bluuebunny/crossref_metadata_2025 huggingface dataset:
Les ambiguïtés
Authors: Gross Maurice
Published: September 2009

Summary

Homography of utterances (words or meaningful sequences of words) is a term used for ambiguity at the spelling level. Ambiguity is the preferred term for phrases and sentences. The present paper is an attempt to clarify the status of this notion.

When people talk, write, read or listen to discourses, they seldom raise questions of ambiguity of words or phrases. Discourses, spoken or written, are rarely perceived as ambivalent at the linguistic level, hence the words from which they are composed are not ambiguous. Questions of ambiguity arise immediately when words are isolated from any context. In such cases, the discussion of the meaning of a word amounts to defining its dictionary entry, that is to enumerating its different meanings. The discrepancy between the two situations is summed up in one sentence: Contexts resolve ambiguities. When a word, a priori ambiguous according to dictionaries, is put to use in a discourse, this discourse filters out all irrelevant interpretations of the word. The organization of a dictionary is intended to provide contexts for the use of words. This information takes on different forms:

–definitions incorporate semantic clues of use,

–examples of usage provide syntactic and semantic information.

Such information cannot be considered as explicit contexts, thus it is up to the human user to generalize these indications in order to apply them to the interpretation of texts.

We present a number of situations where contexts can be formalized and systematically described.
Levée d’ambiguïtés sur les mots lexicaux et grammaticaux
Authors: Dister Anne
Published: September 2009

Summary

Ambiguity is a central problem in computational linguistics. In this paper, we propose a reflexion based on our work of morpho-syntaxic disambiguation with the intex system. intex is an environment of linguistic development which includes large coverage dictionaries constructed at LADL. With the examples of verbs and adjectives, we show that choices on the encoding of linguistic information in the dictionary are central in the definition of ambiguity. The expected accuracy in tags (in linear tagging mode) considerably influences the results of disambiguation. In the second part of the paper, we examine the most frequent ambiguous words in a big corpus, in terms of words or of parts of speech. Based on these figures, we apply our method with local grammars to disambiguate words: determinants or pronouns; names, adjectives or verbs.
Organization of the lexicon-grammar of French verbs
Authors: Leclère Christian
Published: September 2009

Summary

The “Lexicon-grammar” of LADL describes about 15,000 simple verbs and 25,000 complex verbs, according to the syntactic, distributional or semantic properties of their main constructions. I present the types of properties that have been selected as the basis for the classification of these verbs.
Verbes de «mouvement» à complémentation infinitive en polonais contemporain
Authors: Miladi Lidia
Published: September 2009

Summary

Verbs of “movement” in the infinitive complement in contemporary Polish: comparison with other languages

In this article we analyse the syntactic properties of the infinitive complement (“locative”) which appears after verbs of “movement” (Vmt) in contemporary Polish. Many of these properties are identical to properties of the infinitive complement (V-inf W) the verbs of “movement” in French and in other languages (Italian, Spanish, Portuguese and Korean). However, some properties are specific to the Polish construction No Vmt V-inf W.
Pour un Bescherelle des prédicats nominaux
Authors: Gross Gaston
Published: September 2009

The Bescherelle is a well-known reference where one can look up — in the form of tables — the conjugation of all French verbs. It is often forgotten that all predicates can be conjugated whether they are expressed in verbal or nominal forms. This article outlines the basis of linguistic descriptions which can be used to generate all the forms of “nominal conjugations” in French. As the form of support verbs depends on the semantic class of the nominal predicate, we need first to establish a semantic typology of predicative nouns where the distinction between actions, events and states plays an important role. Moreover, we need to enumerate the appropriate support forms (active, passive and reciprocal). In addition, it is necessary to list for each class of predicative nouns the support verbs expressing aspectual meanings (inchoative, progressive, iterative, etc.). Once these forms have been listed, we will be able to provide an alphabetic list of predicative nouns, where each entry will be coded in terms of the conjugation forms it assumes. Such a table will have obvious applications for the automatic analysis of French.
A survey of named entity recognition and classification
Authors: Nadeau David , Sekine Satoshi
Published: September 2009

This survey covers fifteen years of research in the Named Entity Recognition and Classification (NERC) field, from 1991 to 2006. We report observations about languages, named entity types, domains and textual genres studied in the literature. From the start, NERC systems have been developed using hand-made rules, but now machine learning techniques are widely used. These techniques are surveyed along with other critical aspects of NERC such as features and evaluation methods. Features are word-level, dictionary-level and corpus-level representations of words in a document. Evaluation techniques, ranging from intuitive exact match to very complex matching techniques with adjustable cost of errors, are an indisputable key to progress.
Named Entity Recognition and transliteration in Bengali
Authors: Ekbal Asif , Naskar Sudip Kumar , Bandyopadhyay Sivaji
Published: September 2009

The paper reports about the development of a Named Entity Recognition (NER) system in Bengali using a tagged Bengali news corpus and the subsequent transliteration of the recognized Bengali Named Entities (NEs) into English. Three different models of the NER have been developed. A semi-supervised learning method has been adopted to develop the first two models, one without linguistic features (Model A) and the other with linguistic features (Model B). The third one (Model C) is based on statistical Hidden Markov Model. A modified joint-source channel model has been used along with a number of alternatives to generate the English transliterations of Bengali NEs and vice-versa. The transliteration models learn the mappings from the bilingual training sets optionally guided by linguistic knowledge in the form of conjuncts and diphthongs in Bengali and their representations in English. The NER system has demonstrated the highest average Recall, Precision and F-Score values of 89.62%, 78.67% and 83.79% respectively in Model C. Evaluation of the proposed transliteration models demonstrated that the modified joint source-channel model performs best in terms of evaluation metrics for person and location names for both Bengali to English (B2E) transliteration and English to Bengali transliteration (E2B). The use of the linguistic knowledge during training of the transliteration models improves performance.
Structures à subordonnée comparative en français
Authors: Fuchs Catherine , Fournier Nathalie , Le Goffic Pierre
Published: September 2009

This article deals with syntactic and semantic representation of comparative structures in French. We propose an analysis of quantitative comparatives (plus, moins, aussi … que) and qualitative comparatives (comme) which highlights their common properties as well as their specificities. The first section (§ 1) offers a syntactic typology of matrix clause structures and (comparative) subordinate clause structures. The following sections consider the various aspects of semantic representations, as related to syntactic structures : we successively deal with (§ 2.) the type of parameter, (§ 3.) the type of differential constituant in the subordinate clause, (§ 4.) the type of parallel constituant in the matrix clause (with restitution of ellipses and anaphora), (§ 5.) the type of compared terms, by contrasting quantitative comparisons and qualitative comparison, and (§ 6.) the type of comparison, accounting for prototypical structures as well as for pragmatic effects induced by certain configurations.
Hierarchical Numbering Based Addressing and Stateless Routing Scheme for Wireless Sensor Networks
Authors: Uddin Mohammad Yusuf Sarwar , Akbar Mohammad Mostofa , Masum Salahuddin Mohammad
Published: September 2009

Due to energy and other relevant constraints, addressing of nodes and data routing techniques in sensor networks differ significantly from other networks. In this article, we present an energy-efficient addressing and stateless routing paradigm for wireless sensor networks. We propose a dynamic and globally unique address allocation scheme for sensors in such a way that these addresses can later be used for data routing. We build a tree like organization of sensors rooted by the sink node based on their transmission adjacency and then set labels on each sensor with a number according to the preorder traversal of the tree from the root. In this addressing process, each sensor keeps necessary information so that they can later route data packets to the destination depending on these addresses, without keeping the large routing table and running any no route discovery phase. Moreover, the scheme does not use location information as well (as done by geo-routing) and can be used in the indoor environment. We conduct simulations to measure the soundness of our approach and make a comparison with another similar technique TreeCast. Simulation results reveal that our approach performs better than its counterpart in several important performance metrics like address length and communication energy.
Comparison of Petri Net and Finite State Machine Discrete Event Control of Distributed Surveillance Network
Authors: Zhu Mengxia , Brooks Richard R.
Published: September 2009

Wireless sensor networks are an important military technology with civil and scientific applications. In this article, we derive a discrete event controller system for distributed surveillance networks that consists of three interacting hierarchies—sensing, communications, and command. Petri Net representations of the hierarchies provide plant models of resource contention and internal consistency. Control specifications are derived that enforce consistency across the hierarchies. Three controllers are created using different methodologies to satisfy these specifications. The methods used are Petri Net, finite state automata using the Ramadge and Wonham approach, and vector addition control using the Wonham and Li approach. We use the controllers derived to contrast the design methodologies. Our results find these three approaches to be roughly equivalent. Each method has advantages and disadvantages.
What's on your mind: The influence of the contents of working memory on choice
Authors: Weaver Starla M. , Arrington Catherine M.
Published: September 2009

Information maintained in working memory (WM) has the potential to bias selective attention and limit executive attention. The current study assessed the influence of information in WM on the tasks one chooses to perform in a multitasking environment. Participants held either identities or locations in WM while performing voluntary task-switching trials on stimuli that did or did not match the information they were attempting to maintain. A bias toward performing the task associated with stimuli that had recently been encoded into WM was found. The results suggest that information in WM can influence choice within a multitasking environment.
Infection Control in Public Hospitals
Authors: Wurtz Rebecca
Published: September 2009

Public hospitals face challenging infection control problems that differ from those in other hospitals. This article reviews some of the unique aspects of infection control in public hospitals, including governance, physical plant, patient mix, communicable diseases, and employee issues, and suggests management strategies.
Recorded Criteria as a “Gold Standard” for Sensitivity and Specificity Estimates of Surveillance of Nosocomial Infection: A Novel Method to Measure Job Performance
Authors: Ehrenkranz N. Joel , Shultz James M. , Richter Emily I.
Published: September 2009

Objectives:

To compare the accuracy of infection control practitioners' (ICPs') classifications of operative site infection in Florida Consortium for Infection Control (FCIC) hospitals, in two time periods, 1990 to 1991 and 1991 to 1992, and to estimate the effect of duration of surveillance experience on that accuracy.

Methods:

Medical record reviewers examined records of all patients classified by an ICP as infected, to distinguish false-positives from true infections based on evidence of standard infection criteria and the ICP's contemporaneous clinical observations. Reviewers also examined a random sample of 100 records from patients classified as noninfected for evidence of undetected infections (false-negatives). These observations permitted estimates of the sensitivity and specificity of each ICP's classification of infection status.

Setting:

Fourteen FCIC communit:y hospitals at which performance of 16 ICPs was monitored.

Results:

There was a strong linear trend relating increasing sensitivity to numbers of years of ICP surveillance experience (P<.001). For ICPs with <4 years of experience, satisfactory sensitivity (≥80%) was reached in only one of 10 ICP-years of observation. For ICPs with ≥4 years' experience, satisfactory sensitivity was achieved for 14 of 18 person-years (P=.001). Estimated specificity was 97% to 100% for all ICP-years observed.

Conclusions:

ICPs with <4 years of surveillance experience in FCIC community hospitals rarely achieved a satisfactory sensitivity estimate, whereas ICPs with ≥4 years' experience generally did. Monitoring ICP surveillance accuracy through retrospective medical record audits offers an objective approach to evaluating ICP performance and to interpreting infection rates at different hospitals.
SHEA-CDC TB Survey, Part I: Status of TB Infection Control Programs at Member Hospitals, 1989-1992
Authors: Fridkin Scott K. , Manangan Lilia , Bolyard Elizabeth ,   The Society for Healthcare Epidemiology of America, Jarvis William R.
Published: September 2009

Objective:

To determine trends in Mycobacterium tuberculosis infection in healthcare workers, tuberculosis (TB) control measures, and compliance with the 1990 Centers for Disease Control and Prevention (CDC) guideline for preventing transmission of TB in healthcare facilities.

Design:

Voluntary questionnaire sent to all members of the Society for Healthcare Epidemiology of America, representing 359 hospitals.

Results:

Respondents’ hospitals (210 [58%]) had a median of 2,400 healthcare workers (range, 396 to 13,745), 437 beds (range, 48 to 1,250), 5.6 patients with TB per year (range, 0 to 492), and 0 multidrug-resistant (MDR) TB patients per year (range, 0 to 33). Of 166 respondents’ hospitals for which data were provided for 1989 through 1992, the number caring for MDR-TB patients increased from 10 (6%) in 1989 to 49 (30%) in 1992. Reported policies for routine healthcare worker tuberculin skin testing varied. The median skin-test positivity rate for healthcare workers at the time of hire increased from 0.54% in 1989 to 0.81% in 1992, but the median conversion rate during routine testing remained similar: 0.35% in 1989 and 0.33% in 1992. Among 196 hospitals with reported data on respiratory protection use for 1989 through 1992, the use of either surgical submicron, dust-mist, or dust-fume-mist respirators for healthcare workers increased from 9 (5%) in 1989 to 85 (43%) in 1992. Of 181 hospitals with reported data, 113 (62%) had acid-fast bacilli isolation facilities consistent with the 1990 CDC guideline (ie, a single patient room, negative air pressure relative to the hallway, air exhausted directly outside, and ≥ 6 air exchanges per hour).

Conclusions:

While the number of surveyed hospitals caring for TB and MDR-TB patients increased during 1989 through 1992, TB infection control measures at many hospitals still did not meet the 1990 CDC guideline recommendations.
SHEA-CDC TB Survey, Part II: Efficacy of TB Infection Control Programs at Member Hospitals, 1992
Authors: Fridkin Scott K. , Manangan Lilia , Bolyard Elizabeth ,   The Society for Healthcare Epidemiology of America, Jarvis William R.
Published: September 2009

Objective:

To assess the efficacy of current Myco-bacterium tuberculosis control measures.

Design:

Voluntary questionnaire to members of the Society for Healthcare Epidemiology of America.

Results:

Healthcare worker (HCW) tuberculin skin-test (TST) conversion rates were significantly higher in larger hospitals ( ≥ 437 beds) (0.9% versus 0.6%; P < 0.05), or in hospitals reporting ≥ 6 TB patients in 1992 (1.2% versus 0.6%; P < 0.05). Among larger hospitals or those hospitals surveyed reporting ≥ 6 TB patients, those without at least three of the four criteria suggested in the 1990 Centers for Disease Control and Prevention (CDC) TB guidelines for acid-fast bacilli (AFB) isolation (specifically, a single-patient room; negative pressure; and air exhausted directly outside) had significantly higher annual TST conversion rates than those with these criteria (1.8% versus 0.6%; P < 0.05). Respiratory therapist or bronchoscopist TST conversion rates were significantly lower in hospitals compliant with the exhaust criteria (1.2% versus 2.8%; P < 0.05). Regardless of hospital characteristic, HCW TST conversion rates did not differ between hospitals in which HCWs used surgical masks or used disposable particulate respirators.

Conclusion:

Among larger hospitals or hospitals reporting ≥ 6 TB patients per year, failure to comply with the 1990 CDC TB recommendations for AFB isolation room guidelines was associated with higher HCW TST conversion rates. These data suggest that complete implementation of the 1990 CDC TB guidelines would decrease HCWs’ risk of nosocomial transmission of TB in larger hospitals or those reporting more TB patients. However, in nonoutbreak situations, disposable particulate respirators or submicron surgical masks may not offer significantly greater protection to HCWs than surgical masks.
The Hospital Epidemiologist: Practical Ideas
Authors: Wenzel Richard P.
Published: September 2009

The modem hospital epidemiologist has broad perspectives and influence across clinical departmental lines. The opportunities to improve patient care by expanding traditional areas of focus beyond infection control are great. Useful skills include epidemiology, communication, and respect for colleagues.
Studies of Ventilation Efficiency in a Protective Isolation Room by the Use of a Scale Model
Authors: Marshall John W. , Vincent James H. , Kuehn Thomas H. , Brosseau Lisa M.
Published: September 2009

Objective:

To assess the ability of a protective isolation room ventilation system to reduce patient exposure to airborne infectious agents, using a small-scale model that permits cost-effective and unobtrusive study of relevant indices of performance.

Design:

A one-half scale model of a protective isolation room at the University of Minnesota Hospital was constructed and equipped for tracer gas experiments to assess ventilation efficiency.

Measurements:

Tracer gas (SF6) was injected into the model supply air. Tracer gas concentration was recorded over time and analyzed to determine local and room mean age of air. Age of air is a direct measurement of ventilation efficiency and can be used to predict patient exposure to contamination.

Results:

Although for the room taken as a whole, ventilation efficiency was close to 50% (a value corresponding to perfect mixing), the experimental results for the local mean age of air indicate that some parts of the model were ventilated much better than others.

Conclusion:

Room air exchange rate is only one parameter useful in assessing ventilation in patient areas. Effective distribution of ventilation air also is critical to the control of airborne contamination. Areas of the room with poor ventilation would be expected to have higher concentrations of airborne infectious agents and other contaminants. Patient exposure can be minimized by placing the patient in well-ventilated areas of the room. Improved ventilation designs may reduce patient exposure further without increasing actual airflow rate.
Resistant Enterococci: A Prospective, Study of Prevalence, Incidence, and Factors Associated With Colonization in a University Hospital
Authors: Weinstein Jeffrey W. , Roe Matthew , Towns Michael , Sanders Linda , Thorpe Jackie J. , Corey G. Ralph , Sexton Daniel J.
Published: September 2009

Objective:

To determine the prevalence of gastrointestinal tract colonization with antibiotic-resistant enterococci at ward entry and to study the incidence and risk factors for nosocomial acquisition of colonization with resistant enterococci.

Design:

A prospective cohort study conducted between February 1 and March 15, 1993.

Methods:

Rectal cultures were obtained within 24 hours of admission or transfer onto the study wards and repeated at weekly intervals and at the time of discharge. Patients harboring antibiotic-resistant enterococci at the time of admission or after admission were compared to patients who were not colonized with these organisms. Clinical and epidemiologic risk factors for colonization were abstracted prospectively by daily chart review. Following a univariate analysis of risk factors associated with colonization, a multivariate statistical analysis using three separate models was done.

Setting:

A 1,125-bed, tertiary-care teaching hospital in North Carolina.

Patients:

A total of 350 patients admitted to two general medical wards and the medical intensive care unit during the study period.

Results:

Antibiotic-resistant enterococci were isolated from 52 patients: 19 were colonized at admission to the study, and 33 later acquired resistant strains. At the time of admission, 5.4% of the patients were colonized with ampicillin-resistant enterococci (ARE), including 1.1% that were colonized with vancomycin-resistant enterococci. Prior hospitalization was associated with colonization with ARE at admission (P=.01). Independent risk factors for nosocomial acquisition of ARE included treatment with more than three antibiotics, empiric use of antibiotics, use of third-generation cephalosporins, and the use of enteral tube feedings. Antibiotics used prophylactically were not associated with resistant enterococcal colonization.

Conclusions:

Our data help to elucidate the epidemiology of gastrointestinal tract colonization with resistant enterococci. We hypothesize that surveillance and control programs will be more likely to succeed if targeted at patients receiving more than three antibiotics, empiric antibiotics, and enteral tube feedings.
The Infection Control Committee
Authors: Wiblin R Todd , Wenzel Richard P.
Published: September 2009

Hospital epidemiologists translate their expertise into institutional policy and gain the support of administrators through the infection control committee. Committee members have the important task of helping to disseminate information to all important hospital constituencies. The infection control team can facilitate its goals by properly preparing committee members for the meeting. A well-educated committee will approve policies efficiently. The committee periodically should reassess its accomplishments and goals. This article will explore the workings of the infection control committee and will suggest strategies that the hospital epidemiologist can use to make the committee an asset rather than a hindrance.
Cost-Effectiveness of Perioperative Mupirocin Nasal Ointment in Cardiothoracic Surgery
Authors: VandenBergh Marjolein F.Q. , Kluytmans Jan A.J.W. , van Hout Ben A. , Maat Alexander P.W.M. , Seerden Rob J. , McDonnel Joseph , Verbrugh Henri A.
Published: September 2009

Objective:

To assess the cost-effectiveness of perioperative intranasal application of mupirocin calcium ointment in cardiothoracic surgery.

Design:

Cost-effectiveness analysis based on results of an intervention study with historical controls.

Setting:

University Hospital Rotterdam, a tertiary referral center for cardiac and pulmonary surgery.

Patients:

Consecutive patients undergoing cardiothoracic surgery between August 1, 1989, and February 1, 1991 (control group, n=928), and between March 1, 1991, and August 1, 1992 (intervention group, n=868).

Intervention:

Perioperative nasal application of mupirocin calcium ointment started on the day before surgery, continued for 5 days, twice daily.

Results:

Postoperative costs were increased significantly in patients with a surgical-site infection (SSI), compared with uninfected patients (P<.001). Mean SSI-attributable costs were estimated at $16,878 (95% confidence interval, $15,575-$18,181). The incidence of SSIs was 7.3% in the control group and 2.8% in the intervention group, mupirocin effectiveness being 62%. The costs of mupirocin were $11 per patient. Thus, the savings per SSI prevented were $16,633. To validate this comparative estimate of SSI-attributable costs, a noncomparative analysis of the postoperative length of stay (POLS) was performed, according to the Appropriateness Evaluation Protocol. Approximately 50% of the comparative SSI-attributable POLS were judged SSI-attributable in the noncomparative analysis. Sensitivity analyses, testing for the robustness of our conclusions, indicated that the presented model is rather insensitive to variations in the incidence of SSIs and for the effectiveness and costs of mupirocin. SSI-attributable costs were shown to be the only variable with substantial effect on the cost-effectiveness ratio. Perioperative mupirocin would result in net costs instead of savings only if SSI-attributable costs were less than $245.

Conclusions:

SSIs in patients undergoing cardiothoracic surgery are associated with a substantial increase in postoperative costs. Provided that perioperative mupirocin reduces the SSI rate, this measure will be highly cost-effective in most centers providing cardiothoracic surgical services.
Elimination of Nasal Carriage of Staphylococcus aureus in Hemodialysis Patients
Authors: Kluytmans Jan A.J.W. , Manders Marie-Jose , van Bommel Erik , Verbrugh Henri
Published: September 2009

Objective:

To study the efficacy of mupirocin for the elimination of nasal carriage of Staphylococcus aureus in hemodialysis patients.

Design:

The efficacy of mupirocin was studied in a prospectively followed cohort. The effect of this intervention on the rate of S aureus bacteremia was evaluated using a historic control group.

Setting:

Patients on the hemodialysis unit of the University Hospital Rotterdam, a tertiary referral center.

Patients:

The study group consisted of consecutive patients on hemodialysis from February 1, 1992, until November 1, 1993. They were screened by taking nasal cultures monthly during their time on hemodialysis. If S aureus was isolated, treatment with mupirocin nasal ointment was initiated. The control group consisted of patients treated on the same hemodialysis unit from January 1, 1990, until January 1, 1992.

Results:

The study group consisted of 226 patients, of whom 172 were evaluated to determine the efficacy of mupirocin. Sixty-seven (39%) were identified as nasal carriers. Following the initial treatment, 66 nasal cultures (98.5%) became negative. After 3 months and 6 months, respectively, 63 (94%) and 61 (91%) of the treated carriers had negative cultures. The rate of bacteremia (defined as the number of episodes of 5 aureus bacteremia per patient-year on hemodialysis) was significantly lower among the 226 patients in the study group (0.04 per patient-year) than among the 273 patients in the control group (0.25 per patient year; P <.001). Development of resistance and adverse effects were not observed.

Conclusions:

Mupirocin nasal ointment effectively eliminates nasal carriage of 5 aureus in patients on hemodialysis. This was associated with a significant reduction of the incidence of 5 aureus bacteremia, as compared to historic controls.
A Prolonged Outbreak of Methicillin-Resistant Staphylococcus aureus in the Burn Unit of a Tertiary Medical Center
Authors: Meier Patricia A. , Carter Cheryl D. , Wallace Sarah E. , Hollis Richard J. , Pfaller Michael A. , Herwaldt Loreen A.
Published: September 2009

Objective:

To report an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) in our burn unit and the steps we used to eradicate the organism.

Design And Setting:

Outbreak investigation in the burn unit of a 900-bed tertiary-care medical center.

Outbreak:

Between March and June 1993, MRSA was isolated from 10 patients in our burn unit. All isolates had identical antibiograms and chromosomal DNA patterns.

Control Measures:

Infection control personnel encouraged healthcare workers to wash their hands after each patient contact. The unit cohorted all infected or colonized patients, placed each affected patient in isolation, and, if possible, transferred the patient to another unit. Despite these measures, new cases occurred. Infection control personnel obtained nares cultures from 56 healthcare workers, 3 of whom carried the epidemic MRSA strain. One healthcare worker cared for six affected patients, and one cared for five patients. We treated the three healthcare workers with mupirocin. Subsequently, no additional patients became colonized or infected with the epidemic MRSA strain.

Conclusions:

The outbreak ended after we treated healthcare workers who carried the epidemic strain with mupirocin. This approach is not appropriate in all settings. However, we felt it was justified in this case because of a persistent problem after less intrusive measures.
The Role of Understaffing in Central Venous Catheter-Associated Bloodstream Infection
Authors: Fridkin Scott K. , Pear Suzanne M. , Williamson Theresa H. , Galgiani John N. , Jarvis William R.
Published: September 2009

Objective:

To determine risk factors for central venous catheter-associated bloodstream infections (CVC-BSI) during a protracted outbreak.

Design:

Case-control and cohort studies of surgical intensive care unit (SICU) patients.

Setting:

A university-affiliated Veterans Affairs medical center.

Patients:

Case-control study: all patients who developed a CVC-BSI during the outbreak period (January 1992 through September 1993) and randomly selected controls. Cohort study: all SICU patients during the study period (January 1991 through September 1993).

Measurements:

CVC-BSI or site infection rates, SICU patient clinical data, and average monthly SICU patient-to-nurse ratio.

Results:

When analyzed by hospital location and site, only CVC-BSI in the SICU had increased significantly in the outbreak period compared to the previous year (January 1991 through December 1991: pre-outbreak period). In SICU patients, CVC-BSI were associated with receipt of total parenteral nutrition [TPN]; odds ratio, 16; 95% confidence inter val, 4 to 73). When we controlled for TPN use, CVC-BSI were associated with increasing severity of illness and days on assisted ventilation. SICU patients in the out-break period had shorter SICU and hospital stays, were younger, and had similar mortality rates, but received more TPN compared with patients in the pre-outbreak period. Furthermore, the patient-to-nurse ratio significantly increased in the outbreak compared with the pre-outbreak period. When we controlled for TPN use, assisted ventilation, and the period of hospitalization, the patient-to-nurse ratio was an independent risk factor for CVC-BSI in SICU patients.

Conclusions:

Nursing staff reductions below a critical level, during a period of increased TPN use, may have contributed to the increase in CVC-BSI in the SICU by making adequate catheter care difficult. During healthcare reforms and hospital downsizing, the effect of staffing reductions on patient outcome (ie, nosocomial infection) needs to be critically assessed.
Tuberculosis in the Workplace: OSHA's Compliance Experience
Authors: McDiarmid Melissa , Gamponia Melissa J. , Ryan Margaret A.K. , Hirshon Jon Mark , Gillen N.A. , Cox Maureen
Published: September 2009

Objective:

Inspections of 272 facilities were performed between May 1992 and October 1994 to determine compliance with applicable Occupational Safety and Health Administration (OSHA) requirements for prevention of tuberculosis (TB) transmission.

Design:

Retrospective record review of two data sources: (1) OSHA's Computerized Integrated Management Information System and (2) an inspector-completed questionnaire on inspection results.

Setting/Participants:

Inspections of five types of facilities: healthcare institutions, correctional facilities, homeless shelters, long-term–care facilities for the elderly, and others, including drug treatment centers that the Centers for Disease Control and Prevention (CDC) identified as having a higher than expected rate of TB.

Methods:

The OSHA Compliance Memorandum, based on the 1990 CDC Guidelines, which outlined elements of a TB prevention program, was used in performing 272 inspections of facilities between May 1992 and October 1994. Elements of compliance were recorded and reviewed from the IMIS database and inspectors' questionnaires.

Results:

Regulated facilities were not fully compliant with OSHA guidance. Generally, healthcare facilities performed better than other facilities. Most facilities (79%) were compliant with administrative elements of a comprehensive TB control program, such as early identification of known or suspected infectious TB patients and skin testing of workers. Only 29% of inspected facilities were found to have acceptable respiratory protection programs for the prevention of occupational TB.

Conclusion:

Facilities have not been fully compliant with the OSHA memorandum describing protection of workers from TB. Facility compliance was better with some traditionally recognized TB infection control elements, but was weaker in the area of respiratory protection programs. This may reflect a lack of familiarity with the latter type of hazard protection.
An Outbreak of Cutaneous Aspergillosis in a Tertiary-Care Hospital
Authors: Bryce E.A. , Walker M. , Scharf S. , Lim A.T. , Walsh A. , Sharp N. , Smith J.A.
Published: September 2009

A cluster of four cases of surgical and burn wound aspergillosis occurred in a 900-bed, adult, tertiary-care hospital. The source was traced to the outside packages of dressing supplies, which had become contaminated during construction in the central Inventory Control area. This resulted in patients with large exposed surface areas being inoculated directly with Aspergillus spores.
Comparative Killing Kinetics of Methicillin-Resistant Staphylococcus aureus by Bacitracin or Mupirocin
Authors: Chapnick Edward K. , Gradon Jeremy D. , Kreiswirth Barry , Lutwick Larry I. , Schaffer Benjamin C. , Schiano Thomas D. , Levi Michael H.
Published: September 2009

The in vitro activities of bacitracin and mupirocin were compared for seven different strains of methicillin-resistant Staphylococcus aureus. Six of seven strains showed bacitracin minimum inhibitory concentrations (MICs) of 0.5 to 1.0 units/mL, and all seven had mupirocin MICs of 0.5 to 2 μg/mL. Time-kill studies revealed 2.6- to 4.5-log reduction in 24 hours with strains susceptible to bacitracin (4 units/mL) and 0 to 2.2 reduction with mupirocin (16 μg/mL). Bacitracin should be considered further for in vivo studies because of enhanced bacteriocidal effect and lower cost.
Educational Needs and Opportunities for the Hospital Epidemiologist
Authors: Dembry Louise M. , Hierholzer Walter J.
Published: September 2009

The role of the hospital epidemiologist has changed substantially over the last 30 years as medical care has become more complex. The hospital epidemiologist needs training in methods for sur veillance, prevention, and control of nosocomial infections. The hospital epidemiologist also must know how to apply these methods to other areas, including the epidemiology of noninfectious adverse out-comes of medical care. Training in hospital epidemiology should be a defined part of every infectious disease fellowship training program. Ancillary and additional training is available from several sources.
Loss of Antimicrobial Susceptibility in Aerobic Gram-Negative Bacilli Repeatedly Isolated From Patients in Intensive-Care Units
Authors: Manian Farrin A. , Meyer Lynn , Jenne Joane , Owen Amy , Taff Terry
Published: September 2009

Objective:

To study the loss of antimicrobial susceptibility in repeat (same patient, same bacterial species, and same site) aerobic gram-negative bacilli (AGNB) isolated from individual patients during their stay in the intensive-care unit (ICU).

Setting:

A 792-bed, tertiary-care community hospital with a total of 107 adult, pediatric, and neonatal ICU beds. METHOD: An obser vational prospective study performed November 1992 through mid-July 1993.

Results:

Of 594 consecutive AGNB from 287 ICU patients, 117 isolates (20%) from 55 patients (19%) were repeat isolates, with the majority obtained from respiratory secretions (83%). Pseudomonas aeruginosa and Enterobacter species accounted for 61% of the isolates. Forty-two (36%) of the repeat isolates from 24 patients (44%) had >4-fold increase in minimum inhibitory concentration to at least one antibiotic and no longer were considered fully susceptible based on National Committee on Clinical Laboratory Standards criteria. Loss of antimicrobial susceptibility often developed within several (median 8) days and was associated only infrequently with simultaneous transition from colonization to infection in the individual patient. Use of certain β-lactam antibiotics was associated with increasing resistance to several other antibiotics in the same class. Concurrent use of β-lactams and aminoglycosides did not prevent loss of antimicrobial susceptibility to the former in repeat isolates.

Conclusion:

We conclude that loss of antimicrobial susceptibility in repeat AGNB isolated from ICU patients is common, usually is not associated with transition from colonization to infection, and often is associated with prior use of antibiotics. Minimizing antibiotic use in ICU patients should help reduce the risk of antimicrobial resistance in repeat AGNB isolates.
Risk Factors Associated With Clostridium difficile Diarrhea in Hospitalized Adult Patients: A Case-Control Study—Sucralfate Ingestion is Not a Negative Risk Factor
Authors: Watanakunakorn Paul W. , Watanakunakorn Chatrchai , Hazy John
Published: September 2009

Objectives:

To assess risk factors associated with Clostridium difficile diarrhea in hospitalized adult patients, and to test the hypothesis that sucralfate ingestion is associated with nondetection of C difficile cytotoxin in stool specimens.

Design:

A retrospective case-control study of hospitalized adult patients who had stool specimens assayed for C difficile cytotoxin. For each patient who had positive C difficile cytotoxin, a patient who had negative C difficile cytotoxin was used as a control. The study period was January to December 1993.

Setting:

A community teaching hospital affiliated with a medical school in northeastern Ohio.

Results:

There were 91 case patients and 91 control patients. Cephalosporin exposure was identified as a risk factor in patients with C difficile diarrhea. The number of patients who had sucralfate ingestion was comparable in both groups of patients.

Conclusions:

Administration of cephalosporins was identified as a risk factor in patients with C difficile diar-rhea. We were not able to confirm a recent report of the association between ingestion of sucralfate and nondetection of C difficile cytotoxin in stool specimens. Our findings suggest that sucralfate ingestion is not associated with nondetection of C difficile cytotoxin in stool specimens. Assay of C difficile cytotoxin in stool specimens remains a valid method of diagnosing C difficile diarrhea, even in patients who ingest sucralfate.
Quantitative Epidemiology
Authors: Freeman Jonathan
Published: September 2009

We provide guidance for new practitioners in the vocabulary of modern epidemiology and the application of quantitative methods. Most hospital epidemiology involves surveillance (observational) data that were not part of a planned experiment, so the rubric and logic of controlled experimental studies cannot be applied. Forms of incidence and prevalence often are confused. The names “cohort study” and “case-control study” are unfortunate, as cohort studies rarely involve cohorts and case-control studies allow no active control by the investigator. Either type of study can be prospective or retrospective. Results of studies with discrete outcomes (infected or not, lived or died) often are represented best by a form of the risk ratio with 95% confidence intervals. The potential distorting effects of selection bias, misclassification, and confounding need to be considered.
Capture-Recapture Methods in Epidemiological Studies
Authors: Stephen Craig
Published: September 2009

Medical researchers often are faced with the challenge of estimating the total number of cases in a population based on incomplete samples. Because of a lack of explicit methods for determining if all cases have been counted, indirect methods for estimating the abundance of disease have been developed. Capture-recapture models are an indirect method of estimating population sizes that have been employed in recent epidemiological studies. These methods, derived from techniques developed for studies of animal abundance, estimate the true population size by evaluating the degree of overlap among incomplete lists of cases from existing data sources. Although intuitively appealing, the successful application of these methods is dependent upon a clear understanding of the biology of the disorder involved, the dynamics of the reference population, and the assumptions and robustness of the specific models used. Failure to address these issues can lead to inaccurate and sometimes misleading results. This article describes some of the strengths and limitations of recapture techniques and provides the reader with a foundation from which to explore the methods in further detail.
Does a Cheaper Mask Save Money? The Cost of Implementing a Respiratory Personal Protective Equipment Program
Authors: Rivera Pedro , Louther Joyce , Mohr James , Campbell Angela , DeHovitz Jack , Sepkowitz Kent A.
Published: September 2009

Objective:

To determine the annual cost of implementing and maintaining a respiratory personal protective equipment (PPE) program at an urban hospital.

Setting:

St Clare's Hospital and Health Center, a 250-bed hospital in Manhattan that treats 60 to 100 cases of tuberculosis annually.

Methods:

Review of Purchasing Department records for all masks acquired by the hospital from 1992 to 1995, and an estimate of administrative time spent developing and implementing the guidelines recommended by various agencies during the study interval.

Results:

Respiratory isolation was provided for 6,360 to 10,883 days annually during the 4-year interval. Yearly costs for the PPE program ranged from $86,560 to $175,690. Of note, the daily cost for a respiratory isolation day decreased dramatically between 1994 and 1995 ($25/day to $13/day), when the high-efficiency particulate air-filter (HEPA) respirator was used by all staff. The decrease occurred because of lower administrative costs and a sharp decrease in the numbers of HEPA units purchased. Objective measures of worker compliance with HEPA respirators demonstrated the decrease was not due to less HEPA use but rather that employees were using each HEPA unit for several weeks, as recommended.

Conclusion:

We found a significant decrease in cost in the second year of our HEPA program due to increasing employee familiarity with the program. Newly approved, cheaper, but less durable, N-95 masks are unlikely to withstand multiple wearings and may be discarded after a few uses. Thus, cheaper masks may result in a more expensive PPE program.
Implementation of Consensus Guidelines for the Follow-Up of Positive Blood Cultures
Authors: Herchline Thomas , Gros Sheila
Published: September 2009

Objective:

Assess the effect and use of resources associated with implementation of a program for the systematic follow-up of positive blood cultures.

Design:

Prospective epidemiologic study.

Setting:

Tertiary-care military medical center.

Intervention:

All positive blood cultures (BC) were reported via E-mail to an infectious disease specialist as soon as growth was noted. This individual reviewed all Gram stains, clinical data, and antibiotic information on these patients.

Results:

From June 26, 1994, through January 25, 1995, there were 3,121 BCs drawn, of which 199 (6.4%) were positive from 145 episodes. Sixty-three episodes involved probable contaminants, and 82 episodes were considered true bacteremias. Six patients with true bacteremia died, two were transferred, and three were discharged within 24 hours of drawing the positive BC. Of the remaining 71 true bacteremias, 9 patients were on inadequate empiric therapy, as judged by the final organism susceptibilities. Changes in empiric therapy were recommended for five of the nine episodes and were implemented by the primary physicians in each case. Each of the changes resulted in improved coverage (as judged by the final identification and susceptibilities).

Conclusions:

This program has improved the quality of care at Keesler Medical Center at the cost of one additional hour of consultant time per week.
Nosocomial Infection in an Intensive-Care Unit Identification of Risk Factors
Authors: Fernandez-Crehuet Rafael , Diaz-Molina Carmen , de Irala Jokin , Martinez-Concha Diego , Salcedo-Leal Inmaculada , Masa-Calles Josefa
Published: September 2009

Objective:

To identify risk factors predictive of nosocomial infection in an intensive-care unit (ICU) and to identify patients with a higher risk of nosocomial infection using a predictive model of nosocomial infection in our ICU.

Design:

Prospective study; daily concurrent surveillance of intensive-care-unit patients.

Setting/Patients:

All patients admitted for at least 24 hours to the ICU of a tertiary-level hospital from February to November 1994 were followed daily.

Methods:

Variables measuring extrinsic and intrinsic risk factors for nosocomial infection were collected on each patient during their ICU stay, and the Cox Proportional Hazards multivariable technique was used to identify the variables significantly associated with infection.

Results:

The population studied consisted of 944 patients. The main risk factors identified were intrinsic; the significant extrinsic risk ofactors identified were head of the bed in a horizontal (<30°) position (this variable presented the highest increase of the infection hazard ratio) and the use of sedative medication. Patients presenting the highest risk scores using the predictive model are those with the highest risk of nosocomial infection.

Conclusion:

The important preventive measures derived from our results are that underlying conditions suffered by the patient at the ICU admission should be corrected promptly, the depression of the patient's level of consciousness with sedatives should be monitored carefully, and the horizontal position of the head of the bed should be avoided totally. Patients with a high risk of infection can be the target of special preventive measures.
Exposure Workups
Authors: Herwaldt Loreen A. , Pottinger Jean M. , Carter Cheryl D. , Barr Brenda A. , Miller Elyse D.
Published: September 2009

Exposure workups are an important responsibility for infection control personnel. A well-designed plan for investigating exposures, which includes appropriate algorithms, will enable infection control personnel to evaluate exposures rapidly and consistently so that nosocomial transmission is minimized. Infection control personnel should use their own data to develop policies and procedures that suit the needs of their facility. After they have imple-merited the plan, infection control personnel should continue to collect data on exposures so they can continuously improve their performance.