bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Evaluation of a Bioeconomic Model for Weed Management in Corn (Zea mays)
Authors: Buhler Douglas D. , King Robert P. , Swinton Scott M. , Gunsolus Jeffery L. , Forcella Frank
Published: May 2019

A bioeconomic weed management model was tested as a decision aid for weed control in corn at Rosemount, MN, from 1991 to 1994. The model makes recommendations for preemergence control tactics based on the weed seed content of the soil and postemergence decisions based on weed seedling densities. Weed control, corn yield, herbicide active ingredient applied, and economic return with model-generated treatments were compared to standard herbicide and mechanical control treatments. Effects of these treatments on weed populations and soybean yield the following year were also determined. In most cases, the model-generated treatments controlled weeds as well as the standard herbicide treatment. The quantity of herbicide active ingredient applied decreased 27% with the seed bank model and 68% with the seedling model relative to the standard herbicide treatment. However, the frequency of herbicide application was not reduced. In 1 yr, seed bank model treatments did not control weeds as well as the standard herbicide or seedling model treatments. Corn yields reflected differences in weed control. Net economic return to weed control was not increased by using model-generated control recommendations. Weed control treatments the previous year affected weed density in the following soybean crop. In 2 of 3 yr, these differences did not after weed control or soybean yield. Although tactics differed, the bioeconomic model generally resulted in weed control and corn yield similar to the standard herbicide. The model was responsive to differing weed populations, but did not greatly after economic returns under the weed species and densities in this research.
Surface Wheat (Triticum aestivum) Residues, Giant Foxtail (Setaria faberi), and Soybean (Glycine max) Yield
Authors: Vidal Ribas A. , Bauman Thomas T.
Published: May 2019

Experiments were conducted from 1992 through 1994 to determine the effect of 0 to 12 Mg ha−1of surface wheat residues (SWR) on giant foxtail density and crown node length, and soybean yield. Giant foxtail density decreased as SWR increased from 0 to 12 Mg ha−1. SWR of 6 to 12 Mg ha−1reduced giant foxtail density by 2 to 50 % compared to bare soil. The crown node of giant foxtail was 2 cm above the soil surface with 12 Mg ha−1of SWR. Frost in 1992 injured soybean more than weeds in plots with SWR while soybean in soil with no SWR was not injured. In absence of frost in 1993 and 1994, yield of weedy soybean increased 20 to 29%, respectively, with the increase of SWR from 0 to 6 Mg ha−1. In weed-free plots, soybean yield was similar across all SWR levels. These results confirm the hypothesis that high levels of SWR increased soybean yield in weedy plots because of decreased giant foxtail infestation.
Weed Control in Cole Crops and Onion (Allium cepa) Using Ammonium Nitrate
Authors: Bitterlich Iris , Upadhyaya Mahesh K. , Shibairo Solomon I.
Published: May 2019

Weed control in cole crops and onion by postemergence spraying with liquid ammonium nitrate was studied to determine its feasibility under Fraser Valley, British Columbia conditions. Ammonium nitrate solutions (7.5, 10, 15 and 20% N) were applied at 800 L ha−1 on warm, sunny days. Shepherd's-purse, low cudweed, redroot pigweed and ladysthumb were susceptible to this treatment; common lambsquarters, common purslane and annual bluegrass were tolerant. In order to determine the effect of weed density on weed control, several shepherd's-purse densities were established in broccoli and sprayed with ammonium nitrate solution (20% N; 800 L ha−1). Two days after treatment, weed control was 87.2% for an initial density of 500 shepherd's-purse plants m−2 (1987) and 76.1% for an initial density of 988 plants m−2 (1988). The seedlings that survived the treatment were sufficiently set back that they did not cause any adverse effect on crop yield. In a separate study, cabbage and onion were found to be tolerant to the ammonium nitrate treatment. Initially, cauliflower, broccoli and Brussels sprouts growth was slightly inhibited by the ammonium nitrate treatment but the plants recovered and crop yield was not affected.
Clomazone Dissipation in Two Tennessee Soils
Authors: Kirksey K. Bruce , Hayes Robert M. , Krueger William A. , Mullins Charles A. , Mueller Thomas C.
Published: May 2019

Clomazone dissipation in soil was examined in field and laboratory experiments. Field studies suggested a potential for injury to rotational crops such as wheat. Field half-lives were 5 to 29 d (average of 9 field studies was 19 d) for the Etowah clay loam (fine-loamy, siliceous, thermic typic Paleudult) and Lily loam (fine-loamy, siliceous, thermic typic Hapludult) soils. Clomazone had an average half-life of 34 d under lab conditions, indicating slower dissipation in the lab than in the field. Clomazone was moderately adsorbed to soil as indicated by a Kdof about 1, and a Komof 52 in the two soils.
Introduction: Special Issue on Ageing, Biography and Practice
Authors: Ruth Jan-Erik , Kenyon Gary M.
Published: May 2019

The experiences of maturing and ageing constitute a rather unexplored field within Gerontology. The ‘inner’ aspects of ageing have been left relatively untouched by researchers, largely out of methodological considerations. The ‘outer’ aspect of ageing, or ageing defined as behaviour, has been considered more fruitful due to its consistency with criteria for science created by logical positivism. Psychogerontologists in particular have been mesmerized by this research paradigm. However, this trend has also, for some time now, been criticized for underestimating theperceptionsof the reality upon which we form our reasons for action (Runyan 1982; Carr 1986). Further, there are exceptions to this main stream of research. For example, the German psychogerontologist Thomae created a theory of ageing in 1970 based on the perceptual, evaluative and meaning – giving processes within the individual (Thomae 1970). In a series of studies (The BOLSA studies), he has been able to lend support to most of his theoretical claims (see Kruse and Schmitz-Schertzer 1995). Also the Canadian gerontologists Reker and Wong (1988) belong to the group of pioneers advocating the importance of personal meaning in successful ageing.
The Projects of Life Reflected in Autobiographies of Old Age
Authors: Ruth Jan-Erik , Birren James E. , Polkinghorne Donald E.
Published: May 2019

The present investigation was based on the analysis of twenty respondents, ten men and ten women, all retired. The written texts were obtained from the archives of one of the authors who gathered autobiographies using a guided method of assigned topics of life. The main objective for this analysis was to find those central life goals and dominant activities around which the projects of life were formed. Sorting of life projects was done according to the constant comparison method described by Glaser and Strauss in their Grounded Theory model. Five types of life projects were identified in the narratives:living is achieving, living is being social, living is loving, living is family life, living is struggling.Considerable gender differences appeared in the findings with women showing a broader participation and interpretation of life where family life, community work and job careers were important. The men tended to be more monothematic focusing either on a personal achievement or a career development in a more social context. The rhetoric in the discourse of life themes was quite different between the sexes reflecting the sex role scripts of the cohort studied. Only in some of the types was the class dimension clearly visible where the typeliving is achievingand to a certain extent evenliving is being socialreflected upper middle class and upper class occupations whileliving is lovingreflected middle class occupations. The positive narrative tone and the telling of well-managed life projects and success stories in most of the accounts were considered as American features in comparison to some Finnish life stories that contained more of the telling of hardships. The most gender bound accounts such as the masculineliving is achievingand the feminineliving is lovinglife projects showed the greatest resemblances between these two western cultures revealing comparable master scripts.
The Absent Body – A Social Gerontological Paradox
Authors: Öberg Peter
Published: May 2019

This contribution, which is mainly theoretical, focuses on the paradox that, to a considerable extent, the body has been absent from social gerontology, despite the fact that in our culture, ageing is presented both in terms of surface and body and is experienced via the body. This paradox is brought into the open and clarified using as a starting point the ontological dualism of the Platonic-Christian tradition in which body and soul are seen as hierarchical opposites. The article shows how this dualism penetrates society and science and is carried on into the construction of gerontological concepts and theories, e.g. the ‘ageless self’ concept. The article also illustrates what consequences this dualism has for the everyday understanding of ageing based on biographical interviews with elderly Finnish people.
Current and Future Incomes for Older People
Authors: Hutton Sandra
Published: May 2019

Income in retirement does not normally feature in national headlines, but scandals such as the misuse of the company pension fund by Robert Maxwell, and the financial advice given to join personal pension schemes have done just that. The ‘demographic time bomb’ has become a media cliché. In this first of two reviews of the incomes and financial circumstances of older people we examine the influence of these headlines and clichés on present and future incomes. To set the scene, the current levels and sources of income for older people are outlined and compared with those of the younger population. The following section describes the trends and changes in pensioners’ incomes and what has influenced these trends. The next sets out the main issues in providing a secure income in old age, and finally the current policy debate is reviewed and some questions are identified for re-examination in two years’ time.
Socioeconomic Factors and Behavioural Problems of the Elderly Population: A Study of Rural Areas of Eastern Uttar Pradesh
Authors: Yadava K. N. S. , Yadava Surendar S. , Sharma C. L. N.
Published: May 2019

This paper attempts to study the socioeconomic and demographic profile of the elderly population at a micro level based on data collected in a sample survey, entitled ‘Ageing and health conditions in rural areas - a sample survey 1990’, conducted in the eastern part of Uttar Pradesh, India. The distribution of the elderly population according to their work status, health problems and needs is also discussed. The views and actions of the younger family members toward the elderly members are examined and found to vary according to caste group, sex, and work status of the latter. It is noted that elderly females are usually relatively more dependent on their families than their male counterparts. The behaviour of the family members towards their elders is also significantly affected by the literacy and income levels of family members. Provision for an old-age pension is strongly recommended.
Constructing Familiarity and Managing the Self: Ways of Adapting to Life in Nursing and Residential Homes for Older People
Authors: Reed Jan , Payton Valerie Roskell
Published: May 2019

This paper reports on the analysis of data collected in a study looking at older people moving into nursing and residential homes. Using life history methodology, participants are interviewed before and after arrival at homes in order to determine the process of adapting to their new environment. Initial data analysis indicates that this process requires extensive social activity on the part of the new resident, involving negotiation of complex social conventions. The discussion focuses on two themes which have been identified from the data: constructing familiarity whereby participants use sometimes tenuous knowledge of people and places to make the home seem less strange, and managing the self, whereby familiarity is used as a means of permitting social conversation to take place without leaving residents open to the dangers of being intrusive. These two themes have relevance for the way in which new residents can be introduced to homes, and the way in which the social skills of older people are viewed.
Unemployment and the Older Worker in the Netherlands: Re-entry into the Labour Force or Resignation
Authors: Henkens Kène , Sprengers Maarten , Tazelaar Frits
Published: May 2019

In this article we present the results of a panel survey in which 242 men aged 40 to 55 were followed for approximately seven years after they became involuntarily unemployed. The study focused on reintegration probabilities of the older workers and on the question of their reaction to a situation of prolonged unemployment. The study shows that if policy is not changed, the probability of the reintegration of older, long-term unemployed persons into the labour force will remain extremely low. Re-entry via a ‘normally’ functioning labour market (formal application procedures and official job intermediaries) takes place almost exclusively during the first year after dismissal. If a new job is not found, a resigned feeling occurs among almost all of this older unemployed group. Most of the older people adjust to the new circumstances sooner or later. If one wishes to protect older persons from the trap of long-term unemployment (and in many cases total exclusion), more rapid interventions must be made, and reorientation and retraining efforts must be started sooner, before it is ‘too late’. From the employer’s point of view, there is not much interest in those who are still unemployed after one year.
Stories and Metaphors: Talking about the Past in a Psychotherapy Group for People with Dementia
Authors: Cheston Rik
Published: May 2019

Social constructionist approaches to the talk of older adults diagnosed as suffering from a dementing illness have emphasised the importance of analysing such talk in terms of its social function. Drawing on this work together with the increasing clinical impetus towards the development of psychotherapy in this area, this paper examines two sequences of stories produced during a psychotherapy group. These stories are seen as having two related functions: first, they enable individuals to explore the significance of their experiences and thus, it is argued, act as metaphors for the personal experience of having a dementing illness; and secondly they act as a means of creating a series of social identities. As such they serve as explanations of ‘what it is to lose one’s mind’ (Sutton 1994).
Is America Exporting Another New Social Idea?
Authors: Sheppard Harold L. , Myles John F. , Polivka Larry
Published: May 2019

The focus in the United States on ‘setting limits’ to the provision of such services as health care for old people may be spreading to Europe. This article points up the empirical deficiencies in some of the unexamined assumptions in such proposals, especially the belief that an inordinate share of medical expenditures occur in the final weeks or months of elderly patients. The setting-limits doctrine is viewed as a subset of broader socio-political-ideological thrusts aimed at (or resulting in) anti-elderly, intergenerational-conflict policy proposals. Such proposals should be evaluated in terms of their social constructionist, partially contrived, and historically distorted bases. Apocalyptic gerontology needs to be weighed in terms of its moral implications.
The Effect of Respirator Training on the Ability of Healthcare Workers to Pass a Qualitative Fit Test
Authors: Hannum Donna , Cycan Kerrie , Jones Linda , Stewart Melinda , Morris Steve , Markowitz Sheldon M. , Wong Edward S.
Published: May 2019

Objectives:

To determine the effect of different methods of training on the ability of hospital workers to wear respirators and pass a qualitative fit test, and to compare the direct cost of the training.

Design:

179 hospital employees were recruited for study and were stratified into three groups based on the type of training they received in the use of respirators. Employees in Group A received one-on-one training by the hospital's industrial hygienist and were fit tested as part of this training. Employees in Group B received classroom instruction and demonstration by infection control nurses in the proper use of respirators, but were not fit tested as part of training. Employees in Group C received no formal training. Each participant in our study underwent a subsequent qualitative fit test using irritant smoke to check for the employee's ability to adjust correctly the fit and seal of the respirator. The direct cost of each method of training was determined by accounting for the cost of trainers and the cost of employee-hours lost during training.

Setting:

775-bed Veterans' Affairs hospital.

Results:

94% of Group A participants (49 of 52) passed the qualitative fit test, compared to 91% of Group B participants (58 of 64) and 79% of Group C participants (50 of 63; P=.036, 2 × 3 chi-square). Group A had a significantly higher pass rate than Group C (P=.043), but Group B did not differ significantly from Group A or Group C. Location or professional status did not affect pass rate, but prior experience wearing respirators did. When the study groups were compared after stratifying for prior experience, we found no difference in pass rates, except when Groups A and B (those with any training) were combined and compared with Group C (107 of 116 versus 50 of 63, P=.05, Mantel-Haenszel chi-square).

We estimate that the method of training involving individual instruction followed by fit testing took 20 minutes per employee to complete, compared to 10 minutes per six employee class for the method of classroom demonstration. The difference in direct cost between the two methods, applied to the training of 1,200 employees at our hospital, would be approximately $19,000 per year.

Conclusion:

Our study indicates that training in the proper use of respirators is important, but the method of training may not be, as the two methods we evaluated were nearly equivalent in their pass rates on fit testing (94% versus 91%). Fit testing as part of training may have enhanced the performance of our participants marginally, but was more time consuming and accounted for most of the excess cost.
Prevention of Nosocomial Influenza
Authors: Adal Karim A. , Flowers Richard H. , Anglim Anne M. , Hayden Frederick G. , Titus Maureen G. , Coyner Betty J. , Farr Barry M.
Published: May 2019

Objective:

To study compliance with preventive strategies at a university hospital during an outbreak of nosocomial influenza A during the winter of 1988, and the rates of vaccination of healthcare workers and of nosocomial influenza following changes in vaccine practices after the outbreak.

Design:

Retrospective review of employee health, hospital epidemiology, hospital computing, and clinical microbiology records.

Setting:

A university hospital.

Interventions:

Unvaccinated personnel with exposure within the previous 72 hours to an unisolated case of influenza were offered influenza vaccine and 14 days of amantadine hydrochloride prophylaxis. Personnel with exposure more than 72 hours before evaluation were offered vaccine. A mobile cart was introduced for vaccinating personnel after the 1988 outbreak.

Results:

An outbreak of influenza with 10 nosocomial cases occurred in 1988. Only 4% of exposed employees had been vaccinated previously and 23% of exposed, unvaccinated employees agreed to take vaccine, amantadine, or both. A mobile-cart vaccination program was instituted, and annual vaccination rates steadily increased from 26.3% in 1989 to 1990 to 38% in 1993 to 1994 (P<.0001). The relative frequency of documented cases of influenza in employees with symptoms of influenza decreased significantly during this period (P=.025), but nosocomial influenza rates among patients did not change significantly.

Conclusion:

A mobile-cart influenza vaccination program was associated with a significant increase in compliance among healthcare workers, but a majority still remained unvaccinated. The rate of nosocomial influenza among patients was not reduced by the modest increase in the vaccination rate, but influenza rates remained acceptably low, perhaps due to respiratory isolation of patients and furlough of employees with influenza.
Colonization byStaphylococcus AureusResistant to Methicillin and Ciprofloxacin During 20 Months' Surveillance in a Private Skilled Nursing Facility
Authors: Lee Yee-Lean , Gupta Geeta , Cesario Thomas , Lee Richard , Nothvogel Sandra , Nassar James , Flionis Leo , Thrupp Lauri
Published: May 2019

Objective:

To evaluate endemic colonization withStaphylococcus aureusresistant to methicillin, ciprofloxacin, or both among patients of a private skilled nursing facility, with regard to colonization rate and site, and relation to infection and prior antibiotic use.

Design:

Prospective quarterly culture surveillance of nares and rectal specimens over 20 months' observation.

Results:

The mean prevalence was 3.8% in new admissions and 5.4% for in-house patients; cumulatively, 7.5% of the patients were colonized during the study period. The colonization rate remained stable during the study period. Screening of rectal, as well as nares, specimens detected substantially more colonized patients than would have been detected by nasal cultures alone. Five to seven percent of the colonized patients developed later infection with methicillin-ciprofloxacin-resistantS aureus. Colonized patients did not differ significantly from the noncolonized group in prior use of quinolones, but the colonized group was exposed significantly more frequently to other antibiotics than the noncolonized group. Eighty-three percent of methicillin-resistantS aureus(MRSA) isolated from infections and 89% from colonization were also ciprofloxacin resistant.

Conclusion:

Although all infecting and most colonizing isolates of MRSA were resistant to quinolones, the overall rate of colonization remained low and stable despite the continued use of quinolones. The findings suggest that good infection control practice has prevented broader spread of such strains in this facility.
Monitoring Persistence of Coagulase-Negative Staphylococci in a Hematology Department Using Phenotypic and Genotypic Strategies
Authors: van Belkum Alex , Kluijtmans Jan , van Leeuwen Willem , Goessens Wil , ter Averst Ellen , Wielenga Jenne , Verbrugh Henri
Published: May 2019

Objective:

To determine persistence of coagulase-negative staphylococci (CNS) on a hematology-oncology ward and to determine the value of phenotypic and genotypic procedures for establishing clonality among CNS isolates.

Design:

Strains of CNS isolated from bacteremic patients (n=139) were typed by biochemical reactivity, antibiotic susceptibility, DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE), and arbitrary primed polymerase chain reaction (AP PCR). Coagulase-negative staphylococci were subgrouped in a random collection (n=20) used for the evaluation of the typing procedures and a collection of 119 CNS isolates from hematologic patients displaying multiple bacteremic episodes.

Results:

Analysis of the reference collection demonstrated the usefulness of the DNA typing procedures, indicating that AP PCR and PFGE can be used for epidemiologic typing of CNS in a concordant fashion. Certain strains appeared to be permanent colonizers of the hematology ward or ward-related personnel. In individual patients, persistent colonization by a single type was demonstrated. However, a number of patients also experienced bacteremic episodes caused by CNS belonging to different types.

Conclusion:

We conclude that monitoring of CNS infections on a hematology ward by various genotypic techniques provides insight into nosocomial epidemiology and elucidates the complexity of the infections taking place. DNA typing is preferred over phenotypic procedures and can identify persistent CNS strains in a given location.
Plasmid Analysis of 26 Staphylococcal Species by a Rapid Microscale Technique
Authors: Herchline Thomas , Maher William
Published: May 2019

Objective:

Evaluate a plasmid typing technique for a diverse group of staphylococci.

Design:

In vitro testing on known isolates.

Setting:

University hospital.

Intervention:

The plasmid content of 195 isolates representing 26 staphylococcal species was analyzed by agarose gel electrophoresis following lysostaphin-alkaline-SDS lysis, with and without acetone treatment.

Results:

Isolates yielded plasmid profiles with 0 to 7 extra-chromosomal bands (median, 1; 1.5); 171 (88%) had a profile with at least 1 band. Species with more than one isolate available for testing showed considerable diversity of plasmid profiles, except forStaphylococcus haemolyticus.

Conclusions:

The ease of the procedure and the diversity of plasmid profiles within each species examined suggests that plasmid profiling is an accessible and useful epidemiologic tool applicable to most staphylococcal species by epidemiologic units or clinical laboratories.
Prevention and Control of Varicella-Zoster Infections in Healthcare Facilities
Authors: Weber David J. , Rutala William A. , Hamilton Holli
Published: May 2019

Varicella-zoster virus (VZV) is the causative agent of two diseases: varicella (chickenpox) and zoster (shingles). Although varicella generally is a mild disease in children, serious morbidity and mortality are common if infection occurs in neonates, pregnant women, adults, or immunocompromised patients. For this reason, the Centers for Disease Control and Prevention recommends that all the hospitals institute control measures. Healthcare workers should be screened for VZV immunity and, if susceptible, should receive the recently licensed Oka/Merck vaccine (unless contraindicated). This article reviews nosocomial outbreaks associated with VZV and provides detailed algorithms for preexposure immunization and postexposure management of healthcare workers exposed to VZV.
Development of Mupirocin Resistance Among Methicillin-ResistantStaphylococcus aureusAfter Widespread Use of Nasal Mupirocin Ointment
Authors: Miller Mark A. , Dascal Andre , Portnoy Joseph , Mendelson Jack
Published: May 2019

All methicillin-resistantStaphylococcus aureus(MRSA) strains isolated from colonized or infected patients in a 625-bed public teaching hospital during an epidemic, and for 3 years thereafter, underwent susceptibility testing to mupirocin. Mupirocin resistance among MRSA increased markedly over this period (1990, 2.7%; 1991, 8.0%; 1992, 61.5%; 1993, 65%) in association with increased use of mupirocin ointment as an adjunct to infection control measures.
Bladder Management and Urinary Tract Infections in Danish Hospitals, Nursing Homes, and Home Care: A National Prevalence Study
Authors: Zimakoff Jette , Stickler David J. , Pontoppidan Birgitte , Larsen Severin O.
Published: May 2019

Objective:

To establish the prevalence of urinary tract infection in patients undergoing various forms of bladder management.

Design:

A nationwide descriptive point-prevalence survey with logistic regression analysis of the data relating infection to bladder management.

Setting:

Fifteen hospitals, 21 nursing homes, and 13 home care districts throughout Denmark.

Patients:

Information was collected on 3,665 patients. On the day of the study, 349 patients had indwelling catheters and 1,150 were using external urine drainage systems (condoms or diapers) for bladder management.

Results:

The prevalence of urinary tract infections in catheterized patients and those using external drainage systems was 13.2% and 8.1%, respectively. The prevalence of hospital-acquired urinary tract infection (4.2%) had not changed from that reported in 1978. The proportion of these infections related to the indwelling catheter, however, had reduced from 66% to 30%. Logistic regression analysis confirmed that, when corrected for the patient-related confounders (female gender, age >60 years, incontinence, immobility, and stay in hospital for longer than 15 days), condoms (odds ratio [OR], 5.94; 95% confidence interval [CI95], 2.8 to 12.5), indwelling catheters (OR, 3.3; CI95, 2.3 to 4.8), and diapers (OR, 1.5; CI95, 1.1 to 2.1) were significantly (P<.001, P<.001, and P=.008, respectively) related to infection.

Conclusions:

Prevalence surveys have revealed that over the period 1978 to 1991, during which efforts have been made to restrict the use of indwelling catheters and to encourage the care of catheterized patients according to guidelines recommended by the Danish National Centre for Hospital Hygiene, the percentage of hospital-acquired urinary tract infections associated with indwelling catheters has been halved. External urine drainage systems, however, have emerged as significant risk factors for urinary tract infection.
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: May 2019

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.
Nosocomial Infection Caused by Antibiotic-Resistant Organisms in the Intensive-Care Unit
Authors: Flaherty John P. , Weinstein Robert A.
Published: May 2019

Resistance to antimicrobial agents is an evolving process, driven by the selective pressure of heavy antibiotic use in individuals living in close proximity to others. The intensive care unit (ICU), crowded with debilitated patients who are receiving broad-spectrum antibiotics and being cared for by busy physicians, nurses, and technicians, serves as an ideal environment for the emergence of antibiotic resistance. Problem pathogens presently include multiply resistant gram-negative bacilli, methicillin-resistantStaphylococcus aureus, and the recently emerged vancomycin-resistant enterococci. The prevention of antimicrobial resistance in ICUs should focus on recognition via routine unit-based sur veillance, improved compliance with handwashing and barrier precautions, and antibiotic-use policies tailored to individual units within hospitals.
Quantitative Epidemiology
Authors: Freeman Jonathan
Published: May 2019

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: May 2019

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.
Emerging Infectious Diseases in the Institutional Setting: Another Hot Zone
Authors: Ostroff Stephen M.
Published: May 2019

During the closing years of the 20th century, there has been an unprecedented number of newly recognized infectious agents and a resurgence of infectious diseases only recently thought to be conquered. These problems have been compounded by the increasing number of pathogens that have evolved resistance to antimicrobial agents. Hospitals and other institutional settings occupy a pivotal niche in the emergence of infectious agents due to factors such as the large concentrations of ill and immunocompromised persons, evolving technologies in healthcare settings, routine breeches of host defense mechanisms, and frequent use of antimicrobial agents. Any comprehensive strategy to address emerging infectious diseases must incorporate provisions for healthcare settings, including efforts to enhance surveillance, response capacity, training, education, applied research, and routine implementation of prevention measures.
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: May 2019

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.
Methicillin-ResistantStaphylococcus aureusControl in Hospitals: The Dutch Experience
Authors: Vandenbroucke-Grauls C.M.J.E.
Published: May 2019

The Netherlands is one of the few countries where methi-cillin-resistantStaphylococcus aureus(MRSA) still is uncommon. In 1988, the Werkgroep Infectie Preventie (Working Party on Infection Prevention) issued guidelines on the control of MRSA that could be applied nationwide. The mainstay of the guideline is that all patients who carry MRSA are strictly isolated in single rooms. In 1989, a surveillance study was started by the National Institute of Public Health and the Environment. This study showed that approximately 200 new cases of MRSA colonization or infection occur each year. Small outbreaks of MRSA occur occasionally in The Netherlands, but the surveillance data confirm the success of the Dutch policy.
Host-Bacteria Interactions in Foreign Body Infections
Authors: François Patrice , Vaudaux Pierre , Foster Timothy J. , Lew Daniel P.
Published: May 2019

Persistent staphylococcal infections are a major medical problem, especially when they occur on implanted materials or intravascular catheters. This review describes some of the recently discovered molecular mechanisms ofStaphylococcus aureusattachment to host proteins coating biomedical implants. These interactions involve specific surface proteins, called bacterial adhesins, that recognize specific domains of host proteins deposited on indwelling devices, such as fibronectin, fibrinogen, or fibrin. Elucidation of molecular mechanisms ofS aureusadhesion to the different host proteins may lead to the development of specific inhibitors blocking attachment ofS aureus, which may decrease the risk of bacterial colonization of indwelling devices.
How to Limit the Spread of Creutzfeldt-Jakob Disease
Authors: Dormont Dominique
Published: May 2019

Transmissible spongiform encephalopathies are rare lethal diseases induced in humans and animals by unconventional agents called transmissible spongiform encephalopathy agents (TSEAs), virions, or prions. Several cases of iatrogenic Creutzfeldt-Jakob disease (CJD) have been reported in the literature after neuro-surgery, treatment with pituitary-derived hormones, corneal grafting, and use of dura mater lyophilisates. In a given infected individual, TSEA-associated infectiousness depends on the nature of the organ: the central nervous system has the highest infectiousness, spleen and lymph nodes a medium infectiousness, and organs such as bone, skin, or skeletal muscles do not harbor any detectable infectiousness in experimental models. Transmissible spongiform encephalopathy/prions have unconventional properties; in particular, they resist almost all the chemical and physical processes that inactivate conventional viruses. Therefore, prevention of CJD agent transmission must be taken into account in daily hospital practice. Efficient sterilization procedures should be determined. In tissue and blood donation, donors with a neurologic history must be excluded, and patients treated with pituitary-derived hormones should be considered potentially infected with TSEA and excluded.
Operative Precautions in HIV and Other Bloodborne Virus Diseases
Authors: Raahave Dennis
Published: May 2019

Mathematical means have suggested that the surgical team is at particular risk of acquiring HIV (or other bloodborne viruses) from a source patient. To reduce this risk, it is mandatory to avoid accidental injuries during operative procedures. The surgeon must handle tissues with instruments and must minimize finger use. Sharp instruments should be passed through a neutral zone to ensure that the surgeon and nurse do not touch the same instrument at the same time. Instruments should not be handled blindly, but instead should be accompanied by eye and verbal contact. We find these changes in surgical technique are necessary for present and future generations of surgeons.
AIDS, Emergency Operations, and Infection Control
Authors: Wittmann Mark Matthias , Wittmann Annemarei , Wittmann Dietmar H.
Published: May 2019

Acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) may turn out to be the largest lethal epidemic of infection ever. The estimated global number of HIV-infected adults in 1993 was 13 million, with projections of up to 40 million by the year 2000. Human immunodeficiency virus infections and AIDS are relevant to surgeons with respect to the surgical management of AIDS patients in general, the treatment of the increasingly long list of surgical complications specific to AIDS patients in particular, and the risks of patient-to-surgeon and surgeon-to-patient HIV transmission. Because of migration of individuals and populations throughout the world, even surgeons practicing in relatively unaffected regions should be familiar with the potential surgical implications of AIDS. Ethical considerations arise, as well. Are surgeons obliged to operate on HIV-positive or AIDS patients? Some surgeons adhere strictly to the Hippocratic Oath, whereas others reserve the right to be selective on whom they operate, except in emergencies. Other common ethical considerations in the AIDS patient are similar to those arising in the terminal cancer case: whether to operate or not; whether to provide advanced support such as total parenteral nutrition or hemodialysis. Answers are not simple and require close collaboration between the surgeon, the AIDS specialist, and involved members of other specialties. Emergency operations become necessary to treat AIDS independent disease such as acute cholecystitis and appendicitis or AIDS-related life-threatening conditions such as gastrointestinal bleeding, obstruction, perforation, or ischemia complicating Kaposi's sarcoma, lymphoma, and cytomegalovirus or disseminated nontuberculous mycobacterial infections. Delays and errors in diagnosis are frequent. Poor nutritional state with weight loss, low serum albumin, and leukocyte count prevails in most patients requiring emergency operations and account for a high mortality. By applying solid judgment and selecting management appropriately, the surgeon has the ability to prolong life and to improve the quality of life for these unfortunate patients, and to do so with extremely minimal risk to himself and his team.
Prevention of Fungal Infections in Hematology Patients
Authors: Philpott-Howard John
Published: May 2019

Endogenous infections such as candidiasis can be minimized by oral fluconazole prophylaxis, although oral or intravenous amphotericin, or itraconazole, are suitable for certain patients. Exogenous fungal infections most commonly are transmitted by the airborne route, but the benefits of high-efficiency particulate air-filtered room air probably are diminishing as broad-spectrum prophylaxis againstAspergillusspecies and other fungi improves. However, high-risk environmental sources such as construction work always must be avoided near neutropenic patients. Reactivation of quiescent pulmonaryAspergillusinfection can be prevented by surgical resection during remission, or by systemic amphotericin prophylaxis during subsequent neutropenic episodes.
Epidemiology, Diagnosis, and Therapy of Fungal Infections in Surgery
Authors: Giamarellou Helen , Antoniadou Anastasia
Published: May 2019

Over the past decade, the incidence of hospital-acquired bloodstream infections caused byCandidastrains has risen, while the implicated species have changed.Candida tropicalis, Candida parapsilosis, andCandida glabrataall have increased in incidence. Data from the Centers for Disease Control and Prevention reveal that, between 1980 and 1990,Candidaemerged as the sixth most common nosocomial pathogen (7.2.%) and was the fourth most common pathogen in nosocomial bloodstream infections, surpassed only by coagulase-negative staphylococci,Staphylococcus aureus, and enterococci. The incidence of candidemia is dramatically higher in high-risk critical-care units: 25% of cases occur in surgical intensive-care units (ICUs) versus 25% in bone marrow transplantation units, 20% in medical ICUs, 20% in general medical wards, and 10% in oncology-hematology units. Burns and gastrointestinal surgery predispose to nosocomial candidemia. Independent risk factors include prior therapy with multiple antibiotics, isolation ofCandidafrom sites other than blood, and prior hemodialysis. Crude mortality exceeds 55% and is associated with older age and concomitant renal failure, hepatic failure, acute respiratory diseases, or postoperative shock. In addition to extreme vigilance for early recognition ofCandidasepsis in critically ill surgical patients, the high risk for candidemia probably necessitates fungal surveillance cultures and initiation of preemptive antifungal therapy in high-risk surgical patients.
Implementation and Evaluation of an Algorithm for Isolation of Patients With Suspected Pulmonary Tuberculosis
Authors: Pegues Clare F. , Johnson Douglas C. , Pegues David A. , Spencer Maureen , Hopkins Cyrus C.
Published: May 2019

Objective: To implement and evaluate an algorithm designed to assist in the consistent placement of patients with suspected pulmonary tuberculosis into negative-pressure isolation rooms (NPIRs).

Design: A standard algorithm was designed for the appropriate room placement of patients with suspected pulmonary tuberculosis using clinical, radiographic, and laboratory criteria and reported risk factors. A case-patient was defined as an inpatient who had at least one Mycobacterium tuberculosis culture-positive respiratory specimen from January 1, 1993, through December 31, 1994. Demographic, clinical, laboratory, case contact, and isolation and room placement data were collected prospectively on all case-patients.

Setting: A 900-bed university teaching and referral center.

Results: During 1993 and 1994, 69 patients were evaluated for possible pulmonary tuberculosis, and 31 case-patients were identified. Of the 31 case-patients, 26 (84%) were placed on respiratory isolation in NPIRs, including 19 (61%) who were isolated within 24 hours of admission (1993, 14 of 20 [70%]; 1994, 5 of 11 [45%]). Seven case-patients (23%) were isolated in NPIRs following delays that ranged from 2 to 31 days (median, 9 days), and five case-patients (16%) never were isolated during admissions of from 3 to 28 days (median, 4 days). These 12 case-patients contributed a total of 136 patient-exposure days during their hospitalizations. Misclassification of patient risk status by user error delayed isolation of five (42%) of the 12 improperly isolated case-patients.

Conclusions: The use of an algorithm incorporating radiographic, laboratory, and clinical criteria and reported risk factors may assist in the rapid isolation of patients with suspected pulmonary tuberculosis.