Central venous catheter (CVC)-related bloodstream infections (BSIs) are known to increase rates of morbidity and mortality in both inpatients and outpatients, including hematology-oncology patients and those undergoing hemodialysis or home infusion therapy. Biofilm-associated organisms on the lumens of these catheters have reduced susceptibility to antimicrobial chemotherapy. This study tested the efficacy of tetrasodium EDTA as a catheter lock solution on biofilms of several clinically relevant microorganisms.

Biofilms of Staphylococcus epidermidis, methicillin-resistant S. aureus, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, and Candida albicans were grown to levels of approximately 1 × 105 colony-forming units (CFU)/cm−1 on CVC segments in a model system, then subjected to the tetrasodium EDTA lock treatment.

Comparisons of biofilms before and after exposure to the 40-mg/mL−1 tetrasodium EDTA lock for 21 hours showed that the biofilm viable cell counts of all organisms tested were significantly reduced (P < .05) after exposure to the treatment.

Antimicrobial lock treatment using 40 mg/mL−1 of tetrasodium EDTA for at least 21 hours could significantly reduce or potentially eradicate CVC-associated bio-films of clinically relevant microorganisms (Infect Control Hosp Epidemiol 2005;26:515-519).

We previously demonstrated that minocycline-EDTA was efficacious at preventing catheter-related bloodstream infections (BSIs) in three patients with recurrent infections. This study compared heparin with minocycline-EDTA as flush solutions used among dialysis patients with central venous catheters, a high-risk group for catheter-related BSI.

Patients were enrolled within 72 hours of catheter insertion and randomized to receive heparin or minocycline-EDTA as a flush after each dialysis session. Each syringe containing flush solution was wrapped in orange plastic to conceal the type of solution it contained. Patients were observed for evidence of infection and catheter thrombosis. After catheters were removed, cultures were performed to determine whether microbial colonization had occurred.

During a 14-month period, 60 patients were enrolled (30 in each group). The two groups had similar demographics and underlying diseases. Catheter survival at 90 days was 83% for the minocycline-EDTA group versus 66% for the heparin group (P = .07). Significant catheter colonization, a surrogate measure of catheter-related infection, was significantly more frequent in the heparin group (9 of 14 vs 1 of 11; P= .005). There was only one catheter-related bacteremia and it occurred in the heparin group.

When compared with heparin, minocycline-EDTA had a better 90-day catheter survival (P = .07) and a decreased rate of catheter colonization. This pilot study warrants a larger prospective, randomized trial (Infect Control Hosp Epidemiol 2005;26:520-524).

High morbidity of CVC-related infections has led to national guidelines for their prevention. Despite recommendations for the use of maximal barrier precautions (mask, sterile gloves, gown, and large drape) and skin antisepsis with 2% Chlorhexidine gluconate during CVC insertion, internists in the United States are not implementing these practices frequently. This study sought to identify and characterize the obstacles to and potential opportunities for improving adherence.

Cross-sectional survey.

One thousand randomly selected physician-members of the American College of Physicians-American Society of Internal Medicine.

Several potential determinants of adherence to maximal barrier precautions were assessed, including awareness of, agreement with, and ability to implement the recommendation, as well as the practice and training characteristics of the respondents. Factors influencing antiseptic selection were also recorded.

Of 526 respondents, 178 (34%) had recently inserted CVCs. Clinician experience and subspecialty, awareness of CDC guidelines, and external influences (eg, time to collect equipment) did not affect maximal barrier precautions adherence. The only independent predictor of adherence was high outcome expectancy for the use of large sterile drapes (OR, 5.3; CI95, 2.2-12.6). Availability had the greatest influence on internists' selection of specific antiseptic agents, whereas cost was the least important determinant.

Despite established efficacy, use of maximal barrier precautions and Chlorhexidine gluconate is low among internists. Because improved adherence to these practices will require increased outcome expectancy for maximal barrier precautions and availability of Chlorhexidine gluconate, targeting these areas through focused education and systems modifications is essential (Infect Control Hosp Epidemiol 2005;26:525-533).

To examine the clinical outcomes and costs associated with Staphylococcus aureus bacteremia among hemodialysis-dependent patients.

Prospectively identified cohort study.

A tertiary-care university medical center in North Carolina.

Two hundred ten hemodialysis-dependent adults with end-stage renal disease hospitalized with S. aureus bacteremia.

The majority of the patients (117; 55.7%) underwent dialysis via tunneled catheters, and 29.5% (62) underwent dialysis via synthetic arteriovenous fistulas. Vascular access was the suspected source of bacteremia in 185 patients (88.1%). Complications occurred in 31.0% (65), and the overall 12-week mortality rate was 19.0% (40). The mean cost of treating S. aureus bacteremia, including readmissions and outpatient costs, was $24,034 per episode. The mean initial hospitalization cost was significantly greater for patients with complicated versus uncomplicated S. aureus bacteremia ($32,462 vs $17,011; P= .002).

Interventions to decrease the rate of S. aureus bacteremia are needed in this high-risk, hemodialysis-dependent population (Infect Control Hosp Epidemiol 2005;26:534-539).

To determine the mortality, hospital stay, and total hospital charges and cost of hospitalization attributable to candidemia by comparing patients with candidemia with control-patients who have otherwise similar illnesses. Prior studies lack broad patient and hospital representation or cost-related information that accurately reflects current medical practices.

Our case-control study included case-patients with candidemia and their cost-related data, ascertained from laboratory-based candidemia surveillance conducted among all residents of Connecticut and Baltimore and Baltimore County, Maryland, during 1998 to 2000. Control-patients were matched on age, hospital type, admission year, discharge diagnoses, and duration of hospitalization prior to candidemia onset.

We identified 214 and 529 sets of matched case-patients and control-patients from the two locations, respectively. Mortality attributable to candidemia ranged between 19% and 24%. On multivariable analysis, candidemia was associated with mortality (OR, 5.3 for Connecticut and 8.5 for Baltimore and Baltimore County; P < .05), whereas receiving adequate treatment was protective (OR, 0.5 and 0.4 for the two locations, respectively; P < .05). Candidemia itself did not increase the total hospital charges and cost of hospitalization; when treatment status was accounted for, having received adequate treatment for candidemia significantly increased the total hospital charges and cost of hospitalization ($6,000 to $29,000 and $3,000 to $22,000, respectively) and the length of stay (3 to 13 days).

Our findings underscore the burden of candidemia, particularly regarding the risk of death, length of hospitalization, and cost associated with treatment (Infect Control Hosp Epidemiol 2005;26:540-547).

To analyze the secular trends of candidemia in a large tertiary-care hospital to determine the overall incidence, as well as the incidence by ward and by species, and to detect the occurrence of outbreaks.

Retrospective descriptive analysis. Secular trends were calculated using the Mantel-Haenszel test.

A large tertiary-care referral center in Spain with a pediatric intensive care unit (ICU) to which more than 500 children with congenital cardiac disease are admitted annually.

All patients with candidemia occurring from 1988 to 2000 were included. Cases were identified from laboratory records of blood cultures.

There were 331 episodes of candidemia. The overall incidence of nosocomial candidemia was 0.6 episode per 1,000 admissions and remained stable throughout the study period (P = .925). The species most frequently isolated was Candida albicans, but the incidence of C. parapsilosis candidemia increased (P = .035). In the pediatric ICU, the incidence of C. parapsilosis was 5.6 episodes per 1,000 admissions and it was the predominant species. Outbreaks occurred occasionally in the pediatric ICU, suggesting nosocomial transmission.

During this 13-year period, the incidence of candidemia remained stable in this hospital, but C. parapsilosis increased in frequency. Occasional outbreaks of candidemia suggested nosocomial transmission of Candida species (Infect Control Hosp Epidemiol 2005;26:548-552).

To report an outbreak of Pichia anomala fungemia that occurred in a Brazilian pediatric intensive care unit (ICU) from October 2002 to January 2004.

Unmatched case-control study.

We randomly selected four control-patients for each case-patient from a list of all patients admitted to the ICU for at least 48 hours during the outbreak. A second control group was composed of all consecutive patients with nosocomial candidemia in the ICU during the outbreak. An environmental study was performed, and genetic relatedness among the clinical isolates was characterized by randomly amplified polymorphic DNA assay.

During the study period, 1,046 children were admitted to the pediatric ICU, 17 of whom developed P. anomala fungemia (attack rate, 1.6%). The median age was 1.1 years, and the main underlying conditions were congenital malformations (35.3%) and neoplastic diseases (11.8%). The overall mortality rate was 41.2%. Two patients received no antifungal treatment; all of the others were treated with amphotericin B. On multivariate analysis, only the presence of a central venous catheter was significantly associated with P. anomala fungemia. The yeast was not found on healthcare workers' hands or in the environment. Molecular studies showed that the outbreak was caused by a single strain. The distribution of risk factors was similar between patients with P. anomala fungemia and control-patients with candidemia.

This study highlights the importance of P. anomala as an emerging nosocomial fungal pathogen. Patients with P. anomala fungemia seem to have risk factors in common with those who have candidemia.

Coagulase-negative staphylococci are both an important cause of nosocomial bloodstream infections and the most common contaminants of blood cultures. Judging the clinical significance of coagulase-negative staphylococci is vital but often difficult and can have a profound impact on an institution's bloodstream infection rates. Our objective was to develop an algorithm to assist in determining the clinical significance of coagulase-negative staphylococci.

A single experienced reviewer examined the medical records of 960 consecutive patients with positive blood cultures in a tertiary-care referral teaching hospital. Four hundred five of the cultures contained coagulase-negative staphylococci. A determination of clinical significance was made and the performances of various published algorithms that contained readily available clinical and laboratory data were compared.

Eighty-nine (22%) of the episodes were considered significant, whereas 316 were contaminants. Patients with bacteremia were significantly more likely to be neutropenic and exhibit signs of sepsis syndrome. The algorithm with the best combined sensitivity (62%) and specificity (91%) for determining the clinical significance of coagulase-negative staphylococci was defined as at least two blood cultures positive for coagulase-negative staphylococci within 5 days, or one positive blood culture plus clinical evidence of infection, which includes abnormal white blood cell count and temperature or blood pressure.

Use of this algorithm could potentially reduce misclassification of nosocomial bloodstream infections and inappropriate use of vancomycin for positive blood cultures likely to represent contamination (Infect Control Hosp Epidemiol 2005;26:559-566).

Catheter colonization is a necessary but poorly characterized step in the pathogenesis of catheter-related infections. Colonization dynamics of central venous hemodialysis catheters were studied with emphasis on coagulase-negative staphylococci (CoNS) and their population genetics, antibiotic resistance, and biofilm formation. The homogeneity of CoNS colony morphotypes was evaluated.

Prospective, longitudinal study during 1,158 catheter-days with microbiological analysis of skin swabs, weekly catheter blood and brush samples, and catheter tips.

Hemodialysis unit of a university hospital.

Twenty-six patients with 24 non-tunneled and 5 tunneled catheters.

Nineteen (65.5%) of the catheters became colonized, 17 by CoNS. CoNS colonization of the inner lumen was observed in 17.2% of the catheters and was first detectable after 3 weeks. Colonization of the outer surface occurred in 44.8% of the catheters within a minimum of 2 weeks. PFGE of 53 CoNS revealed 10 clones and 20 unique isolates. Isolates from clones were more frequent in catheter blood and brush cultures than were unique isolates (41% vs 15%), were resistant to more antibiotics (median, 7 vs 2), and tended to more often carry the icaA gene (64.1% vs 40%). Four (23.5%) of the catheters showed colonization with a mixture of CoNS based on PFGE. The time from catheter insertion to such mixed CoNS colonization was longer than that for colonization with one CoNS PFGE pattern only (42 vs 25 days).

Colonization of hemodialysis catheters is dominated by multidrug-resistant, icaA-positive CoNS clones. Mixed CoNS colonization occurs, but is delayed, suggesting a process of sequential superinfection (Infect Control Hosp Epidemiol 2005;26:567-574).

Timely initiation of antibiotic therapy is crucial for severe infection. Appropriate antibiotic therapy is often delayed for nosocomial infections caused by antibiotic-resistant bacteria. The relationship between knowledge of colonization caused by antibiotic-resistant gram-negative bacteria (ABR-GNB) and rate of appropriate initial antibiotic therapy for subsequent bacteremia was evaluated.

Retrospective cohort study.

Fifty-four-bed intensive care unit (ICU) of a university hospital. In this unit, colonization surveillance is performed through routine site-specific surveillance cultures (urine, mouth, trachea, and anus). Additional cultures are performed when presumed clinically relevant.

ICU patients with nosocomial bacteremia caused by ABR-GNB.

Infectious and microbiological characteristics and rates of appropriate antibiotic therapy were compared between patients with and without colonization prior to bacteremia. Prior colonization was defined as the presence (detected ≥ 2 days before the onset of bacteremia) of the same ABR-GNB in colonization and subsequent blood cultures. During the study period, 157 episodes of bacteremia caused by ABR-GNB were suitable for evaluation. One hundred seventeen episodes of bacteremia (74.5%) were preceded by colonization. Appropriate empiric antibiotic therapy (started within 24 hours) was administered for 74.4% of these episodes versus 55.0% of the episodes that occurred without prior colonization. Appropriate therapy was administered within 48 hours for all episodes preceded by colonization versus 90.0% of episodes without prior colonization.

Knowledge of colonization status prior to infection is associated with higher rates of appropriate therapy for patients with bacteremia caused by ABR-GNB (Infect Control Hosp Epidemiol 2005;26:575-579).