Field-based assessments of the seasonality of Culex pipiens sensu lato in England: an important enzootic vector of Usutu and West Nile viruses

BACKGROUND

Usutu virus (USUV), which is closely related to West Nile virus (WNV), sharing a similar ecology and transmission cycle, was first reported in the UK in the southeast of England in 2020. Both USUV and WNV are emerging zoonotic viruses hosted by wild birds. The 2020 finding of USUV in England raised awareness of this virus and highlighted the importance of understanding the seasonality of Culex pipiens sensu lato (Cx. pipiens s.l.), the main enzootic vector of these viruses. Zoos are prime locations for trapping mosquitoes because of their infrastructure, security, and range of vertebrate hosts and aquatic habitats.

METHODS

Three independent zoo-based case studies at four locations that cover the seasonality of Cx. pipiens s.l. in England were undertaken: (i) London Zoo (Zoological Society London [ZSL]) and surrounding areas, London; (ii) Chester Zoo (Cheshire); (ii) Twycross Zoo (Leicestershire); and (iv) Flamingo Land (zoo; North Yorkshire). Various adult mosquito traps were used to catch adult Cx. pipiens s.l. across seasons.

RESULTS

High yields of Cx. pipiens s.l./Culex torrentium were observed in Biogents-Mosquitaire and Center for Disease Control and Prevention Gravid traps in all studies where these traps were used. Mosquito counts varied between sites and between years. Observations of adult Cx. pipiens s.l./Cx. torrentium abundance and modelling studies demonstrated peak adult abundance between late July and early August, with active adult female Cx. pipiens s.l./Cx. torrentium populations between May and September.

CONCLUSIONS

The information collated in this study illustrates the value of multiple mosquito monitoring approaches in zoos to describe the seasonality of this UK vector across multiple sites in England and provides a framework that can be used for ongoing and future surveillance programmes and disease risk management strategies.

Corticosteroid Treatment During Sepsis Alters Hippocampal Function in Male and Female Survivors

Background

Millions of sepsis survivors annually face neuropsychiatric sequelae of their illness. Corticosteroids are frequently administered for sepsis, and their use improves neuropsychiatric outcomes, but the mechanisms are unknown. In light of prior work that has shown persistent inflammation in sepsis survivors, we hypothesized that short-term corticosteroid treatment during illness would reverse the long-term impact of sepsis on inflammatory gene expression in the hippocampus and rescue associated changes to affective behaviors.

Methods

Male and female mice underwent cecal ligation and puncture or a sham surgery to induce acute infection and were treated for 5 days with corticosterone or vehicle. Starting 2 weeks after the surgery, we performed functional phenotyping in the survivor mice followed by hippocampal RNA sequencing to identify underlying mechanisms.

Results

Long-term cecal ligation and puncture survivors exhibited anxiety-like behavior, increased central hypothalamic-pituitary-adrenal axis activity, and persistent systemic and neuroinflammation. Corticosterone treatment during illness did not reverse anxiety-like behavior or inflammation in survivors. Instead, corticosterone treatment impaired object memory and increased active coping behavior in females. History of corticosterone treatment influenced the expression of >10% of detectable transcripts in the dorsal and ventral hippocampus, including a coordinated downregulation of activity-dependent genes.

Conclusions

Corticosterone treatment during sepsis impaired memory formation in survivors and caused a lasting decrease in hippocampal neural activity, which could underlie its effect on memory. Future studies should focus on how this lasting effect of corticosteroid treatment on hippocampal activity and memory translates into improved neuropsychiatric outcomes in human sepsis survivors.

Development and validation of a prognostic model for death 30 days after adult emergency laparotomy

The probability of death after emergency laparotomy varies greatly between patients. Accurate pre-operative risk prediction is fundamental to planning care and improving outcomes. We aimed to develop a model limited to a few pre-operative factors that performed well irrespective of surgical indication: obstruction; sepsis; ischaemia; bleeding; and other. We derived a model with data from the National Emergency Laparotomy Audit for patients who had emergency laparotomy between December 2016 and November 2018. We tested the model on patients who underwent emergency laparotomy between December 2018 and November 2019. There were 4077/40,816 (10%) deaths 30 days after surgery in the derivation cohort. The final model had 13 pre-operative variables: surgical indication; age; blood pressure; heart rate; respiratory history; urgency; biochemical markers; anticipated malignancy; anticipated peritoneal soiling; and ASA physical status. The predicted mortality probability deciles ranged from 0.1% to 47%. There were 1888/11,187 deaths in the test cohort. The scaled Brier score, integrated calibration index and concordance for the model were 20%, 0.006 and 0.86, respectively. Model metrics were similar for the five surgical indications. In conclusion, we think that this prognostic model is suitable to support decision-making before emergency laparotomy as well as for risk adjustment for comparing organisations.

Corticosterone enhances formation of non-fear but not fear memory during infectious illness

Introduction

Survivors of critical illness are at high risk of developing post-traumatic stress disorder (PTSD) but administration of glucocorticoids during the illness can lower that risk. The mechanism is not known but may involve glucocorticoid modulation of hippocampal- and amygdala-dependent memory formation. In this study, we sought to determine whether glucocorticoids given during an acute illness influence the formation and persistence of fear and non-fear memories from the time of the illness.

Methods

We performed cecal ligation and puncture in male and female mice to induce an acute infectious illness. During the illness, mice were introduced to a neutral object in their home cage and separately underwent contextual fear conditioning. We then tested the persistence of object and fear memories after recovery.

Results

Glucocorticoid treatment enhanced object discrimination but did not alter the expression of contextual fear memory. During context re-exposure, neural activity was elevated in the dentate gyrus irrespective of fear conditioning.

Conclusions

Our results suggest that glucocorticoids given during illness enhance hippocampal-dependent non-fear memory processes. This indicates that PTSD outcomes in critically ill patients may be improved by enhancing non-fear memories from the time of their illness.

Mapping and monitoring tick (Acari, Ixodida) distribution, seasonality, and host associations in the United Kingdom between 2017 and 2020

Tick-borne disease risk is intrinsically linked to the distribution of tick vector species. To assess risk and anticipate disease emergence, an understanding of tick distribution, host associations, and seasonality is needed. This can be achieved, to some extent, using passive surveillance supported by engagement with the public, animal health, and public health experts. The Tick Surveillance Scheme (TSS) collects data and maps tick distribution across the United Kingdom (UK). Between 2017 and 2020, 3720 tick records were received and 39 tick species were detected. Most records were acquired in the UK, with a subset associated with recent overseas travel. The dominant UK acquired species was Ixodes ricinus (Ixodida: Ixodidae, Linnaeus), the main vector of Lyme borreliosis. Records peaked during May and June, highlighting a key risk period for tick bites. Other key UK species were detected, including Dermacentor reticulatus (Ixodida: Ixodidae, Fabricius) and Haemaphysalis punctata (Ixodida: Ixodidae, Canestrini & Fanzago) as well as several rarer species that may present novel tick-borne disease risk to humans and other animals. Updated tick distribution maps highlight areas in the UK where tick exposure has occurred. There is evidence of increasing human tick exposure over time, including during the COVID-19 pandemic, but seasonal patterns remain unchanged.

Direct Evidence of the Exfoliation Efficiency and Graphene Dispersibility of Green Solvents toward Sustainable Graphene Production

Achieving a sustainable production of pristine high-quality graphene and other layered materials at a low cost is one of the bottlenecks that needs to be overcome for reaching 2D material applications at a large scale. Liquid phase exfoliation in conjunction with N-methyl-2-pyrrolidone (NMP) is recognized as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here, we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors, we demonstrate that the exfoliation efficiency of a given solvent is independent of its dispersibility. Our studies revealed that isopropanol can be used to exfoliate graphite as efficiently as NMP. Our finding is corroborated by the matching ratio between the polar and dispersive energies of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at a large scale.

Snap-shot assessment of adult mosquito (Diptera: Culicidae) densities on the Turks and Caicos Islands, February 2022

In many of the small island communities of the Caribbean, much of the vector surveillance effort is focussed on house-to-house peri-focal surveys to collect data on larval indices. Adult mosquito trapping is not always routine or affordable and is usually focussed on ad hoc biting issues or small-scale investigations. This makes understanding the relative importance and densities of the common urban mosquitoes, such as Aedes aegypti and Culex quinquefasciatus, problematic. This snap-shot survey in February 2022 using BG-Sentinel traps at 30 different locations across five islands of the Turks and Caicos, aimed to provide the first island-wide assessment of urban mosquito densities. In total, 2,820 adult mosquitoes were collected over 285 trap nights. Aedes aegypti was most common on the island of Providenciales, with very low densities recorded on South Caicos, North and Middle Caicos, with Ae. aegypti most highly abundant in the main commercial centres. The highest densities of Cx. quinquefasciatus were trapped on North Caicos. Small numbers of other species were also collected, including the first record of Anopheles in TCI. This established framework of trapping and initial assessment provides a platform for continued monitoring of mosquitoes in TCI to better inform mosquito-borne disease risk assessment and future vector control efforts.

Postradioiodine Graves' management: The PRAGMA study

OBJECTIVE

Thyroid status in the months following radioiodine (RI) treatment for Graves' disease can be unstable. Our objective was to quantify frequency of abnormal thyroid function post-RI and compare effectiveness of common management strategies.

DESIGN

Retrospective, multicentre and observational study.

PATIENTS

Adult patients with Graves' disease treated with RI with 12 months' follow-up.

MEASUREMENTS

Euthyroidism was defined as both serum thyrotropin (thyroid-stimulating hormone [TSH]) and free thyroxine (FT4) within their reference ranges or, when only one was available, it was within its reference range; hypothyroidism as TSH ≥ 10 mU/L, or subnormal FT4 regardless of TSH; hyperthyroidism as TSH below and FT4 above their reference ranges; dysthyroidism as the sum of hypo- and hyperthyroidism; subclinical hypothyroidism as normal FT4 and TSH between the upper limit of normal and <10 mU/L; and subclinical hyperthyroidism as low TSH and normal FT4.

RESULTS

Of 812 patients studied post-RI, hypothyroidism occurred in 80.7% and hyperthyroidism in 48.6% of patients. Three principal post-RI management strategies were employed: (a) antithyroid drugs alone, (b) levothyroxine alone, and (c) combination of the two. Differences among these were small. Adherence to national guidelines regarding monitoring thyroid function in the first 6 months was low (21.4%-28.7%). No negative outcomes (new-onset/exacerbation of Graves' orbitopathy, weight gain, and cardiovascular events) were associated with dysthyroidism. There were significant differences in demographics, clinical practice, and thyroid status postradioiodine between centres.

CONCLUSIONS

Dysthyroidism in the 12 months post-RI was common. Differences between post-RI strategies were small, suggesting these interventions alone are unlikely to address the high frequency of dysthyroidism.

Evidence for overwintering and autochthonous transmission of Usutu virus to wild birds following its redetection in the United Kingdom

Usutu virus (USUV) is an emerging zoonotic arbovirus in Europe, where it primarily impacts Eurasian blackbirds (Turdus merula). For mosquito-borne viruses to persist in temperate areas, transovarial transmission in vectors or overwintering in either hosts or diapausing vectors must occur to facilitate autochthonous transmission. We undertook surveillance of hosts and vectors in 2021 to elucidate whether USUV had overwintered in the United Kingdom (UK) following its initial detection there in 2020. From 175 dead bird submissions, we detected 1 case of USUV infection, in a blackbird, from which a full USUV genome was derived. Using a molecular clock analysis, we demonstrate that the 2021 detection shared a most recent common ancestor with the 2020 Greater London, UK, USUV sequence. In addition, we identified USUV-specific neutralizing antibodies in 10 out of 86 serum samples taken from captive birds at the index site, demonstrating in situ cryptic infection and potential sustained transmission. However, from 4966 mosquitoes, we detected no USUV RNA suggesting that prevalence in the vector community was absent or low during sampling. Combined, these results suggest that USUV overwintered in the UK, thus providing empirical evidence for the continued northward expansion of this vector-borne viral disease. Currently, our detection indicates geographically restricted virus persistence. Further detections over time will be required to demonstrate long-term establishment. It remains unclear whether the UK, and by extension other high-latitude regions, can support endemic USUV infection.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Development and validation of multivariable machine learning algorithms to predict risk of cancer in symptomatic patients referred urgently from primary care: a diagnostic accuracy study

OBJECTIVES

To develop and validate tests to assess the risk of any cancer for patients referred to the NHS Urgent Suspected Cancer (2-week wait, 2WW) clinical pathways.

SETTING

Primary and secondary care, one participating regional centre.

PARTICIPANTS

Retrospective analysis of data from 371 799 consecutive 2WW referrals in the Leeds region from 2011 to 2019. The development cohort was composed of 224 669 consecutive patients with an urgent suspected cancer referral in Leeds between January 2011 and December 2016. The diagnostic algorithms developed were then externally validated on a similar consecutive sample of 147 130 patients (between January 2017 and December 2019). All such patients over the age of 18 with a minimum set of blood counts and biochemistry measurements available were included in the cohort.

PRIMARY AND SECONDARY OUTCOME MEASURES

sensitivity, specificity, negative predictive value, positive predictive value, Receiver Operating Characteristic (ROC) curve Area Under Curve (AUC), calibration curves RESULTS: We present results for two clinical use-cases. In use-case 1, the algorithms identify 20% of patients who do not have cancer and may not need an urgent 2WW referral. In use-case 2, they identify 90% of cancer cases with a high probability of cancer that could be prioritised for review.

CONCLUSIONS

Combining a panel of widely available blood markers produces effective blood tests for cancer for NHS 2WW patients. The tests are affordable, and can be deployed rapidly to any NHS pathology laboratory with no additional hardware requirements.

Mosquito Magnet® traps as a potential means of monitoring blackflies of medical and veterinary importance

Mosquito Magnet® traps, deployed in widespread parts of England as part of nationwide mosquito surveillance projects, also caught blackflies. As many as 1242 blackflies were caught in a trapping session lasting 4 days. Principal among the species caught were Simulium equinum, Simulium lineatum and Simulium ornatum s.l. As S. ornatum s.l. is a vector that transmits Onchocerca linealis to cattle and S. equinum is responsible for dermatitis ('sweet itch') in cattle and horses, it is suggested that Mosquito Magnet® traps could be used to monitor and partially control these pests, as well as nuisance anthropophilic blackflies such as Simulium posticatum that can cause simuliidosis in southern England.

UV-Vis Spectroscopic Characterization of Nanomaterials in Aqueous Media

The physicochemical characterization of nanomaterials (NMs) is often an analytical challenge, due to their small size (at least one dimension in the nanoscale, i.e. 1-100 nm), dynamic nature, and diverse properties. At the same time, reliable and repeatable characterization is paramount to ensure safety and quality in the manufacturing of NM-bearing products. There are several methods available to monitor and achieve reliable measurement of nanoscale-related properties, one example of which is Ultraviolet-Visible Spectroscopy (UV-Vis). This is a well-established, simple, and inexpensive technique that provides non-invasive and fast real-time screening evaluation of NM size, concentration, and aggregation state. Such features make UV-Vis an ideal methodology to assess the proficiency testing schemes (PTS) of a validated standard operating procedure (SOP) intended to evaluate the performance and reproducibility of a characterization method. In this paper, the PTS of six partner laboratories from the H2020 project ACEnano were assessed through an interlaboratory comparison (ILC). Standard gold (Au) colloid suspensions of different sizes (ranging 5-100 nm) were characterized by UV-Vis at the different institutions to develop an implementable and robust protocol for NM size characterization.

Benchmarking the ACEnano Toolbox for Characterisation of Nanoparticle Size and Concentration by Interlaboratory Comparisons

ACEnano is an EU-funded project which aims at developing, optimising and validating methods for the detection and characterisation of nanomaterials (NMs) in increasingly complex matrices to improve confidence in the results and support their use in regulation. Within this project, several interlaboratory comparisons (ILCs) for the determination of particle size and concentration have been organised to benchmark existing analytical methods. In this paper the results of a number of these ILCs for the characterisation of NMs are presented and discussed. The results of the analyses of pristine well-defined particles such as 60 nm Au NMs in a simple aqueous suspension showed that laboratories are well capable of determining the sizes of these particles. The analysis of particles in complex matrices or formulations such as consumer products resulted in larger variations in particle sizes within technologies and clear differences in capability between techniques. Sunscreen lotion sample analysis by laboratories using spICP-MS and TEM/SEM identified and confirmed the TiO₂ particles as being nanoscale and compliant with the EU definition of an NM for regulatory purposes. In a toothpaste sample orthogonal results by PTA, spICP-MS and TEM/SEM agreed and stated the TiO₂ particles as not fitting the EU definition of an NM. In general, from the results of these ILCs we conclude that laboratories are well capable of determining particle sizes of NM, even in fairly complex formulations.

Gonadectomy in conditions affecting sex development: a registry-based cohort study

OBJECTIVES

To determine trends in clinical practice for individuals with DSD requiring gonadectomy.

DESIGN

Retrospective cohort study.

METHODS

Information regarding age at gonadectomy according to diagnosis; reported sex; time of presentation to specialist centre; and location of centre from cases reported to the International DSD Registry and who were over 16 years old in January 2019.

RESULTS

Data regarding gonadectomy were available in 668 (88%) individuals from 44 centres. Of these, 248 (37%) (median age (range) 24 (17, 75) years) were male and 420 (63%) (median age (range) 26 (16, 86) years) were female. Gonadectomy was reported from 36 centres in 351/668 cases (53%). Females were more likely to undergo gonadectomy (n = 311, P < 0.0001). The indication for gonadectomy was reported in 268 (76%). The most common indication was mitigation of tumour risk in 172 (64%). Variations in the practice of gonadectomy were observed; of the 351 cases from 36 centres, 17 (5%) at 9 centres had undergone gonadectomy before their first presentation to the specialist centre. Median age at gonadectomy of cases from high-income countries and low-/middle-income countries (LMIC) was 13.0 years (0.1, 68) years and 16.5 years (1, 28), respectively (P < 0.0001) with the likelihood of long-term retention of gonads being higher in LMIC countries.

CONCLUSIONS

The likelihood of gonadectomy depends on the underlying diagnosis, sex of rearing and the geographical setting. Clinical benchmarks, which can be studied across all forms of DSD will allow a better understanding of the variation in the practice of gonadectomy.

Corticosterone Enhances Formation of Neutral but Not Fear Memory During Infectious Illness

Survivors of critical illness often report traumatic memories of their illness period, and these memories are thought to contribute to development of neuropsychiatric disorders, such as PTSD. Many patients are treated with high doses of glucocorticoids for their vasoactive and anti-inflammatory properties, and glucocorticoids have also been shown to prevent the development of PTSD after trauma. Due to their activity in the hippocampus and amygdala, the putative protective effect of glucocorticoids may occur via memory formation during illness. To examine the effect of glucocorticoids on memory formation during acute infectious illness, male and female C57BL/6 mice (N=80, 40 male/40 female) underwent cecal ligation and puncture and were treated with either corticosterone (16 mg/kg) or vehicle in the early afternoon daily for five days beginning on the day of surgery. All mice were habituated to a neutral object in their home cage for five days and underwent one 30-minute footshock/no shock training session during the illness period. After physiologic recovery (2 weeks), the mice underwent behavioral testing including open field exploration, object recognition testing in which they were presented with both the familiar (habituated) object and a novel object, and testing in the shock context. The results showed that drug treatment had no effect on behavior in the open field, including time spent in the center (VEH: 20.19±10.81 vs CORT: 22.32±12.87 sec; P=0.476). Drug treatment increased overall object exploration (12.28±10.79 vs 19.17±15.88 sec; P=0.049). Corticosterone-treated mice showed a preference for the familiar object (60.9±23.0% of total exploration time with familiar object; P=0.015), while vehicle-treated mice did not (54.1±23.3%; P=0.378). The increase in overall object exploration seen in corticosterone-treated mice could be accounted for by an increase in exploration of the familiar object. History of footshock increased freezing in the training context (3.96±2.54% vs 36.08±15.42%; P<0.0001) and corticosterone treatment had no effect (18.06±17.65% vs 22.16±21.19%; P=0.557). In conclusion, administration of corticosterone during infectious illness facilitated memory of a neutral object from the illness period, and recovered mice exhibited a preference for this object over a novel one. Corticosterone treatment had no impact on fear memory formed during illness. This is consistent with human literature suggesting that hydrocortisone decreases PTSD symptoms without impacting traumatic memories. These findings suggest that glucocorticoids selectively enhance the formation, consolidation, and/or recall of neutral but not fear memories during illness, which may rely on hippocampal circuitry. We further suggest that accurate memories of the illness period may influence patients’ perception of this experience and alter their risk for psychiatric sequelae.

Investigations into the synthesis of a nucleotide dimer via mechanochemical phosphoramidite chemistry

Liquid-assisted mechanochemistry as a versatile approach for the coupling of a nucleoside phosphoramidite with a 5'-OH partially protected nucleoside has been investigated. Noted advantages over reported methods were a simplified reaction protocol, a drastic reduction in the use of toxic solvents, the facilitation of mechanochemical reactions through the improved mixing of solid reagents, and low hydrolytic product formation.

Phosphorus stocks and flows in an intensive livestock dominated food system

Current use and management of phosphorus (P) in our food systems is considered unsustainable and considerable improvements in the efficiency of P use are required to mitigate the environmental impact of poor P stewardship. The inherent low P use efficiency of food production from animals means food systems dominated by livestock agriculture can pose unique challenges for improving P management. This paper presents the results of a substance flow analysis for P in the Northern Ireland (NI) food system for the year 2017 as a case study for examining P stewardship in a livestock dominated agricultural system. Imported livestock feed was by far the largest flow of P into the NI food system in 2017 (11,700 t ± 1300 t) and P from livestock excreta the largest internal flow of P (20,400 ± 1900t). The P contained in livestock slurries and manures alone that were returned to agricultural land exceeded total crop and grass P requirement by 20% and were the largest contributor to an annual excess soil P accumulation of 8.5 ± 1.4 kg ha^-1. This current livestock driven P surplus also limits the opportunities for P circularity and reuse from other sectors within the food system, e.g. wastewater biosolids and products from food processing waste. Management of livestock P demand (livestock numbers, feed P content) or technological advancements that facilitate the processing and subsequent export of slurries and manures are therefore needed.

Nanoparticle Tracking Analysis of Gold Nanoparticles in Aqueous Media through an Inter-Laboratory Comparison

In the field of nanotechnology, analytical characterization plays a vital role in understanding the behavior and toxicity of nanomaterials (NMs). Characterization needs to be thorough and the technique chosen should be well-suited to the property to be determined, the material being analyzed and the medium in which it is present. Furthermore, the instrument operation and methodology need to be well-developed and clearly understood by the user to avoid data collection errors. Any discrepancies in the applied method or procedure can lead to differences and poor reproducibility of obtained data. This paper aims to clarify the method to measure the hydrodynamic diameter of gold nanoparticles by means of Nanoparticle Tracking Analysis (NTA). This study was carried out as an inter-laboratory comparison (ILC) amongst seven different laboratories to validate the standard operating procedure's performance and reproducibility. The results obtained from this ILC study reveal the importance and benefits of detailed standard operating procedures (SOPs), best practice updates, user knowledge, and measurement automation.

Working towards a Co-Ordinated Approach to Invasive Mosquito Detection, Response and Control in the UK

The United Kingdom (UK) has reported a single detection of the eggs of the invasive mosquito vector Aedes albopictus in each of the three years from 2016 to 2018, all in southeast England. Here, we report the detection of mosquito eggs on three occasions at two sites in London and southeast England in September 2019. Mosquito traps were deployed at 56 sites, in England, Scotland, Wales, and Northern Ireland, as part of a coordinated surveillance programme with local authorities, Edge Hill University, and government departments. Response to each detection was coordinated by Public Health England’s (PHE) local health protection teams, with technical support from PHE’s Medical Entomology group, and control conducted by the respective local authority. Control, including source reduction and larviciding, was conducted within a 300 metre radius of the positive site. The response followed a National Contingency Plan for Invasive Mosquitoes: Detection of Incursions. Although the response to these incidents was rapid and well co-ordinated, recommendations are made to further develop mosquito surveillance and control capability for the UK.

Health Care Workers and Patients as Trojan Horses: a COVID19 ward outbreak

Background

Transmission in healthcare settings can result in significant infections in healthcare workers and patients. Understanding infection dynamics has important implications for methods employed in hospitals to prevent nosocomial transmission events.

Methods

In this case series report we describe a cluster of COVID-19 (Coronavirus disease 2019) in a tertiary care university hospital, in the early phases of the epidemic, after hospital visiting had been stopped and when the UK lockdown was in place.

Findings

A 48 year old patient developed COVID-19 31 days post-admission and four days after admission to a medical ward from ITU. Infection was likely acquired from an asymptomatic or minimally symptomatic healthcare worker (HCW). Subsequent investigation over a 14 day period revealed symptoms in 23 staff members and five linked cases in patients on the same ward.

Nine of the 23 affected staff members provided care for and had direct exposure with the index case. Four staff reported caring for the index case without use of personal protective equipment. One was coughed on directly by the patient 24 hours prior to the onset of symptoms.

Conclusion

SARS CoV2 infection can be introduced to a ward area by asymptomatic and minimally symptomatic healthcare workers. Staff members and patients can act as Trojan horses carrying infection into and around the hospital, setting up unexpected transmission events.

Transmission of infection from pre-symptomatic, asymptomatic and minimally symptomatic individuals means that universal use of measures to prevent transmission is required for successful reduction of transmission events in the hospital setting.

Diagnostic accuracy of SUVmax in predicting malignancy of supraclavicular lymph nodes from primary oesophageal cancer

PURPOSE

To determine the diagnostic accuracy and optimum cut-off value of SUVmax on PET to predict malignancy of supraclavicular lymph nodes (SCLNs) in patients with oesophageal carcinoma.

MATERIAL AND METHODS

All diagnosed cases of oesophageal cancer were retrospectively reviewed (2010-2016). Patients that had a confirmed diagnosis of oesophageal cancer with avid SCLNs on staging PET were included in the study. 33 SCLNs that subsequently underwent ultrasound guided biopsy for staging were analysed. The maximum uptake values (SUVmax) of the SCLNs and primary tumours were measured. A receiver operating characteristic (ROC) analysis was performed to determine the optimum cut off of SUVmax in predicting malignancy.

RESULTS

24/33 PET-detected SCLNs were malignant. ROC analysis identified the best nodal SUVmax cut-off to be 3.0. The diagnostic accuracy of PET was 76.0 % (sensitivity = 78.9 %, specificity = 66.6 %). For SCLNs with SUVmax > 3.0, PET showed a positive predictor value of 88.2 %; for SCLNs < 3.0, PET showed a negative predictor value of 50 %. The median SUVmax of pathologically negative and positive nodes were 2.8 (range 1.8-6.0) and 5.3 (range 1.9-13.4). The median primary tumour SUVmax was 13.8 (range 3.7-30.0). The SUVmax of metastatic lymph nodes were significant higher than those of benign lesions (p < 0.05).

CONCLUSION

Our study revealed an accuracy rate of 76 % for PET detected SCLNs in patients with oesophageal carcinoma. For SCLNs with SUVmax > 3.0, PET had a high PPV (88 %), which can minimize the need for further diagnostic tests.

A survey of Anopheles species composition and insecticide resistance on the island of Bubaque, Bijagos Archipelago, Guinea-Bissau

Background

Bubaque is the most populous island of the Bijagos archipelago, a group of malaria-endemic islands situated off the coast of Guinea-Bissau, West Africa. Malaria vector control on Bubaque relies almost exclusively on the use of long-lasting insecticidal nets (LLINs). However, there is little information on local vector bionomics and insecticide resistance.

Methods

A survey of mosquito species composition was performed at the onset of the wet season (June/July) and the beginning of the dry season (November/December). Sampling was performed using indoor adult light-traps and larval dipping. Anopheles mosquitoes were identified to species level and assessed for kdr allele frequency by TaqMan PCR. Females were analysed for sporozoite positivity by CSP-ELISA. Resistance to permethrin and α-cypermethrin was measured using the CDC-bottle bioassay incorporating the synergist piperonyl-butoxide.

Results

Several Anopheles species were found on the island, all belonging to the Anopheles gambiae sensu lato (s.l.) complex, including An. gambiae sensu stricto, Anopheles coluzzii, Anopheles melas, and An. gambiae/An. coluzzii hybrids. Endophagic Anopheles species composition and abundance showed strong seasonal variation, with a majority of An. gambiae (50% of adults collected) caught in June/July, while An. melas was dominant in November/December (83.9% of adults collected). Anopheles gambiae had the highest sporozoite rate in both seasons, with infection rates of 13.9% and 20% in June/July and November/December, respectively. Moderate frequencies of the West African kdr allele were found in An. gambiae (36%), An. coluzzii (35%), An. gambiae/An. coluzzii hybrids (42%). Bioassays suggest moderate resistance to α-cypermethrin, but full susceptibility to permethrin.

Conclusions

The island of Bubaque maintained an An. gambiae s.l. population in both June/July and November/December. Anopheles gambiae was the primary vector at the onset of the wet season, while An. melas is likely to be responsible for most dry season transmission. There was moderate kdr allele frequency and synergist assays suggest likely metabolic resistance, which could reduce the efficacy of LLINs. Future control of malaria on the islands should consider the seasonal shift in mosquito species, and should employ continuous monitoring for insecticide resistance.

Scalable, Large-Area Printing of Pore-Array Electrodes for Ultrahigh Power Electrochemical Energy Storage

Through-electrode thickness honeycomb architectures were layer-by-layer self-assembled directly through a scalable printing process for ultrapower hybrid lithium-ion capacitor applications. Initially, the electrochemical performance of the pore-array electrodes was investigated as a function of the active material type (graphene plates, carbon nanofibers, and activated carbon). Inactive components (conductive carbon and polymer binder) were then minimized to 5 wt %. Finally, an optimized activated carbon-based cathode was paired with a spray-printed Li₄Ti₅O₁₂-based anode and a range of anode-to-cathode mass ratios in a lithium-ion capacitor arrangement were investigated. A 1:5 anode/cathode mass ratio provided an attractive energy density comparable with a Li₄Ti₅O₁₂/LiFePO₄ lithium-ion battery but with outstanding power capability that was an order of magnitude greater than typical for lithium-ion batteries. The pore-array electrode was reproduced over areas of 20 cm × 15 cm in a double-sided coated configuration, and the option for selectively patterning electrodes was also demonstrated.

Association between surgeon special interest and mortality after emergency laparotomy

Background

Approximately 30 000 emergency laparotomies are performed each year in England and Wales. Patients with pathology of the gastrointestinal tract requiring emergency laparotomy are managed by general surgeons with an elective special interest focused on either the upper or lower gastrointestinal tract. This study investigated the impact of special interest on mortality after emergency laparotomy.

Methods

Adult patients having emergency laparotomy with either colorectal or gastroduodenal pathology were identified from the National Emergency Laparotomy Audit database and grouped according to operative procedure. Outcomes included all-cause 30-day mortality, length of hospital stay and return to theatre. Logistic and Poisson regression were used to analyse the association between consultant special interest and the three outcomes.

Results

A total of 33 819 patients (28 546 colorectal, 5273 upper gastrointestinal (UGI)) were included. Patients who had colorectal procedures performed by a consultant without a special interest in colorectal surgery had an increased adjusted 30-day mortality risk (odds ratio (OR) 1·23, 95 per cent c.i. 1·13 to 1·33). Return to theatre also increased in this group (OR 1·13, 1·05 to 1·20). UGI procedures performed by non-UGI special interest surgeons carried an increased adjusted risk of 30-day mortality (OR 1·24, 1·02 to 1·53). The risk of return to theatre was not increased (OR 0·89, 0·70 to 1·12).

Conclusion

Emergency laparotomy performed by a surgeon whose special interest is not in the area of the pathology carries an increased risk of death at 30 days. This finding potentially has significant implications for emergency service configuration, training and workforce provision, and should stimulate discussion among all stakeholders.

Outcomes of growing rod surgery for severe compared with moderate early-onset scoliosis: a matched comparative study

Aims

The aim of this study was to compare the outcomes of surgery using growing rods in patients with severe versus moderate early-onset scoliosis (EOS).

Patients and Methods

A review of a multicentre EOS database identified 107 children with severe EOS (major curve ≥ 90°) treated with growing rods before the age of ten years with a minimum follow-up of two years and three or more lengthening procedures. From the same database, 107 matched controls with moderate EOS were identified.

Results

The mean preoperative major curve was 101° (90 to 139) in the severe group and 67° (33° to 88°) in the moderate group (p < 0.001), which was corrected at final follow-up to 57° (10° to 96°) in the severe group and 40° (3° to 85°) in the moderate group (p < 0.001). T1-S1 height increased by a mean of 54 mm (-8 to 131) in the severe group and 27 mm (-4 to 131) in the moderate group at the initial surgery (p < 0.001), and by 50 mm (-17 to 200) and 54 mm (-11 to 212), respectively, during distraction (p = 0.84). The mean number of complications per patient was 2.6 (0 to 14) in the severe group and 1.9 (0 to 10) in the moderate group (p = 0.040). Five patients (4.7%) in the severe group and three (2.8%) in the moderate group developed a neurological deficit postoperatively (p = 0.47).

Conclusion

Severe EOS can be treated effectively using growing rods, but the risk of complications is high. Cite this article: Bone Joint J 2018;100-B:772-9.

Hyponatraemia and Moduretic-Grand Mal Seizures: A Review

Three cases are presented which emphasize the importance of hyponatraemia as a cause of grand mal seizures. The combination of hydrochlorothiazide and amiloride appears to increase the risk of hyponatraemia. We discuss the aetiology and treatment of hyponatraemia and review the necessity for such combination therapy. We recommend caution in prescribing diuretics and preparations such as Moduretic should be used only in those few patients shown to need potassium supplementation.

What do Key Stakeholders Think About HIV Self-Testing in Canada? Results from a Cross-Sectional Survey

Human immunodeficiency virus (HIV) self-testing presents an empowering alternative to facility-based testing for reaching undiagnosed HIV infected individuals, but is not currently available in Canada. We surveyed stakeholders (clinical providers, public health professionals, researchers) engaged in HIV testing initiatives nationwide to identify the concerns, opportunities and challenges to implementing HIV self-testing in Canada. An online cross-sectional survey was disseminated by the Canadian Institutes of Health Research Centre for REACH 2.0 National HIV & sexually transmitted and blood borne infections working group to stakeholders nationwide, with a target sample size of 200. Quantitative and qualitative data were analyzed using a mixed-methods, respondent-informed approach, to inform subsequent HIV self-testing in a country where self-testing is not yet accessible. A total of 183 responses were received. A majority (70.7%) (128/181) felt that self-testing was a necessary investment to reach the undiagnosed. 64.6% (117/181) felt that self-tests should be made available to their clients and 71.5% (128/179) of respondents agreed that self-test instructions required improvements. However, 50% (90/180) felt that self-testing will pose an economic challenge to current HIV testing models. Regardless, 21% urged for timely action and availability of HIV self-tests. Thematic analyses reflected the following concerns: (a) need for affordable self-tests, (b) need for expedited, customized, and accessible linkages to counselling, (c) concern for patients to cope with positive self-test results, (d) accuracy of self-tests to detect acute HIV and (e) liability in the context of non-disclosure. Stakeholders agreed to the provision of an option of HIV self-testing to reach the undiagnosed individuals. Concerns regarding costs and accuracy of self-tests, expedited linkages to counselling, and integration of self-test within prevailing HIV testing models, will need to be addressed before their widespread implementation.

Stakeholders' views of the introduction of assistive technology in the classroom: How family-centred is Australian practice for students with cerebral palsy?

BACKGROUND

With family-centred care widely recognized as a cornerstone for effective assistive technology service provision, the current study was undertaken to investigate to what extent such approaches were used by schools when assistive technology assessments and implementation occurred in the classroom.

METHOD

In this cross-sectional study, we compare survey results from parents (n = 76), school staff (n = 33) and allied health professionals (n = 65) with experience in the use of high-tech assistive technology. Demographic characteristics and the stakeholders' perceived helpfulness and frequency attending assessment and set-up sessions were captured. To evaluate how family-centred the assistive technology services were perceived to be, the parents filled out the Measure of Processes of Care for Caregivers, and the professionals completed the Measure of Processes of Care for Service Providers. Descriptive statistics and one-way analysis of variance were used to conduct the data analysis.

RESULTS

Findings show that parents are more involved during the assessment stage than during the implementation and that classroom teachers are often not involved in the initial stage. Speech pathologists in particular are seen to be to a great extent helpful when implementing assistive technology in the classroom. This study found that family-centred service is not yet fully achieved in schools despite being endorsed in early intervention and disability services for over 20 years. No statistically significant differences were found with respect to school staff and allied health professionals' roles, their years of experience working with students with cerebral palsy and the scales in the Measure of Processes of Care for Service Providers.

CONCLUSION

To enhance the way technology is matched to the student and successfully implemented, classroom teachers need to be fully involved in the whole assistive technology process. The findings also point to the significance of parents' involvement, with the support of allied health professionals, in the process of selecting and implementing assistive technology in the classroom.

In situ hybridization and histopathological observations during ostreid herpesvirus-1-associated mortalities in Pacific oysters Crassostrea gigas

In a previous longitudinal study conducted during a mortality investigation associated with ostreid herpesvirus-1 (OsHV-1) microvariant in New Zealand Pacific oysters in 2010-2011, temporality of OsHV-1 nucleic acid detection by real-time PCR assay and onset of Pacific oyster mortality was observed. The present study further elucidated the role of OsHV-1 using an in situ hybridization (ISH) assay on sections of Pacific oysters collected from the same longitudinal study. Hybridization of the labelled probe with the target region of the OsHV-1 genome in infected cells was detected colorimetrically using nitro blue tetrazolium (NBT). OsHV-1 presence and distribution in spat indicated by the ISH signal was then compared with the existence of pathological changes in oyster tissues. Dark blue to purplish black NBT cell labelling was seen predominantly in the stroma of the mantle and gills at Day 5 post introduction to the farm. The distribution and location of ISH signals indicated the extent of OsHV-1-infected cells in multiple tissues. Histopathological abnormalities were mostly non-specific; however, a progressive pattern of increasingly widespread haemocytosis coincided with the appearance of OsHV-1-infected cells in spat collected at different time-points. The visualisation of an increasing number of OsHV-1-positive cells in spat prior to a marked increase in mortality indicated the strong likelihood of an on-going and active viral infection in some oysters. Further studies are recommended to elucidate OsHV-1 pathogenesis in Pacific oysters in association with other potentially causal variables, such as elevated temperature and interaction with Vibrio spp. bacteria.