Pseudomonas aeruginosa has been increasingly recognized for its ability to cause significant hospital-associated outbreaks, particularly since the emergence of multidrug-resistant strains. Biofilm formation allows the pathogen to persist in environmental reservoirs. Thus, multiple hospital room design elements, including sink placement and design, can impact nosocomial transmission of P. aeruginosa and other pathogens.

From December 2004 through March 2006, 36 patients exposed to the intensive care unit or transplant units of a tertiary care hospital were infected with a multidrug-resistant strain of P. aeruginosa. All phenotypically similar isolates were examined for genetic relatedness by means of pulsed-field gel electrophoresis. Clinical characteristics of the affected patients were collected, and a detailed epidemiological and environmental investigation of potential sources was carried out.

Seventeen of the infected patients died within 3 months; for 12 (71%) of these patients, infection with the outbreak organism contributed to or directly caused death. The source of the outbreak was traced to hand hygiene sink drains, where biofilms containing viable organisms were found. Testing by use of a commercial fluorescent marker demonstrated that when the sink was used for handwashing, drain contents splashed at least 1 meter from the sink. Various attempts were made to disinfect the drains, but it was only when the sinks were renovated to prevent splashing onto surrounding areas that the outbreak was terminated.

This report highlights the importance of biofilms and of sink and patient room design in the propagation of an outbreak and suggests some strategies to reduce the risks associated with hospital sinks.

Healthcare-acquired infections (HAIs) cause substantial patient morbidity and mortality. Items in the environment harbor microorganisms that may contribute to HAIs. Reduction in surface bioburden may be an effective strategy to reduce HAIs. The inherent biocidal properties of copper surfaces offer a theoretical advantage to conventional cleaning, as the effect is continuous rather than episodic. We sought to determine whether placement of copper alloy-surfaced objects in an intensive care unit (ICU) reduced the risk of HAI.

Intention-to-treat randomized control trial between July 12, 2010, and June 14, 2011.

The ICUs of 3 hospitals.

Patients presenting for admission to the ICU.

Patients were randomly placed in available rooms with or without copper alloy surfaces, and the rates of incident HAI and/or colonization with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in each type of room were compared.

The rate of HAI and/or MRSA or VRE colonization in ICU rooms with copper alloy surfaces was significantly lower than that in standard ICU rooms (0.071 vs 0.123; P = .020). For HAI only, the rate was reduced from 0.081 to 0.034 (P = .013).

Patients cared for in ICU rooms with copper alloy surfaces had a significantly lower rate of incident HAI and/or colonization with MRSA or VRE than did patients treated in standard rooms. Additional studies are needed to determine the clinical effect of copper alloy surfaces in additional patient populations and settings.

To describe the epidemiology, diagnosis, risk factors, patient impact, and treatment strategies for recurrent Clostridium difficile-associated disease (CDAD).

Data were collected as part of a blinded, placebo-controlled clinical trial testing a new combination treatment for recurrent CDAD. Retrospective data regarding prior CDAD episodes were collected from interviews and medical-chart review. Prospective data on the current CDAD episode, risk factors, and recurrence rates were collected during a 2-month follow-up.

National referral study.

Patients with recurrent CDAD.

Treatment with a 10-day course of low-dose (500 mg/d) or high-dose (2 g/d) vancomycin or metronidazole (1 g/d).

Recurrent CDAD was found to have a lengthy course involving multiple episodes of diarrhea, abdominal cramping, nausea, and fever. CDAD may recur over several years despite frequent treatment with antibiotics. Recurrence rates were similar regardless of the choice or dose of antibiotic. Recurrent CDAD is not a trivial disease: patients may have multiple episodes (as many as 14), may require hospitalization, and the mean lifetime cost of direct medical care was $10,970 per patient. Fortunately, the disease does not become progressively more severe as the number of episodes increase. Two risk factors predictive for recurrent CDAD were found: increasing age and a decreased quality-of-life score at enrollment.

Recurrent CDAD is a persistent disease that may result in prolonged hospital stays, additional medical costs, and rare serious complications.

To evaluate the economic impact of ventilator-associated pneumonia (VAP) on length of stay and hospital costs.

Retrospective matched cohort study.

Premier database of hospitals in the United States.

Eligible patients were admitted to intensive care units (ICUs), received mechanical ventilation for ≥2 calendar-days, and were discharged between October 1, 2008, and December 31, 2009.

VAP was defined by International Classification of Diseases, Ninth Revision (ICD-9), code 997.31 and ventilation charges for ≥2 calendar-days. We matched patients with VAP to patients without VAP by propensity score on the basis of demographics, administrative data, and severity of illness. Cost was based on provider perspective and procedural cost accounting methods.

Of 88,689 eligible patients, 2,238 (2.5%) had VAP; the incidence rate was 1.27 per 1,000 ventilation-days. In the matched cohort, patients with VAP (n = 2,144) had longer mean durations of mechanical ventilation (21.8 vs 10.3 days), ICU stay (20.5 vs 11.6 days), and hospitalization (32.6 vs 19.5 days; all P< .0001) than patients without VAP (n = 2,144). Mean hospitalization costs were $99,598 for patients with VAP and $59,770 for patients without VAP (P< .0001), resulting in an absolute difference of $39,828. Patients with VAP had a lower in-hospital mortality rate than patients without VAP (482/2,144 [22.5%] vs 630/2,144 [29.4%]; P<.0001).

Our findings suggest that VAP continues to occur as defined by the new specific ICD-9 code and is associated with a statistically significant resource utilization burden, which underscores the need for cost-effective interventions to minimize the occurrence of this complication.

Infect Control Hosp Epidemiol 2012;33(3):250-256

Peripherally inserted central catheters (PICCs) are associated with central line-associated bloodstream infection (CLABSI). The magnitude of this risk relative to central venous catheters (CVCs) is unknown.

To compare risk of CLABSI between PICCs and CVCs.

MEDLINE, CinAHL, Scopus, EmBASE, and Cochrane CENTRAL were searched. Full-text studies comparing the risk of CLABSI between PICCs and CVCs were included. Studies involving adults 18 years of age or older who underwent insertion of a PICC or a CVC and reported CLABSI were included in our analysis. Studies were evaluated using the Downs and Black scale for risk of bias. Random effects meta-analyses were used to generate summary estimates of CLABSI risk in patients with PICCs versus CVCs.

Of 1,185 studies identified, 23 studies involving 57,250 patients met eligibility criteria. Twenty of 23 eligible studies reported the total number of CLABSI episodes in patients with PICCs and CVCs. Pooled meta-analyses of these studies revealed that PICCs were associated with a lower risk of CLABSI than were CVCs (relative risk [RR], 0.62; 95% confidence interval [CI], 0.40-0.94). Statistical heterogeneity prompted subgroup analysis, which demonstrated that CLABSI reduction was greatest in outpatients (RR [95% CI], 0.22 [0.18-0.27]) compared with hospitalized patients who received PICCs (RR [95% CI], 0.73 [0.54-0.98]). Thirteen of the included 23 studies reported CLABSI per catheter-day. Within these studies, PICC-related CLABSI occurred as frequently as CLABSI from CVCs (incidence rate ratio [95% CI], 0.91 [0.46-1.79]).

Only 1 randomized trial met inclusion criteria. CLABSI definition and infection prevention strategies were variably reported. Few studies reported infections by catheter-days.

Although PICCs are associated with a lower risk of CLABSI than CVCs in outpatients, hospitalized patients may be just as likely to experience CLABSI with PICCs as with CVCs. Consideration of risks and benefits before PICC use in inpatient settings is warranted.

Analyze changes that have occurred among U.S. hospitals over a 17-year period, 1975 through 1991, in the percentage of Staphylococcus aureus resistant to b-lactam antibiotics and associated with nosocomial infections.

Retrospective review. The percentage of methicillin-resistant S aureus (MRSA) was defined as the number of S aureus isolates resistant to either methicillin, oxacillin, or nafcillin divided by the total number of S aureus isolates for which methicillin, oxacillin, or nafcillin susceptibility test results were reported to the National Nosocomial Infections Surveillance (NNIS) System.

NNIS System hospitals.

Of the 66,132 S aureus isolates that were tested for susceptibility to methicillin, oxacillin, or nafcillin during 1975 through 1991, 6,986 (11%) were resistant to methicillin, oxacillin, or nafcillin. The percentage MRSA among all hospitals rose from 2.4% in 1975 to 29% in 1991, but the rate of increase differed significantly among 3 bed-size categories: <200 beds, 200 to 499 beds, and 2500 beds. In 1991, for hospitals with <200 beds, 14.9% of S aureus isolates were MRSA, for hospitals with 200 to 499 beds, 20.3% were MRSA; and for hospitals with >500 beds, 38.3% were MRSA. The percentage MRSA in each of the bed-size categories rose above 5% at different times: in 1983, for hospitals with 2500 beds; in 1985, for hospitals with 200 to 499 beds; and in 1987, for hospitals with <200 beds.

This study suggests that hospitals of all sizes are facing the problem of MRSA, the problem appears to be increasing regardless of hospital size, and control measures advocated for MRSA appear to require re-evaluation. Further study of MRSA in hospitals would benefit our understanding of this costly pathogen.

To elucidate behavioral determinants of handwashing among nurses.

Statistical modeling using the Theory of Planned Behavior and relevant components to handwashing behavior by nurses that were derived from focus-group discussions and literature review.

The community and 3 tertiary care hospitals.

Children aged 9-10 years, mothers, and nurses.

Responses from 754 nurses were analyzed using backward linear regression for handwashing intention. We reasoned that handwashing results in 2 distinct behavioral practices—inherent handwashing and elective handwashing—with our model explaining 64% and 76%, respectively, of the variance in behavioral intention. Translation of community handwashing behavior to healthcare settings is the predominant driver of all handwashing, both inherent (weighted β = 2.92) and elective (weighted β = 4.1). Intended elective in-hospital handwashing behavior is further significantly predicted by nurses' beliefs in the benefits of the activity (weighted β = 3.12), peer pressure of senior physicians (weighted β = 3.0) and administrators (weighted β = 2.2), and role modeling (weighted β = 3.0) but only to a minimal extent by reduction in effort (weighted β = 1.13). Inherent community behavior (weighted β = 2.92), attitudes (weighted β = 0.84), and peer behavior (weighted β = 1.08) were strongly predictive of inherent handwashing intent.

A small increase in handwashing adherence may be seen after implementing the use of alcoholic hand rubs, to decrease the effort required to wash hands. However, the facilitation of compliance is not simply related to effort but is highly dependent on altering behavioral perceptions. Thus, introduction of hand rub alone without an associated behavioral modification program is unlikely to induce a sustained increase in hand hygiene compliance.

Clostridium difficile spores persist in hospital environments for an extended period. We evaluated whether admission to a room previously occupied by a patient with C. difficile infection (CDI) increased the risk of acquiring CDI.

Retrospective cohort study.

Medical intensive care unit (ICU) at a tertiary care hospital.

Patients admitted from January 1, 2005, through June 30, 2006, were evaluated for a diagnosis of CDI 48 hours after ICU admission and within 30 days after ICU discharge. Medical, ICU, and pharmacy records were reviewed for other CDI risk factors. Admitted patients who did develop CDI were compared with admitted patients who did not.

Among 1,844 patients admitted to the ICU, 134 CDI cases were identified. After exclusions, 1,770 admitted patients remained for analysis. Of the patients who acquired CDI after admission to the ICU, 4.6% had a prior occupant without CDI, whereas 11.0% had a prior occupant with CDI (P = .002). The effect of room on CDI acquisition remained a significant risk factor (P = .008) when Kaplan-Meier curves were used. The prior occupant's CDI status remained significant (P = .01; hazard ratio, 2.35) when controlling for the current patient's age, Acute Physiology and Chronic Health Evaluation III score, exposure to proton pump inhibitors, and antibiotic use.

A prior room occupant with CDI is a significant risk factor for CDI acquisition, independent of established CDI risk factors. These findings have implications for room placement and hospital design.

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.

To determine the attributable hospital stay and costs for nosocomial methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S aureus (MRSA) primary bloodstream infections (BSIs).

Pairwise-matched (1:1) nested case-control study.

University-based tertiary-care medical center.

Patients admitted between December 1993 and March 1995 were eligible. Cases were defined as patients with a primary nosocomial S aureus BSI; controls were selected according to a priori matching criteria.

Length of hospital stay and total and variable direct costs of hospitalization.

The median hospital stay attributable to primary nosocomial MSSA BSI was 4 days, compared with 12 days for MRSA (P=.023). Attributable median total cost for MSSA primary nosocomial BSIs was $9,661 versus $27,083 for MRSA nosocomial infections (P=.043).

Nosocomial primary BSI due to S aureus significantly prolongs the hospital stay. Primary nosocomial BSIs due to MRSA result in an approximate threefold increase in direct cost, compared with those due to MSSA.

To assess the relative importance of independent risk factors for peripheral intravenous catheter (PIVC) failure.

Secondary data analysis from a randomized controlled trial of PIVC dwell time. The Prentice, Williams, and Peterson statistical model was used to identify and compare risk factors for phlebitis, occlusion, and accidental removal.

Three acute care hospitals in Queensland, Australia.

The trial included 3,283 adult medical and surgical patients (5,907 catheters) with a PIVC with greater than 4 days of expected use.

Modifiable risk factors for occlusion included hand, antecubital fossa, or upper arm insertion compared with forearm (hazard ratio [HR], 1.47 [95% confidence interval (CI), 1.28–1.68], 1.27 [95% CI, 1.08–1.49], and 1.25 [95% CI, 1.04–1.50], respectively); and for phlebitis, larger diameter PIVC (HR, 1.48 [95% CI, 1.08–2.03]). PIVCs inserted by the operating and radiology suite staff had lower occlusion risk than ward insertions (HR, 0.80 [95% CI, 0.67–0.94]). Modifiable risks for accidental removal included hand or antecubital fossa insertion compared with forearm (HR, 2.45 [95% CI, 1.93–3.10] and 1.65 [95% CI, 1.23–2.22], respectively), clinical staff insertion compared with intravenous service (HR, 1.69 [95% CI, 1.30–2.20]); and smaller PIVC diameter (HR, 1.29 [95% CI, 1.02–1.61]). Female sex was a nonmodifiable factor associated with an increased risk of both phlebitis (HR, 1.64 [95% CI, 1.28–2.09]) and occlusion (HR, 1.44 [95% CI, 1.30–1.61]).

PIVC survival is improved by preferential forearm insertion, selection of appropriate PIVC diameter, and insertion by intravenous teams and other specialists.

The original randomized controlled trial on which this secondary analysis is based is registered with the Australian New Zealand Clinical Trials Registry (http://www.anzctr.org.au; ACTRN12608000445370).

To determine the relative importance of different risk factors for the development of surgical-site infections (SSIs) in orthopedic surgery with prosthetic implants.

In a cohort of 272 patients, the following possible risk factors were studied: age, gender, method of hair removal, duration of operation, surgeon, underlying illness, and nasal carriage of Staphylococcus aureus. Infections were recorded following the Centers for Disease Control criteria. The relation between risk factors and SSI was tested in univariate and multiple logistic regression analysis.

Community hospital in Breda, The Netherlands.

18 (6.6%) of 272 patients experienced SSI: 11 superficial and 7 deep SSI. These infections led in three cases to removal of the prosthesis and caused 286 extra days in hospital. The main causative pathogen was S aureus. In multiple logistic regression analysis, the following factors were independent risk factors for the development of SSI: high-level nasal carriage of S aureus (P=.04), male gender (P=.005), and surgeon 1 (P=.006). The only independent risk factor for SSI with S aureus was high-level nasal carriage of S aureus (P=.002).

High-level nasal carriage of S aureus was the most important and only significant independent risk factor for developing SSI with S aureus.