To determine whether Staphylococcus aureus isolates from the nares of patients on a burn trauma unit were related to isolates colonizing or infecting other body sites.

Active surveillance for S. aureus, a case-control study, and pulsed-field gel electrophoresis of S. aureus isolates.

A burn trauma unit of a Midwestern university teaching hospital.

Patients admitted from February 1, 2002, through March 30, 2007, who had S. aureus isolated either from a nasal culture and from another body site (case patients) or from a nasal culture alone (control subjects).

Nineteen patients met the case patient definition and had paired isolates from the nares and an additional site available for typing. Of the 19 case patients, 8 had infections, 7 of which were caused by methicillin-resistant S. aureus (5 USA100 strain and 2 USA300 strain). A total length of stay of more than 3 weeks (odds ratio [OR], 8.75 [95% confidence interval {CI}, 2.2–34.6]; P = .002), residence in a long-term care facility (OR, 9.4 [95% CI, 2.1–42.5]; P = .004), and diabetes (OR, 3.2 [95% CI, 1.0–10.0]; P = .05) were associated with the isolation of S. aureus from the nares and other sites. Seventeen case patients (89.5%) had closely related isolates obtained from culture of samples from the nares and from other sites.

Prolonged length of stay, diabetes, or residing in a long-term care facility increased the risk of having S. aureus at sites other than the nares. S. aureus isolates from other body sites usually were closely related to nasal isolates. Most case patients had colonized or infected wounds that could be a source of S. aureus for other patients.

Creation of a mixture model based on Poisson processes for assessment of the extent of cross-transmission of multidrug-resistant pathogens in the hospital.

We propose a 2-component mixture of Poisson processes to describe the time series of detected cases of colonization. The first component describes the admission process of patients with colonization, and the second describes the cross-transmission. The data set used to illustrate the method consists of the routinely collected records for methicillin-resistant Staphylococcus aureus (MRSA), imipenem-resistant Pseudomonas aeruginosa, and multidrug-resistant Acinetobacter baumannii over a period of 3 years in a German tertiary care hospital.

For MRSA and multidrug-resistant A. baumannii, cross-transmission was estimated to be responsible for more than 80% of cases; for imipenem-resistant P. aeruginosa, cross-transmission was estimated to be responsible for 59% of cases. For new cases observed within a window of less than 28 days for MRSA and multidrug-resistant A. baumannii or 40 days for imipenem-resistant P. aeruginosa, there was a 50% or greater probability that the cause was cross-transmission.

The proposed method offers a solution to assessing of the extent of cross-transmission, which can be of clinical use. The method can be applied using freely available software (the package FlexMix in R) and it requires relatively little data.

To describe the French program for the prevention of healthcare-associated infections and antibiotic resistance and provide results for some of the indicators available to evaluate the program. In addition to structures and process indicators, the 2 outcome indicators selected were the rate of surgical site infection and the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates among the S. aureus isolates recovered.

Descriptive study of the evolution of the national structures for control of healthcare-associated infections since 1992. Through national surveillance networks, process indicators were available from 1993 to 2006, surgical site infection rates were available from 1999 to 2005, and prevalence rates for MRSA infection were available from 2001 to 2007.

A comprehensive national program has gradually been set up in France during the period from 1993 to 2004, which included strengthening of organized infection control activities at the local, regional, and national levels and developing large networks for surveillance of specific infections and antibiotic resistance. These achievements were complemented by instituting mandatory notification for unusual nosocomial events, especially outbreaks. The second phase of the program involved the implementation of 5 national quality indicators with public reporting. Surgical site infection rates decreased by 25% over a 6-year period. In France, the median proportion of MRSA among S. aureus isolates recovered from patients with bacteremia decreased from 33.4% to 25.7% during the period from 2001 to 2007, whereas this proportion increased in many other European countries.

Very few national programs have been evaluated since the Study on the Efficacy of Nosocomial Infection Control. Although continuing efforts are required, the French program appears to have been effective at reducing infection rates.

To determine risk factors and outcomes for patients with meropenem high–level-resistant Pseudomonas aeruginosa (MRPA) (minimum inhibitory concentration [MIC] ≥ 32 μg/mL).

Case-control-control.

An 867-bed urban, teaching hospital.

Fifty-eight MRPA case patients identified from an earlier P. aeruginosa study; 125 randomly selected control patients with meropenem-susceptible P. aeruginosa (MSPA) (MIC ≤ 4 μg/mL), and 57 control patients without P. aeruginosa (sampled by case date/location).

Patient data, outcomes, and costs were obtained via administrative database. Cases were compared to each control group while controlling for time at risk (days between admission and culture, or entire length of stay [LOS] for patients without P. aeruginosa).

A multivariable model predicted risks for MRPA versus MSPA (odds ratio [95% confidence interval]): more admissions (in the prior 12 months) (1.41 [1.15, 1.74]), congestive heart failure (2.19 [1.03, 4.68]), and Foley catheter (2.53 [1.18, 5.45]) (adj. R2 = 0.28). For MRPA versus no P. aeruginosa, risks were age (in 5-year increments) (1.17 [1.03, 1.33]), more prior admissions (1.40 [1.08, 1.81]), and more days in the intensive care unit (1.10 [1.03, 1.18]) (adj. R2 = 0.32). Other invasive devices (including mechanical ventilation) and previous antibiotic use (including carbapenems) were nonsignificant. MRPA mortality (31%) did not differ from that of MSPA (15%) when adjusted for time at risk (P = .15) but did from mortality without P. aeruginosa (9%) (P = .01 ). Median LOS and costs were greater for MRPA patients versus MSPA patients and patients without P. aeruginosa: 30 days versus 16 and 10 (P < .01 ) and $88,425 versus $28,620 and $22,605 (P <.01).

Although antibiotic use has been shown to promote resistance, our data found that prior antibiotic use was not associated with MRPA acquisition. However, admission frequency and Foley catheters were, suggesting that infection control measures are essential to reducing MRPA transmission.

To ascertain whether cystic fibrosis (CF) patients are colonized or infected with unique or multiple strains of Stenotrophomonas maltophilia; to understand whether some strains colonize or infect more than 1 patient, indicating clonal spread; and to explore the molecular heterogeneity of hospital water isolates and their correlation with clinical isolates.

The regional CF center of Policlinico “Umberto I” of Rome, Italy.

The study was carried out on a random sample of S. maltophilia isolates (n = 110) collected from CF patients (n = 50) during the period 2002–2005 and on 24 water isolates obtained during a monitoring program in the first 6 months of 2005. Home environmental samplings were not performed. All isolates, which were recovered from cultures of specimens obtained in both inpatient and outpatient settings, were genotyped with DNA macrorestriction analysis with the restriction enzyme Xbal and pulsed-field gel electrophoresis.

One-third of the patients with repeated episodes of S. maltophilia infection or colonization hosted more than 1 strain. A potential transmission, defined as the isolation of the same strain in 2 or more patients, occurred 5 times, showing a frequency of potential transmission episodes slightly higher than previously reported. Water, taps, and sinks of the different rooms of the CF center tended to be persistently colonized with the same strain of S. maltophilia, with no correlation between clinical and water-associated isolates.

The study does not provide sufficient data to conclude definitively that isolation of colonized or infected CF patients and control of hospital water systems contamination would be beneficial infection control measures. Epidemiologic analytical studies that correlate the presence of S. maltophilia with clinical outcomes are strongly needed.

To conduct a cost-effectiveness analysis of the economic outcomes of ventilator-associated pneumonia (VAP) prevention associated with silver-coated endotracheal tubes versus uncoated endotracheal tubes.

We used a simple decision model based on a hypothetical 1,000-patient cohort intubated with silver-coated or uncoated endotracheal tubes. The primary end point was marginal hospital savings per case of VAP prevented (savings from using silver-coated endotracheal tubes minus acquisition cost divided by number of VAP cases prevented).

We followed each branch of the decision model to VAP or no VAP and conducted Monte Carlo simulations and sensitivity analyses. Inputs for VAP incidence, relative risk reduction, and hospital costs were derived from publicly available sources. Relative risk reduction was derived from the pivotal study of the silver-coated endotracheal tube.

In the base-case analysis, we reduced the pivotal study relative risk in incidence of microbiologically confirmed VAP in patients intubated ≥24 hours from 35.9% to 24%. Thus, 23 of 97 expected cases of VAP could be prevented with silver-coated endotracheal tubes. The savings per case of VAP prevented was $12,840 in the base case, with assumed marginal VAP cost of $16,620 and costs of $90.00 for coated and $2.00 for uncoated endotracheal tubes. Estimates were most sensitive to assumptions regarding VAP cost and relative risk reduction with silver-coated endotracheal tubes. Nonetheless, in multivariate sensitivity analyses, the silver-coated endotracheal tubes yielded persistent savings (95% confidence interval, $9,630-$16,356) per case of VAP prevented. With other base-case inputs held constant, breakeven cost for silver-coated endotracheal tubes was $388.

The silver-coated endotracheal tube represents a strategy for preventing VAP that may yield hospital savings.

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.