bluuebunny/crossref_metadata_2025 huggingface dataset:
Bloodborne Pathogen Exposures in a Developmental Center 1993–2000
Authors: Lohiya Ghan-Shyam , Tan-Figueroa Lilia , Lohiya Sonia
Published: February 2006

In a developmental center, 257 potential bloodborne pathogen exposures (119 bites, 91 scratches, 30 sharps injuries, 17 mucosal breaks) occurred during 8 years (13,187 employee-years and 6,980 resident-years). Of the residents, 9% were hepatitis B virus (HBV) surface antigen carriers. Serological follow-up of exposed, susceptible employees and residents identified no transmission of HBV, hepatitis C virus (HCV), or human immunodeficiency (HIV) virus. This outcome has been due primarily to hepatitis B immunization and low prevalences of HCV or HIV infections among the subjects. Proper follow-up of all potential exposures is crucial to identify transmission promptly, allay anxiety, and prevent unwarranted workmen's compensation claims. Measures are suggested to reduce exposure further.
Infrequent Isolation of MultiresistantAcinetobacter baumanniiFrom the Staff Tending a Colonized Patient With Severe Burns
Authors: Paavilainen Teemu , Alanen Markku , Mäkelä Mika , Routamaa Marianne , Järvinen Helinä , Huovinen Pentti , Kotilainen Pirkko
Published: February 2006

A patient with severe burns who was colonized by multiresistantAcinetobacter baumanniiwas cared for in contact isolation by staff intensively trained on hospital hygiene. Of the 1,907 post-exposure cultures from the staff and 425 environmental samples, only 0.7% and 4%, respectively, yielded this microorganism. These data show that strict hygienic measures may limit staff colonization and contamination of the environment byA baumannii.
The Effects of Contamination on Biological Monitoring
Authors: Kleinegger Cynthia L. , Yeager Dennis L. , Huling Judith K. , Drake David R.
Published: February 2006

We investigated the frequency and patterns of biological-monitoring–test contamination and the effect of contamination on the growth of test organisms. Overall, the contamination rate was 0.81%, but the rate of contamination varied significantly by sterilization method. Contamination did not appear to inhibit growth of test organisms.
An Episodic Outbreak of Genetically RelatedBurkholdebja cepaciaAmong Non-Cystic Fibrosis Patients at a University Hospital
Authors: Siddiqui Anwer H. , Mulligan Maury E. , Mahenthiralingam Eshwar , Hebden Joan , Brewrink Jeanine , Qaiyumi Sadaf , Johnson Judith A. , LiPuma John J.
Published: February 2006

Objective:

To investigate an outbreak ofBurkholderia cepacia.

Design:

Observational study and chart review.

Patients:

Adult non-cystic fibrosis (CF) patients.

Setting:

Intensive care units (ICUs) at a university-affiliated teaching hospital.

Methods:

As part of the epidemiological investigation, we conducted a chart review and collected environmental samples. A review of work schedules of healthcare workers also was performed. We usedB cepaciaselective agar for preliminary screening for all isolates, which subsequently were confirmed as members of theB cepaciacomplex by polyphasic analysis employing conventional biochemical reactions and genus- and species-specific polymerase chain reaction assays. Pulsed-field gel electrophoresis, randomly amplified polymorphic DNA typing, and automated ribotyping were used to genotype the isolates. As part of the intervention, contact isolation precautions were initiated for all patients identified as having had a culture positive forB cepacia.

Results:

Between September 1997 and September 1999,B cepaciawas isolated from 31 adult patients without CF in ICUs at a university-affiliated teaching hospital. Based on geographic clustering and genotypic analysis, three distinct clusters were observed involving 20 patients. Isolates from 17 of these patients were available for testing and were found to be of the same strain (outbreak strain). Further taxonomic analysis indicated that the outbreak strain wasB cepaciacomplex genomovar III. Twelve (71%) of the 17 patients were judged to be infected, and 5 (29%) were colonized with this strain. Six of 200 environmental cultures from multiple sources in the hospital's ICUs yieldedB cepacia.Two of these isolates, both recovered from rooms of colonized patients, were the same genotype as the outbreak strain recovered from patients.

Conclusion:

Despite an extensive investigation, the source of theB cepaciaclone involved in this outbreak remains unknown. The spatial and temporal pattern of cases suggests that cross-transmission of a genetically related strain contributed to clustering among patients. The initiation of contact isolation may have limited the extent of this transmission. Additional studies are needed to elucidate better the epidemiology of nosocomialB cepaciainfection among non-CF adult patients.
Effectiveness of Surveillance of Central Catheter-Related Bloodstream Infection in an ICU in Korea
Authors: Yoo Sunmi , Ha Mina , Choi Daeok , Pai Hyunjoo
Published: February 2006

Objective:

To determine whether surveillance and infection control interventions decrease the incidence of catheter-related (CR) bloodstream infections (BSIs) in Korea.

Setting:

A medical-surgical intensive care unit (ICU) of a university hospital in Korea.

Design:

The CR infection rate of the intervention period was compared to that of historical controls for a 4-month period.

Patients:

All patients with a central venous catheter in the intensive care unit (ICU) from October 1998 to January 1999.

Methods:

Active infection control programs were initiated during the intervention period. Data collected included patient characteristics, risk factors of CR infection, and the microbiology laboratory results. Laboratory-proven CR infection rates were compared between the intervention group and control group.

Results:

304 catheters were inserted into 248 patients. The intervention group and the control group showed similar characteristics, but more patients in the intervention group received steroid therapy, and subclavian insertion was more common in the intervention group. CR BSI occurred in 1.3 per 1,000 catheter-days in the intervention group and 4.2 in the control group (binomial test, P=.14). CR infections were associated with the duration of ICU admission by multivariate logistic regression.

Conclusions:

The data suggested that an active infection surveillance and control program could reduce the rate of CR BSI in an ICU.
Evaluating Sharps Safety Devices Meeting OSHA's Intent
Authors: Pugliese Gina , Germanson Teresa P. , Bartley Judene , Luca Judith , Lamerato Lois , Cox Jack , Jagger Janine
Published: February 2006

The Occupational Safety and Health Administration (OSHA) revised the Bloodborne Pathogen Standard and, on July 17, 2001, began enforcing the use of appropriate and effective sharps devices with engineered sharps-injury protection. OSHA requires employers to maintain a sharps-injury log that records, among other items, the type and brand of contaminated sharps device involved in each injury. Federal OSHA does not require needlestick injury rates to be calculated by brand or type of device. A sufficient sample size to show a valid comparison of safety devices, based on injury rates, is rarely feasible in a single facility outside of a formal research trial. Thus, calculations of injury rates should not be used by employers for product evaluations to compare the effectiveness of safety devices. This article provides examples of sample-size requirements for statistically valid comparisons, ranging from 100,000 to 4.5 million of each device, depending on study design, and expected reductions in needlestick injury rates.
Etiology of Fever and Opportunities for Reduction of Antibiotic Use in a Pediatric Intensive Care Unit
Authors: Toltzis Philip , Rosolowski Bonnie , Salvator Ann
Published: February 2006

Objective:

To determine the cause of fever in critically ill children and to identify opportunities for reducing antibiotic use in this population.

Design:

Prospective case series.

Setting:

A tertiary-care medical-surgical pediatric intensive care unit (PICU).

Patients:

Children admitted to the PICU who experienced fever (axillary temperature >38.3°C).

Measurements:

Consecutive children who were febrile at any point in their PICU stay were investigated over two winter seasons. Etiology of the fever was determined by physical examination and routine microbiology and radiographic tests. Three subgroups were reviewed to approximate the number of antibiotic-days that could have been reduced; namely, those with an indeterminate source, those with a documented viral infection, and those receiving a prolonged course of antibiotics. A set of standards reflecting common antibiotic use then was applied to these three patient groups.

Results:

Of 211 subjects, the majority (83.3%) had either a definitive or suspected focus for their fever, and nearly all of these patients were judged to have an infectious etiology. The study population received a total of 2,036 antibiotic-days. Despite the high incidence of infectious causes of fever in our subjects, however, approximately 15% of total antibiotic-days could have been reduced by applying common-use standards.

Conclusions:

Fever in the PICU was usually of defined focus and infectious in origin. However, among febrile patients in the PICU, substantial opportunity exists for reduction of antibiotic use. Trials determining the safety of antibiotic reduction in this population should be pursued vigorously.
Negative-Pressure Monitoring of Tuberculosis Isolation Rooms Within New York State Hospitals
Authors: Pavelchak Nicholas , Cummings Karen , Stricof Rachel , Marshall Elizabeth , Oxtoby Margaret , London Matthew
Published: February 2006

A previously published study recommended the daily use of visible smoke to test for negative air pressure in isolation rooms occupied by potentially infectious tuberculosis cases. Continuous monitoring devices were found to have poor reliability. Findings from our survey of engineering controls in acute-care hospitals within New York State support this recommendation.
Using Epidemiology to Target Staff Influenza Vaccination Programs
Authors: Russell Margaret L. , Ferguson Cheryl A.
Published: February 2006

We examined staff influenza vaccination rates in rural hospitals that had both acute- and long-term-care (LTC) units. After controlling for hospital, acute-care staff were less likely to be vaccinated than LTC staff. There was no consistent association between type of worker and vaccination after controlling for both hospital and type of care.
Infection Control Practices Among Correctional Healthcare Workers: Effect of Management Attitudes and Availability of Protective Equipment and Engineering Controls
Authors: Green-McKenzie Judith , Gershon Robyn R.M. , Karkashian Christine
Published: February 2006

Objectives:

To determine the relation of the availability of personal protective equipment (PPE) and engineering controls to infection control (IC) practices in a prison healthcare setting, and to explore the effect on IC practices of a perceived organizational commitment to safety.

Design:

Cross-sectional survey.

Setting:

The study population was drawn from the 28 regional Correctional Health Care Workers Facilities in Maryland.

Participants:

All full-time Maryland correctional healthcare workers (HCWs) were surveyed, and 225 (64%) of the 350 responded.

Method:

A confidential, self-administered questionnaire was mailed to all correctional HCWs employed in the 28 Maryland Correctional Health Care Facilities. The questionnaire was analyzed psychometrically and validated through extensive pilot testing. It included items on three major constructs: IC practices, safety climate (defined as the perception of organizational commitment to safety), and availability of IC equipment and supplies.

Results:

A strong correlation was found between the availability of PPE and IC practices. Similarly, a strong correlation was found between IC practices and the presence of engineering controls. In addition, an equally strong association was seen between the adoption of IC practices and employee perception of management commitment to safety. Those employees who perceived a high level of management support for safety were more than twice as likely to adhere to recommended IC practices. IC practices were significantly more likely to be followed if PPE was always readily available. Similarly, IC practices were more likely to be followed if engineering controls were provided.

Conclusion:

These findings suggest that ready availability of PPE and the presence of engineering controls are crucial to help ensure their use in this high-risk environment. This is especially important because correctional HCWs are potentially at risk of exposure to bloodborne pathogens such as human immunodeficiency virus and hepatitis B and C viruses. Commitment to safety was found to be highly associated with the adoption of safe work practices. There is an inherent conflict of “custody versus care” in this setting; hence, it is especially important that we understand and appreciate the relation between safety climate and IC practices. Interventions designed to improve safety climate, as well as availability of necessary IC supplies and equipment, will most likely prove effective in improving employee compliance with IC practices in this healthcare setting.
The Prevalence of Fecal Colonization With VRE Among Residents of Long-Term–Care Facilities in Melbourne, Australia
Authors: Padiglione Alexander A. , Grabsch Elizabeth , Wolfe Rory , Gibson Kimberly , Grayson M. Lindsay
Published: February 2006

A point-prevalence survey performed among residents of eight nursing homes in Melbourne, Australia, found a rate of fecal VRE colonization of 3.1% (9/292; 95% confidence interval, 1.1-5.1), allvanBEnterococcusfaecium.This is a higher rate than in the general community (3.1% vs 0.2%). Many residents (16%) had been inpatients in acute-care hospitals in the previous 3 months.
Models and Mechanisms for Building and Funding Partnerships
Authors: Bisby Mark
Published: February 2006

The Canadian Institutes of Health Research (CIHR) recently replaced two former federal agencies, the Medical Research Council and the National Health Research and Development Program. CIHR has attracted widespread international attention as a grand experimental model that emphasizes excellence, interdisciplinarity, networking, partnership, and a collective process for priority setting, alongside continuing support for the best ideas of the most talented investigators. CIHR identified four cross-cutting health research themes (biomedical research; clinical research; health service; systems research; and research into the societal, cultural, and environmental determinants of health) across its 13 virtual institutes. Each institute is required to bring together investigators working in specific aspects of health research, as they relate to the mandate of the institute, in order to stimulate novel interdisciplinary research approaches. The challenge to Canadian members of the Society for Healthcare Epidemiology of America and their collaborators from other countries is to engage in partnership with CIHR, so that together we can ensure unparalleled quality, safety, and efficacy of healthcare systems in Canada and around the world.
The Direct Costs of Nosocomial Catheter-Associated Urinary Tract Infection in the Era of Managed Care
Authors: Tambyah Paul A. , Knasinski Valerie , Maki Dennis G.
Published: February 2006

Objective:

To determine the additional direct costs of hospitalization attributable to catheter-associated urinary tract infection (CAUTI) in 1,497 newly catheterized patients.

Design:

Prospective observational and laboratory study.

Setting:

University hospital.

Methods:

Data were collected on risk factors for CAUTI (defined as > 103 colony-forming units [CFU]/mL), severity of illness, and diagnostic and therapeutic interventions in consenting newly catheterized patients. Daily urine cultures were obtained from each newly catheterized patient, but the results of these cultures were not revealed to his or her physician. During the study, one of the investigators (DGM) reviewed each patient's record and made a judgment as to which of the diagnostic tests and treatments ordered and what incremental length of stay could reasonably be ascribed to his or her CAUTI. The total hospital costs for each patient were also obtained.

Results:

Overall, 235 patients acquired CAUTIs during the study; most of the CAUTIs were completely asymptomatic, and only 52% were diagnosed by the patients' physicians using the hospital laboratory. Only 1 patient with a CAUTI had a secondary bloodstream infection. Thirty-three (13%) of the CAUTIs were caused by Escherichia coli; 63 (25%) by Klebsiella, Enterobacter, Citrobacter, Pseudomonas aeruginosa, or other antibiotic-resistant, gram-negative bacilli; 87 (35%) by enterococci or staphylococci; and 67 (27%) by Candida species. The 123 CAUTIs diagnosed by the hospital laboratory were judged to have been responsible for an additional $20,662 in extra costs of diagnostic tests and $35,872 in extra medication costs, a mean of $589 (median, $356) per CAUTI. CAUTIs caused by E. coli cost considerably less than infections caused by other gram-negative bacilli ($363.3 ± $228.2 vs $690.4 ± $783.7; P = .02) or yeasts ($821.2 ± $2,169.9). There were less striking differences in the costs per CAUTI caused by staphylococci or enterococci ($387.1 ± $434.8).

Conclusions:

The extra direct costs associated with nosocomial CAUTI found in this prospective study, which was done in the era of managed care during the late 1990s, are substantially lower than those reported in the largest comparable studies done more than 15 years ago, most of which were retrospective, reflecting the powerful impact of cost-containment measures that are now implemented in managed care.
Hand Washing and Physicians: How to Get Them Together
Authors: Salemi Charles , Canola M. Teresa , Eck Enid K.
Published: February 2006

Objective:

To determine the motivating and behavioral factors responsible for improving compliance with hand washing among physicians.

Design:

Five unobtrusive, observational studies recording hand washing after direct patient contact, with study results reported to physicians.

Setting:

A 450-bed hospital in a health maintenance organization with an 18-bed medical-surgical intensive care unit (ICU) and a 12-bed cardiac care unit.

Methods:

An infectious disease physician met individually with participants to report study results and obtain a commitment to hand washing guidelines. Follow-up interviews were conducted to evaluate behavioral factors and educational programs. Hand washing study results were presented to all staff physicians by live and videotaped inservice presentations and electronic mail (e-mail) newsletters. The importance of influencing factors and the educational effectiveness of the hand washing program were evaluated.

Results:

Five observational hand washing studies were conducted in the ICU between April 1999 and September 2000. Rates of physician compliance with hand washing were 19%, 85%, 76%, 74%, and 68%, respectively. There were 71 initial encounters and 55 follow-up interviews with the same physicians. Physician interviews revealed that 73% remembered the initial encounter, 70% remembered the hand washing inservice presentations, and 18% remembered the e-mail newsletters. Personal commitment and meeting with an infectious disease physician had the most influence on hand washing behavior. Direct inservice presentations (either live or videotaped) had more influence than did e-mail information. Rates of ventilator-associated pneumonia did not significantly change before and during the study periods. A decrease in the rate of central-line–related bloodstream infections from 3.2 to 1.4 per 1,000 central-line days was found, but could not be solely attributed to improved physician compliance with hand washing.

Conclusions:

Physician compliance with hand washing can improve. Personal encounters, direct meetings with an infectious disease physician, and videotaped presentations had the greatest impact on physician compliance with hand washing at our medical center, compared with newsletters sent via e-mail. Local data on compliance with hand washing and physician involvement are factors to be considered for physician hand washing compliance programs in other medical centers.
Masking of Neutropenic Patients on Transport From Hospital Rooms Is Associated With a Decrease in Nosocomial Aspergillosis During Construction
Authors: Raad Issam , Hanna Hend , Osting Cheryl , Hachem Ray , Umphrey Jan , Tarrand Jeffrey , Kantarjian Hagop , Bodey Gerald P.
Published: February 2006

To prevent nosocomial pulmonary aspergillosis during hospital construction, neutropenic patients with hematologic malignancy were required to wear high-efficiency masks when leaving their rooms. The rate of nosocomial aspergillosis decreased from 0.73 per 1,000 hospital patient-days during fiscal years 1993 to 1996 to 0.24 per 1,000 hospital patient-days during fiscal years 1996 to 1999 (P < .001). High-efficiency masks reduced nosocomial aspergillosis during hospital construction.
Failure of Oral Antimicrobial Agents in Eradicating Gastrointestinal Colonization With Vancomycin-Resistant Enterococci
Authors: Hachem Ray , Raad Issam
Published: February 2006

Eradication of gastrointestinal colonization with vancomycin-resistant enterococci (VRE) using a combination of oral bacitracin and gentamicin was evaluated. Twenty-eight evaluable treated patients were matched with 28 control patients. After 3 months of follow-up, 5 patients (18%) in the treatment group versus 1 patient (4%) in the control group (P= .2) had negative results on stool cultures, with a similar frequency of VRE bacteremia (P= .8). The use of oral bacitracin plus gentamicin did not reduce VRE colonization or bacteremia.
The Best Hospital Practices for Controlling Methicillin-Resistant Staphylococcus Aureus: On the Cutting Edge
Authors: Arnold Meredith S. , Dempsey Jane M. , Fishman Marlene , McAuley Patricia J. , Tibert Cynthia , Vallande Nancy C.
Published: February 2006

Objective:

A performance improvement task force of Rhode Island infection control professionals was created to develop an epidemiologic model of statewide consistent infection control practices that could reduce the spread of methicillin-resistant Staphylococcus aureus (MRSA).

Design:

This model encompasses screening protocols, isolation techniques, methods of cohorting positive patients, decolonization issues, postexposure follow-up, microbiology procedures, and standardized surveillance methodologies. These “best practice guidelines” include three categories of recommendations that define priority levels based on the availability of scientific data.

Setting:

From 1995 through 2000, several Rhode Island hospitals experienced a fivefold increase in nosocomial acquisition of MRSA.

Participants:

Rhode Island infection control professionals are a highly interactive group in the unique position of sharing patients and ultimately experiencing similar trends and problems.

Intervention:

The task force collaborated on developing the best hospital infection control practices to prevent and control the spread of MRSA in Rhode Island.

Results:

The task force met with local infectious disease physicians and representatives from the Rhode Island Department of Health, the Hospital Association of Rhode Island, and Rhode Island Quality Improvement Partners. Discussions identified numerous and diverse MRSA control practices, issues of consensus, and approaches to resolving controversial methods of reducing the spread of MRSA The guidelines regarding the best hospital practices for controlling MRSA were finalized 8 months later.

Conclusion:

These guidelines were distributed to all chief executive officers of Rhode Island hospitals by the Rhode Island Department of Health in December 2001. They were issued separate and apart from any regulations, with the intent that hospitals will adopt them as best hospital practices in an attempt to control MRSA.
An Outbreak ofStaphylococcus aureusin a Pediatric Cardiothoracic Surgery Unit
Authors: Weber Stefan , Herwaldt Loreen A. , McNutt Louise-Anne , Rhomberg Paul , Vaudaux Pierre , Pfaller Michael A. , Perl Trish M.
Published: February 2006

Objective:

To investigate an outbreak ofStaphylococcus aureussurgical-site infections.

Design:

Case–control study.

Setting:

Pediatric cardiothoracic surgery service of a tertiary-care university medical center.

Method:

Molecular typing was used to identify healthcare workers who carried the epidemic strain.

Results:

Three children acquired surgical-site infections caused by a single strain ofS. aureus. Fourteen (25%) of the staff members in the operating room and 17 (11%) on nursing units carried the epidemic strain (P= 01). A case–control study identified 4 healthcare workers who were associated statistically with the outbreak, 2 of whom (a cardiothoracic surgeon and a perfusionist) carried the epidemic strain in their nares. The surgeon also carried the epidemic strain on his hands. Each staff member who carried the epidemic strain was treated with mupirocin; those carrying the strain on their hands were required to wash their hands with chlorhexidine. The surgeon was not allowed to perform surgery until 2 of his hand cultures did not growS. aureus.

Conclusions:

Only three children were infected with the epidemic strain, but it was disseminated widely among staff who cared for children who underwent cardiothoracic surgery. No additional cases were identified after staff members who carried the epidemic strain were decolonized. Both classic epidemiologic methods and molecular typing techniques were necessary to identify the source and extent of this outbreak.
The Effectiveness of Influenza Vaccine Against Influenza A (H3N2) Virus Infections in Nursing Homes in Niigata, Japan, During the 1998-1999 and 1999-2000 Seasons
Authors: Saito Reiko , Suzuki Hiroshi , Oshitani Hitoshi , Sakai Takatsugu , Seki Nao , Tanabe Naohito
Published: February 2006

Objective:

To evaluate the effectiveness of influenza vaccines against influenza-like illness (ILI) among nursing home residents.

Design:

Prospective, nonrandomized, cohort study.

Setting:

Nine nursing homes during the 1998-1999 influenza season and 11 nursing homes during the 1999-2000 influenza season in Niigata Prefecture, Japan.

Participants:

Six hundred ninety-nine residents and 440 healthcare workers (HCWs) during the first season, and 930 residents and 517 HCWs during the second season, with vaccination rates ranging from 0% to 97.7%.

Results:

Overall, ILI decreased from 24.3% during the 1998-1999 season to 8.8% during the 1999-2000 season. Multivariate analysis adjusted for several factors, including gender, age, underlying diseases, and resident and HCW vaccination rates, failed to demonstrate clear individual protection of residents (relative risk [RR], 1.42; P = .2 for the first season; RR, 0.95; P = .9 for the second season). However, vaccination rates of 60% or greater for residents and HCWs reduced the risk of ILI, and also could prevent outbreaks during the 2 seasons. Highly impaired activities of daily living and chronic respiratory diseases were significantly associated with increased ILI.

Conclusions:

A high vaccination rate for both residents and HCWs may reduce the risk of ILI and institutional outbreaks in nursing homes
How Many Nosocomial Infections are Associated with Cross-Transmission? A Prospective Cohort Study in A Surgical Intensive Care Unit
Authors: Weist Klaus , Pollege Kathrin , Schulz Ines , Rüden Henning , Gastmeier Petra
Published: February 2006

Objective:

To determine the percentage of cross-transmissions in an intensive care unit (ICU) with high nosocomial infection (NI) rates according to the data of the German Nosocomial Infection Surveillance System.

Setting:

A 14-bed surgical ICU of a 1,300-bed, tertiary-care teaching hospital.

Method:

Prospective surveillance of NIs during a period of 9 months. If an NI was present, the isolates of the following indicator pathogens were stored and typed by species:Staphylococcus aureus, Enterococcus species, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacterspecies. Pulsed-field gel electrophoresis was performed for typing ofS. aureusstrains and arbitrarily primed polymerase chain reaction was applied for the other pathogens. The presence of two indistinguishable strains in two patients was considered as one episode of cross-transmission.

Results:

Two hundred sixty-two patients were observed during a period of 2,444 patient-days; 96 NIs were identified in 59 patients and the overall incidence density of NI was 39.3 per 1,000 patient-days. For 104 isolates, it was possible to consider typing results. Altogether, 36 cross-transmissions have lead to NIs in other patients. That means at least 37.5% of all NIs identified were due to cross-transmissions.

Conclusion:

Because of the method of this study, the percentage of NIs due to cross-transmission identified for this ICU is an “at least number”. In reality, the number of cross-transmissions, and thus the number of avoidable infections, may have been even higher. However, it is difficult to assess whether the percentage of NIs due to cross-transmission determined for this ICU may be the crucial explanation for the relatively high infection rate in comparison to other surgical ICUs.
The Role of Nurse Understaffing in Nosocomial Viral Gastrointestinal Infections on a General Pediatrics Ward
Authors: Stegenga Jacob , Bell Erica , Matlow Anne
Published: February 2006

Objective:

To examine the relationship between nurse staffing levels and the rate of nosocomial viral gastrointestinal infections (NVGIs) in a general pediatrics population.

Design:

Retrospective descriptive study.

Setting:

A general pediatrics ward at The Hospital for Sick Children in Toronto, Ontario, Canada, a 320-bed, tertiary-care pediatric institution.

Results:

Forty-three NVGIs were detected in 37 patients of 2,929 admissions (1.3%). The monthly NVGI rate correlated significantly with the monthly night patient-to-nurse ratio (r = 0.56) and the monthly day patient-to-nurse ratio (r = 0.50). The nursing hours per patient-day during the preinfection period (PIP) were significantly lower than those during the nonpreinfection period (NPIP; 12.5 vs 13.0). There was no difference between the PIP and the NPIP day patient-to-nurse ratios (3.31 vs 3.32), but there was a significant difference between the PIP and the NPIP night patient-to-nurse ratios (3.26 vs 3.16). The incidence of NVGIs in the 72-hour period after any day when the nursing hours per patient-day were less than 10.5 was 6.39 infections per 1,000 patient-days, compared with 2.17 infections per 1,000 patient-days in periods with more than 10.5 nursing hours per patient-day (rate ratio, 2.94; 95% confidence interval, 2.16 to 4.01).

Conclusion:

Nurse understaffing contributed to an increased NVGI rate in our general pediatrics population, and should be assessed as a risk factor in outbreak investigations.
Preventing Nosocomial Transmission of Pulmonary Tuberculosis: When may Isolation be Discontinued for Patients with Suspected Tuberculosis?
Authors: Siddiqui Anwer H. , Perl Trish M. , Conlon Martha , Donegan Nancy , Roghmann Mary-Claire
Published: February 2006

Objective:

The Centers for Disease Control and Prevention and the American Thoracic Society recommend obtaining cultures of at least three sputum specimens for acid-fast bacilli (AFB) from patients in whom tuberculosis (TB) is suspected. On the basis of this, most hospitals isolate patients with suspected TB for 3 days or more until three smear (not culture) results are negative. Our objective was to evaluate the predictive value and sensitivity of these smears.

Design:

Observational study.

Setting:

Four urban medical centers.

Methods:

The posttest probability of TB given sequential negative AFB smears from 274 patients isolated for suspected TB and the sensitivity of sequential AFB smears from 209 patients with positive results on culture for pulmonary TB were measured.

Results:

The posttest probabilities of having TB given one, two, and three negative AFB smears were low: 1.1% (3 of 265; 95% confidence interval [CI95], 0.23% to 3.27%), 0.4% (1 of 262; CI95, 0% to 2.1%), and 0% (0 of 260; CI95, 0% to 1.4%), respectively. Among the 209 patients with positive results on culture for pulmonary TB, 169 (81%) had an expectorated sputum specimen sent, of which 91 (54%) were positive for AFB. Forty (24%) of the 169 patients had a second expectorated sputum specimen sent after the results of the first specimen were negative; only 6 (15%) of these had positive AFB smears. None of the 10 patients in whom the first two expectorated sputum samples yielded an AFB smear without an organism had a third AFB smear that was positive.

Conclusion:

Unless there is high clinical suspicion of pulmonary TB in a specific patient, the use of three AFB smears on expectorated sputa is a rational approach to discontinuing isolation for patients with suspected TB.
The Use of Heteroduplex Analysis of Polymerase Chain Reaction Products to Support the Possible Transmission ofLegionella pneumophilaFrom a Malfunctioning Automobile Air Conditioner
Authors: Pinar Ahmet , Ramirez Julio A. , Schindler Laura L. , Miller Richard D. , Summersgill James T.
Published: February 2006

Air conditioner condensates have not been previously associated with cases of Legionnaires' disease. We report the possible transmission of Legionella pneumophila serogroup 1 from a malfunctioning automobile air conditioning system's leaking water onto the floorboard of a car driven for a long distance by the patient. Heteroduplex analysis of polymerase chain reaction products was used to help establish an epidemiologic link between the water specimen and the patient.
Characteristics of a Large Cluster of Vancomycin-Resistant Enterococci in an Australian Hospital
Authors: Cooper Elizabeth , Paull Amalie , O'Reilly Mary
Published: February 2006

Investigation of a cluster of hospital inpatients colonized with vancomycin-resistant enterococci (VRE) revealed a point-prevalence of 19.1%. The outbreak was controlled using established guidelines and additional strategies, including minimizing patient transfers and enforcing appropriate antibiotic prescribing. The incidence of VRE has remained low during the ensuing 30 months.
Nonrandom Selection and The Attributable Cost of Surgical-Site Infections
Authors: Hollenbeak Christopher S. , Murphy Denise , Dunagan William C. , Fraser Victoria J.
Published: February 2006

Objective:

To study the extent to which selection bias poses problems for estimating the attributable cost of deep chest surgical-site infection (SSI) following coronary artery bypass graft (CABG) surgery.

Design:

Reanalysis of a prospective case–control study.

Setting:

A large, Midwestern community medical center.

Patients:

Cases were all patients who had an SSI (N = 41) following CABG and CABG and valve surgery between April 1996 and March 1998. Controls were every tenth uninfected patient (N = 160).

Methods:

Estimates of the attributable cost of deep chest SSI were computed using unmatched comparison, matched comparison, linear regression, and Heckman's two-stage approach.

Results:

The attributable cost of deep chest SSI was estimated to be $20,012 by unmatched comparison, $19,579 by matched comparison, $20,103 by linear regression, and $14,211 by Heckman's two-stage method. Controlling for selection bias substantially reduced the cost estimate, but the coefficient capturing selection bias was not statistically significant.

Conclusions:

Deep chest SSI significantly increases the cost of care for patients who undergo CABG surgery. Unmatched comparison, matched comparison, and linear regression estimated the attributable cost to be approximately $20,000. Although controlling for selection bias with Heckman's two-stage method resulted in a substantially smaller estimate, the coefficient for selection bias was not statistically significant, suggesting that the estimates derived from the other models should be acceptable. However, the magnitude of the difference between the models shows that the effect of selection bias can be substantial. Some exploration for selection bias is recommended when estimating the attributable cost of SSIs.
The Impact of Surgical-Site Infections Following Orthopedic Surgery at a Community Hospital and a University Hospital Adverse Quality of Life, Excess Length of Stay, and Extra Cost
Authors: Whitehouse James D. , Friedman N. Deborah , Kirkland Kathryn B. , Richardson William J. , Sexton Daniel J.
Published: February 2006

Objective:

To measure the impact of orthopedic surgical-site infections (SSIs) on quality of life, length of hospitalization, and cost.

Design:

A pairwise-matched (1:1) case-control study within a cohort.

Setting:

A tertiary-care university medical center and a community hospital.

Patients:

Cases of orthopedic SSIs were prospectively identified by infection control professionals. Matched controls were selected from the entire cohort of patients undergoing orthopedic surgery who did not have an SSI. Matching variables included type of surgical procedure, National Nosocomial Infections Surveillance risk index, age, date of surgery, and surgeon.

Main Outcome Measures:

Quality of life, duration of postoperative hospital stay, frequency of hospital readmission, overall direct medical costs, and mortality rate.

Results:

Fifty-nine SSIs were identified. Each orthopedic SSI accounted for a median of 1 extra day of stay during the initial hospitalization (P= .001) and a median of 14 extra days of hospitalization during the follow-up period (P= .0001). Patients with SSI required more rehospitalizations (median, 2 vs 1;P= .0001) and more total surgical procedures (median, 2 vs 1;P= .0001). The median total direct cost of hospitalizations per infected patient was $24,344, compared with $6,636 per uninfected patient (P= .0001). Mortality rates were similar for cases and controls. Quality of life was adversely affected for patients with SSI. The largest decrements in scores on the Medical Outcome Study Short Form 36 questionnaire were seen in the physical functioning and role-physical domains.

Conclusions:

Orthopedic SSIs prolong total hospital stays by a median of 2 weeks per patient, approximately double rehospitalization rates, and increase healthcare costs by more than 300%. Moreover, patients with orthopedic SSIs have substantially greater physical limitations and significant reductions in their health-related quality of life.
Hospital-Acquired, Laboratory-Confirmed Bloodstream Infection: Increased Hospital Stay and Direct Costs
Authors: Orsi Giovanni Battista , Stefano Lidia Di , Noah Norman
Published: February 2006

Objectives:

To determine increased hospital stay and direct costs attributable to hospital-acquired, laboratory-confirmed bloodstream infection (BSI), and to evaluate the matching variable length of stay (LOS).

Design:

Retrospective (historical) cohort study with 1:2 matching in intensive care units and surgical wards.

Setting:

A 2,000-bed university hospital in Rome, Italy.

Patients:

All patients admitted between January 1994 and June 1995 who had hospital-acquired, laboratory-confirmed BSI were considered cases; all others were eligible as controls.

Methods:

Two controls (A and B) were selected per case in a stepwise fashion. Controls in group A were selected according to the following six criteria: ward, gender, age, diagnosis, central venous catheter, and LOS equal to the interval from admission to infection in a matched case ± 20% (LOS ± 20%). Controls in group B were selected according to the first five criteria, but excluded LOS ± 20%.

Results:

One hundred five of 108 patients were each matched with two controls. The matching appropriateness score was greater than 90%. With the use of controls in groups A and B, the case-fatality rates attributable to hospital-acquired, laboratory-confirmed BSI were 35.2% and 40.9%, respectively; the estimated risk ratios for death were 2.60 and 3.52 (P = .0001), respectively. The increased hospital stay per case attributable to hospital-acquired, laboratory-confirmed BSI was 19.1 (mean) and 13.0 (median) days for matched pairs in control group A and 19.9 (mean) and 15.0 (median) days for matched pairs in control group B. With controls in group A, the cost of increased hospital stay per patient attributable to hospital-acquired, laboratory-confirmed BSI was Euro 15,413. The additional cost per patient due to treatment was Euro 943, making the overall direct cost Euro 16,356 per case.

Conclusions:

This study should make it possible to estimate the cost of hospital-acquired, laboratory-confirmed BSI in most hospitals after adjusting for incidence rate. It also confirmed the use of LOS ± 20% as a matching variable to limit overestimation of increased hospital stay. To our knowledge, this is among the first such studies in Europe.
Duration of Colonization with Vancomycin-ResistantEnterococcus
Authors: Byers Karin E. , Anglim Anne M. , Anneski Cynthia J. , Farr Barry M.
Published: February 2006

Objective:

To determine the duration of colonization with vancomycin-resistantEnterococcus(VRE) and the adequacy of 3 consecutive negative cultures to determine clearance.

Design:

Retrospective cohort study.

Setting:

A university hospital.

Population:

Patients identified by perirectal cultures as VRE carriers who had follow-up cultures.

Methods:

Follow-up perirectal cultures were collected in inpatient and outpatient settings, at least 1 week apart, when patients were not receiving antibiotics with activity against VRE. The likelihood of culture positivity was analyzed given prior culture results and time from the initial positive culture.

Results:

A total of 116 patients colonized with VRE had 423 follow-up cultures, a mean of 204 days (range, 4 to 709 days) after their initial isolate. The first follow-up culture, collected a mean of 125 days after the initial positive isolate, was negative in 64%. After 1 negative follow-up culture, the next one was negative in 92% of the patients. After 2 negative cultures, 95% remained culture-negative. After 3 sequential negative cultures, 35 (95%) of 37 patients remained culture-negative. As the interval between the initial and the follow-up isolates increased, the probability that a subsequent culture would be positive decreased (P< .001, chi square for trend). Prolonged hospitalization, intensive care, and antibiotic use each decreased the likelihood of clearing VRE.

Conclusion:

These data support the Centers for Disease Control and Prevention criterion of 3 sequential negative cultures, at least 1 week apart, to remove patients from VRE isolation. Nevertheless, this may reflect a decrease in the quantity of VRE to an undetectable level and these patients should be observed for relapse, especially when re-treated with antibiotics.
Prevalence of Measles Antibody Among Young Adult Healthcare Workers in a Cancer Hospital: 1980s Versus 1998–1999
Authors: Seo Susan K. , Malak Sharp F. , Lim Suzanne , Eagan Janet , Sepkowitz Kent A.
Published: February 2006

Despite the 1989 Advisory Committee on Immunization Practices recommendation of a second dose of vaccine, measles seropositivity rates had declined for adult healthcare workers in their 20s hired at a cancer hospital between 1998 and 1999 compared with those of the same age hired between 1983 and 1988. Continued monitoring will be important as individuals born after 1989 enter the workforce.
Environmental Legionellosis and Oropharyngeal Colonization byLegionellain Immunosuppressed Patients
Authors: Pedro-Botet Maria Luisa , Sabria Miquel , Sopena Nieves , Núñez Marian García , Morera Josep , Reynaga Esteban
Published: February 2006

Inhalation of contaminated aerosols is considered the most common route ofLegionellatransmission. The aim of this study was to determine whether contact with water contaminated byLegionellawas related to oropharyngeal colonization in immunosuppressed patients. Eighty-five oropharyngeal swabs (April 1996 to June 1996) were seeded on selective and nonselective buffered charcoal-yeast extract media.Legionellawas not isolated.
Near arithmetic progressions in sparse sets
Authors: Leth Steven
Published: February 2006

Nonstandard methods are used to obtain results in combinatorial number theory. The main technique is to use the standard part map to translate density properties of subsets of

∗

N

^{\ast }\mathbb {N}

into Lebesgue measure properties on

[
0
,
1
]

[0,1]

. This allows us to obtain a simple condition on a standard sequence

A
A

that guarantees the existence of intervals in arithmetic progression, all of which contain elements of

A
A

with various uniform density conditions.
Extensions of orthosymmetric lattice bimorphisms
Authors: Toumi Mohamed
Published: February 2006

Let

E
E

be an Archimedean vector lattice, let

E

d

E^{\mathfrak {d}}

be its Dedekind completion and let

B
B

be a Dedekind complete vector lattice. If

Ψ

0

:
E
×
E
→
B

\Psi _{0}:E\times E\rightarrow B

is an orthosymmetric lattice bimorphism, then there exists a lattice bimorphism

Ψ
:

E

d

×

E

d

→
B

\Psi :E^{\mathfrak {d}}\times E^{\mathfrak {d}} \rightarrow B

that not just extends

Ψ

0

\Psi _{0}

but also has to be orthosymmetric. As an application, we prove the following: Let

A
A

be an Archimedean

d
d

-algebra. Then the multiplication in

A
A

can be extended to a multiplication in

A

d

A^{\mathfrak {d}}

, the Dedekind completion of

A
A

, in such a fashion that

A

d

A^{\mathfrak {d}}

is again a

d
d

-algebra with respect to this extended multiplication. This gives a positive answer to the problem posed by C. B. Huijsmans in 1990.
One-dimensional metric foliations on the Heisenberg group
Authors: Munteanu Marius
Published: February 2006

We prove that the one-dimensional metric foliations on the

(
2
n
+
1
)

(2n+1)

-dimensional Heisenberg group equipped with a left invariant metric are homogeneous.
Fractional powers of the algebraic sum of normal operators
Authors: Diagana Toka
Published: February 2006

The main concern in this paper is to give sufficient conditions such that if

A
,
B

A, B

are unbounded normal operators on a (complex) Hilbert space

H

\mathbb H

, then for each

α
∈
(
0
,
1
)

\alpha \in (0 , 1)

, the domain

D
(
(

A
+
B

¯

)

α

)

D((\overline {A+B})^{\alpha })

equals

D
(

A

α

)
∩
D
(

B

α

)

D(A^{\alpha }) \cap D(B^{\alpha })

. It is then verified that such a result can be applied to characterize the domains of fractional powers of a large class of the Hamiltonians with singular potentials arising in quantum mechanics through the study of the Schrödinger equation.
On character groups arising from dimension groups
Authors: Zerr Ryan
Published: February 2006

Character groups associated with certain dimension groups are considered. It is shown how these character groups can be used to construct an AF groupoid whose dimension group is isomorphic to the original dimension group.
Perturbation theoretic entropy of the boundary actions of free groups
Authors: Okayasu Rui
Published: February 2006

We compute the exact value of Voiculescu’s perturbation theoretic entropy of the boundary actions of free groups. This result is a partial answer of Voiculescu’s question.
Short-time existence of solutions to the cross curvature flow on 3-manifolds
Authors: Buckland John
Published: February 2006

Given a compact 3-manifold with an initial Riemannian metric of positive (or negative) sectional curvature, we prove the short-time existence of a solution to the cross curvature flow. This is achieved using an idea first introduced by DeTurck (1983) in his work establishing the short-time existence of solutions to the Ricci flow.
Bundles of 𝐶*-correspondences over directed graphs and a theorem of Ionescu
Authors: Quigg John
Published: February 2006

We give a short proof of a recent theorem of Ionescu which shows that the Cuntz-PimsnerC∗C^*-algebra of a certain correspondence associated to a Mauldin-Williams graph is isomorphic to the graph algebra.