Foot and Mouth Epidemic Reduces Cases of Human Cryptosporidiosis in Scotland.

In Scotland, rates of cryptosporidiosis infection in humans peak during the spring, a peak that is coincident with the peak in rates of infection in farm animals (during lambing and calving time). Here we show that, during the outbreak of foot and mouth disease (FMD) in 2001, there was a significant reduction in human cases of cryptosporidiosis infection in southern Scotland, where FMD was present, whereas, in the rest of Scotland, there was a reduction in cases that was not significant. We associate the reduction in human cases of cryptosporidiosis infection with the reduction in the number of young farm animals, together with restrictions on movement of both farm animals and humans, during the outbreak of FMD in 2001. We further show that, during 2002, there was recovery in the rate of cryptosporidiosis infection in humans throughout Scotland, particularly in the FMD-infected area, but that rates of infection remained lower, though not significantly, than pre-2001 levels

Operationalising factors that explain the emergence of infectious diseases : A case study of the human campylobacteriosis epidemic

Peer reviewedPublisher PD

Stratigraphy of a Lateglacial lake basin sediment sequence at Turret Bank, upper Glen Roy, Lochaber: implications for the age of the Turret Fan

New lithostratigraphical, pollen-stratigraphical and tephrostratigraphical data are presented for a sediment sequence at Turret Bank, a site that lies close to the confluence of the River Turret with the River Roy in Lochaber, the western Scottish Highlands. The site is also adjacent to the inner margin of a major gravel fan, the Glen Turret Fan, the age of which has been debated and has a crucial bearing on the overall sequence of events in Glen Roy, especially concerning the maximum limit of Loch Lomond Readvance (Younger Dryas) ice. Several lines of evidence point to the sediment sequence at Turret bank having been wholly deposited during the Loch Lomond Stadial-early Holocene transition: (i) the pollen sequence is typical for this transitional period; (ii) varved deposits preserved in the sequence bear a strong resemblance to mid-Stadial varves in a regional master varve scheme for Glen Roy and vicinity (the Lochaber Master Varve Chronology); and (iii) an early Holocene tephra – the Askja-S Tephra – is preserved within the sequence. Some limitations with the new data are considered, but it is concluded that the coherent integration of lithostratigraphic, geomorphological, pollen-stratigraphical and tephrostratigraphical data point to the likelihood that Loch Lomond Readvance ice extended to the inner margin of the Glen Turret Fan, and that the fan was probably constructed by glacial meltwaters at this time

Potential for tree rings to reveal spatial patterns of past drought variability across western Australia

Proxy records have provided major insights into the variability of past climates over long timescales. However, for much of the Southern Hemisphere, the ability to identify spatial patterns of past climatic variability is constrained by the sparse distribution of proxy records. This is particularly true for mainland Australia, where relatively few proxy records are located. Here, we (1) assess the potential to use existing proxy records in the Australasian region—starting with the only two multi-century tree-ring proxies from mainland Australia—to reveal spatial patterns of past hydroclimatic variability across the western third of the continent, and (2) identify strategic locations to target for the development of new proxy records. We show that the two existing tree-ring records allow robust reconstructions of past hydroclimatic variability over spatially broad areas (i.e. > 3° × 3°) in inland north- and south-western Australia. Our results reveal synchronous periods of drought and wet conditions between the inland northern and southern regions of western Australia as well as a generally anti-phase relationship with hydroclimate in eastern Australia over the last two centuries. The inclusion of 174 tree-ring proxy records from Tasmania, New Zealand and Indonesia and a coral record from Queensland did not improve the reconstruction potential over western Australia. However, our findings suggest that the addition of relatively few new proxy records from key locations in western Australia that currently have low reconstruction skill will enable the development of a comprehensive drought atlas for the region, and provide a critical link to the drought atlases of monsoonal Asia and eastern Australia and New Zealand

An outbreak of Salmonella Saintpaul in a Scottish childcare facility: the influence of parental under-reporting

Background: Salmonella outbreaks in childcare facilities are relatively rare, most often occurring secondary to contaminated food products or poor infection control practices. We report an outbreak of Salmonella Saintpaul at a pre-school facility in Ayrshire, Scotland with atypical clinical and epidemiological features. Methods: Following notification of the initial two cases, the multi-disciplinary Incident Management Team initiated enhanced active case finding and two environmental inspections of the site, including food preparation areas. Parent and staff interviews were conducted by the Public Health department covering attendance, symptomatology and risk factors for all probable and confirmed cases. Microbiological testing of stool samples and the facility water tank was conducted. Whole Genome Sequencing (WGS) was performed for positive stool samples at the national reference laboratory. Infection control measures were introduced iteratively due to the atypical progression of the outbreak. Results: There were 15 confirmed cases and 3 children admitted to hospital during the outbreak. However, 35.7% of cases reported extremely mild symptoms. The attack rate was 15.2%, and age of affected children ranged from 18 to 58 months (mean 35 months). All cases were the same Multilocus Sequence Type (MLST50). Epidemiological investigation strongly suggested person-to-person spread within the facility. Existing infection control practices were found to be of a high standard, but introduction of additional evidence-based control measures was inadequate in halting transmission. Facility staff reported concerns about lack of parental disclosure of gastrointestinal symptoms, particularly where these were mild, with 50.0% of cases having attended while symptomatic against public health advice. Voluntary two-week closure of the facility was implemented to halt transmission, following which there were no new cases. WGS results were unavailable until after the decision was taken to close the facility. Conclusions: This is the first reported instance of a Salmonella Saintpaul outbreak at a childcare facility, or where person-to-person transmission is indicated. Clinicians should consider the influence of parental under-reporting on gastrointestinal outbreaks in childcare settings, particularly where perceived severity is low and financial or social pressures to attend work may reduce compliance. WGS cannot yet replace conventional microbiological techniques during short, localised outbreaks due to delays receiving results

Progressing the science of effluent treatment using Lasersizer diffraction analysis - a pilot study

Disinfection of waste water with ultraviolet (UV) light is a common procedure in many sewage treatment plants because it is used to inactivate coliform bacteria in the effluent. The number of coliform bacteria in a given sample is used as a proxy to indicate the presence of targeted pathogenic organisms. Typically the coliform bacteria exist in a particle-associated state which results in their being shielded from the UV light (Darby et al., 1999). Such particles are documented in the size range 20 to 80 μm, and therefore measurement of the size distribution in a sample could be used to indicate the degree of shielding. UV treatment is less effective for particles larger than about 40 μm in size (Table 1). Our pilot study used the laser diffraction technique to generate particle-size distributions of samples of effluent. By quantifying the amount of bacteria-shielding particles using this technique we were able to estimate the general efficacy of the UV sterilization process. The surface weighted mean diameter statistic was taken as a numerical measure of the bacteriashielding particle size distribution

Tree Rings Show Recent High Summer-Autumn Precipitation in Northwest Australia Is Unprecedented within the Last Two Centuries

An understanding of past hydroclimatic variability is critical to resolving the significance of recent recorded trends in Australian precipitation and informing climate models. Our aim was to reconstruct past hydroclimatic variability in semi-arid northwest Australia to provide a longer context within which to examine a recent period of unusually high summer-autumn precipitation. We developed a 210-year ring-width chronology from Callitris columellaris, which was highly correlated with summer-autumn (Dec–May) precipitation (r = 0.81; 1910–2011; p < 0.0001) and autumn (Mar–May) self-calibrating Palmer drought severity index (scPDSI, r = 0.73; 1910–2011; p < 0.0001) across semi-arid northwest Australia. A linear regression model was used to reconstruct precipitation and explained 66% of the variance in observed summer-autumn precipitation. Our reconstruction reveals inter-annual to multi-decadal scale variation in hydroclimate of the region during the last 210 years, typically showing periods of below average precipitation extending from one to three decades and periods of above average precipitation, which were often less than a decade. Our results demonstrate that the last two decades (1995–2012) have been unusually wet (average summer-autumn precipitation of 310 mm) compared to the previous two centuries (average summer-autumn precipitation of 229 mm), coinciding with both an anomalously high frequency and intensity of tropical cyclones in northwest Australia and the dominance of the positive phase of the Southern Annular Mode

Elevated circulating amyloid concentrations in obesity and diabetes promote vascular dysfunction

Diabetes, obesity and Alzheimer’s disease (AD) are associated with vascular complications and impaired nitric oxide (NO) production. Furthermore, increased β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1), APP and β-amyloid (Aβ) are linked with vascular disease development and raised BACE1 and Aβ accompany hyperglycemia and hyperlipidemia. However, the causal relationship between obesity and diabetes, raised Aβ and vascular dysfunction is unclear. We report that diet-induced obesity (DIO) in mice raised plasma and vascular Aβ42 that correlated with decreased NO bioavailability, endothelial dysfunction and raised blood pressure. Genetic or pharmacological reduction of BACE1 activity and Aβ42 prevented and reversed, respectively, these outcomes. In contrast, expression of human mutant APP in mice or Aβ42 infusion into control diet-fed mice to mimic obese levels impaired NO production, vascular relaxation and raised blood pressure. In humans, raised plasma Aβ42 correlated with diabetes and endothelial dysfunction. Mechanistically, higher Aβ42 reduced endothelial NO synthase (eNOS), cyclic GMP and protein kinase G (PKG) activity independently of diet whereas endothelin-1 was increased by diet and Aβ42. Lowering Aβ42 reversed the DIO deficit in the eNOS-cGMP-PKG pathway and decreased endothelin-1. Our findings suggest that BACE1 inhibitors may have therapeutic value in the treatment of vascular disease associated with diabetes

Post-Depositional Movement of Methanesulphonic Acid at Law Dome, Antarctica, and the Influence of Accumulation Rate

A series of ice cores from sites with different snow-accumulation rates across Law Dome, East Antarctica, was investigated for methanesulphonic acid (MSA) movement. The precipitation at these sites (up to 35 km apart) is influenced by the same air masses, the principal difference being the accumulation rate. At the low-accumulation-rate W20k site (0.17 in ice equivalent), MSA was completely relocated from the summer to winter layer. Moderate movement was observed at the intermediate-accumulation-rate site (0.7 in ice equivalent), Dome Summit South (DSS), while there was no evidence of movement at the high-accumulation-rate DE08 site (1.4 in ice equivalent). The main DSS record of MSA covered the epoch AD 1727-2000 and was used to investigate temporal post-depositional changes. Co-deposition of MSA and sea-salt ions was observed of the surface layers, outside of the main summer MSA peak, which complicates interpretation of these peaks as evidence of movement in deeper layers. A seasonal study of the 273 year DSS record revealed MSA migration predominantly from summer into autumn (in the up-core direction), but this migration was suppressed during the Tambora (1815) and unknown (1809) volcanic eruption period, and enhanced during an epoch (1770-1800) with high summer nitrate levels. A complex interaction between the gradients in nss-sulphate, nitrate and sea salts (which are influenced by accumulation rate) is believed to control the rate and extent of movement of MSA

Pocket-size near-IR spectrometers for rapid examination of contaminated textile fibres at the crime-scene

In a typical forensic investigation, fabric analysis plays a vital role in solving different crimes. Several types of textile fibre materials (cotton, polyester, denim, polypropylene, polycotton, and viscose) were analysed in the presence of common contaminants (blood, rainwater, seawater, sand and gunshot-residue) to evaluate the performance of two NIR spectrometers for in situ analysis of different crime scene conditions. The spectrometers used were SCIO® by Consumer Physics and NIRscan Nano by Texas Instruments. The SCIO instrument covers the third overtone region (740-1070 nm) and NIRscan Nano instrument covers the first and second overtone regions (900-1700 nm). Spectra from both instruments were pre-processed using the PRFFECTv2 software to eliminate noise and smooth the data for classification model construction. The models showed high accuracy, sensitivity and specificity with a range of 69-100% for binary classification (one class versus others) and range of 76-100% for multi-class classification of fibre material. This study shows for the first time the capability of pocket-size spectrometers coupled with random forest models for classification of fibre material in the presence of common contaminants in a rapid and non-destructive manner, and so is suitable for investigation of crime scenes