determine which risk factors were independently associated with MRSA colonization.

Care homes for older residents in Leeds, United Kingdom.

All residents in participating homes who were able to give informed consent.

A total of 159 of 715 residents tested positive for MRSA, for a prevalence of 22% (95% confidence interval, 18%—27%) The resultant multivariate model showed that residence in a home with a low ratio of nurses to beds, residence in a care home in a deprived area, male sex, presence of an invasive device, and a hospitalization duration of more than 10 days during the previous 2 years were independently associated with MRSA colonization.

This study found a large reservoir of MRSA within the care home population. Control strategies need to be coordinated between care homes and hospitals. Increasing the ratio of nurses to beds, reducing the duration of hospitalization, and improving the management of invasive devices could help reduce the prevalence of MRSA colonization. Further research is required to ascertain the potential health benefits of reducing the rate of MRSA colonization among care home residents.

The impact of the outbreak of severe acute respiratory syndrome (SARS) was enormous, but few studies have focused on the infectious and general health status of healthcare workers (HCWs) who treated patients with SARS.

We prospectively evaluated the general health status of HCWs during the SARS epidemic.The Medical Outcome Study Short-Form 36 Survey was given to all HCWs immediately after caring for patients with SARS and 4 weeks after self-quarantine and off-duty shifts. Tests for detection of SARS Coronavirus antibody were performed for HCWs at these 2 time points and for control subjects during the SARS epidemic.

Tertiary care referral center in Taipei, Taiwan.

Ninety SARS-care task force members (SARS HCWs) and 82 control subjects.

All serum specimens tested negative for SARS antibody. Survey scores for SARS HCWs immediately after care were significantly lower than those for the control group (P < .05 by the t test) in 6 categories. Vitality, social functioning, and mental health immediately after care and vitality and mental health after self-quarantine and off-duty shifts were among the worst subscales. The social functioning, role emotional, and role physical subscales significantly improved after self-quarantine and off-duty shifts (P < .05, by paired t test). The length of contact time (mean number of contact-hours per day) with patients with SARS was associated with some subscales (role emotional, role physical, and mental health) to a mild extent. The total number of contact-hours with symptomatic patients with SARS was a borderline predictor (adjusted R2 = 0.069; P = .038) of mental health score.

The impact of the SARS outbreak on SARS HCWs was significant in many dimensions of general health. The vitality and mental health status of SARS HCWs 1 month after self-quarantine and off-duty shifts remained inferior to those of the control group.

Infective endocarditis caused by Staphylococcus aureus is an ominous prognosis associated with a high prevalence of embolic episodes and neurological involvement. Whether methicillin resistance decreases the risk of embolism in infective endocarditis is unclear. We sought to assess the association between methicillin resistance and risk factors for embolism in S. aureus infective endocarditis.

Retrospective chart review. Data from patients with infective endocarditis due to methicillin-resistant S. aureus were compared with data from patients with endocarditis due to methicillin-susceptible S. aureus. Logistic regression was used to identify independent risk factors for embolism.

A 2,000-bed, university-affiliated tertiary care hospital.

Between 1995 and 2005, 123 patients with S. aureus infective endocarditis were included in the study. There were 74 male patients and 49 female patients, with a median age of 54 years (range, 0-89 years).

Of 123 infections, 30 (24%) were nosocomial infections, and 14 (11%) were prosthetic valve infections. Of 123 S. aureus isolates, 48 (39%) were methicillin resistant. In total, embolism occurred in 45 (37%) of these patients: pulmonary embolism in 22 (18%), cerebral embolism in 21 (17%), and peripheral embolism in 6 (5%). The independent risk factors for an embolism were injection drug use, presence of a cardiac vegetation with a size of 10 mm or greater, and absence of nosocomial infection. For 83 patients with aortic or mitral infective endocarditis, independent risk factors for an embolism were the presence of a cardiac vegetation with a size of 10 mm or greater and endocarditis due to methicillin-susceptible S. aureus. Overall, in-hospital death occurred for 32 (26%) of 123 Patients. Methicillin-resistant infection was not an independent risk factor for death.

Methicillin-resistant S. aureus infection was associated with decreased risk of embolism in left-side endocarditis, but was not associated with in-hospital death.

Staphylococcus aureus is an important pathogen that leads to serious infections in the community and in hospitals. Evidence has shown that the prevalence of infection and colonization with drug-resistant S. aureus, such as methicillin-resistant S. aureus (MRSA) and glycopeptide intermediately susceptible S. aureus, is increasing. Authorities must be aware of the prevalence of MRSA infection and colonization in their country in order to implement and monitor infection control policies that help curtail further emergence of this pathogen.

To examine the trend of hospital-acquired MRSA infection and colonization in a tertiary care institution in Saudi Arabia during a 5-year period in order to identify specific areas at high risk for MRSA transmission, and to review our MRSA decolonization procedure and outcomes.

Surveillance data prospectively collected from January 1, 2000, through December 31, 2004, on hospital-acquired (HA) MRSA were analyzed, with an emphasis on the trend of HA-MRSA infection and colonization, areas of high transmission, risk factors, and effectiveness of the implemented decolonization policy.

During the study period, 442 cases of HA-MRSA infection and colonization were identified. Of these, 51.2% were infections, and 48.8% were colonizations. An increasing trend in the incidence rates of infection and colonization was noticed during the study period, and most cases were identified on the surgical ward (33.3%) and medical ward (32.1%). Of the 34 infected patients who underwent systematic decolonization, 35.3% were successfully decolonized, and of the 11 who underwent topical decolonization, 63.6% were successfully decolonized.

The increasing trend of HA-MRSA infections has been a noticeable global problem. We identified a gradual increase in the rates of MRSA colonization and infection in a tertiary care center Saudi Arabia and recognize the importance of abiding by strict infection control policies, including hand hygiene and proper isolation practices. Continued surveillance for MRSA and other emerging multidrug-resistant pathogens is also needed.