bluuebunny/crossref_metadata_2025 huggingface dataset:
Guideline for Prevention of Intravascular-Device–Related Infections
Authors: Pearson Michele L. ,   Hospital Infection Control Practices Advisory Committee
Published: September 2009

The “Guideline for Prevention of Intravascular Device-Related Infections” is designed to reduce the incidence of intravascular device-related infections by providing an over view of the evidence for recommendations considered prudent by consensus of Hospital Infection Control Practices Advisor y Committee (HICPAC) members. This two-part document updates and replaces the previously published Centers for Disease Control's (CDC) Guideline for Intravascular Infections (Am J Infect Control 1983;11:183-199). Part I, “Intravascular Device-Related Infections: An Over view” discusses many of the issues and controversies in intravascular-device use and maintenance. These issues include definitions and diagnosis of catheter-related infection, appropriate barrier precautions during catheter insertion, inter vals for replacement of catheters, intravenous (IV) fluids and administration sets, catheter-site care, the role of specialized IV personnel, and the use of prophylactic antimi-crobials, flush solutions, and anticoagulants. Part II, “Recommendations for Prevention of Intravascular Device-Related Infections” provides consensus recommendations of the HICPAC for the prevention and control of intravascular device-related infections. A working draft of this document also was reviewed by experts in hospital infection control, internal medicine, pediatrics, and intravenous therapy. However, all recommendations contained in the guideline may not reflect the opinion of all reviewers.
Sixteenth-Century Paduan Annotations to the First Edition of Vasari'sVite(1550)*
Authors: Ruffini Marco
Published: September 2009

The discovery of annotations to a copy of Vasari'sVite(1550) in the Beinecke Library at Yale University gives us a rare insight into how the book and contemporary art literature were read and how the information they provided circulated in the Veneto. This article traces the origin of the annotations to the circle of artists and amateurs around the painter Domenico Campagnola in Padua. In polemical reaction to the Florentinism of theVite,the annotations repeat the major anti-Vasarian arguments elaborated by art writers, but also offer new information about Veneto art. There is also a biographical note on Titian, which precedes the publication of the artist's biography in the second edition of theVite(1568).
Piety, Patriotism, and Empire: Lessons for England, Spain, and the New World in the Works of Richard Hakluyt*
Authors: Boruchoff David A.
Published: September 2009

This essay examines the didactic intent of historical works that modern critics, under the influence of a later, especially Victorian, view of English history, have construed as unalloyed propaganda for Protestant England in the pursuit of empire and in its rivalry with Catholic Spain. Careful analysis of the editorial practices of Richard Hakluyt (ca. 1552–1616) reveals that he and others of his generation instead employed patriotic conceits, such as the claim to God's Providence and protection, in a more complex and circumspect manner: as both encouragement and a corrective to national endeavor and as a yardstick against which to measure what was actually done.
Methicillin-Resistant Staphylococcus aureus Control in Hospitals: The French Experience
Authors: Richet Hervé , Wiesel Michel , Le Gallou Florence , André-Richet Béatrice , Espaze Eric ,   Association des Pays de la Loire pour l'Eviction des Infections Nosocomiales
Published: September 2009

The first cases of isolation of Staphylococcus aureus resistant to methicillin in France were published in 1962. However, until recently, very few epidemiological studies or attempts to control the epidemic have been done in France. In this article, we present the results of a prospective study performed during a 3-month period in 27 hospitals of the Région des Pays de la Loire. Among the 94,605 hospitalized patients included in the study, 0.45% (427) developed methicillin-resistant Staphylococcus aureus (MRSA) infections, the incidence rate ranging from 0% to 1.2%. Thirty-four percent of MRSA-infected patients were 80 years old or older, 30% had been transferred from another service and 19% from another hospital, 56% were hospitalized at least once during the previous year, MRSA had been isolated at least once previously in 18% of MRSA-infected patients, 19% died, 16% were transferred to another service and 11% to another hospital, and only 32% were discharged to their homes. A poor compliance to contact isolation precautions was observed in all hospitals: 46% of MRSA-infected patients were hospitalized in a private room; gloves, masks, and gowns were worn for the care of 63.4%, 14%, and 42.5% of MRSA-infected patients, respectively; and handwashing was feasible in the rooms of 52% of the patients.
Local Antibiotic Prophylaxis in Surgery
Authors: Martin Claude , Viviand Xavier , Potié Frédéric
Published: September 2009

The perioperative use of antibiotics is an established and accepted technique for the prevention of postoperative infection. Intravenous administration often is preferred, and intramuscular administration is possible, although it has certain drawbacks. This article examines a variety of other routes of administration for delivering antibiotics locally to the surgical site. These techniques merit further study in prospectively randomized trials.
Selected Aspects of the Socioeconomic Impact of Nosocomial Infections: Morbidity, Mortality, Cost, and Prevention
Authors: Jarvis William R.
Published: September 2009

Approximately 2 million nosocomial infections occur annually in the United States. These infections result in substantial morbidity, mortality, and cost. The excess duration of hospitalization secondary to nosocomial infections has been estimated to be 1 to 4 days for urinary tract infections, 7 to 8.2 days for surgical site infections, 7 to 21 days for bloodstream infections, and 6.8 to 30 days for pneumonia. The estimated mortalities associated with nosocomial bloodstream infections and pneumonia are 23.8% to 50% and 14.8% to 71% (overall), or 16.3% to 35% and 6.8% to 30% (attributable), respectively. The estimated average costs of these infections are $558 to $593 for each urinary tract infection, $2,734 for each surgical site infection, $3,061 to $40,000 for each bloodstream infection, and $4,947 for each pneumonia. Even minimally effective infection control programs are cost-effective. In countries with prospective payment systems based on diagnosis-related groups, hospitals lose from $583 to $4,886 for each nosocomial infection. As administrators focus on cost containment, increased support should be given to infection control programs so that preventable nosocomial infections and their associated expenditures can be averted.
Risk Factors for Mortality Associated With Enterococcal Bloodstream Infections
Authors: Stroud Leonardo , Edwards Jonathan , Danzig Lisa , Culver David , Gaynes Robert
Published: September 2009

Objective:

To determine risk factors for mortality in patients with a nosocomial enterococcal primary bloodstream infection (EPBI) and to assess whether vancomycin resistance placed a patient at increased risk of death.

Design/Setting:

A retrospective cohort study was conducted in four National Nosocomial Infection Surveillance System hospitals.

Results:

Of 145 patients identified with EPBIs, 74 (51%) died, and 26 (18%) had a vancomycin-resistant isolate. Upon comparing patients with EPBIs who survived to those who died, no associations were found between mortality and prior invasive device use, procedure history, type or number of prior nosocomial infections, length of hospitalization before infection, or receipt of vancomycin. Independent predictors of mortality were indices of severity of illness (APACHE II score and comorbidity weighted index), age, the use of third-generation cephalosporins or metronidazole during the week prior to infection, and female gender.

Conclusions:

Vancomycin resistance was not an independent predictor of death, and its role was difficult to establish, because cohort patients were among the most severely ill of all hospitalized patients. Enterococcal primary bloodstream infections appear to indicate severe, life-threatening disease processes. The pathogenicity of enterococci and the role of vancomycin resistance as a cause of mortality in patients with EPBIs need to be assessed further.
Rapid Identification of Respiratory Viruses: Impact on Isolation Practices and Transmission Among Immunocompromised Pediatric Patients
Authors: Beekmann Susan E. , Engler Howard D. , Collins Amy S. , Canosa Jeanne , Henderson David K. , Freifeld Alison
Published: September 2009

Objective:

To determine whether empiric isolation of patients with acute respiratory virus infection symptoms could be discontinued when preliminary shell vial cultures were negative, and the impact of this approach on hospital resources.

Design:

In 1993, we retrospectively reviewed respiratory virus test results from 1992 to 1993 and extended data collection prospectively through the 1993 to 1994 season. The rapid test and 48-hour shell vial results were compared to a standard of rapid test plus 5-day shell vial culture results to determine the sensitivity and specificity of these “preliminary” results.

Setting:

A 400-bed tertiary referral research hospital.

Patients:

Patients from any inpatient unit or clinic with acute respiratory virus infection symptoms who had a specimen submitted for respiratory virus culture. Patients were placed on empiric respiratory isolation pending culture results.

Results:

The overall sensitivity of the combined rapid and 48-hour culture results in adults and children was 97%. All 15 pediatric patients with respiratory syncytial virus infection who had specimens submitted on first suspicion of respiratory virus infection were positive by rapid test. Culture results were positive within 48 hours for 100% of patients with influenza A (15 patients), influenza B (6), and parainfluenza (18) viruses. Of 59 pediatric inpatients who were isolated empirically awaiting 5-day culture results, 31 (52%) ultimately were determined to be culture negative.

Conclusions:

Empiric isolation of symptomatic children can be discontinued at 48 hours when both the rapid test and the early culture results are negative. Our institution would have saved 93 days of unnecessary isolation over 2 years had such a policy been in place.
An Outbreak of Viral Gastroenteritis in a Nursing Home: Importance of Excluding Ill Employees
Authors: Rodriguez Evelyn M. , Parrott Colleen , Rolka Henry , Monroe Stephan S. , Dwyer Diane M.
Published: September 2009

Background:

In May 1994, 43 persons in a nursing home were reported with gastroenteritis. An outbreak investigation was conducted to determine risk factors for gastroenteritis among residents and staff.

Methods:

Data were analyzed using contingency tables; relative risks (RR) and statistical significance were determined with Fisher's Exact Test. The chi-squared statistic to perform a goodness of fit test for the binomial distribution was used to determine whether cases occurred randomly and independently of each other. Stools were tested for bacterial enteric pathogens, ova, and parasites and were examined by electron microscopy, Southern hybridization, and reverse transcription-polymerase chain reaction. Paired sera were collected to detect fourfold rises in antibody titer by enzyme immunoassay against Norwalk viruses.

Results:

Of 121 residents, 62 (51%) had gastroenteritis, as did 64 (47%) of the 136 staff. The index case was a nurse who became ill at work and continued to work, while symptomatic, for another 2 days. Only residents who had received medications from this nurse between May 17 and May 20 became ill on the first day of the outbreak (13 of 35 versus 0 of 5). Nurses and nurse aides were more likely than employees without direct resident contact to be cases (46 of 68 versus 18 of 58; RR, 2.18;P<.001). Bacterial stool cultures and parasite examinations were negative. Results of electron microscopy, polymerase chain reaction with Southern hybridization, and enzyme immunoassay indicated the causative agent was a small, round, structured virus similar to the Snow Mountain Agent.

Conclusion:

To minimize outbreaks in nursing homes, we recommend that ill staff be excluded from work until symptoms resolve.
Epidemiologic Typing Systems
Authors: Maslow Joel , Mulligan Maury Ellis
Published: September 2009

Microbial strain typing is a useful adjunct to clinical epidemiology. Phenotypic typing systems examine expressed characteristics, whereas genotypic systems, including recent PCR-based systems, examine chromosomal or plasmid DNA. Typing systems have evaluated bacteria, fungi, and viruses successfully. The criteria used to assess the utility of each system include typeability, reproducibility, and discriminatory power.
Prevention and Control of Nosocomial Infections in Spain: Current Problems and Future Trends
Authors: Trilla Antoni , Vaqué Josep , Roselló Jose , Salles Montserrat , Marco Francesc , Prat Andreu , Bayas Jose M. , de Anta Maria Teresa Jimenez , Asenjo Miguel A.
Published: September 2009

Spain is a state member of the European Union, with more than 180,000 hospital beds and 800 public and private institutions. Only 6.9% of our gross national product is devoted to health expenditures. All citizens receive free health care through the National Health System. This system has given increasing attention to the prevention and control of nosocomial infections since 1986. In this article, results of serial prevalence surveys of antibiotic use and resistance patterns of microorganisms isolated from nosocomial infections are discussed. The needs for future development of infection control and quality assurance training programs in Spain also are discussed. Overall, a clinically and epidemiologically oriented approach to infection control is preferred, with greater emphasis in the role of infection control practitioners and infection control committees.
Cost-Effectiveness of Hepatitis A Vaccination in Healthcare Workers
Authors: Smith Shanon , Weber Stefan , Wiblin Todd , Nettleman Mary
Published: September 2009

Objective:

To study the cost-effectiveness of vaccination for hepatitis A.

Setting:

Hypothetical analysis of students currently enrolled in medical school in the United States.

Method:

A Markov-based model was developed using data from the literature, actual hospital costs, and an annual discount rate of 5%. The incidence rate was based on the lowest annual rate for the US population during the past decade.

Results:

Over the lifetimes of students currently in medical school, the model estimated that there would be 286 hepatitis A cases with four deaths and 107 lost years of life. With routine vaccination, these numbers would decrease to 17, 0.3, and 6, respectively. The costs per life-year saved and quality adjusted life-year saved were $58,000 and $47,000, respectively. Serologic screening prior to vaccination was less cost-effective than universal vaccination. If the incidence of hepatitis A was underestimated by a factor of 5, the cost per life-year saved would decrease to $5,500. If the incidence of hepatitis was underestimated by a factor of 10, vaccination would result in a net cost savings.

Conclusion:

We conclude that the cost per life-year saved by routine hepatitis A vaccination was similar to many other standard medical modalities. For routine vaccination of medical students to be cost-saving, the incidence rate for hepatitis A must be at least 10 times higher than the rate presently reported for the general population. Serological screening prior to vaccination was not cost-effective.
The Infection Control Practices of General Dental Practitioners
Authors: McCarthy Gillian M. , MacDonald John K.
Published: September 2009

Objectives:

To investigate the infection control practices of general dentists in Ontario in 1994.

Design:

Confidential coded questionnaires were mailed to all general dental practitioners in Ontario (n=5,176), with three follow-up attempts. Data were analyzed using Pearson's chi-squared test and multiple logistic regression.

Setting:

Offices of general dental practitioners in Ontario.

Participants:

General dental practitioners actively involved in treating patients.

Results:

The response rate adjusted for nondelivery was 70%. A high proportion of respondents reported using gloves (always, 91.8%; sometimes, 7.8%), masks (always, 74.8%; sometimes, 21.1%), or protective eyewear (always, 83.6%; sometimes, 13%); heat sterilization of hand-pieces (83.9%); and hepatitis B (HBV) vaccination of dentists (92.3%). However, only 61.4% of respondents reported HBV vaccination of all clinical staff, and 87.7% used additional precautions for patients with human immunodeficiency virus (HIV). Significant predictors of the use of recommended infection control procedures (ie, always using gloves, masks, and eye protection; heat sterilization of handpieces; HBV vaccination for dentist and staff; and no extra precautions for patients with HIV) were age ?40 years (odds ratio [OR], 2.6), lack of concern regarding increased personal risk (OR, 2.0) or costs of infection control procedures (OR, 1.5), and knowledge of the low infectivity of HIV after a needlestick injury (OR, 2.0) and that infection control procedures for HBV are adequate for HIV (OR, 2.7).

Conclusion:

Additional education is required to promote a more realistic perception of risk of HIV transmission in the dental office and the use of all recommended infection control practices, including Universal Precautions.
Serratia Marcescens Outbreak Associated With Extrinsic Contamination of 1% Chlorxylenol Soap
Authors: Archibald Lennox K. , Corl Ann , Shah Bhavesh , Schulte Myrna , Arduino Matthew J. , Aguero Sonia , Fisher Donna J. , Stechenberg Barbara W. , Banerjee Shailen N. , Jarvis William R.
Published: September 2009

Objectives:

To determine risk factors for Serratia marcescens infection or colonization, and to identify the source of the pathogen and factors facilitating its persistence in a neonatal intensive-care unit (NICU) during an outbreak.

Design:

Retrospective case-control study; review of NICU infection control policies, soap use, and hand-washing practices among healthcare workers (HCWs); and selected environmental cultures.

Setting:

A university-affiliated tertiary-care hospital NICU.

Patients:

All NICU infants with at least one positive culture for S marcescens during August 1994 to October 1995. Infants who did not develop S marcescens infection or colonization were selected randomly as controls.

Results:

Thirty-two patients met the case definition. On multivariate analysis, independent risk factors for S marcescens infection or colonization were having very low birth weight (<1,500 g), a patent ductus arteriosus, a mother with chorioamnionitis, or exposure to a single HCW. During January to July 1995, NICU HCWs carried their own bottles of 1% chlorxylenol soap, which often were left standing inverted in the NICU sink and work areas. Cultures of 16 (31%) of 52 samples of soap and 1 (8%) of 13 sinks yielded S marcescens. The 16 samples of soap all came from opened 4-oz bottles carried by HCWs. DNA banding patterns of case infant, HCW soap bottle, and sink isolates were identical.

Conclusions:

Extrinsically contaminated soap contributed to an outbreak of S marcescens infection. Very-low-birth-weight infants with multiple invasive procedures and exposures to certain HCWs were at greatest risk of S marcescens infection or colonization.
Mycobacterium tuberculosis Specimen Contamination Revisited: The Role of Laboratory Environmental Control in a Pseudo-outbreak
Authors: Segal-Maurer Sorana , Kreiswirth Barry N. , Burns Janice M. , Lavie Sol , Lim Mimi , Urban Carl , Rahal James J.
Published: September 2009

Objective:

To investigate suspected pseudo-outbreaks of Mycobacterium tuberculosis (MTB) during August 1994 and July 1995 among patients who did not have clinical findings consistent with tuberculosis.

Design:

Retrospective and prospective surveys of all clinical and laboratory data using standard epidemiological tools and DNA fingerprinting.

Setting:

A university-affiliated community hospital.

Patients:

Those with positive MTB cultures during periods when we noted that the number of MTB positive cultures greatly outnumbered the usual monthly average (retrospective analysis, 1994) and patients with positive MTB cultures without clinical findings consistent with tuberculosis (prospective survey, 1995).

Results:

Epidemiological and molecular studies revealed specimen cross-contamination in the laboratory due to a faulty exhaust hood. Improvement in laboratory ventilation and change of the implicated hood prevented further specimen contamination.

Conclusions:

The identification of positive MTB cultures from patients without clinical evidence of tuberculosis should be a signal to suspect laboratory contamination and implement control measures. These should include a thorough epidemiological investigation, DNA fingerprint analysis, and an environmental inspection.
True Community-Acquired Methicillin-Resistant Staphylococcus aureus Bacteremia
Authors: Akram Javed , Glatt Aaron E.
Published: September 2009

Methicillin-resistant Staphylococcus aureus (MRSA) recently has been reported as an outpatient pathogen. We assessed this and found our institution's frequency quite low. Only 16 patients (4%) had true community-acquired MRSA bacteremia. Ten had no recorded previous hospitalization; twelve (75%) had significant underlying medical problems. Substance abuse and prior outpatient antibiotic use were not identified as major risks for community-acquired MRSA bacteremia.
Absence of Rectal Colonization With Vancomycin-Resistant Enterococci Among High-Risk Pediatric Patients
Authors: Trabulsi Adnan , Glover Anne-Marie , Reising Shirley F. , Christie Celia D. C.
Published: September 2009

We prospectively surveyed for rectal colonization with vancomycin-resistant Enterococcus among 93 high-risk pediatric patients who were hospitalized at least 5 (median, 20) days. Fifty-two patients (56%) had enterococcal colonization; none had active infection with Enterococcus. All enterococci were vancomycin-susceptible (minimum inhibitory concentration ≤4 μg/mL). Associated exposures included recent antibiotics (50, 96%), surgical procedures (26, 58%), and immunosuppression (15, 29%).
Requirements for Infrastructure and Essential Activities of Infection Control and Epidemiology in Hospitals: A Consensus Panel Report
Authors: Scheckler William E. , Brimhall Dennis , Buck Alfred S. , Farr Barry M. , Friedman Candace , Garibaldi Richard A. , Gross Peter A. , Harris Jo-Ann , Hierholzer Walter J. , Martone William J. , McDonald Linda L. , Solomon Steven L.
Published: September 2009

The scientific basis for claims of efficacy of nosocomial infection surveillance and control programs was established by the Study on the Efficacy of Nosocomial Infection Control project. Subsequent analyses have demonstrated nosocomial infection prevention and control programs to be not only clinically effective but also cost-effective. Although governmental and professional organizations have developed a wide variety of useful recommendations and guidelines for infection control, and apart from general guidance provided by the Joint Commission on Accreditation of Healthcare Organizations, there are surprisingly few recommendations on infrastructure and essential activities for infection control and epidemiology programs. In April 1996, the Society for Healthcare Epidemiology of America established a consensus panel to develop recommendations for optimal infrastructure and essential activities of infection control and epidemiology programs in hospitals. The following report represents the consensus panel's best assessment of needs for a healthy and effective hospital-based infection control and epidemiology program. The recommendations fall into eight categories: managing critical data and information; setting and recommending policies and procedures; compliance with regulations, guidelines, and accreditation requirements; employee health; direct intervention to prevent transmission of infectious diseases; education and training of healthcare workers; personnel resources; and nonpersonnel resources. The consensus panel used an evidence-based approach and categorized recommendations according to modifications of the scheme developed by the Clinical Affairs Committee of the Infectious Diseases Society of America and the Centers for Disease Control and Prevention's Hospital Infection Control Practices Advisory Committee.
Nosocomial Infections in a Rural Regional Hospital in a Developing Country: Infection Rates by Site, Service, Cost, and Infection Control Practices
Authors: Orrett Fitzroy A. , Brooks Phyllis J. , Richardson Elizabeth G.
Published: September 2009

Objective:

To assess the prevalence of nosocomial infections at a rural government hospital from 1992 to 1995.

Design:

Retrospective review of data from 1992 to 1995 regarding rates of nosocomial infections, cost to government, and infection control practices.

Setting:

653-bed rural hospital providing primary and tertiary care.

Patients:

Patients admitted to the hospital between 1992 and 1995 who were found with hospital-acquired infections during their stay.

Interventions:

None.

Results:

Over the 4-year period, 7,158 nosocomial infections were identified from 72,532 patients (10.0/100 admissions). High nosocomial infection rates were found on the intensive-care unit (67/100 admissions), urology (30/100 admissions), neurosurgery (29.5/100 admissions), and newborn nursery (28.4/100 admissions). Urinary tract infections (4.1/100 admissions) accounted for most nosocomial infections (42%), followed by postoperative wound infections (26.8%) with a rate of 2.6/100 admissions. Nosocomial pneumonias and bloodstream infections also were common with 13.2% and 8.0%, respectively. The highest rates occurred on the intensive-care unit for both pneumonia (26.4/100 admissions) and bloodstream infection (7.0/100 admissions). The cost to the government for nosocomial infections was estimated at US $697,000 annually (US $1=$6 Trinidad and Tobago). Poor infection control practices, inadequate handwashing facilities, lack of supplies, and nonexistent garbage cans on most wards were quite evident.

Conclusions:

Strict adherence to proper infection control practices, such as handwashing techniques, and improvement of facilities are crucial steps in preventing cross-infections in the hospital environment. Implementing these measures may substantially reduce the massive drain on the hospital budget in treating nosocomial infections. The saved revenue could go toward improvement of ward facilities and reduction of over-crowding, thus further reducing cross-infection.
Total and Attributable Costs of Surgical-Wound Infections at a Canadian Tertiary-Care Center
Authors: Zoutman Dick , McDonald Shirley , Vethanayagan Dilini
Published: September 2009

OBJECTIVE: To determine the total and attributable costs of surgical-wound infections in a Canadian teaching hospital.

DESIGN: Retrospective incidence series study with chart review and examination of resource utilization attributable to wound infection. The charts of inpatients with wound infections were examined using the Appropriateness Evaluation Protocol (AEP), a validated chart review instrument designed to determine appropriateness of care, modified for wound infections.

SETTING: A university referral center in Canada.

PATIENTS: Medical records were abstracted from patients with wound infections who underwent an inpatient clean or clean-contaminated procedure during 1991.

MEASUREMENTS: During the wound-infection treatment period, the hospital costs associated with providing care were tabulated for all inpatient days and for outpatient and emergency visits. Costs taken into account included nursing salary and benefits, nonphysician professional services, operating room time, laboratory, pharmacy, supplies, ancillary tests, and hotel costs.

RESULTS: We identified 108 wound infections. Twenty-two patients required 28 surgical procedures related to a wound infection. Inpatient days totalled 1,116, costing $394,337. Fifty-five emergency and 42 clinic visits occurred, costing $27,193. By applying the AEP to the inpatient days, 833 days, or 10.2 days per case, were directly attributable to the wound infection. The hospital costs for inpatient care attributable to wound infections were $321,533 in total, or $3,937 per infection. Costs were distributed as follows: nursing, 51%; hotel, 14%; pharmacy, 10%; laboratory, 9%; emergency and outpatient clinic, 6%; professional services, 5%; operating room, 3%; and ancillary tests, 2%.

CONCLUSIONS: Wound infections contribute markedly to extra days of hospitalization and related costs. The AEP method is applied easily to determine attributable days of care and costs of wound infections, which are necessary to calculate the cost-benefit of infection control programs.
Statistical Quality Control Methods in Infection Control and Hospital Epidemiology, Part II: Chart Use, Statistical Properties, and Research Issues
Authors: Birnbaum David , Benneyan James C.
Published: September 2009

This is the second in a two-part series discussing and illustrating the application of statistical process control (SPC) in hospital epidemiology. The basic philosophical and theoretical foundations of statistical quality control and their relation to epidemiology are emphasized in order to expand the mutual understanding and cross-fertilization between these two disciplines. Part I provided an overview of the philosophy and general approach of SPC, illustrated common types of control charts, and provided references for further information or statistical formulae. Part II now discusses alternate possible SPC approaches, statistical properties of control charts, chart-design issues and optimal control limit widths, some common misunderstandings, and more advanced issues. The focus of both articles is mostly nonmathematical, emphasizing important concepts and practical examples rather than academic theory and exhaustive calculations.
Epidemiology of Methicillin-Resistant Staphylococcus aureus in Three Canadian Tertiary-Care Centers
Authors: Suh Kathryn , Toye Baldwin , Jessamine Peter , Chan Francis , Ramotar Karam
Published: September 2009

OBJECTIVE:

To describe the epidemiology and spread of methicillin-resistant Staphylococcus aureus (MRSA) in three tertiary-care centers in Ottawa, Ontario, Canada, where MRSA is encountered infrequently.

DESIGN:

Retrospective review over a 6-year period, from January 1, 1990, through December 31, 1995.

SETTING:

Three tertiary-care teaching hospitals in Ottawa.

PARTICIPANTS:

Patients and healthcare workers (HCWs) with MRSA isolated from any body site.

METHODS:

Patients and HCWs were identified retrospectively through hospital microbiology and infection control records. Patient charts were reviewed for clinical and epidemiological data, including age, gender, previous hospital admissions (where noted), and current and recent antibiotic use. MRSA isolates that were available were typed using pulsed-field gel electrophoresis (PFGE). Methicillin resistance was confirmed by standard methods and by polymerase chain reaction using mecA-specific primers.

RESULTS:

MRSA was identified in 53 patients and 2 HCWs. Three patients were excluded from further analysis because medical records were incomplete. Epidemiological data were collected on the remaining 52 individuals. Thirty-nine isolates from 31 patients and 2 HCWs were available for PFGE typing. Five epidemiologically linked nosocomial clusters involving 10 patients and 2 HCWs were identified and were confirmed by PFGE. MRSA isolates from a sixth cluster were not available for PFGE. In each cluster, nosocomial spread was minimized by standard infection control practices, including strict isolation of patients and screening of contacts. There was no evidence of secondary spread of MRSA involving the remaining 36 patients. Recent antibiotic use, surgery, admission to an intensive-care unit, and previous hospitalization were common among patients. There was no evidence of spread of MRSA among the three hospitals, and no endemic strains were apparent in any of these centers.

CONCLUSIONS:

MRSA remains an infrequent isolate in our centers, with no apparent interhospital spread. In institutions with little or no endemic MRSA, rigorous application of standard infection control practices is effective in limiting nosocomial transmission of this organism.
Spread of Vancomycin-Resistant Enterococci: Why Did It Happen in the United States?
Authors: Martone William J.
Published: September 2009

The question of why vancomycin-resistant enterococci (VRE) became epidemic in the United States can be answered on at least three basic levels: (1) molecular and genetic, (2) factors affecting host-microbe interactions, and (3) epidemiological. This article will address the epidemiological issues and seek to defend the assertion that, once VRE had evolved, its spread throughout hospitals in the United States was all but assured. Nosocomial VRE outbreaks were reported first in the mid- and late-1980s. Since that time, scientific reports of VRE have increased over 20-fold. Among hospitals participating in the National Nosocomial Infection Surveillance System from 1989 to 1997, the percentage of enterococci reported as resistant to vancomycin increased from 0.4% to 23.2% in intensive-care settings and from 0.3% to 15.4% in non-intensive-care settings. Factors leading to the spread of VRE in US hospitals include (1) antimicrobial pressure, (2) sub-optimal clinical laboratory recognition and reporting, (3) unrecognized “silent” carriage and prolonged fecal carriage, (4) environmental contamination and survival, (5) intrahospital and interhospital transfer of colonized patients, (6) introduction of unrecognized carriers from community settings such as nursing homes, and (7) inadequate compliance with hand washing and barrier precautions. Guidelines developed by the Centers for Disease Control and Prevention's Hospital Infection Control Practices Advisory Committee address each of these factors. The impact of these guidelines on the spread of VRE within individual institutions has been variable, and the overall impact of the guidelines nationally is unknown.
Spread of Vancomycin-Resistant Enterococci: Differences Between the United States and Europe
Authors: Goossens Herman
Published: September 2009

There are major differences in the epidemiology of vancomycin-resistant enterococci (VRE) between the United States and Europe. In contrast with Europe, VRE in the United States are resistant to many antibiotics, and there appears to be less genetic variability among these isolates. European VRE of human origin are usually susceptible to many other antibiotics and are highly polyclonal. These clinical isolates have the same susceptibility profiles as VRE isolated from animals.

The differences in the spread of VRE between the United States and Europe might be explained by the overconsumption of glycopeptides and other antibiotics in hospitals in the United States and the use of avoparcin as a growth promotor in Europe.
Methicillin-Resistant Staphylococcus aureus and Its Relationship to Antimicrobial Use: Possible Implications for Control
Authors: Monnet Dominique L.
Published: September 2009

The control of methicillin-resistant Staphylococcus aureus (MRSA) is still an unresolved issue in numerous healthcare institutions worldwide. Guidelines for the control of MRSA in hospitals focus on measures to control cross-transmission and prevent colonization, but rarely specifically mention the control of antimicrobial use. We reviewed the different types of evidence for a causal relationship between MRSA and antimicrobial use by classifying them in four categories: consistent associations, dose-effect relationships, concomitant variations, and arguments to support a plausible biological model to explain this relationship. Although the relative participation of cross-transmission and antimicrobial selection pressure in the level of MRSA observed in a healthcare setting remains to be determined, we found lines of evidence to support the existence of a relationship between MRSA and antimicrobial use in each of the four categories. This review points out the relative lack of studies specifically designed to investigate this aspect of MRSA epidemiology and the need to implement such studies quickly. In the meantime, the results presented here should encourage the implementation of antimicrobial-use improvement programs in hospitals in addition to existing infection control measures, which are still a priority in countries with high MRSA prevalence.
Comparative and Library Epidemiological Typing Systems: Outbreak Investigations Versus Surveillance Systems
Authors: Struelens Marc J. , Gheldre Yves De , Deplano Ariane
Published: September 2009

A number of high-resolution molecular typing systems have been developed in recent years. Their availability raises the new issues of selecting the method(s) best suited for a particular purpose and interpreting and communicating typing results. Most of the currently available methods are comparative only: they allow testing of a sample of isolates for delineation of those closely related from those markedly different in genomic backgrounds. This approach is adequate for outbreak investigation, allowing determination of clonal spread in a microenvironment and identification of the source of infection. Comparative methods with sufficient resolution for most pathogens include restriction fragment-length polymorphism (RFLP), pulsed-field gel electrophoresis (PFGE), and arbitrarily primed and randomly amplified polymorphic DNA-polymerase chain reaction (PCR) analysis. For surveillance systems, monitoring clonal spread and prevalence in populations over extended periods of time requires library typing systems. These must be standardized, must have a high throughput, and must use a uniform nomenclature. Promising or validated methods include serotyping, insertion sequence fingerprinting, ribotyping, PFGE, amplified fragment-length polymorphism (AFLP), infrequent-restriction-site amplification PCR, interrepetitive element PCR typing (rep-PCR) and PCR-RFLP of polymorphic loci. PCR methods generating arrays of size-specific amplicons (AFLP, rep-PCR) can be more reproducibly analyzed by using denaturing polyacrylamide gel or capillary electrophoresis with automated laser detection. Binary probe typing systems appear optimal and should be enhanced further through use of DNA chip technology. In these systems, amplification of polymorphic regions is followed by solid-phase hybridization with a reference panel of sequence-variant specific probes. The resulting binary type results allow determination of reproducible, numeric profiles. However, interpretation and nomenclature of typing results for large-scale surveillance purposes still require a better understanding of population structure and microevolution of most microbial pathogens.
Nosocomial Transmission of Opportunistic Infections
Authors: Gerberding Julie Louise
Published: September 2009

Immunocompromised patients are at high risk for opportunistic infections. Traditionally, these infections were thought to arise from endogenous reactivation of previously acquired latent infections, and nosocomial transmission therefore was deemed to be so unlikely that no special infection control interventions were needed to prevent transmission in healthcare settings. However, new data have challenged this view and suggest that some opportunistic pathogens are transmissible from one immunosuppressed patient to another. Epidemiological investigations, molecular genotyping, animal studies, and air-sampling experiments lend support to the hypothesis that reinfection with opportunistic pathogens does occur, that airborne transmission is possible, and that nosocomial spread is a plausible explanation for case clusters. Taken together, these observations support the view that some opportunistic infections are exogenous in origin and that additional epidemiological investigations are needed to define the true risk of nosocomial spread and need for isolation.
Is Streptococcus pneumoniae a Nosocomially Acquired Pathogen?
Authors: Paradisi Franco , Corti Giampaolo
Published: September 2009

Streptococcus pneumoniae is most prominently a major cause of community-acquired infections of the respiratory tract, central nervous system, and bloodstream, but there is an increasing interest in its role in the epidemiology of hospital-acquired infections. Penicillin-resistant pneumococcal strains appeared 3 decades ago and now are present worldwide, often displaying multiple resistance due to antibiotic selective pressure. Horizontal spread can cause either sporadic cases or hospital outbreaks, primarily in younger children and elderly patients. Pneumococcal transmission from one patient to another can be documented by polymerase chain reaction or pulsed-field gel electrophoresis typing. Nosocomial acquisition of infection, along with pediatric age, previous hospitalization, and previous β-lactam therapy, are the main risk factors significantly associated with penicillin-resistant pneumococcal infections. Nosocomial acquisition also is associated with higher mortality from pneumo-coccal disease. The importance of penicillin resistance as a risk factor significantly associated with higher mortality from pneumococcal infection is found in some studies, but not in others. Mortality from pneumococcal pneumonia is approximately the same for human immunodeficiency virus (HIV)-infected patients without acquired immunodeficiency syndrome (AIDS) as for HIV-negative subjects, but it is significantly higher in AIDS patients. Penicillin-resistant strains are involved in the vast majority of hospital outbreaks, whether presenting as clinically manifest infection or a simple colonization. Pneumococcal vaccination is recommended universally in order to lower the incidence of invasive infection, although a number of problems can limit its effectiveness.
Increasing Bacteremia Due to Coagulase-Negative Staphylococci: Fiction or Reality?
Authors: Thylefors Joakim D. , Harbarth Stephan , Pittet Didier
Published: September 2009

BACKGROUND:

The role of coagulase-negative staphylococci (CNS) in bacteremias continues to be controversial. Until the 1970s, CNS were mostly recognized as contaminants, being part of the cutaneous flora. Since then, several studies have reported increasing incidence and severity of infections due to CNS.

PURPOSE:

To review the literature concerning the epidemiology of CNS bacteremia in the United States and Europe with reference to the multiple definitions of infection versus contamination, considering the effect of potential biases influencing the validity of the reported results.

METHODS:

Literature search of the MEDLINE database from January 1980 to February 1998. Studies with fewer than 500 episodes of bloodstream infections or fewer than 100 episodes of CNS bacteremia were not included in the pooled analysis.

RESULTS:

(1) CNS remain the most frequent contaminants (58%-83% of positive blood cultures); (2) the proportion of all bloodstream infections caused by CNS is increasing (R=.51); (3) the overall incidence of true CNS bacteremia is increasing (R=.54, P=.0014); (4) comparing the United States to Europe, there is an increasing trend in the incidence of nosocomial bacteremia due to CNS in the United States (R=.82, P=.0006), but no trend is seen in European studies; (5) the mortality associated with true CNS bacteremia varies between 4.9% and 28%.

DISCUSSION:

This review confirms the increasing importance of CNS bacteremias, measured both as a proportion and as an incidence of bloodstream infections. The contributions of several possible explanations for the incidence increase and the difference between the United States and Europe need further evaluation: (1) increased recognition and awareness of CNS infections among clinicians; (2) a gradual change in the definition of true bacteremia from an obligatory two positive blood cultures to one positive blood culture associated with a clinical picture compatible with infection; (3) a change in blood culture practices and techniques; (4) an increase in the numbers of blood cultures performed, which is reported both in the United States and in Europe; (5) a shift toward more elderly patients with increasingly severe underlying illnesses; and (6) increasing use of intravascular devices.

CONCLUSIONS:

The apparent trend of increasing CNS bacteremia seems to be valid. Whether there is a real difference between the United States and Europe concerning the increase of CNS bacteremia is difficult to establish due to the large number of confounding factors. Few studies take into account the number of blood cultures performed or the use of intravascular devices to adjust for the observed trends. Further on-site surveillance studies are needed to investigate the phenomenon more extensively.
Strategies for Prevention of Infection in Short-Duration Neutropenia
Authors: Fenelon Lynda
Published: September 2009

Although infection continues to be a major cause of morbidity and mortality in neutropenic patients, newer strategies have resulted in a shorter duration of neutropenia. The prime risk to patients with short-duration neutropenia (defined as neutropenia of less than 14 days) is bacterial infection, which is reduced by the administration of prophylactic antibiotics, and possibly by the use of clean food, sterile water, and protection against transmission of organisms from healthcare workers' hands.
Occult Nosocomial Infections
Authors: Petignat Christiane , Blanc Dominique S. , Francioli Patrick
Published: September 2009

Even with a good surveillance program, nosocomial infections may be not recognized because of several reasons: absence of symptoms or prolonged incubation period (eg, viral bloodborne infections, tuberculosis); problems with the microbiological diagnosis, because adequate specimens may be difficult to obtain or special methods should be used (eg, fungal infections, virus, new agents); shorter hospital stays (eg, surgical-site infections); difficulty in distinguishing between nosocomial and community-acquired infections (eg, influenza); and failure to detect clinically relevant colonization (eg, multiresistant microorganisms). Because of the important potential consequences of occult nosocomial infections, specific surveillance programs should be designed to address these problems.
Wild knots in higher dimensions as limit sets of Kleinian groups
Authors: Boege Margareta , Hinojosa Gabriela , Verjovsky Alberto
Published: September 2009

In this paper we construct infinitely many wild knots,

S

n

↪

S

n
+
2

\mathbb {S}^{n}\hookrightarrow \mathbb {S}^{n+2}

, for

n
=
1
,
2
,
3
,
4

n=1,2,3,4

and

5
5

, each of which is a limit set of a geometrically finite Kleinian group. We also describe some of their properties.