To describe the epidemiology of nosocomial coagulase-negative staphylococci (CoNS) bacteremia and to evaluate the clinical significance of a single blood culture positive for CoNS.

A 3-year retrospective cohort study based on data prospectively collected through hospital-wide surveillance. Bacteremia was defined according to CDC criteria, except that a single blood culture growing CoNS was not systematically considered as a contaminant. All clinically significant blood cultures positive for CoNS nosocomial bacteremia were considered for analysis.

A large university teaching hospital in Geneva, Switzerland.

A total of 2,660 positive blood cultures were identified. Of these, 1,108 (41.7%) were nosocomial; CoNS were recovered from 411 nosocomial episodes (37.1%). Two hundred thirty-four episodes of CoNS bacteremia in the presence of signs of sepsis were considered clinically relevant and analyzed. Crude mortality and associated mortality were 24.4% and 12.8%, respectively. Associated mortality was similar among patients with one positive blood culture and those with two or more (16.2% vs 10.8%, respectively; P = .3). Mortality rates after bacteremia for patients with a single positive blood culture and for those with two or more were 15.3% and 7.0%, respectively, at day 14 (RR, 2.2; CI%, 0.87-5.46) and 20.8% and 11.3%, respectively, at day 28 (RR, 1.9; CI95, 0.9-3.8). On multivariate analysis, only age and a rapidly fatal disease were independently associated with death.

CoNS bacteremia harbor a significant mortality and a single positive blood culture in the presence of signs of sepsis should be considered as clinically relevant.

To determine human immunodeficiency virus (HIV) type 1 genotypic antiretroviral drug resistance profiles of patients presenting a risk or potential risk for occupational exposure of healthcare workers.

Observational survey involving HIV-infected patients. Blood samples collected from source-patients and potential source-patients underwent HIV-1 genotypic antiretroviral resistance testing and determination of CD4 counts and viral load. Affected healthcare workers were monitored for 6 months after exposure.

The survey was conducted in a tertiary-care hospital located in Sao Paulo, Brazil. Sao Paulo is considered the epicenter of the HIV-acquired immunodeficiency (AIDS) virus epidemic in Brazil.

Source-patients, potential source-patients, and affected healthcare workers.

A total of 371 occupational exposures to biological materials were reported, 46 (12.3%) of which were from HIV-seropositive source-patients. Samples from 18 source-patients and 26 patients considered “potential sources for accidents” were analyzed. Of these 44 samples, 18 (41%) presented resistance-related mutations in reverse transcriptase, protease, or both. Of these 18 samples, 16 (89%) had resistance to drugs included in the prophylactic schedule recommended by the Brazilian Ministry of Health.

Use of the Centers for Disease Control and Prevention-Brazilian post-exposure prophylaxis regimen will result in the administration of antiretroviral agents to which the source HIV-1 isolate will often be resistant. Therefore, it would be advisable to carefully investigate the history of use of antiretroviral agents by source-patients and adjust the prophylactic therapy based on those data and, subsequently, the results of resistance testing.

Although guidelines for multidrug-resistant organisms generally include recommendations for contact precautions and surveillance cultures, it is not known how frequently U.S. hospitals implement these measures on a routine basis and whether infectious diseases consultants endorse their use.

The Emerging Infections Network surveyed its members, infectious diseases consultants, to assess their use of and support for contact precautions and surveillance cultures for routine management of multidrug-resistant organisms in their principal inpatient workplace. Specifically, members were asked about use of these strategies for methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and multidrug-resistant, gram-negative bacilli on general wards, ICUs, and transplant units.

Overall, 400 (86%) of 463 respondents supported the routine use of contact precautions to control one or more multidrug-resistant organisms in at least one unit, and 89% worked in hospitals that use them. In contrast, 50% of respondents favored routine use of surveillance cultures to manage at least one multidrug-resistant organism in any unit, and 30% of respondents worked in hospitals that use them routinely in any unit. Members favored routine use of surveillance cultures significantly more in ICUs and transplant units than in general wards for each multidrug-resistant organism (P <.001).

Most of the infectious diseases consultants endorsed the use of contact precautions for routine management of patients colonized or infected with multidrug-resistant organisms and work in hospitals that have implemented them. In contrast, infectious diseases consultants are divided about the role of routine surveillance cultures in multidrug-resistant organism management, and few work in hospitals that use them.

Most research on hospital falls has focused on predictors of falling, whereas less is known about predictors of serious fall-related injury. Our objectives were to characterize inpatients who fall and to determine predictors of serious fall-related injury.

We performed a retrospective observational study of 1,082 patients who fell (1,235 falls) during January 2001 to June 2002 at an urban academic hospital. Multivariate analysis of potential risk factors for serious fall-related injury (vs no or minor injury) included in the hospital's adverse event reporting database was conducted with logistic regression to calculate adjusted odds ratios (aORs) with 95% confidence intervals (CI95).

The median age of patients who fell was 62 years (interquartile range, 49-77 years), 50% were women, and 20% were confused. The hospital fall rate was 3.1 falls per 1,000 patient-days, which varied by service from 0.86 (women and infants) to 6.36 (oncology). Some (6.1%) of the falls resulted in serious injury, ranging by service from 3.1% (women and infants) to 10.9% (psychiatry). The most common serious fall-related injuries were bleeding or laceration (53.6%), fracture or dislocation (15.9%), and hematoma or contusion (13%). Patients 75 years or older (aOR, 3.2; CI95, 1.3-8.1) and those on the geriatric psychiatry floor (aOR, 2.8; CI95,1.3-6.0) were more likely to sustain serious fall-related injuries.

There is considerable variation in fall rates and fall-related injury percentages by service. More detailed studies should be conducted by floor or service to identify predictors of serious fall-related injury so that targeted interventions can be developed to reduce them.

To create an affordable and accurate method for continuously monitoring bacterial transmission rates in healthcare settings.

We present a discrete simulation model that relies on the relationship between in-hospital transmission rates and strain diversity. We also present a proof of concept application of this model to a prospective molecular epidemiology data set to estimate transmission rates for Pseudomonas aeruginosa and Staphylococcus aureus.

Inpatient units of an academic referral center.

All inpatients with nosocomial infections.

Mathematical model to estimate transmission rates.

Maximum likelihood estimates for transmission rates of these two species on different hospital units ranged from 0 to 0.36 transmission event per colonized patient per day.

This approach is feasible, although estimates of transmission rates based solely on strain typed clinical cultures may be too imprecise for routine use in infection control. A modest level of surveillance sampling substantially improves the estimation accuracy. (Infect Control Hosp Epidemiol 2005;26:638-645)

To determine the efficacy and tolerability of octenidine hydrochloride, a non-alcoholic skin antiseptic, for the care of central venous catheter (CVC) insertion sites.

Prospective, observational study.

Bone marrow transplantation unit of a university hospital.

All consecutive patients with a nontunneled CVC were enrolled prospectively after informed consent.

Octenidine hydrochloride (0.1%) was applied for disinfection at the CVC insertion site during dressing changes. The following cultures were performed weekly as well as at the occurrence of any systemic inflammatory response syndrome criteria: cultures of the skin surrounding the CVC entry site, cultures of the three-way hub connected to the CVC, blood cultures, and cultures of the CVC tip on removal. Enhanced microbiological methods (skin swabs of a 24-cm2 standardized area, roll plate, and sonication of catheter tips) were applied.

One hundred thirty-five CVCs were inserted in 62 patients during the study period and remained for a mean period of 19.1 days, corresponding to 2,462 catheter-days. Bacterial density at the insertion site declined substantially over time, and most cultures became negative 2 weeks after insertion. Only 6 patients had a documented catheter-related bloodstream infection. The incidence density was 2.39 catheter infections per 1,000 catheter-days. No side effects were noted with application of the antiseptic.

Disinfection with a skin antiseptic that contains octenidine hydrochloride is highly active and well tolerated. It leads to a decrease in skin colonization over time and may be a new option for CVC care.

To date, it has not been adequately proven whether the published formulas used to obtain incidence from the prevalence of nosocomial infections provide a good estimate of real incidence. With the hypothesis that within the hospital setting prevalence may be lower than incidence, the aim of this study was to analyze the behavior of point prevalence as it relates to cumulative incidence and duration of infection.

Hospital simulation study.

By randomly selecting a sample of infected patients within a specific range of cumulative incidences and infection durations, we constructed a simulated hospital population, allowing us to estimate daily point prevalences and their maximum and minimum values. The association between the different components of stay and cumulative incidence was evaluated to obtain a more accurate estimate of incidence.

Prevalence can be lower than, equal to, or higher than the corresponding incidence. For all incidence levels, prevalence was increasing with duration. Between 14 and 20 days of infection duration, prevalence was consistently lower than incidence. Prevalence duration of infection was approximately half the time of the total duration.

The existing formulas relating incidence and prevalence can frequently be inadequate. Until a validated system for converting prevalence into incidence is available, we do not believe their use is appropriate.

We report a community cluster of methicillin-resistant Staphylococcus aureus (MRSA) in Denmark with emphasis on routes of transmission and infection control measures. The objective is to extend knowledge of MRSA in a community setting where a nosocomial link could effectively be ruled out.

Population-based observational study from November 1997 until June 2003.

North Jutland County, with approximately 495,000 inhabitants.

The cluster encompassed 46 individuals and 26 households.

Infection control measures included repeated visits to affected households by an infection control nurse who undertook screening for carriage among all household members and provided a program for decolonization.

The causal strain was identical to a newly described international clone, ST80; SSCmec type IV; and Panton–Valentine leukocidin positive. Plausible routes of transmission included household contact and contact at work, kindergarten, and school. We did not detect a nosocomial source or any secondary cases in hospitals. Transmission by healthcare contact outside the hospital was plausible for three cases. We found evidence that the clone was introduced on more than one occasion to immigrant families from the Middle East. A 5-day decolonization program was successful at first attempt in 15 of 16 households that could be evaluated.

Despite the described infection control measures, we continued to see new cases, underlining a need for a national policy to contain MRSA in the community.

To characterize vancomycin use at a pediatric tertiary-care hospital, to discriminate between initial (≤ 72 hours) and prolonged (> 72 hours) inappropriate use, and to define patient characteristics associated with inappropriate use.

Vancomycin courses were retrospectively reviewed using an algorithm modeled on HICPAC guidelines. Data were collected regarding patient demographics, comorbidities, other medication use, and nosocomial infections. The association between each variable and the outcome of inappropriate use was determined by longitudinal regression analysis. A multi-variable model was constructed to assess risk factors for inappropriate initial and prolonged vancomycin use.

A pediatric tertiary-care medical center.

Children older than 1 year who received intravenous vancomycin from November 2000 to June 2001.

Three hundred twenty-seven vancomycin courses administered to 260 patients were evaluated for appropriateness. Of initial courses, 114 (35%) were considered inappropriate. Of 143 prolonged courses, 103 (72%) were considered inappropriate. Multivariable risk factor analysis identified the following variables as significantly associated with inappropriate initial use: admission to the surgery service, having a malignancy, receipt of a stem cell transplant, and having received a prior inappropriate course of vancomycin. No variables were identified as significant risk factors for inappropriate prolonged use.

Substantial inappropriate use of vancomycin was identified. Prolonged inappropriate use was a particular problem. This risk factor analysis suggests that interventions targeting patients admitted to certain services or receiving multiple courses of vancomycin could reduce inappropriate use.

In August 2001, the Centers for Disease Control and Prevention (CDC) notified the Texas Department of Health (TDH) of an unusually high number of wounds infected with group A streptococci (GAS) in an acute care facility. The TDH initiated an investigation, ultimately identifying 28 cases of non-pharyngeal, non-community-acquired GAS that had occurred between December 2000 and August 2001 and resulted in 3 deaths and 4 nonfatal cases of invasive disease. Ten specimens were sent to the CDC for emm typing; all isolates were emm type 114. However, the source of the outbreak could not be confirmed through laboratory testing at that time.

A case–control study was conducted comparing the 10 case-patients with 52 control-patients with wounds that were not infected with GAS. Age, gender, type of wound, underlying medical conditions, and treatment by the wound care team were examined for association with GAS infection.

The odds of having wound care team treatment versus not having it were 424.2 (95% confidence interval, 19.0 to 9,495.2) among case-patients when compared with control-patients. No other risk factor showed this magnitude of association.

This study provided overwhelming epidemiologic evidence that the wound care team was the means of transmission. One year later, when two patients receiving wound care were concurrently diagnosed as having GAS, a member of the wound care team was found to be GAS positive for the matching emm type. This is the first report of a GAS hospital outbreak linked to a wound care team.

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 study the dependence of infection risk and outbreak size on the type of index case (ie, patient or staff).

Nosocomial outbreaks were reviewed and categorized into those started by patients and those started by staff. Infection risks and outbreak sizes were evaluated taking into account the index case category.

Of the 30 nosocomial outbreaks of norovirus with person-to-person transmission, 20 (67%) involved patients as the index cases. Patient-indexed outbreaks affected significantly more patients than did staff-indexed outbreaks (difference in means, 16.25; 95% confidence interval [CI95], 5.1 to 27.0). For the numbers of affected staff, no dependence on the index case category was detectable (difference in means, -1.05; CI95, -9.0 to 6.9). For patients exposed during patient-indexed outbreaks, the risk of acquiring a norovirus infection was approximately 4.8 times as high as the corresponding risk for patients exposed during staff-indexed outbreaks (odds ratio [OR], 4.79; CI95,1.82 to 8.28). The infection risk for exposed staff during patient-indexed outbreaks was approximately 1.5 times as high as the corresponding risk during staff-indexed outbreaks (OR, 1.51; CI95, 0.92 to 2.49).

Patient-indexed norovirus outbreaks generally affect more patients than do staff-indexed outbreaks. Staff appear to be similarly affected by both outbreak index category groups. This study demonstrates the importance of obtaining complete outbreak data, including the index case classification as staff or patient, during norovirus outbreak investigations. Such information may be useful for further targeting prevention measures.

Multidrug-resistant organisms (MDROs), such as vancomycin-resistant enterococci (VRE), cause serious infections, especially among high-risk patients in NICUs. When VRE was introduced and transmitted in our NICU despite recommended infection control practices, we instituted active surveillance cultures to determine their efficacy in detecting and controlling spread of VRE among high-risk infants.

Active surveillance cultures, other infection control measures, and a mandatory in-service education module on preventing MDRO transmission were implemented. Cultures were performed on NICU admission and then weekly during their stay. Molecular DNA fingerprinting of VRE isolates facilitated targeting efforts to eliminate clonal spread of VRE. Repetitive sequence PCR (rep-PCR)-based DNA fingerprinting was used to compare isolates recovered from patients with VRE infection or colonization. Environmental VRE cultures were performed around VRE-colonized or -infected patients. DNA fingerprints were prepared from the products of rep-PCR amplification and analyzed using software to determine strain genetic relatedness.

Active surveillance cultures identified 65 patients with VRE colonization or infection among 1,820 admitted to the NICU. Rep-PCR performed on 60 VRE isolates identified 3 clusters. Cluster 1 included isolates from 21 patients and 4 isolates from the environment of the index patient. Clusters 2 and 3 included isolates from 23 and 3 patients, respectively. Similarity coefficients among the members of each cluster were 95% or greater.

Control of transmission of multi-clonal VRE strains was achieved. Active surveillance cultures, together with implementation of other infection control measures, combined with rep-PCR DNA fingerprinting were instrumental in controlling VRE transmission in our NICU. (Infect Control Hosp Epidemiol 2005;26:646-649)

Fluoroquinolones have not been frequently implicated as a cause of Clostridium difficile outbreaks. Nosocomial C. difficile infections increased from 2.7 to 6.8 cases per 1,000 discharges (P < .001). During the first 2 years of the outbreak, there were 253 nosocomial C. difficile infections; of these, 26 resulted in colectomy and 18 resulted in death. We conducted an investigation of a large C. difficile outbreak in our hospital to identify risk factors and characterize the outbreak.

A retrospective case-control study of case-patients with C. difficile infection from January 2000 through April 2001 and control-patients matched by date of hospital admission, type of medical service, and length of stay; an analysis of inpatient antibiotic use; and antibiotic susceptibility testing and molecular subtyping of isolates were performed.

On logistic regression analysis, clindamycin (odds ratio [OR], 4.8; 95% confidence interval [CI95], 1.9-12.0), ceftriaxone (OR, 5.4; CI95, 1.8-15.8), and levofloxacin (OR, 2.0; CI95, 1.2-3.3) were independently associated with infection. The etiologic fractions for these three agents were 10.0%, 6.7%, and 30.8%, respectively. Fluoroquinolone use increased before the onset of the outbreak (P < .001); 59% of case-patients and 41% of control-patients had received this antibiotic class. The outbreak was polyclonal, although 52% of isolates belonged to two highly related molecular subtypes.

Exposure to levofloxacin was an independent risk factor for C. difficile-associated diarrhea and appeared to contribute substantially to the outbreak. Restricted use of levofloxacin and the other implicated antibiotics may be required to control the outbreak.

Products containing alcohol are commonly used with intravascular devices at insertion, to remove lipids from occluded intravascular devices used during parenteral nutrition, and increasingly for the prevention and treatment of intravascular device-related bloodstream infection. The effects of alcohol on the integrity of intravascular devices remain unknown.

Two types of widely used commercial peripherally inserted central catheters, one made of polyether-urethane and one made of silicone, were exposed to a 70% etha-nol lock solution for up to 10 weeks. Mechanical testing was performed to identify force-at-break, stress, strain, modulus of elasticity, modulus of toughness, and wall area of ethanol-exposed and control catheters.

No significant differences between exposed and unexposed catheters were identified for any of the mechanical parameters tested except for a marginal reduction in the modulus of elasticity for both polyetherurethane and silicone catheters and minor increases in the wall area of polyetherurethane catheters.

These data indicate that exposure to a 70% ethanol lock solution does not appreciably alter the integrity of selected commercial polyetherurethane and silicone catheters. Given the greatly expanded use of alcoholic solutions with intravascular devices of all types, we believe that manufacturers would be well advised to subject their catheters and other intravascular devices to formal testing of the type employed in this study.