To assess whether infection control indicators are associated with the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection in French hospitals.

We linked the database for the 2006 national prevalence survey of nosocomial infection with the database of infection control indicators (comprised of ICALIN, an indicator of infection control organization, resources, and action, and ICSHA, an indicator of alcohol-based handrub consumption) recorded from hospitals by the Ministry of Health. Data on MRSA infection were obtained from the national prevalence survey database and included the site and origin of infection, the microorganism responsible, and its drug resistance profile. Because the prevalence of MRSA infection was low and often nil, especially in small hospitals, we restricted our analysis to hospitals with at least 300 Patients. We used a multilevel logistic regression model to assess the joint effects of patient-level variables (eg, age, sex, or infection) and hospital-level variables (infection control indicators).

Two hundred two hospitals had at least 300 patients, for a total of 128,631 Patients. The overall prevalence of MRSA infection was 0.34% (95% confidence interval [CI], 0.29%-0.39%). The mean value for ICSHA was 7.8 L per 1,000 patient-days (median, 6.1 L per 1,000 patient-days; range, 0-33 L per 1,000 patient-days). The mean value for ICALIN was 92 of a possible 100 points (median, 94.5;range, 67-100). Multilevel analyses showed that ICALIN scores were associated with the prevalence of MRSA infection (odds ratio for a score change of 1 standard deviation, 0.80;95% CI, 0.69-0.93). We found no association between prevalence of MRSA infection and ICSHA. Other variables significantly associated with the prevalence of MRSA infection were sex, vascular or urinary catheter, previous surgery, and the McCabe score.

We found a significant association between the prevalence of MRSA infection and ICALIN that suggested that a higher ICALIN score may be predictive of a lower prevalence of MRSA infection.

To characterize the clinical and molecular epidemiology of multidrug-resistant (MDR) organisms in residents, in healthcare workers (HCWs), and on inanimate surfaces at a long-term care facility (LTCF).

Point-prevalence study in 4 separate wards at a 600-bed urban LTCF that was conducted from October 31, 2006 through February 5, 2007.

One hundred sixty-one LTCF residents and 13 HCWs.

Nasal and rectal samples were obtained for culture from each resident, selected environmental surfaces in private and common rooms, and the hands and clothing of HCWs in each ward. All cultures were evaluated for the presence of MDR gram-negative bacteria, methicillin-resistant Staphylococcus aureus, and vancomycin-resistant enterococci. Clinical and demographic information were collected for each enrolled resident. Molecular typing was performed to identify epidemiologically related strains.

A total of 37 (22.8%), 1 (0.6%), and 18 (11.1%) residents were colonized with MDR gram-negative bacteria, vancomycin-resistant enterococci, and methicillin-resistant S. aureus, respectively. MDR gram-negative bacteria were recovered from 3 (1.8%) of the 175 environmental samples cultured, all of which were obtained from common areas in LTCF wards. One (7.7%) of the 13 HCWs harbored MDR gram-negative bacteria. Molecular typing identified clonally related MDR gram-negative strains in LTCF residents. After multivariable analysis, length of hospital stay of at least 4 years, fecal incontinence, and antibiotic exposure for at least 8 days were independent risk factors associated with harboring MDR gram-negative bacteria among LTCF residents.

The prevalence of MDR gram-negative bacteria is high among LTCF residents and exceeds that of vancomycin-resistant enterococci and methicillin-resistant S. aureus. Common areas in LTCFs may provide a unique opportunity for person-to-person transmission of MDR gram-negative bacteria.

At the end of 2002, a new, more virulent strain of Clostridium difficile, designated BI/NAP1, was the cause of a massive outbreak of infection in the province of Quebec. This particular strain was associated with a dramatic increase in morbidity and mortality among affected patients in 2003–2004. We tested and implemented a multipronged infection control approach to curtail the rate of C. difficile infection (CDI).

Five-year observational study.

A 554-bed, acute care tertiary hospital, the largest single medical center in Quebec, Canada.

To curtail the magnitude of the outbreak, we implemented a global strategy consisting of rapid C. difficile testing for all hospitalized patients who had at least 1 occurrence of liquid stool, the rapid isolation of patients infected with C. difficile in a dedicated ward with a specially trained housekeeping team, a global hand hygiene program, and the hiring of infection control practitioners. Antibiotic consumption at the institutional level was also monitored during the 5-year surveillance period. Cases of hospital-acquired CDI per 1,000 admissions were continuously monitored on a monthly basis during the entire surveillance period.

The highest recorded CDI rate was 42 cases per 1,000 admissions in January 2004. Once additional infection control resources were put in place, the rate descreased significantly during the period from April 2005 to March 2007. During the 2003–2004 period, there were 762 cases of CDI (mean annual rate, 37.28 cases per 1,000 admissions) recorded in our study, compared with 292 cases of CDI (14.48 cases per 1,000 admissions) during the 2006–2007 period (OR, 0.379 [95% CI, 0.331–0.435]; P < .001 ), a 61% reduction. In March 2007, the equivalent of 4 full-time equivalent infection control practitioners were in place, which gave a ratio of 0.96 infection control practitioners per 133 beds in use, compared with the ratio of 0.24 infection control practitioners per 133 beds in use in 2003, and the total number of hours dedicated to cleaning and housekeeping increased by 26.2%. The total amount of antibiotics used in the hospital did not vary significantly from 2002 to 2007, although there were changes in the classes antibiotic used.

The implementation of a multipronged intervention strategy to control the outbreak of CDI significantly improved the overall situation at the hospital and underlined the importance of investing in stringent infection control practices.

To investigate a nosocomial outbreak of infection with multidrug-resistant (MDR) Acinetobacter baumannii in the intensive care units at China Medical University Hospital in Taiwan.

Prospective outbreak investigation.

Three intensive care units in a 2,000-bed university hospital in Taichung, Taiwan.

Thirty-eight stable patients in 3 intensive care units, all of whom had undergone an invasive procedure, were enrolled in our study. Ninety-four A. baumannii strains were isolated from the patients or the environment in the 3 intensive care units, during the period from January 1 through December 31, 2006. We characterized A. baumannii isolates by use of repetitive extragenic palindromic–polymerase chain reaction (REP-PCR) and random amplified polymorphic DNA (RAPD) fingerprinting. The clinical characteristics of the source patients and the environment were noted.

All of the clinical isolates were determined to belong to the same epidemic strain of MDR A. baumannii by the use of antimicrobial susceptibility tests, REP-PCR, and RAPD fingerprinting. All patients involved in the infection outbreak had undergone an invasive procedure. The outbreak strain was also isolated from the environment and the equipment in the intensive care units. Moreover, an environmental survey of one of the intensive care units found that both the patients and the environment harbored the same outbreak strain.

The outbreak strain of A. baumannii might have been transmitted among medical staff and administration equipment. Routine and aggressive environmental and equipment disinfection is essential for preventing recurrent outbreaks of nosocomial infection with MDR A. baumannii.

Surveillance for latent tuberculosis in high-risk groups such as healthcare workers is limited by the nonspecificity of the tuberculin skin test (TST) in BCG-vaccinated individuals. The Mycobacterium tuberculosis antigen-specific interferon-γ release assays (IGRAs) show promise for more accurate latent tuberculosis detection in such groups.

To compare the utility of an IGRA, the T-SPOT.TB assay, with that of the TST in healthcare workers with a high rate of BCG vaccination.

Two hundred seven medical students from 2 consecutive cohorts underwent the T-SPOT.TB test and the TST in their final year of study. Subjects with negative baseline test results underwent repeat testing after working for 1 year as junior physicians in Singapore's public hospitals.

The baseline TST result was an induration 10 mm or greater in diameter in 177 of the 205 students who returned to have their TST results evaluated (86.3%), while the baseline T-SPOT.TB assay result was positive in 9 (4.3%) of the students. Repeat T-SPOT.TB testing in 182 baseline-negative subjects showed conversion in 9 (4.9%). A repeat TST in 18 subjects with baseline-negative TST results did not reveal any TST result conversion.

The high rate of positive baseline TST results in our BCG-vaccinated healthcare workers renders the TST unsuitable as a surveillance tool in this tuberculosis risk group. Use of an IGRA has enabled the detection and treatment of latent tuberculosis in this group. Our T-SPOT.TB conversion rate highlights the need for greater tuberculosis awareness and improved infection control practices in our healthcare institutions.

TO evaluate the effectiveness of a rigorous search and destroy policy for controlling methicillin-resistant Staphylococcus aureus (MRSA) infection or colonization.

Hospital-based observational follow-up study.

Erasmus University Medical Center Rotterdam, a 1,200-bed tertiary care center in Rotterdam, the Netherlands.

Outbreak control was accomplished by the use of active surveillance cultures for persons at risk, by the preemptive isolation of patients at risk, and by the strict isolation of known MRSA carriers and the eradication of MRSA carriage. For unexpected cases of MRSA colonization or infection, patients placed in strict isolation or contact isolation and healthcare workers (HCWs) were screened. We collected data from 2000–2004.

During the 5-year study period, 51,907 MRSA screening cultures were performed for 21,598 persons at risk (8,403 patients and 13,195 HCWs). By screening, it was determined that 123 (1.5%) of 8,403 patients and 31 (0.2%) of 13,195 HCWs were MRSA carriers. From the performance of clinical cultures, it was determined that 54 additional patients were MRSA carriers, resulting in a total of 177 patients carrying MRSA. Of the 177 patients carrying MRSA, 144 (81%) were primary patients, and 33 (19%) secondary Patients. The average number of nosocomial transmissions was 6.7 per year. The cumulative incidence of MRSA colonization among this group of patients was 0.10 cases per 100 admissions. Of 156 cases of MRSA colonization, 44 (28%) were acquired in a foreign healthcare institution, and 45 (29%) were acquired in other Dutch hospitals, 22 (47%) of which were acquired in a single hospital in our region. There were 16 cases (10%) that occurred in a nursing home and another 16 cases (10%) that fulfilled our definition of community-acquired MRSA colonization; there were 4 cases (3%) categorized as “other” and 31 cases (20%) for which the source of MRSA acquisition remained unknown. The basic reproduction rate was 10-fold less for patients isolated on admission, compared with those who were not. During the 5-year study period, 5 episodes of MRSA bacteremia occurred in which 4 patients died, an incidence rate of 0.28 cases of infection per 100,000 patient-days per year.

Our results show that, during a rigorous search and destroy policy, a low incidence of MRSA in our medical center was continuously observed and that this policy most likely contributed to a very low nosocomial transmission rate.

Nosocomial infection (NI) is one of the most serious healthcare issues currently influencing healthcare costs. This study estimates the impact of NI on costs in intensive care units (ICUs).

Prospective surveillance by a retrospective cohort study.

A medical ICU, a surgical ICU, and a mixed medical and surgical ICU in a large tertiary referral medical center.

Surveillance for NIs was conducted for all patients admitted to adult ICUs from 2003 through 2005. Retrospective chart review was conducted for each patient. The generalized linear modeling approach was used to assess the relationship of NIs to the increase in variable costs in individual ICUs and in all ICUs.

A total of 401 NIs occurred in 320 of 2,757 screened patients. The incidence rate was 12.1% in the medical ICU, 14.7% in the surgical ICU, and 16.7% in the mixed medical and surgical ICU (P> .05). All of the mean variable costs were significantly higher for patients with NI than they were for patients without NI, after controlling for covariates. The medical ICU had the greatest increase in mean cost ($13,456, which was 3.52 times [95% confidence interval {CI}, 2.94–4.22 times] the mean cost for patients without NI), followed by the mixed medical and surgical ICU ($6,748, which was 2.74 times [95% CI, 2.33–3.22 times] the mean cost for patients without NI) and the surgical ICU ($5,433, which was 2.46 times [95% CI, 1.99–3.05 times] the mean cost for patients without NI). Mean cost increases according to the site of NI were $6,056 for bloodstream infection (2.36 times [95% CI, 1.97–2.84 times] the mean cost for patients without NI), $4,287 for respiratory tract infection (1.91 times [95% CI, 1.57–2.32 times] the mean cost for patients without NI), $1,955 for urinary tract infection (1.42 times [95% CI, 1.18–1.72 times] the mean cost for patients without NI), and $1,051 for surgical site infection (1.23 times [95% CI, 0.90–1.68 times] the mean cost for patients without NI).

The medical ICU had the lowest rate of NI and the largest excess costs, the surgical ICU had the lowest excess costs, and the mixed medical and surgical ICU had the highest rate of NI. The cost is largely attributable to bloodstream infection and respiratory tract infection.

To describe and measure reliability of a computer-assisted method of case vignette assembly and expert review to assess the appropriateness of antimicrobial therapy for hospitalized adults.

Feasibility and reliability analysis of computer-assisted tool used to compare the effects of antimicrobial stewardship interventions.

Public teaching hospital.

Randomly selected adult antimicrobial recipients admitted to inpatient medicine services.

Clinical data abstracted from 504 paper medical records were merged with computerized laboratory and pharmacy data to assemble case vignettes that underwent expert review for appropriateness. We performed 3 validations, as follows: data for 35 vignettes abstracted independently by 2 research assistants were assessed for interrater agreement, expert review of 24 vignettes was compared with review of the corresponding paper medical records, and interrater reliability of antimicrobial appropriateness assessments by 2 experts was determined for 70 case vignettes.

Vignette assembly and expert review each required 10–12 minutes per case. Potentially important discrepancies occurred in 0%–32% of clinical findings abstracted independently by 2 research assistants. Expert review of 24 vignettes and the corresponding full paper medical records yielded fair agreement (kappa, 0.30). The 2 experts identified inappropriate initial antimicrobial therapy in 67% and 61% of case vignettes reviewed independently; interrater agreement was improved after sequential case discussion and stringent application of appropriateness criteria (kappa, 0.72).

Our case vignette assembly and expert review method is efficient, but improvements in both technical and human performance are needed to be able to yield valid estimates of the prevalence of inappropriate antimicrobial use. Assessments of antimicrobial appropriateness require validation.

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae is an emerging pathogen with serious clinical and infection control implications. To our knowledge, no study has specifically examined risk factors for KPC-producing K. pneumoniae or its impact on mortality.

To identify risk factors for infection or colonization with KPC-producing K. pneumoniae, a case-control study was performed. Case patients with KPC-producing K. pneumoniae were compared with control subjects with carbapenem-susceptible K. pneumoniae. A cohort study evaluated the association between KPC-producing K. pneumoniae and in-hospital mortality.

Fifty-six case patients and 863 control subjects were identified. In multivariable analysis, independent risk factors for KPC-producing K. pneumoniae were (1) severe illness (adjusted odds ratio [AOR], 4.31; 95% confidence interval [CI], 2.25–8.25), (2) prior fluoroquinolone use (AOR, 3.39; 95% CI, 1.50, 7.66), and (3) prior extended-spectrum cephalosporin use (AOR, 2.55; 95% CI, 1.18, 5.52). Compared with samples from other anatomic locations, K. pneumoniae isolates from blood samples were less likely to harbor KPC (AOR, 0.33; 95% CI, 0.12, 0.86). KPC-producing K. pneumoniae was independently associated with in-hospital mortality (AOR, 3.60; 95% CI, 1.87–6.91).

KPC-producing K. pneumoniae is an emerging pathogen associated with significant mortality. Our findings highlight the urgent need to develop strategies for prevention and infection control. Limiting use of certain antimicrobials, specifically fluoroquinolones and cephalosporins, use may be effective strategies.

The purpose of this study was to investigate whether physicians with larger sepsis caseloads provide better outcomes, defined as lower in-hospital mortality rates, for patients with sepsis.

Retrospective cross-sectional study.

This study used pooled data from the 2002-2004 Taiwan National Health Insurance Research Database. A total of 48,336 patients hospitalized with a principal diagnosis of septicemia were selected and assigned to 1 of 4 caseload groups on the basis of their treating physician's sepsis caseload during the 3 years reflected in the pooled data (low caseload, less than 39 cases; medium caseload, 39–88 cases; high caseload, 89–176 cases; and very high caseload, more than 176 cases). Generalized estimating equation models were used for analysis.

Receipt of treatment from physicians in the very high, high, and medium caseload groups decreased patients' odds of inhospital mortality by 49% (95% confidence interval [CI], 0.41-0.67; P < .001 ), 40% (95% CI, 0.53-0.68; P < .001 ), and 18% (95% CI, 0.73-0.92; P < .001), respectively, compared with the odds for patients treated by low-caseload physicians. These findings persisted after partitioning out systematic physician-specific and hospital-specific variation and isolating the effects of most hospital, physician, and patient confounders.

Patients treated by physicians who had a larger sepsis caseload had a substantially lower in-hospital mortality rate than did patients treated by physicians in the other caseload groups, and the difference was statistically significant. This result supports the “practice makes perfect” hypothesis.

To describe the method used to develop a flexible, computerized database for recording and reporting rates of influenza vaccination among healthcare personnel who were classified by their individual levels (hereafter, “tiers”) of direct patient contact.

Three-year descriptive summary.

Large, academic, tertiary care medical center in the United States.

All of the medical center's healthcare personnel.

The need to develop a computer-based system to record direct patient care tiers and vaccination data for healthcare personnel was identified. A plan that was to be implemented in stages over several seasons was developed.

Direct patient care tiers were defined by consensus opinion on the basis of the extent, frequency, and intensity of direct contact with patients. The definitions of these tiers evolved over 3 seasons. Direct patient care classifications were assigned and recorded in a computerized database, and data regarding the receipt of vaccination were tracked by using the same database. Data were extracted to generate reports of individual, departmental, and institutional vaccination rates, both overall and according to direct patient care tiers.

Development of a computerized database to record direct patient care tiers for individual healthcare workers is a daunting but manageable task. Widespread use of these direct patient care definitions will facilitate uniform comparisons of vaccination rates between institutions. This computerized database can easily be used by infection control personnel to accomplish several other key tasks, including vaccination triage in the context of shortage or delay, prioritization of personnel to receive interventions in times of crisis, and monitoring the status of other employee health or occupational health measures.

Nosocomial outbreaks of Legionnaires disease have been linked to contaminated water in hospitals. Immunocompromised patients are particularly vulnerable and, when infected, have a high mortality rate. We report the investigation of a cluster of cases of nosocomial pneumonia attributable to Legionella pneumophila serogroup 1 that occurred among patients on our stem cell transplantation unit.

We conducted a record review to identify common points of potential exposure, followed by environmental and water sampling for Legionella species from those sources. We used an air sampler to in an attempt to detect aerosolized Legionella and pulsed-field gel electrophoresis to compare clinical and environmental isolates.

The most likely sources identified were the water supply in the patients' rooms and a decorative fountain in the radiation oncology suite. Samples from the patients' rooms did not grow Legionella species. Cultures of the fountain, which had been restarted 4 months earlier after being shut off for 5 months, yielded L. pneumophila serogroup 1. The isolates from both patients and the fountain were identical by pulsed-field gel electrophoresis. Both patients developed pneumonia within 10 days of completing radiation therapy, and each reported having observed the fountain at close range. Both patients' infections were identified early and treated promptly, and both recovered.

This cluster was caused by contamination of a decorative fountain despite its being equipped with a filter and ozone generator. Fountains are a potential source of nosocomial Legionnaires disease despite standard maintenance and sanitizing measures. In our opinion, fountains present unacceptable risk in hospitals serving immunocompromised patients.

TO describe what is, to our knowledge, the first nosocomial outbreak of infection with pan–drug-resistant (including colistin-resistant) Acinetobacter baumannii, to determine the risk factors associated with these types of infections, and to determine their clinical impact.

Nested case-control cohort study and a clinical-microbiological study.

A 1,521-bed tertiary care university hospital in Seville, Spain.

Case patients were inpatients who had a pan-drug-resistant A. baumannii isolate recovered from a clinical or surveillance sample obtained at least 48 hours after admission to an intensive care unit (ICU) during the time of the epidemic outbreak. Control patients were patients who were admitted to any of the “boxes” (ie, rooms that partition off a distinct area for a patient's bed and the equipment needed to care for the patient) of an ICU for at least 48 hours during the time of the epidemic outbreak.

All the clinical isolates had similar antibiotic susceptibility patterns (ie, they were resistant to all the antibiotics tested, including Colistin), and, on the basis of repetitive extragenic palindromic-polymerase chain reaction, it was determined that all of them were of the same clone. The previous use of quinolones and glycopeptides and an ICU stay were associated with the acquisition of infection or colonization with pan-drug-resistant A. baumannii. To control this outbreak, we implemented the following multicomponent intervention program: the performance of environmental decontamination of the ICUs involved, an environmental survey, a revision of cleaning protocols, active surveillance for colonization with pan-drug-resistant A. baumannii, educational programs for the staff, and the display of posters that illustrate contact isolation measures and antimicrobial use recommendations.

We were not able to identify the common source for these cases of infection, but the adopted measures have proven to be effective at controlling the outbreak.

The incidence of surgical site infection (SSI) after hysterectomy ranges widely from 2% to 21%. A specific risk stratification index could help to predict more accurately the risk of incisional SSI following abdominal hysterectomy and would help determine the reasons for the wide range of reported SSI rates in individual studies. To increase our understanding of the risk factors needed to build a specific risk stratification index, we performed a retrospective multihospital analysis of risk factors for SSI after abdominal hysterectomy.

Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from July 1, 2003, to June 30, 2005, at 4 institutions. SSIs were defined by using Centers for Disease Control and Prevention/National Nosocomial Infections Surveillance criteria. Independent risk factors for abdominal hysterectomy were identified by using logistic regression.

There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSIs after abdominal hysterectomy and 14 organ-space SSIs after vaginal hysterectomy. Because risk factors for organ-space SSI were different according to univariate analysis, we focused further analyses on incisional SSI after abdominal hysterectomy. The maximum serum glucose level within 5 days after operation was highest in patients with deep incisional SSI, lower in patients with superficial incisional SSI, and lowest in uninfected patients (median, 189, 156, and 141 mg/dL, respectively; P = .005). Independent risk factors for incisional SSI included blood transfusion (odds ratio [OR], 2.4) and morbid obesity (body mass index [BMI], >35; OR, 5.7). Duration of operation greater than the 75th percentile (OR, 1.7), obesity (BMI, 30–35; OR, 3.0), and lack of private health insurance (OR, 1.7) were marginally associated with increased odds of SSI.

Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer duration of operation and lack of private health insurance were marginally associated with SSI.

Carbapenem resistance among isolates of Klebsiella pneumoniae has been unusual.

To identify risk factors for infection with carbapenem-resistant K. pneumoniae (CRKP) and to characterize microbiological aspects of isolates associated with these infections.

Retrospective case-control study.

A 900-bed tertiary care hospital.

From January 2006 through April 2007, K. pneumoniae was isolated from 461 inpatients; 88 had CRKP infection (case patients), whereas 373 had carbapenem-susceptible K. pneumoniae infection (control subjects). The independent risk factors for infection with CRKP were prior fluoroquinolone use (odds ratio [OR], 1.87 [95% confidence interval {CI}, 1.07–3.26]; P = .026), previous receipt of a carbapenem drug (OR, 1.83 [95% CI, 1.02–3.27]; P = .042), admission to the intensive care unit (OR, 4.27 [95% CI, 2.49–7.31]; P < .001), and exposure to at least 1 antibiotic drug before isolation of K. pneumoniae (OR, 3.93 [95% CI, 1.15–13.47]; P = .029). All CRKP isolates carried the blaKPC gene. Approximately 90% of the tested isolates carried the blaKPC-2 allele, suggesting patient-to-patient transmission. Almost all CRKP isolates were resistant to all antibiotics, except to Colistin (resistance rate, 4.5%), gentamicin (resistance rate, 7%), and tigecycline (resistance rate, 15%).

CRKP should be regarded as an emerging clinical threat. Because these isolates are resistant to virtually all commonly used antibiotics, control of their spread is crucial.

To examine the impact of methicillin resistance on in-hospital mortality, length of stay, and hospital cost after the onset of nosocomial Staphylococcus aureus bloodstream infection (BSI).

A retrospective cohort study.

A tertiary care hospital in Rhode Island.

A cohort of 182 consecutive patients who developed nosocomial BSI due to methicillin-susceptible and methicillin-resistant S. aureus (MSSA and MRSA, respectively)

Patients with MRSA BSI had a significantly longer total length of hospital and intensive care unit (ICU) stay before the onset of BSI and a higher average daily cost. Compared with ICU patients with MSSA BSI, those with MRSA BSI had a higher median total hospital cost ($42,137 vs $113,852), higher hospital cost after infection ($17,603 vs $51,492), and greater length of stay after infection (10.5 vs 20.5 days). After multivariable adjustment, ICU patients with MRSA BSI had significantly increased total hospital cost, hospital cost after infection, and length of stay after infection. However, using a propensity score approach, we found that, among ICU patients, the difference in cost after infection and the difference in length of stay after infection for MRSA, compared with MSSA BSI, were not significant. The differences among non-ICU patients who developed MRSA or MSSA BSI were not significant after multivariable adjustment or by propensity score.

On the basis of propensity score, we found that methicillin resistance did not independently increase hospital cost or length of stay after onset of S. aureus BSI. We believe that use of a propensity score on a comparable subset of patients may be a better method than multivariable adjustment for assessing the impact of methicillin resistance in cohort studies.

To identify healthcare worker (HCW) and work-site characteristics associated with HCWs' reported use of recommended respiratory-infection control practices in primary and emergency care settings.

A cross-sectional study using a self-administered questionnaire for HCWs during the summer and fall of 2005.

Primary and emergency care clinics at 5 medical centers in King County, Seattle, Washington.

Nurse professionals who reported receiving training (odds ratio [OR], 2.5 [confidence interval {CI}, 1.1–5.9]; P = .029), instructional feedback from supervisors (OR, 3.0 [CI, 1.5–5.9]; P = .002), and management support for implementing safe work practices had a higher odds of also reporting adherence to recommended respiratory precautions, compared with nurses who did not. Training was the only important determinant for adherence to respiratory precaution measures among medical practitioners (OR, 5.5 [CI, 1.2–25.8]; P = .031). The reported rate of adherence to hand hygiene practices was higher among nurse professionals who were male (OR, 2.2 [CI, 1.0–4.9]; P = .045), had infants, small children, or older adults living at home (OR, 2.2 [CI, 1.2–3.9]; P = .007), reported cleanliness and orderliness of the establishment where they worked (OR, 2.0 [CI, 1.1–3.5]; P = .019), had received respiratory-infection control training (OR, 3.2 [CI, 1.8–6.0]; P<.001), and reported fears about catching a dangerous respiratory infection at work (OR, 2.3 [CI, 1.2–4.5]; P= .011).

A number of HCW and work-site characteristics associated with HCWs' use of recommended respiratory-infection control measures have been identified. These potentially influential characteristics should be considered as targets or guides for further investigation, which should include the evaluation of intervention strategies.

To investigate the marked increase noted over an 8-month period in the number of Legionella pneumophila isolates recovered from bronchoalveolar lavage fluid specimens obtained during bronchoscopy in our healthcare system.

Bronchoscopy suite that serves a 580-bed tertiary care center and a large, multisite, faculty practice plan with approximately 2 million outpatient visits per year.

Cultures of environmental specimens from the bronchoscopy suite were performed, including samples from the air and water filters, bronchoscopes, and the ice machine, with the aim of identifying Legionella species. Specimens were filtered and acid-treated and then inoculated on buffered charcoal yeast extract agar. Serogrouping was performed on all isolates recovered from patient and environmental samples.

AU L. pneumophila isolates recovered from patients were serogroup 8, a serogroup that is not usually recovered in our facility. An epidemiologic investigation of the bronchoscopy suite revealed the ice machine to be contaminated with L. pneumophila serogroup 8. Patients were exposed to the organism as a result of a recently adopted practice in the bronchoscopy suite that involved directly immersing uncapped syringes of sterile saline in contaminated ice baths during the procedures. At least 1 patient was ill as a result of the pseudo-outbreak. Molecular typing of isolates recovered from patient and environmental samples revealed that the isolates were indistinguishable.

Extensive cleaning of the ice machine and replacement of the machine's water filter ended the pseudo-outbreak. This episode emphasizes the importance of using aseptic technique when performing invasive procedures, such as bronchoscopies. It also demonstrates the importance of reviewing procedures in all patient areas to ensure compliance with facility policies for providing a safe patient environment.

Acinetobacter baumannii is an emerging gram-negative pathogen that can cause healthcare-acquired infections among patients. Treatment is complicated for cases of healthcare-acquired infection with A. baumannii resistant to imipenem.

To elucidate the risk factors for imipenem-resistant A. baumannii (IRAB) infection or colonization and to identify the effect of resistance on clinical and economic outcomes.

We analyzed data from 2 medical centers of the University of Pennsylvania. Longitudinal trends in the prevalence of IRAB clinical isolates were characterized during the period from 1989 through 2004. For A. baumannii isolates obtained from 2001 through 2006, a case-control study was conducted to investigate the association between prior carbapenem use and IRAB infection or colonization, and a cohort study was performed to identify the effect of IRAB infection or colonization on mortality, length of stay after culture, and hospital cost after culture.

From 1989 through 2004, the annual prevalence of IRAB isolates ranged from 0% to 21%. During the period from 2001 through 2006, there were 386 unique patients with A. baumannii isolates, and 89 (23.1%) had IRAB isolates. Prior carbapenem use was independently associated with IRAB infection or colonization (adjusted odds ratio, 3.04 [95% confidence interval, 1.07–8.65]). There was a borderline significant association between IRAB infection or colonization and mortality, although this association was limited to isolates recovered from blood samples (adjusted odds ratio, 5.30 [95% confidence interval, 0.81–34.59]). Compared with patients with imipenem-susceptible A. baumannii infection or colonization, patients with IRAB infection or colonization had a longer hospital stay after culture (median, 21 vs 16 days; P = .07) and greater hospital charges after culture (mean, $334,516 vs $276,059; P = .03). After controlling for patient location in an intensive care unit, transfer from another facility, and length of hospital stay before culture, there was no longer an independent association between IRAB infection or colonization and higher cost after culture and length of stay after positive culture result.

Many A. baumannii isolates exhibit imipenem resistance, which is strongly associated with prior use of carbapenems. Given the high mortality rate associated with A. baumannii infection or colonization, interventions to curb further emergence of cases of IRAB infection and strategies to optimize therapy are needed.