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We studied uninsured patients admitted to Rhode Island Hospital from January 1 through June 30, 2005, and from January 1 through June 30, 2006. The mean total hospital charge for an uninsured patient with a hospital-acquired infection was $18,487; for those without such an infection, it was $4,951 (P < .001). Multivariable linear regression revealed that a hospital-acquired infection accounted for 11.8 excess hospital days (P = .001). Length of stay was the only independent variable associated with total excess hospital charges.

Background: This study was conducted to evaluate the ongoing transmission of methicillin-resistant Staphylococcus aureus (MRSA) in a 10-bed trauma intensive care unit (TICU) in a large teaching hospital., Methods: Surveillance cultures for MRSA were obtained on admission to the TICU. Colonized or infected patients were placed on contact precautions. On February 21, 2003, 19 burn patients were admitted to the TICU after a local mass casualty event. Universal barrier precautions were implemented for all patients, and point-prevalence surveys (nares cultures) were used to detect MRSA acquisition., Results: During March 2003, 58% of the burn patients developed MRSA infection or colonization. Six of 133 health care workers (HCWs) had positive MRSA screening cultures. Seven patients and 4 HCWs harbored the pulsed-field gel electrophoresis clone A. Two patients and 1 HCW harbored clone B. Once the colonized HCWs were successfully decolonized, a sustained reduction in MRSA infections occurred., Conclusion: Transmission of MRSA in an ICU was observed despite various infection control precautions. Identifying and treating colonized HCWs was followed by a significant reduction in the incidence of MRSA. Unrecognized MRSA-colonized HCWs may be an important reservoir in endemic institutions that could impair other control measures.

Background: Catheter lock solutions are used for prevention and management of catheter-related bloodstream infections. We investigated the activity of daptomycin and vancomycin lock solutions against Staphylococcus aureus and Staphylococcus epidermidis in an in vitro central venous catheter (CVC) model., Methods: Biofilm-producing reference strains of S. aureus and S. epidermidis were evaluated. After 24 h of bacterial growth in a CVC model, daptomycin and vancomycin bactericidal activity (+/- preservative-containing heparin sodium) were separately evaluated as a lock solution using 0.5, 1 and 35 mg/ml. Calcium carbonate (50 mg/l) was added to all lock solutions containing daptomycin. Each CVC was drained, flushed and sonicated at 72 h to assess CFU/ml., Results: After 72 h of exposure in the catheter lock solutions, daptomycin and vancomycin at 0.5, 1 and 5 mg/ml demonstrated bactericidal activity (>3.0 log10 CFU/ml) against S. aureus and S. epidermidis (P

Catheter-related bloodstream infections (CRBSI) are a significant cause of morbidity and excess hospital cost. Data from prospective, randomized trials demonstrate that the risk of these infections can be minimized by simple interventions. Changing the behaviour of healthcare workers who insert and care for intravascular catheters is imperative. Creating a culture of patient safety and assuring easy access to the products necessary to maintain strict asepsis during catheter insertion, dressing changes, and when manipulating catheter hubs, will enhance adherence to optimal practice and will reduce the risk posed to the millions of patients in need of such devices.

Infections due to antimicrobial-resistant viridans group streptococci are increasing. The present study was done to determine the frequency of antibiotic resistance among community-acquired viridans group streptococci isolated from blood cultures and to identify the risk factors associated with acquiring antibiotic-resistant viridans group streptococci. Twenty-eight community-acquired viridans group streptococcal isolates were recovered from 27 patients, of which 89%, 86%, 79%, 61%, and 39% were susceptible to ceftriaxone, clindamycin, tetracycline, penicillin, and erythromycin, respectively; 100% were susceptible to levofloxacin and vancomycin. Among the patients with previous antibiotic use, 73% had penicillin non-susceptible viridans group streptococci, compared with 18% who did not receive prior antibiotics (p = 0.006). Patients with and without prior antibiotic use, 27% and 0%, respectively, had ceftriaxone non-susceptible viridans group streptococci isolates, respectively (p = 0.05). Patients with and without prior antibiotic use, 45% and 6%, respectively, had tetracycline non-susceptible viridans group streptococci isolates, respectively (p = 0.02). No other risk factors for isolation of non-susceptible viridans group streptococci were identified.

This study analyzed tourniquets used for orthopedic surgery in our hospital to determine the frequency and type of microbial contamination. Group A tourniquets were from our main operating room, Group B tourniquets were from our ambulatory surgicenter, Group C tourniquets were unused, prepackaged, sterile tourniquets from our main operating room, and Group D tourniquets were sterilely packed tourniquets from our ambulatory surgicenter. Tourniquets from Groups A, B, C, and D had 100%, 40%, 0%, and 0% microbial growth, respectively. For Group A tourniquets, coagulase-negative staphylococci, Bacillus, and Staphylococcus aureus were present in 100%, 60%, and 20% of tourniquets, respectively. Twenty percent were contaminated either with Streptococcus sanguis, Aerococcus viridans, or Cornyebacterium species. Coagulase-negative staphylococci and Bacillus were present in 40% and 30% of Group B tourniquets, respectively. Tourniquet contamination may be a risk factor for the development of surgical site infection in orthopedic surgery.

We investigated blood cultures that revealed growth at night when no technologists were in the microbiology laboratory and at other times when the laboratory was staffed. On average, it took 7 h and 26 min and 2 h and 12 min for laboratory personnel to report positive blood culture Gram stain results to physicians when growth was detected by automated instruments during the former and latter time periods, respectively. When positive blood culture results led to a change in therapy, it took an average of 8 h and 21 min and 5 h and 26 min in the former and latter groups, respectively, from detection to when the order was written.

Objective: To determine the etiology of Pseudomonas aeruginosa surgical-site infections following cardiac surgery., Setting: University teaching hospital., Patients: Those with wound cultures that grew P. aeruginosa after cardiac surgery performed from 1999 to 2001., Methods: Medical records and operating room (OR) records of patients with P. aeruginosa cardiac surgical-site infections from 1999 to 2001 were reviewed. Healthcare workers involved with two or more cases were interviewed and examined. Specimens for environmental cultures were obtained from the ORs and cardiac surgical equipment. Cardiac surgery cases were observed and postoperative care and the cleaning of surgical instruments were investigated. OR air handling system records during the epidemic period were reviewed. Molecular fingerprinting of available P. aeruginosa isolates from infected patients and a healthcare worker was done., Results: There were five P. aeruginosa cardiac surgical-site infections from January to August 2001, compared with no such infections from 1999 to 2000. All were adult patients. One cardiac surgeon with onychomycosis operated on all five cases. He did not routinely double glove. The involved fingernail grew P. aeruginosa. Three P. aeruginosa patient isolates were available for pulsed-field gel electrophoresis; two were identical to the isolate from the involved surgeon's onychomycotic nail. No environmental OR cultures grew P. aeruginosa. The surgeon's culture-positive nail was completely removed. There have been no P. aeruginosa surgical-site infections among cardiac surgery patients since this intervention., Conclusion: At least two cases of a cluster of P. aeruginosa surgical-site infections resulted from colonization of a cardiac surgeon's onychomycotic nail.

We describe two patients who had tuberculomas that were initially misdiagnosed as neurosarcoidosis, leading to prolonged steroid therapy before initiation of antituberculous medications. Neither patient was infected with the human immunodeficiency virus, and one of the patients had a negative tuberculosis skin test.

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996. These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery anesthesiology interventional radiology pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology ofAmerica (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996 These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e., education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Intravascular catheter-associated bloodstream infections significantly increase rates of morbidity and hospital costs. Microbial colonization and development of biofilms, which are known to be recalcitrant to antibiotic therapy, often lead to the loss of otherwise patent vascular access systems. We evaluated a new taurolidine- and citrate-based catheter lock solution (Neutrolin; Biolink Corporation, Norwell, Mass.) for its activity against planktonic microbes, antimicrobial activity in a catheter model, and biofilm eradication activity. In studies of planktonic microbes, after 24 h of contact, 675 mg of taurolidine-citrate solution per liter caused > 99% reductions in the initial counts of Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Entercoccus faecalis. A solution of 13,500 mg/liter was cidal for Candida albicans. Ports and attached catheters inoculated with 50 to 600 CFU of these bloodstream isolates per ml were locked with heparin or the taurolidine-citrate solution. After 72 h, there was no growth in the taurolidine-citrate-treated devices but the heparin-treated devices exhibited growth in the range of 6 x 10(2) to 5 x 10(6) CFU/ml. Biofilms were developed on silicone disks in modified Robbins devices with broth containing 6% serum (initial counts, 10(6) to 10(8) CFU/cm(2)). The axenic biofilms were treated for 24 h with taurolidine-citrate or heparin. Taurolidine-citrate exposure resulted in a median reduction of 4.8 logs, whereas heparin treatment resulted in a median reduction of 1.7 logs (P < 0.01). No significant differences in the effects of the two treatments against P. aeruginosa and C. albicans were observed. These findings suggest that taurolidine-citrate is a promising combination agent for the prevention and treatment of intravascular catheter-related infections.

Staphylococcus epidermidis is a major cause of infections associated with indwelling medical devices. Biofilm production is an important virulence attribute in the pathogenesis of device-related infections. Therefore, elimination of these biofilms is an ideal treatment. Salicylate (5 mM) combined with 1 microg of vancomycin per ml inhibited biofilm formation by S. epidermidis (RP62A) by >or=99.9%. When biofilm-coated polystyrene beads were exposed to 5 mM sodium salicylate and 4 microg of vancomycin per ml (one-half the minimum biofilm eradication concentration), there was a >99.9% reduction in viable count.

Most intravascular catheter-related infections are associated with central venous catheters. Technologic advances shown to reduce the risk for these infections include a catheter hub containing an iodinated alcohol solution, short-term chlorhexidine-silver sulfadiazine- impregnated catheters, minocycline-rifampin-impregnated catheters, and chlorhexidine- impregnated sponge dressings. Nontechnologic strategies for reducing risk include maximal barrier precautions during catheter insertion, specialized nursing teams, continuing quality improvement programs, and tunneling of short-term internal jugular catheters.

Purpose: To review the literature on prevention of intravascular catheter-related infections., Data Sources: The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles. Primary authors were contacted directly if data were incomplete., Study Selection: Studies met the following criteria unless otherwise stated: Trials were prospective and randomized; catheters were inserted into new sites, not into old sites over guidewires; catheter cultures were done by using semi-quantitative or quantitative methods; and, for prospective studies, catheter-related bloodstream infection was confirmed by microbial growth from percutaneously drawn blood cultures that matched catheter cultures., Data Extraction: Data on population, methods, preventive strategy, and outcome (measured as catheter-related bloodstream infections) were gathered. The quality of the data was graded by using preestablished criteria., Data Synthesis: The recommended preventive strategies with the strongest supportive evidence are full barrier precautions during central venous catheter insertion; subcutaneous tunneling short-term catheters inserted in the internal jugular or femoral veins when catheters are not used for drawing blood; contamination shields for pulmonary artery catheters; povidone-iodine ointment applied to insertion sites of hemodialysis catheters; specialized nursing teams caring for patients with short-term peripheral venous catheters, especially at institutions with a high incidence of catheter-related infection; no routine replacement of central venous catheters; antiseptic chamberfilled hub or hub-protective antiseptic sponge for central venous catheters; and use of chlorhexidine-silver sulfadiazine-impregnated or minocycline-rifampin-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies that do not incorporate antimicrobial agents (for example, maximal barrier precautions)., Conclusions: Simple interventions can reduce the risk for serious catheter-related infection. Adequately powered randomized trials are needed.

Our purpose was to determine if specific MRI findings in spinal epidural abscess (SEA), at the time of diagnosis, are associated with the clinical outcome. The clinical records and MRI studies of 18 patients with SEA were reviewed and follow-up was obtained from the outpatient medical record, telephone interview, or both. The association between findings on contrast-enhanced MRI and clinical outcome (weakness, neck or back pain, and incomplete functional recovery) was evaluated. With univariate analysis, narrowing of 50% or more of the central spinal canal (P = 0.03), peripheral contrast-enhancement (P = 0.05), and abnormal spinal cord signal intensity (P = 0.05) were associated with weakness at follow-up. Persistent neck or back pain was associated with spinal canal narrowing (P = 0.02), peripheral contrast-enhancement (P = 0.02), and an abscess longer than 3 cm (P = 0.04) on MRI. Incomplete clinical recovery was associated with both abscess length (P = 0.01) and the severity of canal narrowing (P = 0.01). Abscess length, enhancement pattern, and severity of canal narrowing can be incorporated in a grading system that can be used to predict outcome.

Leptospiosis is a common zoonosis affecting most mammals. Leptospirosis has protean manifestations ranging from a flu-like illness to fulminant hepatic and renal failure culminating in death. Although the diagnosis is often not considered upon presentation, the literature suggests that leptospirosis is a reemerging infectious disease in urban centers throughout the industrialized world. It will be incumbent upon Emergency Physicians to include this spirochetal disease in the differential diagnosis of febrile patients with appropriate risk factors and symptomatology. We present the case of a 36 year-old woman who presented to the Emergency Department with fever and hypotension. We review the literature on leptospirosis with specific focus on risk factors and pathogenesis, clinical manifestations, diagnosis, treatment, and outcome.

Laboratory technologists (22%) developed infections with Shigella sonnei. The isolates had the same antibiogram and pulse-field gel electrophoresis pattern as an unknown isolate handled by a laboratory student. Covering faucet handles with paper towels during hand washing in the laboratory was protective. No further cases occurred after the laboratory was cleaned with a phenolic agent and a handle-free faucet was installed.

An outbreak of community-acquired Legionnaires' disease (LD) occurred in Providence, R.I., in fall 1993. To find the outbreak source, exposures of 17 case patients were compared to those of 33 matched controls. Case patients were more likely than controls to have visited a section of downtown (area A) during the 2 weeks before illness (11 [65%] versus 9 [27%]; matched odds ratio, 6.5; P = 0.01). Water samples were cultured from 27 aerosol-producing devices within area A. Legionella pneumophila serogroup 1 isolates underwent monoclonal antibody (MAb) subtyping and arbitrarily primed PCR (AP-PCR). All four L. pneumophila serogroup 1 isolates available from case patients who visited area A had identical MAb and AP-PCR patterns. Among 14 environmental isolates, 5 had MAb patterns that matched the case patient isolates, but only 1 had a matching AP-PCR pattern. This investigation implicates a cooling tower in area A as the outbreak source and illustrates the usefulness of AP-PCR for identifying sources of LD outbreaks.

This article defines the complex interaction between catheterized patients and invading microbial pathogens. Catheter colonization reflects significant growth of a microbe on a catheter component. Localized intravascular catheter-related infection denotes infection at the exit site, tunnel tract, or pocket, in the absence of bloodstream infection. Systemic intravascular catheter-related infection is a complication of colonization or localized infection, usually documented by invasion of the bloodstream. Catheter sepsis is a systemic infection that is difficult to define because symptoms associated with bloodstream infection caused by the most common pathogens to infect catheterized patients, coagulase-negative staphylococci, may not meet the previously published criteria of sepsis. It is hoped that the information contained here will lead to greater uniformity in the definitions used by the many investigators in this fascinating field.

A Campylobacter jejuni strain of serotype O:10 was isolated from a patient who had Miller-Fisher syndrome. In its biochemical reactions and cellular morphology, the isolate was characteristic of typical C. jejuni. Antibodies against extracted lipopolysaccharide (LPS) were detected by passive hemagglutination in the acute- and convalescent-phase patient sera. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with the O:10 antiserum, it was demonstrated that the strain possessed both low- and high-molecular-weight molecules. Chemical analysis of the LPS revealed that the core oligosaccharide has a terminal trisaccharide epitope consisting of two molecules of sialic acid linked to galactose, a structure reflecting the terminal region of human ganglioside GD3. As this trisaccharide is also present in LPS cores of serotype O:19 strains from patients with Guillain-Barré syndrome but not in cores of nonneuropathic C. jejuni, a possible role for the trisaccharide in the etiology of neuropathies is indicated, and a difference for distinguishing neuropathic strains from nonneuropathic strains may be the presence of a sialyltransferase required for the synthesis of this trisaccharide.

There are over 50,000 intravascular catheter-associated bloodstream infections in the United States each year; globally, the number of these infections is likely to be much higher. At least half of these bloodstream infections are caused by staphylococci. The source of most pathogens causing endemic catheter-associated bloodstream infections is the catheter insertion site or the catheter hub, whereby microbes migrate into the bloodstream along the outside or inside of the catheter, respectively. The pathogenesis of epidemic intravascular catheter-related bloodstream infections is quite different. Epidemic bloodstream infections are due to manufacturer-related contamination or contamination that occurs at the location of catheter use, such as the hospital. These epidemics have most often been traced to contamination of intravenous solutions such as hyperalimentation or medications, blood products, contaminated cutaneous antiseptics or faulty decontamination of reusable devices. The prevention of infection associated with continuous intravenous infusion of factor VIII poses a number of challenges. Assurances of the sterility of the product is of paramount importance, as is proper storage of the product prior to use. Prevention of infection will further require particular attention to the conditions surrounding insertion of the catheter, including the optimal site of insertion, maximal barrier precautions and optimal disinfection of the insertion sites, and also to conditions surrounding maintenance of the device after insertion, including proper disinfection and aseptic techniques when manipulating the catheter hub, daily assessment of the insertion site, and maintaining scheduled changes of the intravenous tubing. With proper precautions, the risk of serious infection associated with a continuous infusion of factor VIII should be minimal.

In August and September 1993, we investigated an outbreak of legionnaires' disease in Fall River, Massachusetts, that involved 11 persons; the attack rate was highest in Flint, a community of Fall River. All cases were infected with Legionella pneumophila serogroup 1 (Lp-1). A case-control study revealed that cases were more likely than matched controls to have visited sites in neighborhood A of Flint. Environmental sampling in Flint found that four of nine aerosol-producing devices sampled contained legionellae; only two, conjoined cooling towers on building A, contained Lp-1. Three independent methods of subtyping--monoclonal antibody subtyping, arbitrary primer polymerase chain reaction, and pulsed-field gel electrophoresis--revealed that Lp-1 isolates from three cases with culture-positive legionnaires' disease matched those from the cooling towers on building A. Water samples from the homes of cases with culture-positive legionnaires' disease contained no legionellae. The results of this epidemiologic and laboratory investigation indicate that the cooling towers on building A were the source of the outbreak of legionnaires' disease and confirm the importance of cooling towers in the transmission of legionnaires' disease.

Arbitrarily primed PCR (AP-PCR) and pulsed-field gel electrophoresis (PFGE) subtyping were applied to clinical and environmental isolates from seven unrelated outbreaks of Legionnaires' disease. The patterns observed with each method matched patient isolates and the epidemiologically linked source of disease for each of the seven outbreaks. PFGE allowed more discrimination among various isolates, although AP-PCR usually gave comparable results. With both methods, certain patterns appeared to predominate in the comparison of the seven outbreaks. Of five clinical isolates not associated with the outbreaks, three gave profiles distinct from those observed in the outbreaks by both methods. This suggests that there are at least two predominant subtypes of Legionella pneumophila serogroup 1 associated with outbreaks. Investigations of outbreaks of legionellosis should employ either PFGE or AP-PCR in addition to monoclonal antibody analysis.

Several recent studies have concluded that the changing of needles prior to inoculation of blood culture bottles does not reduce the contamination rate, although there is a consistent trend toward a reduction in number of contaminated cultures when the needle is changed prior to inoculation. We performed a meta-analysis of available studies prospectively comparing blood culture contamination rates with and without a needle change prior to inoculation. The overall weighted contamination rate when the needle was changed prior to inoculation was 2.0%, compared to 3.7% when the needle was not changed. Since an increase of approximately $5,000 in costs per patient is associated with a contaminated blood culture, this reduction in contamination rate could save approximately $85,000 for every 1,000 cultures performed. Our meta-analysis demonstrates reduced blood culture contamination when the needle used for phlebotomy is changed prior to inoculation. This should be considered when setting clinical policy regarding the performance of blood cultures.

After controlling an epidemic of vanB-type vancomycin-resistant Enterococcus faecium (VRE), we contained a subsequent vanA E faecium outbreak by using prospective laboratory-based surveillance, placing patients with VRE in private rooms, requiring the use of both gowns and gloves by all personnel entering the patients' rooms, and conducting prevalence surveys of patients on affected wards.

Objective: To describe two cases of nosocomial legionellosis and discuss the epidemiology of this infection., Design: Potable water was collected from multiple sites. Patient and environmental isolates were characterized by the Legionella slide agglutination test and monoclonal antibody subtyping. Concordance among isolates was confirmed by pulsed-field gel electrophoresis (PFGE)., Setting: A 713-bed university-affiliated hospital., Results: There was widespread contamination of potable water with Legionella pneumophila during a period of major construction; cooling towers were without growth of Legionella. One patient's isolate was the same by PFGE as the environmental isolate collected from the water faucet in his room. Control measures included superheating water used in all patient care areas to 75 degrees C for 72 hours and flushing superheated water through faucets and showers; cleaning shower heads with a sonicator washer; and raising the hot water storage tank temperature from 43 degrees C to 52 degrees C. After these interventions, repeat environmental cultures over the next 6 months were without growth of Legionella, and no further cases of nosocomial legionnaires' disease were documented. An association between legionnaires' disease and construction is postulated. Heightened surveillance and preventive measures may be warranted during periods of excavation on hospital grounds or when potable water supplies are otherwise shut down and later repressurized.

Enterococci expressing resistance to antimicrobial agents are increasingly important nosocomial pathogens. Effective strategies to prevent or abort outbreaks of resistant enterococcal infection will rely on an accurate understanding of the mechanisms by which these organisms spread. A 1065-bp insertion-like sequence (IS6770) is present in varying copy numbers in > 90% of enterococcal strains thus far examined. Hybridization patterns resulting from hybridization of enterococcal genomic DNA with an internal IS6770 probe vary considerably between unrelated strains and correlate well with results of pulsed-field gel electrophoresis and field-inversion gel electrophoresis in identifying clonal relationships among enterococcal isolates. IS6770 analysis of several outbreaks of resistant enterococci has confirmed the spread of single resistant clones rather than the emergence of resistance within the resident flora. These results suggest that IS6770 hybridization will be a useful tool for tracing the epidemiology of nosocomial enterococcal infections.

Preimplantation cultures of four sterile bone allograft specimens grew Comomonas acidovorans and Pseudomonas species. An epidemiological investigation, including molecular subtyping methods, revealed that the allograft specimens were contaminated in a microbiology laboratory sonicator water bath.

Objectives: To compare the safety of a conventional polyurethane transparent dressing and a novel highly permeable polyurethane dressing, as compared with standard gauze and tape, as site dressings for pulmonary artery catheters; and to rigorously determine the sources of bloodstream infections deriving from these catheters., Design: Prospective, randomized, clinical trial., Setting: General adult intensive care units (ICUs) in a university hospital., Patients: A total of 442 adult patients with pulmonary artery catheters were studied. Two thirds of the catheters had been inserted in the operating room and one third had been inserted in an ICU., Interventions: Patients were randomized at the time of pulmonary artery catheter insertion to have one of three dressing regimens: a) sterile gauze and tape (control), replaced every 2 days; b) a conventional polyurethane dressing, replaced every 5 days; or c) a highly permeable polyurethane dressing, also replaced every 5 days., Measurements and Main Results: The origin of each catheter-associated bloodstream infection was sought by quantitatively culturing the skin of the insertion site and all potential sources on the catheter, including the hub and infusate from each lumen of the introducer sheath and the pulmonary artery catheter, and intravascular segments of the introducer sheath and pulmonary artery catheter. Bloodstream infection was confirmed by demonstrating concordance between isolates from the device and blood cultures by pulsed-field electrophoresis of genomic DNA, digested with low-frequency-cleavage, restriction endonucleases. One hundred thirty catheters were randomized to be dressed with sterile gauze and tape (control), 127 with the conventional polyurethane dressing, and 185 with the highly permeable polyurethane dressing. Patients and catheters in the three dressing groups were very comparable. Ninety-six (21.7%) of the 442 catheters studied showed colonization of the introducer sheath or the pulmonary artery catheter, and five (1.1%) catheters caused bloodstream infection. Catheter-related bloodstream infections were associated with concordant cutaneous colonization of the insertion site (n = 2), a contaminated catheter hub or infusate (n = 3), contamination of the extravascular segment of a repositioned catheter beneath the external protective plastic sleeve (n = 1), or hematogenous colonization of the catheter (n = 1). All pulmonary artery catheter-related bloodstream infections occurred with catheters (introducers) in place for > or = 5 days (p < .001). Cutaneous colonization under the dressing at catheter removal was lowest with gauze (10(1.3) colony-forming units), intermediate with the new highly permeable polyurethane dressing (10(1.8) colony-forming units; p < .01), and highest with the conventional polyurethane dressing (10(2.0) colony-forming units; p < .001). There were no significant differences in catheter colonization (20.0 to 25.2 cases per 100 catheters) or catheter-related bloodstream infection (0.8 to 1.6 cases per 100 catheters) between the three groups., Conclusions: The incidence of pulmonary artery catheter-related bloodstream infection has decreased over the past 5 yrs. Pulmonary artery catheter-related bloodstream infections originate from multiple sources, indicating that measures to prevent bacteremic infections of these devices must focus both on reducing cutaneous colonization at the insertion site and averting contamination of infusate and catheter hubs. Efforts should be made to limit the duration of catheterization with pulmonary artery catheters (including the introducer) to no longer than 4 days. The polyurethane dressings studied appear to be safe for use with pulmonary artery catheters and may be left on for up to 5 days between dressing changes.

The yield of blood cultures depends on the volume of blood cultured. We recently discovered that 15% of blood-culture specimens from adults in our hospital were being collected in 3.5-mL pediatric tubes and that another 5%, drawn in 10-mL adult tubes, contained less than 5 mL of blood. A comparison of 829 matched pairs of standard-volume (mean, 8.7 mL) and low-volume (mean, 2.7 mL) blood cultures showed that standard-volume cultures had a substantially higher detection rate for bloodstream infection than did low-volume cultures (92% compared with 69%; difference, 23% [95% CI, 9% to 37%]; P < 0.001). Our data, together with an analysis of previous studies, show that the yield of blood cultures in adults increases approximately 3% per millilitre of blood cultured. A survey of 158 U.S. clinical microbiology laboratory directors in the American Society of Clinical Pathologists showed that only 20% of 71 responding laboratories record the volume of blood submitted for culture and that the practice of culturing suboptimal volumes of blood from adults is widespread. Clinical laboratories should routinely monitor the volume of blood cultured as a quality-assurance measure. Blood-culture specimens from adults should not be drawn using small pediatric tubes.

Most Swan-Ganz pulmonary artery catheters have heparin bonded to the surface with benzalkonium chloride, a cationic surfactant, to reduce thrombosis. Since benzalkonium is bactericidal, the antimicrobial activity of heparin-bonded pulmonary artery catheters was investigated in an in vitro assay. Each catheter exhibited activity against a wide variety of potential microbial pathogens, including Candida albicans. The magnitude of activity against individual organisms correlated strongly with their in vitro susceptibility to benzalkonium chloride (r = .94, P < .002). A chlorhexidine-silver sulfadiazine-impregnated catheter exhibited even greater activity than the heparin-bonded catheters (P = .01). When exposed to serum for 24 h, heparin-bonded catheters lost > or = 50% of their antimicrobial activity, whereas the activity of the chlorhexidine-silver sulfadiazine-impregnated catheter was minimally affected. The fortuitous surface antimicrobial activity of heparin-bonded catheters may account for the low incidence of catheter-related bacteremia (mean, 1.0%) compared with Swan-Ganz catheters of the same materials but not coated with benzalkonium-heparin (mean, 2.8%).

Serratia odorifera biovar 1 has been infrequently isolated from humans, and infection caused by this organism rarely has been documented. We report what is, to our knowledge, the first case of nosocomial sepsis due to S. odorifera biovar 1 and review the literature for which English-language abstracts were available on this organism. We also discuss the biochemical characteristics and the antimicrobial susceptibility pattern of this organism.

To delineate the pathogenesis and epidemiology of catheter-related infection with Swan-Ganz pulmonary artery (PA) catheters, a prospective clinical study of hospitalized adult medical and surgical patients was done. Role of catheter material was assessed by randomizing insertions to heparin-bonded PA catheters made of polyvinylchloride or polyurethane. Sources of infection and pathogenesis were studied by culturing skin, the introducer, the PA catheter tip, all hubs, infusate from each lumen, and the extravascular portion of the PA catheter beneath the external protective plastic sleeve. Concordance between isolates from sources and infected catheters was determined by speciation, antibiogram, and for coagulase-negative staphylococci, plasmid profile analysis. Risk factors for infection were determined by stepwise logistic regression. Overall, 65 (22%) of 297 Swan-Ganz catheters showed local infection of the introducer (58 catheters) or the intravascular portion of the PA catheter (20 catheters); only two catheters (0.7%) caused bacteremia. Eighty percent of infected Swan-Ganz catheters (the introducer or PA catheter) showed concordance with organisms cultured from skin of the insertion site, 17% with a contaminated hub and 18% with organisms contaminating the extravascular portion of the PA catheter beneath the sleeve. Isolates from infected PA catheters were most likely to show concordance with concomitantly infected introducers (71%). Cutaneous colonization of the insertion site with greater than 10(2) cfu/10 cm2 (relative risk [RR] 5.5; p less than 0.001), insertion into an internal jugular vein (RR 4.3; p less than 0.01), catheterization greater than 3 days (RR 3.1; p less than 0.01), and insertion in the operating room using less stringent barrier precautions (RR 2.1; p = 0.03) were each associated with a significantly increased risk of catheter-related infection. The risk of bacteremic infection with Swan-Ganz catheters is now low, in the range of 1%, with reasonable care. Swan-Ganz catheters are vulnerable to contamination from multiple sources, but the patient's skin is the single most important source of organisms causing invasive infection, which in most cases involves the introducer rather than the PA catheter. Heavy colonization of the insertion site, percutaneous insertion in the internal jugular vein rather than subclavian vein, catheterization longer than 3 days, and insertion with less stringent barrier precautions significantly increase the risk of catheter-related infection. These findings hold promise for application to management of Swan-Ganz catheters and research in catheter design to reduce the risk of catheter-related infection.