Hand hygiene compliance in nursing home wards: the effect of increased accessibility of alcohol-based hand rub

BACKGROUND

Elderly nursing home residents are vulnerable to infection from micro-organisms. Hand hygiene is considered one of the most important measures to prevent transmission.

AIM

To determine the effect of increased accessibility to alcohol-based hand rub (ABHR) in nursing home wards by monitoring hand hygiene compliance (HHC) among healthcare workers (HCWs).

METHODS

An 11-month intervention study was conducted in a Danish six-ward nursing home. Data were collected using an automatic hand hygiene monitoring system (AHHMS). After a baseline period, one extra ABHR dispenser was placed in each of the 150 apartments. Baseline HHC was compared with the HHC during an immediate intervention period and a long-term intervention period.

FINDINGS

A total of 159 HCWs were included. The AHHMS registered 341,078 hand hygiene opportunities. Overall baseline HHC was 31% (95% confidence interval: 30-32). A significant +18% absolute immediate effect (first five months) (95% CI: 17-19; P < 0.0001) and +13 percentage points (95% CI: 11-14; P < 0.0001) long-term effect (another four months) were recorded. HCWs working day shifts and short-term employees had a higher baseline HHC than HCWs working evening/night shifts. However, HCWs working night shifts achieved the greatest long-term effect with a mean +27 percentage point difference (P < 0.0001).

CONCLUSION

Placing an additional ABHR dispenser strategically within staff workflow significantly increased HHC among HCWs, demonstrating a noteworthy effect. The study is the first to report the effect on nursing home dispenser accessibility as a single intervention and to show a significant unmet potential.

Automated measurement of malaria parasitaemia among asymptomatic blood donors in Malawi using the Sysmex XN-31 analyser: could such data be used to complement national malaria surveillance in real time?

BACKGROUND

The recent worldwide increase in malaria cases highlights the need for renewed efforts to eliminate malaria. The World Health Organization advocates that malaria surveillance becomes a core intervention. Current methods to estimate the malaria burden rely on clinical malaria case reports and surveys of asymptomatic parasite infection mainly from children  < 5 years. In this study the hypothesis was that screening blood donors for malaria parasites would provide real-time information on the asymptomatic reservoir of parasites in the adult population and mirror other surveillance data.

METHODS

This study was conducted in Malawi, a high malaria burden country, at the Malawi Blood Transfusion Service, which collects blood units at donation sites countrywide. A secondary analysis was conducted on data obtained from a prior Sysmex XN-31 analyser malaria diagnostic evaluation study utilizing residual donor blood samples. XN-31 malaria results, donor age, sex, geographical location, and collection date, were analysed using standard statistical methods.

RESULTS

The malaria parasite prevalence in blood donors was 11.6% (614/5281 samples) increasing seasonally from December (8.6%) to April (18.3%). The median age was 21 years and 45.9% of donors were from urban areas, which showed a lower prevalence compared to non-urban regions. The Central administrative region had the highest and the Northern region the lowest malaria parasite prevalence. The donors were predominantly male (80.2%), 13.1% of whom had malaria parasites, which was significantly higher (p < 0.0001) than for female donors (7.4%). Multivariable logistic regression analysis showed that age, location, and collection month were significant predictors of malaria positivity in males, whereas in females only location was significant. There was no gender difference in parasite density nor gametocyte carriage.

CONCLUSIONS

This study demonstrates the powerful utility of screening blood donors for malaria parasites using the XN-31, which not only improves the safety of blood transfusion, but provides valuable complementary surveillance data for malaria control, especially targeting males, who are generally excluded from periodic household surveys. Blood donations are sourced countrywide, year-round, and thus provide dynamic, real-time information on the malaria burden. Furthermore, the XN-31 identifies the asymptomatic human reservoir of infectious gametocytes, which must be targeted to eliminate malaria.

A method comparison study of the high throughput automated HISCL® SARS-CoV-2 antigen assay using nasopharyngeal swab samples from symptomatic and asymptomatic subjects against conventional RT-PCR

Our study aim was to evaluate the performance of the automated Sysmex HISCL® severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) antigen assay against reverse‐transcription polymerase chain reaction (RT‐PCR). We tested 277 remnant frozen nasopharyngeal swab samples, stored in universal transport medium (UTM), yielding a sensitivity of 94.9% against historical RT‐PCR results with cycle threshold (C_t) < 30, and a sensitivity of 76.7% for C_t < 35, and specificity of 100% (all C_t values) confirming compatibility of UTM‐diluted samples with the assay system. Thereafter, we prospectively collected 141 nasopharyngeal swab samples in UTM from healthcare workers and 1369 paired swabs (400 UTM; 969 dry) from individuals at a public health testing center, with the first swab (UTM) reserved for RT‐PCR, yielding a positivity rate of 4.6%. HISCL assay performance using UTM swabs was superior to dry swabs, with a sensitivity of 100% (95% confidence interval [CI] 71.5%–100%) at C_t < 30 versus 92.3% (95%CI 81.5%–97.9%), and a specificity of 99.3% (95% CI 98.1–99.89) against 83.3% (95%CI 80.7%–85.6%). We conclude that this antigen assay is suitable for high throughput facilities where the primary indication for testing is to rule out infection with low RT‐PCR C_t values (proxy for high viral loads) to curb viral spread.

Evaluation of the Sysmex XN-31 automated analyser for blood donor malaria screening at Malawi Blood Transfusion Services

Background and Objectives

Balancing blood supply safety and sufficiency is challenging in malaria‐endemic countries where the risk of transfusion‐transmitted malaria (TTM) is ever‐present. In support of reducing this risk, our study aimed at evaluating the performance of the Sysmex XN‐31 analyser in blood donor malaria screening, as compared with current practice in Malawi.

Materials and Methods

This prospective observational study was conducted on remnant venous donor blood samples collected at Malawi Blood Transfusion Service donation sites countrywide for routine blood‐borne pathogen screening. XN‐31 results were compared with routine thick smear malaria microscopy, using expert microscopy (phase 1 and 2) plus qualitative malaria polymerase chain reaction (PCR) (phase 2) to adjudicate discrepancies.

Results

XN‐31 detected malaria in 614 (11.6%) of 5281 study samples compared with 341 (6.5%) for routine microscopy. Of the 273 discrepant samples, 60 smears (phase 1) could not be retrieved for expert microscopic review. Expert microscopy confirmed the XN‐31 positivity in 78.8% (149/189) and 91.7% (22/24) of discrepant samples in phase 1 (n = 4416) and phase 2 (n = 975), respectively, with two cases requiring PCR testing, confirming one each as positive and negative, giving sensitivities of 100% and 75% and specificities of 99.9% and 100%, respectively, for XN‐31 and routine microscopy.

Conclusion

The automated Sysmex XN‐31 analyser's high sensitivity and specificity, ability to detect all Plasmodium species and high throughput with rapid turnaround‐time, overcomes many of the limitations of currently available diagnostic tests, making it well‐suited for malaria screening of donated blood in malaria‐endemic countries in support of TTM risk reduction.

A novel haemocytometric COVID-19 prognostic score developed and validated in an observational multicentre European hospital-based study

COVID-19 induces haemocytometric changes. Complete blood count changes, including new cell activation parameters, from 982 confirmed COVID-19 adult patients from 11 European hospitals were retrospectively analysed for distinctive patterns based on age, gender, clinical severity, symptom duration, and hospital days. The observed haemocytometric patterns formed the basis to develop a multi-haemocytometric-parameter prognostic score to predict, during the first three days after presentation, which patients will recover without ventilation or deteriorate within a two-week timeframe, needing intensive care or with fatal outcome. The prognostic score, with ROC curve AUC at baseline of 0.753 (95% CI 0.723-0.781) increasing to 0.875 (95% CI 0.806-0.926) on day 3, was superior to any individual parameter at distinguishing between clinical severity. Findings were confirmed in a validation cohort. Aim is that the score and haemocytometry results are simultaneously provided by analyser software, enabling wide applicability of the score as haemocytometry is commonly requested in COVID-19 patients.

Idiopathic esophagopathies resembling gastroesophageal reflux disease in dogs

ObjectivePathologic gastroesophageal reflux (GER) has been demonstrated experimentally in dogs, and it is suspected to occur naturally in dogs, yet its clinical significance is unknown. The aim of the study was to demonstrate clinical indicators of pathologic GER in dogs with idiopathic esophagopathies. Materials and methods: Dogs with clinical signs suggestive for esophageal disease (regurgitation, ptyalism, or dysphagia) and where extraesophageal and specific esophageal diseases had been ruled out, were retrospectively diagnosed with idiopathic esophagopathies. History, physical examination findings, clinicopathologic, radiographic, and endoscopic data, and treatment results were obtained from medical records, reviewed and evaluated. Results: Out of 67 dogs with anamnestic esophageal signs, 12 (17.4%) dogs were identified as having idiopathic esophagopathies and were included in the study. Median age was 3.0 years (range 1.0–11.0), and median bodyweight was 28.2 kg (range 8.2–44.0). The most frequent anamnestic esophageal signs were ptyalism (10/12 dogs), regurgitation (8/12 dogs), signs of discomfort, pain (8/12 dogs), and cough (5/12 dogs). The most common radiographic abnormality was segmental esophageal dilation (8/12 dogs). Esophagoscopy revealed single mucosal surface defects at the gastroesophageal junction in 3/12 dogs. In dogs with altered esophageal motility, cytological and microbiological examinations of bronchial aspirates showed goblet cell hyperplasia (8/8 dogs), neutrophilic infiltration (5/8 dogs) and culturable bacteria (4/8 dogs), respectively. All dogs were treated with omeprazole (median 0.7 mg/kg once per day, range 0.5-1.2). Reported median treatment duration until remission of the main clinical signs was 20.0 days (range 8.0–54.0 days). This endpoint was reached in 11/12 dogs. Conclusion and clinical relevance: Results suggest that in some dogs with esophageal clinical signs, and where no primary disease could be identified, clinical indicators of pathologic GER such as pain, mucosal lesions and motility disturbances of the esophagus, respiratory complications, and response to therapy can be observed.

Evaluation of the quality of endoscopically obtained esophageal biopsies in the dog

Objective: An important premise for obtaining diagnostically relevant histology specimens is an appropriate biopsy technique. Goal of this study was to determine if biopsies of adequate quality can be obtained from the canine esophagus at the gastro-esophageal junction (GEJ) during routine upper gastrointestinal endoscopy. Material and methods: Over the course of one year, 58 dogs undergoing upper gastrointestinal endoscopy because of the presence of esophageal (n = 22) or gastrointestinal (n = 36) clinical signs were prospectively included. Five biopsies were repeatedly collected from the same dorsal and ventral locations of the GEJ, fixated individually in 4% neutral buffered formaldehyde, and evaluated histopathologically after standard preparation and haematoxylin and eosin staining. The presence of esophageal squamous epithelium with a basal cell layer and lamina propria mucosae in conjunction with foveolar columnar epithelium and cardiac glands, and the absence of fundic glands in one specimen, respectively, was judged as an adequately sampled biopsy. Results: Adequately sampled biopsies were reported in 45 out of 58 dogs, with 31 samples originating from the dorsal GEJ, 36 samples originating from the ventral GEJ, and with 22 samples originating from both sites, respectively. The incidence of adequately sampled biopsies increased significantly over time (r = 0,22; p < 0,05), with these biopsies being reported significantly more often during the last 6 months compared to the first 6 months of the study (p = 0,03). Histopathological evaluation of the esophageal squamous epithelium showed fibrosis, inflammation, elongation of the stromal papillae, and increased thickness of the basal cell layers in 14 out of 58 dogs. Stromal papillae of the ventral esophageal epithelium were significantly elongated in dogs with esophageal clinical signs compared to dogs with gastrointestinal clinical signs (p = 0,03). Conclusion and clinical relevance: After an initial learning phase adequate esophageal biopsies from the GEJ can be obtained in canine patients undergoing upper gastrointestinal endoscopy, and histological lesions can be found in these biopsies.

Assessment of the histological quality of endoscopic biopsies obtained from the canine gastro-esophageal junction

Objective: In the dog biopsy samples from the gastro-esophageal junction (GEJ) are rarely obtained during routine gastroscopy. The aim of this pilot study was to assess the histological quality of endoscopic biopsies sampled from the canine esophagus and cardia. It was hypothesised that it is possible to sample adequate specimens from these sites.

Materials and methods: For this purpose 10 dogs with an indication for gastroscopy were enrolled in a prospective study. Biopsy samples were obtained with standard biopsy forceps for single use exactly from the GEJ thus containing preferably columnar epithelium from the cardia and squamous epithelium from the esophagus, respectively. In every dog the specimens were examined for size, layers and site, respectively. Study endpoint was reached when specimens originated from cardia and esophagus, showing at least epithelium and lamina propria mucosae, and a diameter > 2 mm on the slide, respectively.

Results: 72 biopsy specimens (median 7, range 5–10) obtained from the GEJ were examined in 10 dogs. Specimens from the esophagus containing squamous epithelium with lamina propria mucosae were found in 5 of 10 (50.0%) dogs. Specimens from the cardia containing columnar epithelium with lamina propria mucosae were found in 10 of 10 (100.0%) dogs. Four of 10 (40.0%), and 10 of 10 (100.0%) dogs showed at least one specimen > 2 mm on the slide originating from the esophagus, and from the cardia, respectively. Histological quality was found to be adequate in 4 of 10 (40.0%) dogs, showing specimens of adequate size, originating from both esophagus and cardia, and containing at least epithelium and lamina propria mucosae.

Conclusion and clinical relevance: The pilot study provides evidence that during routine gastroscopy it is possible to sample endoscopic biopsies from the cardia and with limitations from the esophagus showing a quality adequate for histological examination of the epithelium and the lamina propria mucosae.

[Determination of hyperregeneratory esophagopathy in dogs with clinical signs attributable to esophageal disease]

OBJECTIVE

It was hypothesized that typical characteristics of hyperregeneratory esophagopathy (HRE) in humans such as basal cell hyperplasia and elongation of stromal papillae are also histologically detectable in canine esophageal epithelium, and that these changes are associated with clinical signs and endoscopic findings suggesting gastroesophageal reflux (GER).

MATERIAL AND METHODS

Sixty-five adult dogs with clinical signs attributable to esophageal disease underwent esophagoscopy and biopsy. Clinical signs suggesting GER (regurgitation, ptyalism, painful discomfort) were prospectively evaluated through a questionnaire. Endoscopic mucosal alterations suggesting GER such as minimal endoscopic changes and obvious mucosal defects were assessed via video endoscopy. Biopsy specimens obtained from the esophageal squamous epithelium were evaluated histologically. The squamous epithelium's substructures of esophageal biopsies were quantitatively assessed through microscopic morphometry.

RESULTS

Esophageal squamous epithelium was considered normal in 48 dogs, and HRE was detected histologically in 17 dogs; both pathognomonic changes (basal cell hyperplasia, elongation of stromal papillae) were consistently present. Morphometrically assessed stromal papillary length and basal cell layer thickness was significantly (each, p < 0.0001) higher in the 17 dogs with HRE than in the 48 dogs without HRE, respectively. Overall, clinical signs suggesting GER were significantly (p = 0.02) more frequently encountered and regurgitation was significantly (p = 0.009) more common in the 17 dogs with HRE than in the 48 dogs without HRE. Similarly, endoscopic changes were significantly (p = 0.002) more frequently observed and minimal endoscopic changes suggesting GER were significantly (p = 0.004) more common in 17 dogs with HRE than in the 48 dogs without HRE.

CONCLUSION AND CLINICAL RELEVANCE

Typical characteristics of hyperregeneratory esophagopathy in humans are also histologically detectable in canine esophageal epithelium. Histological changes are associated with clinical signs and endoscopic findings suggesting GER.

Economic and environmental optimization of waste treatment

This article presents the new systems engineering optimization model, OptiWaste, which incorporates a life cycle assessment (LCA) methodology and captures important characteristics of waste management systems. As part of the optimization, the model identifies the most attractive waste management options. The model renders it possible to apply different optimization objectives such as minimizing costs or greenhouse gas emissions or to prioritize several objectives given different weights. A simple illustrative case is analysed, covering alternative treatments of one tonne of residual household waste: incineration of the full amount or sorting out organic waste for biogas production for either combined heat and power generation or as fuel in vehicles. The case study illustrates that the optimal solution depends on the objective and assumptions regarding the background system--illustrated with different assumptions regarding displaced electricity production. The article shows that it is feasible to combine LCA methodology with optimization. Furthermore, it highlights the need for including the integrated waste and energy system into the model.

Future waste treatment and energy systems--examples of joint scenarios

Development and use of scenarios for large interdisciplinary projects is a complicated task. This article provides practical examples of how it has been carried out in two projects addressing waste management and energy issues respectively. Based on experiences from the two projects, recommendations are made for an approach concerning development of scenarios in projects dealing with both waste management and energy issues. Recommendations are given to develop and use overall scenarios for the project and leave room for sub-scenarios in parts of the project. Combining different types of scenarios is recommended, too, in order to adapt to the methods and tools of different disciplines, such as developing predictive scenarios with general equilibrium tools and analysing explorative scenarios with energy system analysis tools. Furthermore, as marginals identified in differing future background systems determine the outcomes of consequential life cycle assessments (LCAs), it is considered advisable to develop and use explorative external scenarios based on possible marginals as a framework for consequential LCAs. This approach is illustrated using an on-going Danish research project.

Challenges when performing economic optimization of waste treatment: a review

Strategic and operational decisions in waste management, in particular with respect to investments in new treatment facilities, are needed due to a number of factors, including continuously increasing amounts of waste, political demands for efficient utilization of waste resources, and the decommissioning of existing waste treatment facilities. Optimization models can assist in ensuring that these investment strategies are economically feasible. Various economic optimization models for waste treatment have been developed which focus on different parameters. Models focusing on transport are one example, but models focusing on energy production have also been developed, as well as models which take into account a plant's economies of scale, environmental impact, material recovery and social costs. Finally, models combining different criteria for the selection of waste treatment methods in multi-criteria analysis have been developed. A thorough updated review of the existing models is presented, and the main challenges and crucial parameters that need to be taken into account when assessing the economic performance of waste treatment alternatives are identified. The review article will assist both policy-makers and model-developers involved in assessing the economic performance of waste treatment alternatives.

Idiopathic esophagopathies resembling gastroesophageal reflux disease in dogs

OBJECTIVE

Pathologic gastroesophageal reflux (GER) has been demonstrated experimentally in dogs, and it is suspected to occur naturally in dogs, yet its clinical significance is unknown. The aim of the study was to demonstrate clinical indicators of pathologic GER in dogs with idiopathic esophagopathies.

MATERIALS AND METHODS

Dogs with clinical signs suggestive for esophageal disease (regurgitation, ptyalism, or dysphagia) and where extraesophageal and specific esophageal diseases had been ruled out, were retrospectively diagnosed with idiopathic esophagopathies. History, physical examination findings, clinicopathologic, radiographic, and endoscopic data, and treatment results were obtained from medical records, reviewed and evaluated.

RESULTS

Out of 67 dogs with anamnestic esophageal signs, 12 (17.4%) dogs were identified as having idiopathic esophagopathies and were included in the study. Median age was 3.0 years (range 1.0-11.0), and median bodyweight was 28.2 kg (range 8.2-44.0). The most frequent anamnestic esophageal signs were ptyalism (10/12 dogs), regurgitation (8/12 dogs), signs of discomfort, pain (8/12 dogs), and cough (5/12 dogs). The most common radiographic abnormality was segmental esophageal dilation (8/12 dogs). Esophagoscopy revealed single mucosal surface defects at the gastroesophageal junction in 3/12 dogs. In dogs with altered esophageal motility, cytological and microbiological examinations of bronchial aspirates showed goblet cell hyperplasia (8/8 dogs), neutrophilic infiltration (5/8 dogs) and culturable bacteria (4/8 dogs), respectively. All dogs were treated with omeprazole (median 0.7 mg/kg once per day, range 0.5-1.2). Reported median treatment duration until remission of the main clinical signs was 20.0 days (range 8.0-54.0 days). This endpoint was reached in 11/12 dogs.

CONCLUSION AND CLINICAL RELEVANCE

Results suggest that in some dogs with esophageal clinical signs, and where no primary disease could be identified, clinical indicators of pathologic GER such as pain, mucosal lesions and motility disturbances of the esophagus, respiratory complications, and response to therapy can be observed.

Evaluation of the quality of endoscopically obtained esophageal biopsies in the dog

OBJECTIVE

An important premise for obtaining diagnostically relevant histology specimens is an appropriate biopsy technique. Goal of this study was to determine if biopsies of adequate quality can be obtained from the canine esophagus at the gastro-esophageal junction (GEJ) during routine upper gastrointestinal endoscopy.

MATERIAL AND METHODS

Over the course of one year, 58 dogs undergoing upper gastrointestinal endoscopy because of the presence of esophageal (n = 22) or gastrointestinal (n = 36) clinical signs were prospectively included. Five biopsies were repeatedly collected from the same dorsal and ventral locations of the GEJ, fixated individually in 4% neutral buffered formaldehyde, and evaluated histopathologically after standard preparation and haematoxylin and eosin staining. The presence of esophageal squamous epithelium with a basal cell layer and lamina propria mucosae in conjunction with foveolar columnar epithelium and cardiac glands, and the absence of fundic glands in one specimen, respectively, was judged as an adequately sampled biopsy.

RESULTS

Adequately sampled biopsies were reported in 45 out of 58 dogs, with 31 samples originating from the dorsal GEJ, 36 samples originating from the ventral GEJ, and with 22 samples originating from both sites, respectively. The incidence of adequately sampled biopsies increased significantly over time (r = 0,22; p < 0,05), with these biopsies being reported significantly more often during the last 6 months compared to the first 6 months of the study (p = 0,03). Histopathological evaluation of the esophageal squamous epithelium showed fibrosis, inflammation, elongation of the stromal papillae, and increased thickness of the basal cell layers in 14 out of 58 dogs. Stromal papillae of the ventral esophageal epithelium were significantly elongated in dogs with esophageal clinical signs compared to dogs with gastrointestinal clinical signs (p = 0,03).

CONCLUSION AND CLINICAL RELEVANCE

After an initial learning phase adequate esophageal biopsies from the GEJ can be obtained in canine patients undergoing upper gastrointestinal endoscopy, and histological lesions can be found in these biopsies.

Assessment of the histological quality of endoscopic biopsies obtained from the canine gastro-esophageal junction

OBJECTIVE

In the dog biopsy samples from the gastro-esophageal junction (GEJ) are rarely obtained during routine gastroscopy. The aim of this pilot study was to assess the histological quality of endoscopic biopsies sampled from the canine esophagus and cardia. It was hypothesised that it is possible to sample adequate specimens from these sites.

MATERIALS AND METHODS

For this purpose 10 dogs with an indication for gastroscopy were enrolled in a prospective study. Biopsy samples were obtained with standard biopsy forceps for single use exactly from the GEJ thus containing preferably columnar epithelium from the cardia and squamous epithelium from the esophagus, respectively. In every dog the specimens were examined for size, layers and site, respectively. Study endpoint was reached when specimens originated from cardia and esophagus, showing at least epithelium and lamina propria mucosae, and a diameter >2mm on the slide, respectively.

RESULTS

72 biopsy specimens (median 7, range 5-10) obtained from the GEJ were examined in 10 dogs. Specimens from the esophagus containing squamous epithelium with lamina propria mucosae were found in 5 of 10 (50.0%) dogs. Specimens from the cardia containing columnar epithelium with lamina propria mucosae were found in 10 of 10 (100.0%) dogs. Four of 10 (40.0%), and 10 of 10 (100.0%) dogs showed at least one specimen >2mm on the slide originating from the esophagus, and from the cardia, respectively. Histological quality was found to be adequate in 4 of 10 (40.0%) dogs, showing specimens of adequate size, originating from both esophagus and cardia, and containing at least epithelium and lamina propria mucosae.

CONCLUSION AND CLINICAL RELEVANCE

The pilot study provides evidence that during routine gastroscopy it is possible to sample endoscopic biopsies from the cardia and with limitations from the esophagus showing a quality adequate for histological examination of the epithelium and the lamina propria mucosae.

Long-term affected energy production of waste to energy technologies identified by use of energy system analysis

Affected energy production is often decisive for the outcome of consequential life-cycle assessments when comparing the potential environmental impact of products or services. Affected energy production is however difficult to determine. In this article the future long-term affected energy production is identified by use of energy system analysis. The focus is on different uses of waste for energy production. The Waste-to-Energy technologies analysed include co-combustion of coal and waste, anaerobic digestion and thermal gasification. The analysis is based on optimization of both investments and production of electricity, district heating and bio-fuel in a future possible energy system in 2025 in the countries of the Northern European electricity market (Denmark, Norway, Sweden, Finland and Germany). Scenarios with different CO(2) quota costs are analysed. It is demonstrated that the waste incineration continues to treat the largest amount of waste. Investments in new waste incineration capacity may, however, be superseded by investments in new Waste-to-Energy technologies, particularly those utilising sorted fractions such as organic waste and refuse derived fuel. The changed use of waste proves to always affect a combination of technologies. What is affected varies among the different Waste-to-Energy technologies and is furthermore dependent on the CO(2) quota costs and on the geographical scope. The necessity for investments in flexibility measures varies with the different technologies such as storage of heat and waste as well as expansion of district heating networks. Finally, inflexible technologies such as nuclear power plants are shown to be affected.

The BEST study--a prospective study to compare business class versus economy class air travel as a cause of thrombosis

BACKGROUND

As many as 10% of airline passengers travelling without prophylaxis for long distances may develop a venous thrombosis. There is, however, no evidence that economy class travellers are at increased risk of thrombosis.

OBJECTIVES

A suitably powered prospective study, based on the incidence of deep-vein thrombosis (DVT) reported in previous studies on long-haul flights, was designed to determine the incidence of positive venous duplex scans and D-dimer elevations in low and intermediate-risk passengers, comparing passengers travelling in business and economy class.

PATIENTS/METHODS

Eight hundred and ninety-nine passengers were recruited (180 travelling business class and 719 travelling economy). D-dimers were measured before and after the flight. A value greater than 500 ng/ml was accepted as abnormal. A thrombophilia screen was conducted which included the factor V Leiden mutation, the prothombin 20210A mutation, protein C and S levels, antithrombin levels, and anticardiolipin antibodies immunoglobulin G (IgG) and immunoglobulin M (IgM). On arrival, lower limb compression ultrasonography of the deep veins was performed. Logistical regression analysis was used to determine the risk factors related to abnormally high D-dimer levels.

RESULTS

Only 434 subjects had a full venous duplex scan performed. None had ultrasonic evidence of venous thrombosis. Nine passengers tested at departure had elevated D-dimer levels and these volunteers were excluded from further study. Seventy-four of the 899 passengers had raised D-dimers on arrival. Twenty-two of 180 business class passengers (12%) developed elevated D-dimers compared with 52 of 719 economy class passengers (7%). There was no significant association between elevation of D-dimers and the class flown (odds ratio (OR) 0.61, p = 0.109). The factor V Leiden mutation, factor VIII levels and the use of aspirin were, however, associated with raised D-dimers (OR 3.36, p = 0.024; OR 1.01, p = 0.014; and OR 2.04, p = 0.038, respectively). Five hundred and five passengers were contacted within 6 months and none reported any symptoms of a clinical thrombosis or pulmonary embolus.

CONCLUSION

The incidence of ultrasonically proven DVT is much lower than previously reported. However, more than 10% of all passengers developed raised D-dimers, which were unrelated to the class flown. A rise in D-dimers is associated with an inherent risk of thrombosis and/or thrombophilia, demonstrates activation of both the coagulation and fibrinolytic systems during long-haul flights, and may indicate the development of small thrombi.

Nitrification and autotrophic denitrification of source-separated urine

In laboratory experiments, source-separated urine was stabilised with nitrification and denitrified via nitritation and anaerobic ammonium oxidation. The highest total ammonia concentration in the influent was 7,300 gN/m3, the maximum pH 9.2. In a moving bed biofilm reactor (MBBR) with Kaldnes biofilm carriers, we stabilised urine as a 1:1 ammonium nitrate solution. The maximum nitrification rate was 380 gN/m3/d corresponding to 1.7 gN/m2(biofilm)/d. Nitrite ammonium solutions were produced in a continuous flow stirred tank reactor (CSTR) with 4.8 days sludge retention time (SRT) at 30 degrees C and in a sequencing batch reactor (SBR) with more than 30 days SRT. Nitrate build-up was negligible in both reactors. Nitritation rates were 780 gN/m3/d in the CSTR and 280 gN/m3/d in the SBR, respectively. However, shortening the cycles would increase nitritation in the SBR. High concentrations of nitrous acid, salts, and presumably hydroxylamine suppressed nitrite oxidation in the nitritation reactors. In all three nitrification reactors, maximally 50% of the influent total ammonia was oxidised without pH control. None of the common inhibition or limitation approaches could explain why ammonia oxidation always stopped at pH values around 6. In a batch experiment, we showed that source-separated urine can be denitrified autotrophically by anammox bacteria.

[Initiation of lipid peroxidation (LPO) in blood during intraoperative mechanical autotransfusion--is hepatotoxicity of lipid peroxidation products of clinical significance?]

Machine autotransfusion using cell-saver is a well-established method of saving homologous blood during extensive surgical procedures. The processing of blood may induce the initiation of lipid peroxidation (LPO) with the release of hepatotoxic products. A series of 42 patients undergoing primary (n = 20) or revision (n = 22) hip arthroplasty comprised the study group. Patients received an average of 1,260 ml of autologous blood and 2.2 units of homologous packed cells. The concentration of thiobarbituric acid reactive substances (TBARS) as LPO metabolites was measured in the patients' plasma, in the autologous packed cells as well as in the supernatants of the cell-saver-processed blood. Additionally, parameters of iron metabolism, haemoglobin levels, haematocrit as well as the activities of so-called liver enzymes aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltranspeptidase and cholinesterase were determined. An initiation of LPO was detectable during the process of machine autotransfusion, but this took place mainly ex vivo. High concentrations of TBARS were detectable in the supernatants after cell-separation processing. We observed a decline in haemoglobin concentration and haematocrit during the perioperative period. Postoperatively, we found a significant iron deficiency as a consequence of the perioperative blood loss. There was not sufficient evidence of a postoperative liver disorder induced by toxic metabolites of LPO. To sum up, there is only a low contamination of the organism with LPO products during the process of machine autotransfusion. Therefore, an induction of liver damage seems to be improbable.

Low molecular weight heparin in the successful treatment of a spontaneous aortic thrombosis in a neonate

A successfully treated case of a spontaneous aortic thrombosis in a neonate is described as an illustration of the advantages of using low molecular weight heparin (LMWH) over unfractionated heparin (UFH) for anticoagulation therapy. A 5-day-old neonate presented with an abdominal aortic thrombosis detected by echocardiography. Intravenous UFH was commenced following thrombectomy. Poor venous access made monitoring the anticoagulation therapy problematic. Subcutaneous LMWH was substituted for UFH. It requires substantially less monitoring and no intravenous access, has fewer side effects, and allows for much earlier discharge from the hospital. Extensive investigation for a hypercoagulable state revealed no definite cause for the thrombus. The findings of homozygosity for a methylene tetrahydrofolate reductase (MTHFR) mutation and a mildly elevated homocysteine level are interesting but unlikely to account for the thrombotic event in this case. Anticoagulation with LMWH proved effective and more convenient than using UFH.

Development of an internal restriction control in the PCR detection of the prothrombin 20210A mutation

Detection of the presence of the 20210A/G allele in the human prothrombin gene is easily achieved by amplification using primers designed to span this region. The downstream primer creates a HindIII restriction site if the 20210A variant is present. A new forward upstream primer was designed to incorporate a naturally occurring HindIII site that, as it is present in both alleles, serves as an internal restriction control. Using this technique, the DNA of 292 unselected patients with venous thromboembolic disease was analysed. Of the 149 white patients, 4.7% were heterozygous for this mutation but none of the African Black patients were positive.

Development of an internal restriction control in the PCR detection of the methylenetetrahydrofolate reductase (MTHFR) C677T mutation

BACKGROUND

Detection of the presence of 677C/T allele in the human MTHFR gene is easily achieved by amplification using primers designed to span this region. Hinf I digestion, occurring only in the 677T allele, subsequently discriminates between the two alleles. Existing methods, however, do not control for failed restriction endonuclease digestion.

METHODS AND RESULTS

A new forward, modified primer was designed and placed further upstream to create a Hinf I site, which, because it is present in both alleles, would serve as an internal restriction control.

CONCLUSIONS

By allowing an additional restriction to take place in both the normal and mutated alleles, the use of the new primer provided for an internal restriction control.

Field evaluation of a novel haemoglobin measuring device designed for use in a rural setting

OBJECTIVE

To evaluate the use of a robust, cheap method for haemoglobin estimation by non-laboratory-trained personnel in a rural setting.

DESIGN

Comparative study.

SETTING

Tintswalo Hospital, Acornhoek.

PARTICIPANTS

7 nursing sisters, 4 medical students, 2 lay persons.

OUTCOME MEASURES

Haemoglobin estimates obtained with the colour scale were compared with the 'true Hb' values determined by the H x 3 Bayer-Technicon automated blood analyser.

RESULTS

Although individuals varied in their abilities to use the colour scale, its performance was generally very good when measured against automated haemoglobinometry, as determined by bias and regression analysis and also in terms of its capacity to detect anaemia, as measured by sensitivity, specificity and positive and negative predictive values.

CONCLUSIONS

Haemoglobin estimates obtained with the World Health Organisation colour scale are generally reliable, although cognisance should be taken of individual variability. While the utility of the device in monitoring response to therapy remains to be seen, it promises to be a suitable method for mass screening for anaemia.

[Specific immunotherapy of canine atopy. A prospective clinical study using tyrosine adsorbents]

It is reported about a non-randomized prospective study of the treatment of 17 atopic dogs over a nine-months-period using tyrosine-precipitated vaccines. All dogs were presented because of perennial atopic skin diseases at a practice for internal medicine between 1992 and 1995. The clinical degree of pruritus and dermatitis was controlled before, after three, six, and nine months of immunotherapy individually. After nine months of immunotherapy five dogs showed a reduction of the symptoms for more than 75%, six dogs for more than 50%, six dogs for less than 50%. Eleven (65%) dogs were classified as having been successfully treated, six (35%) showed poor clinical response. Tyrosine-precipitated vaccines were found to be helpful in the treatment of atopic skin diseases of the dog.

[Ctenocephalides canis and Ctenocephalides felis infestations of dogs and cats. Biology of the agent, epizootiology, pathogenesis, clinical signs, diagnosis and control]

A review is presented of the biology, epizootiology, pathogenesis, clinical features, diagnosis and treatment of canine and feline Ctenocephalides canis and C. felis infestation. Also data are given on the prevalence of fleas in dogs and cats during a year at the 1st Animal Medical Hospital, Munich Veterinary Faculty. 5.5% of the dogs and 18.9% of the cats were infested with fleas.

No increased incidence of postoperative sore throat after administration of suxamethonium in endotracheal anaesthesia

Sixty patients were divided into two groups (A and B) of 30 patients each to investigate the effect of using suxamethonium in endotracheal anaesthesia on the incidence of postoperative sore throat. The patients were anaesthetized with thiopentone, fentanyl, droperidol, N2O and pancuronium. Before endotracheal intubation with a Mallinckrodt lo-pro-tube, patients in Group A were given pancuronium, whereas patients in Group B were given suxamethonium. There was no difference in the incidence or severity of sore throat 20-30 h postoperatively between the two groups (P = 0.5). The type 2 error (beta) was low (the risk of overlooking a "true" difference in incidence of 0.20 was calculated to be 0.04). These results contradict those of a recent study, which demonstrated an increased incidence of postoperative sore throat following the use of suxamethonium in mask anaesthesia.