bluuebunny/crossref_metadata_2025_split huggingface dataset:
How Many Nosocomial Infections are Associated with Cross-Transmission? A Prospective Cohort Study in A Surgical Intensive Care Unit
Authors: Weist Klaus , Pollege Kathrin , Schulz Ines , Rüden Henning , Gastmeier Petra 
Published: February 2006

Objective:To determine the percentage of cross-transmissions in an intensive care unit (ICU) with high nosocomial infection (NI) rates according to the data of the German Nosocomial Infection Surveillance System.Setting:A 14-bed surgical ICU of a 1,300-bed, tertiary-care teaching hospital.Method:Prospective surveillance of NIs during a period of 9 months. If an NI was present, the isolates of the following indicator pathogens were stored and typed by species:Staphylococcus aureus, Enterococcus species, Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacterspecies. Pulsed-field gel electrophoresis was performed for typing ofS. aureusstrains and arbitrarily primed polymerase chain reaction was applied for the other pathogens. The presence of two indistinguishable strains in two patients was considered as one episode of cross-transmission.Results:Two hundred sixty-two patients were observed during a period of 2,444 patient-days; 96 NIs were identified in 59 patients and the overall incidence density of NI was 39.3 per 1,000 patient-days. For 104 isolates, it was possible to consider typing results. Altogether, 36 cross-transmissions have lead to NIs in other patients. That means at least 37.5% of all NIs identified were due to cross-transmissions.Conclusion:Because of the method of this study, the percentage of NIs due to cross-transmission identified for this ICU is an “at least number”. In reality, the number of cross-transmissions, and thus the number of avoidable infections, may have been even higher. However, it is difficult to assess whether the percentage of NIs due to cross-transmission determined for this ICU may be the crucial explanation for the relatively high infection rate in comparison to other surgical ICUs.
The Role of Nurse Understaffing in Nosocomial Viral Gastrointestinal Infections on a General Pediatrics Ward
Authors: Stegenga Jacob , Bell Erica , Matlow Anne 
Published: February 2006

Objective:To examine the relationship between nurse staffing levels and the rate of nosocomial viral gastrointestinal infections (NVGIs) in a general pediatrics population.Design:Retrospective descriptive study.Setting:A general pediatrics ward at The Hospital for Sick Children in Toronto, Ontario, Canada, a 320-bed, tertiary-care pediatric institution.Results:Forty-three NVGIs were detected in 37 patients of 2,929 admissions (1.3%). The monthly NVGI rate correlated significantly with the monthly night patient-to-nurse ratio (r = 0.56) and the monthly day patient-to-nurse ratio (r = 0.50). The nursing hours per patient-day during the preinfection period (PIP) were significantly lower than those during the nonpreinfection period (NPIP; 12.5 vs 13.0). There was no difference between the PIP and the NPIP day patient-to-nurse ratios (3.31 vs 3.32), but there was a significant difference between the PIP and the NPIP night patient-to-nurse ratios (3.26 vs 3.16). The incidence of NVGIs in the 72-hour period after any day when the nursing hours per patient-day were less than 10.5 was 6.39 infections per 1,000 patient-days, compared with 2.17 infections per 1,000 patient-days in periods with more than 10.5 nursing hours per patient-day (rate ratio, 2.94; 95% confidence interval, 2.16 to 4.01).Conclusion:Nurse understaffing contributed to an increased NVGI rate in our general pediatrics population, and should be assessed as a risk factor in outbreak investigations.
Preventing Nosocomial Transmission of Pulmonary Tuberculosis: When may Isolation be Discontinued for Patients with Suspected Tuberculosis?
Authors: Siddiqui Anwer H. , Perl Trish M. , Conlon Martha , Donegan Nancy , Roghmann Mary-Claire 
Published: February 2006

Objective:The Centers for Disease Control and Prevention and the American Thoracic Society recommend obtaining cultures of at least three sputum specimens for acid-fast bacilli (AFB) from patients in whom tuberculosis (TB) is suspected. On the basis of this, most hospitals isolate patients with suspected TB for 3 days or more until three smear (not culture) results are negative. Our objective was to evaluate the predictive value and sensitivity of these smears.Design:Observational study.Setting:Four urban medical centers.Methods:The posttest probability of TB given sequential negative AFB smears from 274 patients isolated for suspected TB and the sensitivity of sequential AFB smears from 209 patients with positive results on culture for pulmonary TB were measured.Results:The posttest probabilities of having TB given one, two, and three negative AFB smears were low: 1.1% (3 of 265; 95% confidence interval [CI95], 0.23% to 3.27%), 0.4% (1 of 262; CI95, 0% to 2.1%), and 0% (0 of 260; CI95, 0% to 1.4%), respectively. Among the 209 patients with positive results on culture for pulmonary TB, 169 (81%) had an expectorated sputum specimen sent, of which 91 (54%) were positive for AFB. Forty (24%) of the 169 patients had a second expectorated sputum specimen sent after the results of the first specimen were negative; only 6 (15%) of these had positive AFB smears. None of the 10 patients in whom the first two expectorated sputum samples yielded an AFB smear without an organism had a third AFB smear that was positive.Conclusion:Unless there is high clinical suspicion of pulmonary TB in a specific patient, the use of three AFB smears on expectorated sputa is a rational approach to discontinuing isolation for patients with suspected TB.
The Use of Heteroduplex Analysis of Polymerase Chain Reaction Products to Support the Possible Transmission ofLegionella pneumophilaFrom a Malfunctioning Automobile Air Conditioner
Authors: Pinar Ahmet , Ramirez Julio A. , Schindler Laura L. , Miller Richard D. , Summersgill James T. 
Published: February 2006

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

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

Objective:To study the extent to which selection bias poses problems for estimating the attributable cost of deep chest surgical-site infection (SSI) following coronary artery bypass graft (CABG) surgery.Design:Reanalysis of a prospective case–control study.Setting:A large, Midwestern community medical center.Patients:Cases were all patients who had an SSI (N = 41) following CABG and CABG and valve surgery between April 1996 and March 1998. Controls were every tenth uninfected patient (N = 160).Methods:Estimates of the attributable cost of deep chest SSI were computed using unmatched comparison, matched comparison, linear regression, and Heckman's two-stage approach.Results:The attributable cost of deep chest SSI was estimated to be $20,012 by unmatched comparison, $19,579 by matched comparison, $20,103 by linear regression, and $14,211 by Heckman's two-stage method. Controlling for selection bias substantially reduced the cost estimate, but the coefficient capturing selection bias was not statistically significant.Conclusions:Deep chest SSI significantly increases the cost of care for patients who undergo CABG surgery. Unmatched comparison, matched comparison, and linear regression estimated the attributable cost to be approximately $20,000. Although controlling for selection bias with Heckman's two-stage method resulted in a substantially smaller estimate, the coefficient for selection bias was not statistically significant, suggesting that the estimates derived from the other models should be acceptable. However, the magnitude of the difference between the models shows that the effect of selection bias can be substantial. Some exploration for selection bias is recommended when estimating the attributable cost of SSIs.
The Impact of Surgical-Site Infections Following Orthopedic Surgery at a Community Hospital and a University Hospital Adverse Quality of Life, Excess Length of Stay, and Extra Cost
Authors: Whitehouse James D. , Friedman N. Deborah , Kirkland Kathryn B. , Richardson William J. , Sexton Daniel J. 
Published: February 2006

Objective:To measure the impact of orthopedic surgical-site infections (SSIs) on quality of life, length of hospitalization, and cost.Design:A pairwise-matched (1:1) case-control study within a cohort.Setting:A tertiary-care university medical center and a community hospital.Patients:Cases of orthopedic SSIs were prospectively identified by infection control professionals. Matched controls were selected from the entire cohort of patients undergoing orthopedic surgery who did not have an SSI. Matching variables included type of surgical procedure, National Nosocomial Infections Surveillance risk index, age, date of surgery, and surgeon.Main Outcome Measures:Quality of life, duration of postoperative hospital stay, frequency of hospital readmission, overall direct medical costs, and mortality rate.Results:Fifty-nine SSIs were identified. Each orthopedic SSI accounted for a median of 1 extra day of stay during the initial hospitalization (P= .001) and a median of 14 extra days of hospitalization during the follow-up period (P= .0001). Patients with SSI required more rehospitalizations (median, 2 vs 1;P= .0001) and more total surgical procedures (median, 2 vs 1;P= .0001). The median total direct cost of hospitalizations per infected patient was $24,344, compared with $6,636 per uninfected patient (P= .0001). Mortality rates were similar for cases and controls. Quality of life was adversely affected for patients with SSI. The largest decrements in scores on the Medical Outcome Study Short Form 36 questionnaire were seen in the physical functioning and role-physical domains.Conclusions:Orthopedic SSIs prolong total hospital stays by a median of 2 weeks per patient, approximately double rehospitalization rates, and increase healthcare costs by more than 300%. Moreover, patients with orthopedic SSIs have substantially greater physical limitations and significant reductions in their health-related quality of life.
Hospital-Acquired, Laboratory-Confirmed Bloodstream Infection: Increased Hospital Stay and Direct Costs
Authors: Orsi Giovanni Battista , Stefano Lidia Di , Noah Norman 
Published: February 2006

Objectives:To determine increased hospital stay and direct costs attributable to hospital-acquired, laboratory-confirmed bloodstream infection (BSI), and to evaluate the matching variable length of stay (LOS).Design:Retrospective (historical) cohort study with 1:2 matching in intensive care units and surgical wards.Setting:A 2,000-bed university hospital in Rome, Italy.Patients:All patients admitted between January 1994 and June 1995 who had hospital-acquired, laboratory-confirmed BSI were considered cases; all others were eligible as controls.Methods:Two controls (A and B) were selected per case in a stepwise fashion. Controls in group A were selected according to the following six criteria: ward, gender, age, diagnosis, central venous catheter, and LOS equal to the interval from admission to infection in a matched case ± 20% (LOS ± 20%). Controls in group B were selected according to the first five criteria, but excluded LOS ± 20%.Results:One hundred five of 108 patients were each matched with two controls. The matching appropriateness score was greater than 90%. With the use of controls in groups A and B, the case-fatality rates attributable to hospital-acquired, laboratory-confirmed BSI were 35.2% and 40.9%, respectively; the estimated risk ratios for death were 2.60 and 3.52 (P = .0001), respectively. The increased hospital stay per case attributable to hospital-acquired, laboratory-confirmed BSI was 19.1 (mean) and 13.0 (median) days for matched pairs in control group A and 19.9 (mean) and 15.0 (median) days for matched pairs in control group B. With controls in group A, the cost of increased hospital stay per patient attributable to hospital-acquired, laboratory-confirmed BSI was Euro 15,413. The additional cost per patient due to treatment was Euro 943, making the overall direct cost Euro 16,356 per case.Conclusions:This study should make it possible to estimate the cost of hospital-acquired, laboratory-confirmed BSI in most hospitals after adjusting for incidence rate. It also confirmed the use of LOS ± 20% as a matching variable to limit overestimation of increased hospital stay. To our knowledge, this is among the first such studies in Europe.
Duration of Colonization with Vancomycin-ResistantEnterococcus
Authors: Byers Karin E. , Anglim Anne M. , Anneski Cynthia J. , Farr Barry M. 
Published: February 2006

Objective:To determine the duration of colonization with vancomycin-resistantEnterococcus(VRE) and the adequacy of 3 consecutive negative cultures to determine clearance.Design:Retrospective cohort study.Setting:A university hospital.Population:Patients identified by perirectal cultures as VRE carriers who had follow-up cultures.Methods:Follow-up perirectal cultures were collected in inpatient and outpatient settings, at least 1 week apart, when patients were not receiving antibiotics with activity against VRE. The likelihood of culture positivity was analyzed given prior culture results and time from the initial positive culture.Results:A total of 116 patients colonized with VRE had 423 follow-up cultures, a mean of 204 days (range, 4 to 709 days) after their initial isolate. The first follow-up culture, collected a mean of 125 days after the initial positive isolate, was negative in 64%. After 1 negative follow-up culture, the next one was negative in 92% of the patients. After 2 negative cultures, 95% remained culture-negative. After 3 sequential negative cultures, 35 (95%) of 37 patients remained culture-negative. As the interval between the initial and the follow-up isolates increased, the probability that a subsequent culture would be positive decreased (P< .001, chi square for trend). Prolonged hospitalization, intensive care, and antibiotic use each decreased the likelihood of clearing VRE.Conclusion:These data support the Centers for Disease Control and Prevention criterion of 3 sequential negative cultures, at least 1 week apart, to remove patients from VRE isolation. Nevertheless, this may reflect a decrease in the quantity of VRE to an undetectable level and these patients should be observed for relapse, especially when re-treated with antibiotics.
Prevalence of Measles Antibody Among Young Adult Healthcare Workers in a Cancer Hospital: 1980s Versus 1998–1999
Authors: Seo Susan K. , Malak Sharp F. , Lim Suzanne , Eagan Janet , Sepkowitz Kent A. 
Published: February 2006

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

AbstractInhalation of contaminated aerosols is considered the most common route ofLegionellatransmission. The aim of this study was to determine whether contact with water contaminated byLegionellawas related to oropharyngeal colonization in immunosuppressed patients. Eighty-five oropharyngeal swabs (April 1996 to June 1996) were seeded on selective and nonselective buffered charcoal-yeast extract media.Legionellawas not isolated.
A note on non-existence results for semi-linear cooperative elliptic systems via moving spheres
Authors: Zou Henghui 
Published: February 2006

In this note, we extend some earlier non-existence, monotonicity and one-dimensionality results of W. Reichel and the author, by replacing the local Lipschitz continuity hypothesis on the non-linearities by a so-called boundedly uniform Lipschitz condition in the magnitude of

u

\mathbf {u}

.
Effects of cognitive abilities on metapopulation connectivity
Authors: Vuilleumier Séverine , Perrin Nicolas 
Published: February 2006

Connectivity among demes in a metapopulation depends on both the landscape's and the focal organism's properties (including its mobility and cognitive abilities). Using individual‐based simulations, we contrast the consequences of three different cognitive strategies on several measures of metapopulation connectivity. Model animals search suitable habitat patches while dispersing through a model landscape made of cells varying in size, shape, attractiveness and friction. In the blind strategy, the next cell is chosen randomly among the adjacent ones. In the near‐sighted strategy, the choice depends on the relative attractiveness of these adjacent cells. In the far‐ sighted strategy, animals may additionally target suitable patches that appear within their perceptual range.Simulations show that the blind strategy provides the best overall connectivity, and results in balanced dispersal. The near‐sighted strategy traps animals into corridors that reduce the number of potential targets, thereby fragmenting metapopulations in several local clusters of demes, and inducing sink–source dynamics. This sort of local trapping is somewhat prevented in the far‐sighted strategy. The colonization success of strategies depends highly on initial energy reserves: blind does best when energy is high, near‐sighted wins at intermediate levels, and far‐sighted outcompetes its rivals at low energy reserves.We also expect strong effects in terms of metapopulation genetics: the blind strategy generates a migrant‐pool mode of dispersal that should erase local structures. By contrast, near‐ and far‐sighted strategies generate a propagule‐pool mode of dispersal and source–sink behavior that should boost structures (high genetic variance among‐ and low variance within local clusters of demes), particularly if metapopulation dynamics is also affected by extinction–colonization processes.Our results thus point to important effects of the cognitive ability of dispersers on the connectivity, dynamics and genetics of metapopulations.
Seeing the trees for the leaves – oaks as mosaics for a host‐specific moth
Authors: Roslin Tomas , Gripenberg Sofia , Salminen Juha‐Pekka , Karonen Maarit , B. O'Hara Robert , Pihlaja Kalevi , Pulkkinen Pertti 
Published: February 2006

From the perspective of a specialist herbivore, how homogenous are individual tree crowns as patches of habitat? We partitioned variation in physical and chemical host leaf traits and in the abundance and performance of a specialist oak leaf miner, Tischeria ekebladella, into variation at different hierarchical levels. For the phenolic contents of the leaves, we examined variation among oak stands, among trees within stands and among branches within trees. For leaf size and water content, we assessed variation among trees within a single stand, among shoots within trees, and among leaves within shoots. For moth abundance and performance, we examined variation across all levels: among oak stands, among trees within stands, among branches within trees, among shoots within branches and among leaves and insect individuals.For measures of phenolic contents, we found little variation among stands but substantial variation among individual trees. Yet, a tree particularly rich in a given compound was often comparatively poor in another. At a finer spatial scale, the phenolic composition of individual parts of a single tree was quite consistent, whereas leaf weight and water content varied widely within individual tree crowns. Moth abundances varied more among shoots within branches than at any other spatial level, whereas moth survival showed equal levels of variation within individual shoots as among separate oak stands. Likewise, for four other measures of larval performance (assessed at the level of trees and lower), we found more variation within than between trees.In conclusion, the large variation observed in the performance of a specialist moth and in the physical traits of the leaves among different parts of single tree crowns refutes the image of an oak tree as an ‘island’ of internally homogeneous quality. Hence, we may expect little evolutionary adaptation of T. ekebladella at the scale of individual trees. The moths may instead evolve to behaviourally select their resource at a very fine scale. Large variation within trees also calls for extensive replication within trees in ecological sampling designs and/or the sampling of maximally similar leaves.
Review article: the role of acid suppression in patients with non‐erosive reflux disease or functional heartburn
Authors: DEVAULT K. R. 
Published: February 2006

SummaryWhen patients with the typical reflux symptoms of heartburn, regurgitation, or both, undergo endoscopy, up to 75% will not have endoscopic oesophagitis or evidence of Barrett's oesophagus. These patients have been described as having endoscopic negative or, more commonly, non‐erosive reflux disease (NERD).Patients without oesophagitis, but with a positive pH test, can be diagnosed with gastro‐oesophageal reflux disease (GERD). Some experts also consider a response to proton pump inhibitor therapy as proof of GERD in a patient with the correct symptoms and a negative endoscopy.Patients with normal acid exposure, but who report symptoms with a majority of their reflux episodes documented during an ambulatory pH study, have also been considered to have NERD, although others have labelled them as having ‘functional heartburn’.Finally, there are some patients who have reflux symptoms and respond to reflux therapy, but have no demonstrable reflux by either endoscopy or ambulatory reflux testing. Whether these patients are part of the GERD spectrum or have another diagnosis is not clear.It seems that the most widely used definition of functional disease (the Rome II criteria) would include these patients as having functional heartburn, as it was defined as ‘greater than or equal to 12 weeks of either continuous or intermittent symptoms of burning retrosternal discomfort or pain without pathologic GERD, achalasia, or other motility disorders with a recognized pathologic basis’.This article reviews potential differences in pathophysiology between erosive oesophagitis and NERD; explores whether symptoms can help distinguish NERD patients from erosive oesophagitis patients; and explores the evaluation and therapy of these patients.