Changes in healthcare-associated Staphylococcus aureus bloodstream infections after the introduction of a national hand hygiene initiative

Background. Interventions that prevent healthcare-associated infection should lead to fewer deaths and shorter hospital stays. Cleaning hands (with soap or alcohol) is an effective way to prevent the transmission of organisms, but rates of compliance with hand hygiene are sometimes disappointingly low. The National Hand Hygiene Initiative in Australia aimed to improve hand hygiene compliance among healthcare workers, with the goal of reducing rates of healthcare-associated infection. Methods. We examined whether the introduction of the National Hand Hygiene Initiative was associated with a change in infection rates. Monthly infection rates for healthcare-associated Staphylococcus aureus bloodstream infections were examined in 38 Australian hospitals across 6 states. We used Poisson regression and examined 12 possible patterns of change, with the best fitting pattern chosen using the Akaike information criterion. Monthly bed-days were included to control for increased hospital use over time. Results. The National Hand Hygiene Initiative was associated with a reduction in infection rates in 4 of the 6 states studied. Two states showed an immediate reduction in rates of 17% and 28%, 2 states showed a linear decrease in rates of 8% and 11% per year, and 2 showed no change in infection rates. Conclusions. The intervention was associated with reduced infection rates in most states. The failure in 2 states may have been because those states already had effective initiatives before the national initiative’s introduction or because infection rates were already low and could not be further reduced.

Changes in healthcare-associated infections after the introduction of a national hand hygiene initiative

Introduction: Interventions that prevent healthcare-associated infections should lead to fewer deaths and shorter hospital stays. Cleaning hands with soap and water or alcohol rub is an effectiveway to prevent the transmission of organisms, but compliance is sometimes low. The National Hand Hygiene Initiative in Australia aimed to improve hand hygiene compliance among healthcare workers, with the goal of reducing rates of healthcare-associated infections. Methods: We examined if the introduction of the National Hand Hygiene Initiative was associated with a change in infection rates. Monthly infection rates for six types of healthcare-associated infections were examined in 38 Australian hospitals across six states. Infection categories were: bloodstream infections, centralline associated bloodstream infections, methicillin-resistant and methicillin-sensitive Staphylococcus aureus, Staphylococcus aureus bacteraemia and surgical site infections. Results: The National Hand Hygiene Initiative was associated with a statistically significant reduction in infection rates in 11 out of 23 state and infection combinations studied. There was no change in infection rates for nine combinations, and there was an increase in three infection rates in South Australia. Conclusions: The intervention was associated with reduced infection rates in many cases. The lack of improvement in nine cases may have been because they already had effective initiatives before the national initiative’s introduction.

Dementia and the population health approach: Promise, pitfalls and progress. An Australian perspective

The increasing prevalence of dementia in Australia (and worldwide) over the next few decades poses enormous social, health and economic challenges. In the absence of a cure, strategies to prevent, delay the onset of, or reduce the impact of dementia are required to contain a growing disease burden, and health and care costs. A population health approach has the potential to substantially reduce the impact of dementia. Internationally, many countries have started to adopt population health strategies that incorporate elements of dementia prevention. The authors examine some of the elements of such an approach and barriers to its implementation. International dementia frameworks and strategies were reviewed to identify options utilized for a population health approach to dementia. Internationally and nationally, dementia frameworks are being developed that include population health approaches. Most of the frameworks identified included early diagnosis and intervention, and increasing community awareness as key objectives, while several included promotion of the links between a healthy lifestyle and reduced risk for dementia. A poor evidence base (especially for illness prevention), diagnostic and technical limitations, and policy and implementation issues are significant barriers in maximizing the promise of population health approaches in this area. The review and analysis of the population health approach to dementia will inform national and jurisdictional policy development.

Costing the Australian National Hand Hygiene Initiative

Background The Australian National Hand Hygiene Initiative (NHHI) is a major patient safety programme co-ordinated by Hand Hygiene Australia (HHA) and funded by the Australian Commission for Safety and Quality in Health Care. The annual costs of running this programme need to be understood to know the cost-effectiveness of a decision to sustain it as part of health services. Aim To estimate the annual health services cost of running the NHHI; the set-up costs are excluded. Methods A health services perspective was adopted for the costing and collected data from the 50 largest public hospitals in Australia that implemented the initiative, covering all states and territories. The costs of HHA, the costs to the state-level infection-prevention groups, the costs incurred by each acute hospital, and the costs for additional alcohol-based hand rub are all included. Findings The programme cost AU$5.56 million each year (US$5.76, £3.63 million). Most of the cost is incurred at the hospital level (65%) and arose from the extra time taken for auditing hand hygiene compliance and doing education and training. On average, each infection control practitioner spent 5 h per week on the NHHI, and the running cost per annum to their hospital was approximately AU$120,000 in 2012 (US$124,000, £78,000). Conclusion Good estimates of the total costs of this programme are fundamental to understanding the cost-effectiveness of implementing the NHHI. This paper reports transparent costing methods, and the results include their uncertainty.

A comparison of stocking methods for beef production in northern Australia: pasture and soil surface condition responses

Historical stocking methods of continuous, season-long grazing of pastures with little account of growing conditions have caused some degradation within grazed landscapes in northern Australia. Alternative stocking methods have been implemented to address this degradation and raise the productivity and profitability of the principal livestock, cattle. Because information comparing stocking methods is limited, an evaluation was undertaken to quantify the effects of stocking methods on pastures, soils and grazing capacity. The approach was to monitor existing stocking methods on nine commercial beef properties in north and south Queensland. Environments included native and exotic pastures and eucalypt (lighter soil) and brigalow (heavier soil) land types. Breeding and growing cattle were grazed under each method. The owners/managers, formally trained in pasture and grazing management, made all management decisions affecting the study sites. Three stocking methods were compared: continuous (with rest), extensive rotation and intensive rotation (commonly referred to as 'cell grazing'). There were two or three stocking methods examined on each property: in total 21 methods (seven continuous, six extensive rotations and eight intensive rotations) were monitored over 74 paddocks, between 2006 and 2009. Pasture and soil surface measurements were made in the autumns of 2006, 2007 and 2009, while the paddock grazing was analysed from property records for the period from 2006 to 2009. The first 2 years had drought conditions (rainfall average 3.4 decile) but were followed by 2 years of above-average rainfall. There were no consistent differences between stocking methods across all sites over the 4 years for herbage mass, plant species composition, total and litter cover, or landscape function analysis (LFA) indices. There were large responses to rainfall in the last 2 years with mean herbage mass in the autumn increasing from 1970 kg DM ha(-1) in 2006-07 to 3830 kg DM ha(-1) in 2009. Over the same period, ground and litter cover and LFA indices increased. Across all sites and 4 years, mean grazing capacity was similar for the three stocking methods. There were, however, significant differences in grazing capacity between stocking methods at four sites but these differences were not consistent between stocking methods or sites. Both the continuous and intensive rotation methods supported the highest average annual grazing capacity at different sites. The results suggest that cattle producers can obtain similar ecological responses and carry similar numbers of livestock under any of the three stocking methods.

Eutrophication and the management of planktonic algae: What Vollenweider couldn't tell us

The ”Vollenweider model” is a sophisticated mathematical statement about the long-range behaviour of (mainly temperate) lakes and their ability to support phytoplankton chlorophyll. Misapplication of the model, against which Vollenweider himself warned, has led to many misconceptions about the dynamics of plankton in lakes and reservoirs and about how best to manage systems subject to eutrophication. This contribution intends to frame the most important issues in context of the phosphorus- loading and phosphorus-limitation concepts. Emphasis is placed on the need to distinguish rate-limitation from capacity-limitation, to understand which is more manageable and why, to discern the mechanisms of internal recycling and their importance, and to appreciate the respective roles of physical and biotic components in local control of algal dynamics. Some general approaches to the management of water quality in lakes and reservoirs to eutrophication are outlined.

The impact of physical processes on algal growth

Mixing and transport processes in surface waters strongly influence the structure of aquatic ecosystems. The impact of mixing on algal growth is species-dependent, affecting the competition among species and acting as a selective factor for the composition of the biocoenose. Were it not for the ever-changing ”aquatic weather”, the composition of pelagic ecosystems would be relatively simple. Probably just a few optimally adapted algal species would survive in a given water-body. In contrast to terrestrial ecosystems, in which the spatial heterogeneity is primarily responsible for the abundance of niches, in aquatic systems (especially in the pelagic zone) the niches are provided by the temporal structure of physical processes. The latter are discussed in terms of the relative sizes of physical versus biological time-scales. The relevant time-scales of mixing and transport cover the range between seconds and years. Correspondingly, their influence on growth of algae is based on different mechanisms: rapid changes are relevant for the fast biological processes such as nutrient uptake and photosynthesis, and the slower changes are relevant for the less dynamic processes such as growth, respiration, mineralization, and settling of algal cells. Mixing time-scales are combined with a dynamic model of photosynthesis to demonstrate their influence on algal growth.

The predicting power of models for eutrophication

Restoration of water-bodies from eutrophication has proved to be extremely difficult. Mathematical models have been used extensively to provide guidance for management decisions. The aim of this paper is to elucidate important problems of using models for predicting environmental changes. First, the necessity for a proper uncertainty assessment of the model, upon calibration, has not been widely recognized. Predictions must not be a single time trajectory; they should be a band, expressing system uncertainty and natural variability. Availability of this information may alter the decision to be taken. Second, even with well-calibrated models, there is no guarantee they will give correct projections in situations where the model is used to predict the effects of measures designed to bring the system into an entirely different ”operating point”, as is typically the case in eutrophication abatement. The concept of educated speculation is introduced to partially overcome this difficulty. Lake Veluwe is used as a case to illustrate the point. Third, as questions become more detailed, such as ”what about expected algal composition”, there is a greater probability of running into fundamental problems that are associated with predicting the behaviour of complex non-linear systems. Some of these systems show extreme initial condition sensitivity and even, perhaps, chaotic behaviour, and are therefore fundamentally unpredictable.

The scope for biomanipulation in improving water quality

Biomanipulation is a form of biological engineering in which organisms are selectively removed or encouraged to alleviate the symptoms of eutrophication. Most examples involve fish and grazer zooplankton though mussels have also been used. The technique involves continuous management in many deeper lakes and is not a substitute for nutrient control. In some lakes, alterations to the lake environment have given longer-term positive effects. And in some shallow lakes, biomanipulation may be essential, alongside nutrient control, in re- establishing former aquatic-plant-dominated ecosystems which have been lost through severe eutrophication. The emergence of biomanipulation techniques emphasises that lake systems are not simply chemical reactors which respond simply to engineered chemical changes, but very complex and still very imperfectly understood ecosystems which require a yet profounder understanding before they can be restored with certainty.

The control of indirect effects of biomanipulation

Results from long-term investigations on biomanipulation show that indirect effects are at least as important as direct effects are for the stability of biomanipulation. Three types of indirect effects can be distinguished: (1) a change in quantity or quality of the resource base, (2) behavioural change of the prey, and (3) development of anti-predator traits. Although indirect effects of type (2), (e.g. a change in the pattern of vertical migration of zooplankton), and type (3), (e.g. development of helmets and neck teeth in Daphnia), are important mechanisms, the most essential indirect effects regarding biomanipulation belong to type (1). An example of the latter will be demonstrated: the complex of indirect effects of enhanced grazing by large herbivores on the phosphorus metabolism of the lake. It is concluded that control of the indirect effects is absolutely necessary to stabilize biomanipulation measures, but this is much more difficult than the control of direct effects and needs deeper insights into the structuring mechanisms of food webs. Proper management of fish stocks, in combination with the control of phosphorus load and/or the physical conditions, seems to be the most promising way of controlling the indirect effects of biomanipulation.

The significance of sedimentation and sediments to phytoplankton growth in drinking-water reservoirs

In the mesotrophic-eutrophic Saidenbach Reservoir in Saxony, the nanoplankton and cyanobacteria have increased at the expense of diatom dominance, due to a doubling of the external phosphorus load in the last 15 years. However, the phosphorus sedimentation flux is still very high (up to 80% of the input), corresponding to more than 2 g m2 d-1 in terms of dry weight. There is a strong correlation between the abundance of diatoms in the euphotic zone and their sedimentation flux (with a delay of about 2 weeks). Only about 25% of the deposited material could be clearly attributed to plankton biomass; the remainder resulted from flocculation and precipitation processes or directly from the inflow of clay minerals. The ash content of the deposited material was high (73%). Thus the sedimentation flux can be considered to operate as an internal water-treatment/oligotrophication process within the lake. The neighbouring Neunzehnhain Reservoir still has a very clear water with a transparency up to 18 m depth. Though the sediment was not much lower than Saidenbach sediment in total phosphorus and total numbers of bacteria, sulphide was always absent and the ratio of Fe 2+ to Fe 3+ was very low in the upper (0- 5 cm) layer. Thus the external and internal phosphorus loads do not attain the critical level necessary to induce a ”phosphorus - phytoplankton” feedback loop.

A Glorious Work in the World : Welsh Methodism and the International Evangelical Revival, 1735-1750

Jones, David, A Glorious Work in the World: Welsh Methodism and the International Evangelical Revival, 1735-1750 (Cardiff: University of Wales Press, 2004), pp.xiv+386 RAE2008

Electrical methods of controlling bacterial adhesion and biofilm on device surfaces.

This review will summarize the significant body of research within the field of electrical methods of controlling the growth of microorganisms. We examine the progress from early work using current to kill bacteria in static fluids to more realistic treatment scenarios such as flow-through systems designed to imitate the human urinary tract. Additionally, the electrical enhancement of biocide and antibiotic efficacy will be examined alongside recent innovations including the biological applications of acoustic energy systems to prevent bacterial surface adherence. Particular attention will be paid to the electrical engineering aspects of previous work, such as electrode composition, quantitative electrical parameters and the conductive medium used. Scrutiny of published systems from an electrical engineering perspective will help to facilitate improved understanding of the methods, devices and mechanisms that have been effective in controlling bacteria, as well as providing insights and strategies to improve the performance of such systems and develop the next generation of antimicrobial bioelectric materials.

A New Analysis of Mars "Special Regions": Findings of the Second MEPAG Special Regions Science Analysis Group (SR-SAG2)

A committee of the Mars Exploration Program Analysis Group (MEPAG) has reviewed and updated the description of Special Regions on Mars as places where terrestrial organisms might replicate (per the COSPAR Planetary Protection Policy). This review and update was conducted by an international team (SR-SAG2) drawn from both the biological science and Mars exploration communities, focused on understanding when and where Special Regions could occur. The study applied recently available data about martian environments and about terrestrial organisms, building on a previous analysis of Mars Special Regions (2006) undertaken by a similar team. Since then, a new body of highly relevant information has been generated from the Mars Reconnaissance Orbiter (launched in 2005) and Phoenix (2007) and data from Mars Express and the twin Mars Exploration Rovers (all 2003). Results have also been gleaned from the Mars Science Laboratory (launched in 2011). In addition to Mars data, there is a considerable body of new data regarding the known environmental limits to life on Earth—including the potential for terrestrial microbial life to survive and replicate under martian environmental conditions. The SR-SAG2 analysis has included an examination of new Mars models relevant to natural environmental variation in water activity and temperature; a review and reconsideration of the current parameters used to define Special Regions; and updated maps and descriptions of the martian environments recommended for treatment as “Uncertain” or “Special” as natural features or those potentially formed by the influence of future landed spacecraft. Significant changes in our knowledge of the capabilities of terrestrial organisms and the existence of possibly habitable martian environments have led to a new appreciation of where Mars Special Regions may be identified and protected. The SR-SAG also considered the impact of Special Regions on potential future human missions to Mars, both as locations of potential resources and as places that should not be inadvertently contaminated by human activity. Key Words: Martian environments—Mars astrobiology—Extreme environment microbiology—Planetary protection—Exploration resources. Astrobiology 14, 887–968.

Effect of high temperature, biaxial stretching on the thermal and mechanical properties of HDPE/MWCNT sheet

High density polyethylene (HDPE)/multi-walled carbon nanotube (MWCNT) composites containing 4 wt% MWCNTs were prepared by melt mixing followed by compression moulding into sheet. Compression moulded sheets were heated to just below the melting temperature and biaxially stretched at ratios (SRs) of 2, 2.5 and 3.0. The effect of stretching on the thermal and mechanical properties of the sheet was studied by differential scanning calorimetry (DSC) and tensile testing. DSC results show that the crystallinity of all the stretched samples increases by approximately 13% due to strain induced crystallization. The melting temperature of the biaxially stretched samples increases only slightly while crystallization temperature is not affected. Tensile test results indicate that at a SR of 2.5 the elastic modulus of the stretched composites increases by 17.6% relative to the virgin HDPE, but the breaking strength decreases by 33%. While the elastic modulus and breaking strength of the HDPE/MWCNT samples continue to increase as SR increases they drop off after a SR of 2.5 for the virgin HDPE. This is probably due to the constraining influence of the nanotubes preventing the relaxation of polymer chains caused by adiabatic heating at high SRs. The addition of MWCNTs results in significant strain hardening during deformation. While this will lead to increased energy requirement in forming it will also result in a more stable process and the ability to produce deep draw containers with more uniform wall thickness