Outbreak of Diarrhea Caused by a Novel Cryptosporidium hominis Subtype During British Military Training in Kenya

Background

We report clinical, epidemiological, and laboratory features of a large diarrhea outbreak caused by a novel Cryptosporidium hominis subtype during British military training in Kenya between February and April 2022.

Methods

Data were collated from diarrhea cases, and fecal samples were analyzed on site using the multiplex polymerase chain reaction (PCR) BioFire FilmArray. Water was tested using Colilert kits (IDEXX, UK). DNA was extracted from feces for molecular characterization of Cryptosporidium A135, Lib13, ssu rRNA, and gp60 genes.

Results

One hundred seventy-two of 1200 (14.3%) personnel at risk developed diarrhea over 69 days. One hundred six primary fecal samples were tested, and 63/106 (59.4%; 95% CI, 0.49%-0.69%) were positive for Cryptosporidium spp. Thirty-eight had Cryptosporidium spp. alone, and 25 had Cryptosporidium spp. with ≥1 other pathogen. A further 27/106 (25.5%; 95% CI, 0.18%-0.35%) had non-Cryptosporidium pathogens only, and 16/106 (15.1%; 95% CI, 0.09%-0.23%) were negative. C. hominis was detected in 58/63 (92.1%) Cryptosporidium spp.-positive primary samples, but the others were not genotypable. Twenty-seven C. hominis specimens were subtypable; 1 was gp60 subtype IeA11G3T3, and 26 were an unusual subtype, ImA13G1 (GenBank accession OP699729), supporting epidemiological evidence suggesting a point source outbreak from contaminated swimming water. Diarrhea persisted for a mean (SD) of 7.6 (4.6) days in Cryptosporidium spp. cases compared with 2.3 (0.9) days in non-Cryptosporidium cases (P = .001).

Conclusions

Real-time multiplex PCR fecal testing was vital in managing this large cryptosporidiosis outbreak. The etiology of a rare C. hominis gp60 subtype emphasizes the need for more genotypic surveillance to identify widening host and geographic ranges of novel C. hominis subtypes.

Associations Between Primary Residence and Mental Health in Global Marginalized Populations

Scholars suggest that marginalized people in non-urban areas experience higher distress levels and fewer psychosocial resources than in urban areas. Researchers have yet to test whether precise proximity to urban centers is associated with mental health for marginalized populations. We recruited 1733 people who reported living in 45 different countries. Participants entered their home locations and completed measures of anxiety, depression, social support, and resilience. Regression and thematic analyses were used to determine what role distance from legislative and urban centers may play in mental health when marginalized people were disaggregated. Greater distance from legislative center predicted higher anxiety and resilience. Greater distance from urban center also predicted more resilience. Thematic analyses yielded five categories (e.g., safety, connection) that further illustrated the impact of geographic location on health. Implications for community mental health are discussed including the need to better understand and further expand resilience in rural areas.

Molnupiravir versus placebo in unvaccinated and vaccinated patients with early SARS-CoV-2 infection in the UK (AGILE CST-2): a randomised, placebo-controlled, double-blind, phase 2 trial

BACKGROUND

The antiviral drug molnupiravir was licensed for treating at-risk patients with COVID-19 on the basis of data from unvaccinated adults. We aimed to evaluate the safety and virological efficacy of molnupiravir in vaccinated and unvaccinated individuals with COVID-19.

METHODS

This randomised, placebo-controlled, double-blind, phase 2 trial (AGILE CST-2) was done at five National Institute for Health and Care Research sites in the UK. Eligible participants were adult (aged ≥18 years) outpatients with PCR-confirmed, mild-to-moderate SARS-CoV-2 infection who were within 5 days of symptom onset. Using permuted blocks (block size 2 or 4) and stratifying by site, participants were randomly assigned (1:1) to receive either molnupiravir (orally; 800 mg twice daily for 5 days) plus standard of care or matching placebo plus standard of care. The primary outcome was the time from randomisation to SARS-CoV-2 PCR negativity on nasopharyngeal swabs and was analysed by use of a Bayesian Cox proportional hazards model for estimating the probability of a superior virological response (hazard ratio [HR]>1) for molnupiravir versus placebo. Our primary model used a two-point prior based on equal prior probabilities (50%) that the HR was 1·0 or 1·5. We defined a priori that if the probability of a HR of more than 1 was more than 80% molnupiravir would be recommended for further testing. The primary outcome was analysed in the intention-to-treat population and safety was analysed in the safety population, comprising participants who had received at least one dose of allocated treatment. This trial is registered in ClinicalTrials.gov, NCT04746183, and the ISRCTN registry, ISRCTN27106947, and is ongoing.

FINDINGS

Between Nov 18, 2020, and March 16, 2022, 1723 patients were assessed for eligibility, of whom 180 were randomly assigned to receive either molnupiravir (n=90) or placebo (n=90) and were included in the intention-to-treat analysis. 103 (57%) of 180 participants were female and 77 (43%) were male and 90 (50%) participants had received at least one dose of a COVID-19 vaccine. SARS-CoV-2 infections with the delta (B.1.617.2; 72 [40%] of 180), alpha (B.1.1.7; 37 [21%]), omicron (B.1.1.529; 38 [21%]), and EU1 (B.1.177; 28 [16%]) variants were represented. All 180 participants received at least one dose of treatment and four participants discontinued the study (one in the molnupiravir group and three in the placebo group). Participants in the molnupiravir group had a faster median time from randomisation to negative PCR (8 days [95% CI 8-9]) than participants in the placebo group (11 days [10-11]; HR 1·30, 95% credible interval 0·92-1·71; log-rank p=0·074). The probability of molnupiravir being superior to placebo (HR>1) was 75·4%, which was less than our threshold of 80%. 73 (81%) of 90 participants in the molnupiravir group and 68 (76%) of 90 participants in the placebo group had at least one adverse event by day 29. One participant in the molnupiravir group and three participants in the placebo group had an adverse event of a Common Terminology Criteria for Adverse Events grade 3 or higher severity. No participants died (due to any cause) during the trial.

INTERPRETATION

We found molnupiravir to be well tolerated and, although our predefined threshold was not reached, we observed some evidence that molnupiravir has antiviral activity in vaccinated and unvaccinated individuals infected with a broad range of SARS-CoV-2 variants, although this evidence is not conclusive.

FUNDING

Ridgeback Biotherapeutics, the UK National Institute for Health and Care Research, the Medical Research Council, and the Wellcome Trust.

Pharmacokinetics of ß-d-N4-Hydroxycytidine, the Parent Nucleoside of Prodrug Molnupiravir, in Nonplasma Compartments of Patients With Severe Acute Respiratory Syndrome Coronavirus 2 Infection

ß-d-N4-hydroxycytidine (NHC), the parent nucleoside of molnupiravir, a COVID-19 antiviral, was quantified at SARS-CoV-2 transmission sites in 12 patients enrolled in AGILE Candidate-Specific Trial-2. Saliva, nasal, and tear NHC concentrations were 3%, 21%, and 22% that of plasma. Saliva and nasal NHC were significantly correlated with plasma (P < .0001). Clinical Trials Registration. NCT04746183.

Optimal dose and safety of molnupiravir in patients with early SARS-CoV-2: a Phase I, open-label, dose-escalating, randomized controlled study

OBJECTIVES

AGILE is a Phase Ib/IIa platform for rapidly evaluating COVID-19 treatments. In this trial (NCT04746183) we evaluated the safety and optimal dose of molnupiravir in participants with early symptomatic infection.

METHODS

We undertook a dose-escalating, open-label, randomized-controlled (standard-of-care) Bayesian adaptive Phase I trial at the Royal Liverpool and Broadgreen Clinical Research Facility. Participants (adult outpatients with PCR-confirmed SARS-CoV-2 infection within 5 days of symptom onset) were randomized 2:1 in groups of 6 participants to 300, 600 and 800 mg doses of molnupiravir orally, twice daily for 5 days or control. A dose was judged unsafe if the probability of 30% or greater dose-limiting toxicity (the primary outcome) over controls was 25% or greater. Secondary outcomes included safety, clinical progression, pharmacokinetics and virological responses.

RESULTS

Of 103 participants screened, 18 participants were enrolled between 17 July and 30 October 2020. Molnupiravir was well tolerated at 300, 600 and 800 mg doses with no serious or severe adverse events. Overall, 4 of 4 (100%), 4 of 4 (100%) and 1 of 4 (25%) of the participants receiving 300, 600 and 800 mg molnupiravir, respectively, and 5 of 6 (83%) controls, had at least one adverse event, all of which were mild (≤grade 2). The probability of ≥30% excess toxicity over controls at 800 mg was estimated at 0.9%.

CONCLUSIONS

Molnupiravir was safe and well tolerated; a dose of 800 mg twice daily for 5 days was recommended for Phase II evaluation.

Did Covid-19 hit harder in peripheral areas? The case of Italian municipalities

The first wave of Covid-19 pandemic had a geographically heterogeneous impact even within the most severely hit regions. Exploiting a triple-differences methodology, we find that in Italy Covid-19 hit relatively harder in peripheral areas: the excess mortality in peripheral areas was almost double that of central ones in March 2020 (1.2 additional deaths every 1000 inhabitants). We leverage a rich dataset on Italian municipalities to explore mechanisms behind this gradient. We first show that socio-demographic and economic features at municipal level are highly collinear, making it hard to identify single-variable causal relationships. Using Principal Components Analysis we model excess mortality and show that areas with higher excess mortality have lower income, lower education, larger households, lower trade and higher industrial employments, and older population. Our findings highlight a strong centre-periphery gradient in the harshness of Covid-19, which we believe is also highly relevant from a policy-making standpoint.

Comparative evaluation of ten lateral flow immunoassays to detect SARS-CoV-2 antibodies

Background: Rapid mobilisation from industry and academia following the outbreak of the novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), led to the development and availability of SARS-CoV-2 lateral flow immunoassays (LFAs). High quality LFAs are urgently needed at the point of care to add to currently available diagnostic tools. In this study, we provide evaluation data for ten LFAs suitable for use at the point of care. Methods: COVID-19 positive patients (N=45), confirmed by reverse transcription – quantitative polymerase chain reaction (RT-qPCR), were recruited through the International Severe Acute Respiratory and Emerging Infection Consortium - Coronavirus Clinical Characterisation Consortium (ISARIC4C) study. Sera collected from patients with influenza A (N=20), tuberculosis (N=5), individuals with previous flavivirus exposure (N=21), and healthy sera (N=4), collected pre-pandemic, were used as negative controls. Ten LFAs manufactured or distributed by ASBT Holdings Ltd, Cellex, Fortress Diagnostics, Nantong Egens Biotechnology, Mologic, NG Biotech, Nal von Minden and Suzhou Herui BioMed Co. were evaluated. Results: Compared to RT-qPCR, sensitivity of LFAs ranged from 87.0-95.7%. Specificity against pre-pandemic controls ranged between 92.0-100%. Compared to IgG ELISA, sensitivity and specificity ranged between 90.5-100% and 93.2-100%, respectively. Percentage agreement between LFAs and IgG ELISA ranged from 89.6-92.7%. Inter-test agreement between LFAs and IgG ELISA ranged between kappa=0.792-0.854. Conclusions: LFAs may serve as a useful tool for rapid confirmation of ongoing or previous infection in conjunction with clinical suspicion of COVID-19 in patients attending hospital. Impartial validation prior to commercial sale provides users with data that can inform best use settings.

Perfluoroalkyl substances and lipid profile in exposed pregnant women in the Veneto Region, Italy

Background

Perfluoroalkyl substances (PFASs) are persistent and widespread environmental pollutants. Residents of a large area of the Veneto Region (North-Eastern Italy) were exposed to high concentrations of PFASs through drinking water from the late-1970s to 2013. PFASs have been consistently associated with raised serum lipids, but only few studies have been conducted among pregnant women, and none has stratified analyses by trimesters of gestation. Our main objective was to evaluate the association between perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) levels and lipid profiles in high-exposed pregnant women.

Methods

A cross-sectional analysis was conducted in 319 pregnant women (age 14-48 years) recruited in the Regional health surveillance program. Serum PFASs were measured by HPLC-MS/MS. Non-fasting serum total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) were measured by enzymatic assays in automated analysers, and low-density lipoprotein cholesterol (LDL-C) was calculated. The associations between ln-transformed PFASs (and categorized into quartiles) and lipids were assessed using generalized additive models. Analyses were adjusted for potential confounders and stratified according to pregnancy trimester.

Results

In the first trimester, plasma concentrations of both PFOA and PFOS were positively associated with TC. However in the third trimester PFOA levels were instead inversely significantly associated with TC and LDL-C levels. Overall, both PFOA and PFOS were positively associated with HDL-C, and PFOA negatively with LDL-C.

Conclusions

In a small highly exposed population of pregnant women, the associations between PFASs concentrations and lipid profile were modified by trimester of gestation. Patterns late in pregnancy were different to the positive associations with LDL-C generally found. Differential transfer and bioaccumulation of lipids and PFAS in the placenta across gestation might explain our findings.

Key messages

This study provides evidence of different patterns of PFAS associations with lipids in pregnant women across the trimesters of gestation. The different patterns of association from general population studies sheds light on the role of fetal nutrition during pregnancy affecting both lipids and PFAS in serum.

Perfluoroalkyl substances and blood pressure in exposed young population in the Veneto Region, Italy

Background

Residents in a large area of the Veneto Region (North-Eastern Italy) were exposed to perfluoroalkyl substances (PFASs) via drinking water. Studies on the association between PFASs and blood pressure (BP) levels are limited and results are inconsistent. Using cross-sectional data from the Regional health surveillance program, we aimed to quantify the associations between PFAS serum concentrations and blood pressure and hypertension prevalence.

Methods

The study included 16,224 individuals aged 20-39 years. Pregnant women (n = 327), participants with self-reported diagnosis or under treatment (n = 296) or with missing information on the selected covariates (n = 114) were excluded, leaving 15,487 subjects. Hypertension (HYP) was defined as any self-reported diagnosis, use of antihypertensive drugs, or raised systolic/diastolic blood pressure (SBP)≥140, DBP ≥90 mmHg). Serum PFASs were measured by HPLC-MS. Generalized additive models were used to investigate the relation between each PFAS (perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA)) ln transformed and by decile, and SBP, DBP, HYP, adjusted for potential confounders.

Results

Both SBP and DBP increased significantly with an increase in the ln-transformed serum PFASs concentration in a monotonic way. The predicted increase in SBP and DBP were 1.62 (95% CI = 0.69, 2.55), 1.64 mmHg (95% CI = 0.96, 2.31) from lowest to highest decile of PFOA. The associations were stronger for SBP in men and DBP in women. One unit increase in each ln-PFAS was positively associated with an increased odds of HYP in men: PFOA OR = 1.07 (1.01-1.14), PFOS OR = 1.18 (1.05-1.32), PFHxS OR = 1.11 (1.03-1.19), PFNA OR = 1.19 (1.01-1.41).

Conclusions

Our findings suggest that exposure to PFAS is associated with increased blood pressure and thus may contribute as a risk factor for the development of cardiovascular diseases.

Key messages

Serum PFASs were associated with raised systolic blood pressure in men and diastolic blood pressure in women in a large highly exposed young adult population. Serum PFASs were associated with raised prevalence of hypertension in men.

Use of public water supply fluoride concentration as an indicator of population exposure to fluoride in England 1995-2015

Public health monitoring of Community Water Fluoridation (CWF) schemes requires estimates of exposure to fluoride in public water supplies (PWS). We aimed to use routine data to estimate population exposure to PWS-fluoride in England and to determine whether PWS-fluoride exposure from 2005 to 2015 could be used as a proxy for exposure for 1995-2004, when fluoride concentration data that could be linked to population health data were unavailable. We calculated annual mean water supply zone PWS-fluoride concentrations from monitoring data for 1995-2015, stratified by fluoridation scheme-flagging. We allocated annual 2005-2015 mean PWS-fluoride concentrations to small area boundaries to describe population exposure within five concentration categories (< 0.1 to ≥ 0.7 mg/L). We compared zone-level 1995-2004 and 2005-2015 mean PWS-fluoride concentrations using Spearman correlation. Most (72%) of the population received PWS with < 0.2 mg/L fluoride and 10% with ≥ 0.7 mg/L. Fluoride concentrations in 1995-2004 and 2005-2015 were similar (median 0.11 mg/L (lower quartile-upper quartile (LQ-UQ) 0.06-0.17) and 0.11 mg/L (LQ-UQ 0.07-0.17), respectively) and highly correlated (coefficient 0.93) if un-fluoridated but differed (1995-2004 median 0.78 mg/L (LQ-UQ 0.59-0.92); 2005-2015 0.84 mg/L (LQ-UQ 0.72-0.95)) and correlated weakly (coefficient 0.31) if fluoridated. Fluoride concentrations in 2005-2015 approximate those in 1995-2004 but with a greater risk of misclassification in fluoridation schemes.

The onset of star formation 250 million years after the Big Bang

A fundamental quest of modern astronomy is to locate the earliest galaxies and study how they influenced the intergalactic medium a few hundred million years after the Big Bang^1-3. The abundance of star-forming galaxies is known to decline^4,5 from redshifts of about 6 to 10, but a key question is the extent of star formation at even earlier times, corresponding to the period when the first galaxies might have emerged. Here we report spectroscopic observations of MACS1149-JD1 ⁶ , a gravitationally lensed galaxy observed when the Universe was less than four per cent of its present age. We detect an emission line of doubly ionized oxygen at a redshift of 9.1096 ± 0.0006, with an uncertainty of one standard deviation. This precisely determined redshift indicates that the red rest-frame optical colour arises from a dominant stellar component that formed about 250 million years after the Big Bang, corresponding to a redshift of about 15. Our results indicate that it may be possible to detect such early episodes of star formation in similar galaxies with future telescopes.

Comparison of non-contact infrared skin thermometers

Non-contact infra-red skin thermometers (NCITs) are becoming more prevalent for use in medical diagnostics. Not only are they used as an alternative means of estimating core body temperature but also to assess the diabetic foot for signs of inflammation prior to ulceration. Previous investigations have compared the performance of NCITs in a clinical setting against other gold standard methods. However, there have been no previous investigations comparing the performance of NCITs in assessing temperature measurement capability traceable to the International Temperature Scale of 1990 (ITS-90). A metrological assessment of nine common NCITs was carried out over the temperature range of 15-45 °C using the National Physical Laboratory's blackbody reference sources to identify their accuracy, repeatability, size-of-source and distance effects. The results are concerning in that five of the NCITs fell far outside the accuracy range stated by their manufacturers as well as the medical standard to which the NCITs are supposed to adhere. Furthermore, a 6 °C step change in measurement error over the temperature range of interest for the diabetic foot was found for one NCIT. These results have implications for all clinicians using NCITs for temperature measurement and demonstrate the need for traceable calibration to ITS-90.

Surface wipe and bulk sampling of household dust: arsenic exposure in Cornwall, UK

Dust elemental levels can be expressed as concentrations (bulk samples) or surface loadings (wipe samples). Wipe sampling has not been widely adopted for elements other than lead (Pb). In this study, 433 wipe samples from 130 households in south west England - a region of widespread, natural and anthropogenic arsenic contamination linked with previous mining activities-were analysed to (i) quantify loadings of arsenic (As); (ii) assess the quality of wipe data using QA/QC criteria; (iii) estimate, using published ingestion rates, human exposure to As in dust using loadings and concentrations from 97 bulk samples and (iv) comparatively assess the performance of wipe and bulk sampling using associations with As biomonitoring data (urine, toenails and hair). Good QC performance was observed for wipes: strong agreement between field duplicates, non-detectable contamination of field blank wipes and good reference material recoveries. Arsenic loadings exceeded an existing urban background benchmark in 67 (52%) households. No exceedances of tolerable daily As intake were observed for adult exposure estimates but infant estimates exceeded for 1 household. Infant estimates calculated using bulk concentrations resulted in 4 (3%) exceedances. Neither wipe nor bulk As metrics were sufficiently better predictors of As in biospecimens. Sampling strategies, analytical protocols, exposure metrics and assessment criteria require refinement to validate dust sampling methodologies.

Variability in the chemistry of private drinking water supplies and the impact of domestic treatment systems on water quality

Tap water from 497 properties using private water supplies, in an area of metalliferous and arsenic mineralisation (Cornwall, UK), was measured to assess the extent of compliance with chemical drinking water quality standards, and how this is influenced by householder water treatment decisions. The proportion of analyses exceeding water quality standards were high, with 65 % of tap water samples exceeding one or more chemical standards. The highest exceedances for health-based standards were nitrate (11 %) and arsenic (5 %). Arsenic had a maximum observed concentration of 440 µg/L. Exceedances were also high for pH (47 %), manganese (12 %) and aluminium (7 %), for which standards are set primarily on aesthetic grounds. However, the highest observed concentrations of manganese and aluminium also exceeded relevant health-based guidelines. Significant reductions in concentrations of aluminium, cadmium, copper, lead and/or nickel were found in tap waters where households were successfully treating low-pH groundwaters, and similar adventitious results were found for arsenic and nickel where treatment was installed for iron and/or manganese removal, and successful treatment specifically to decrease tap water arsenic concentrations was observed at two properties where it was installed. However, 31 % of samples where pH treatment was reported had pH < 6.5 (the minimum value in the drinking water regulations), suggesting widespread problems with system maintenance. Other examples of ineffectual treatment are seen in failed responses post-treatment, including for nitrate. This demonstrates that even where the tap waters are considered to be treated, they may still fail one or more drinking water quality standards. We find that the degree of drinking water standard exceedances warrant further work to understand environmental controls and the location of high concentrations. We also found that residents were more willing to accept drinking water with high metal (iron and manganese) concentrations than international guidelines assume. These findings point to the need for regulators to reinforce the guidance on drinking water quality standards to private water supply users, and the benefits to long-term health of complying with these, even in areas where treated mains water is widely available.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Foreign Medical Teams in support of the Ebola outbreak: a UK military model of pre-deployment training and assurance

We discuss the training methodology developed and utilised to prepare UK military medical teams to establish an Ebola Treatment Centre in Sierra Leone. We highlight the process of identifying and mitigating nosocomial risk in the Pre-Deployment Training process, encompassing the challenges of developing, training and assuring a capability at pace, which deployed to deliver high quality clinical care to patients with Ebola Virus Disease.

Entropy-based particle correspondence for shape populations

PURPOSE

Statistical shape analysis of anatomical structures plays an important role in many medical image analysis applications such as understanding the structural changes in anatomy in various stages of growth or disease. Establishing accurate correspondence across object populations is essential for such statistical shape analysis studies.

METHODS

In this paper, we present an entropy-based correspondence framework for computing point-based correspondence among populations of surfaces in a groupwise manner. This robust framework is parameterization-free and computationally efficient. We review the core principles of this method as well as various extensions to deal effectively with surfaces of complex geometry and application-driven correspondence metrics.

RESULTS

We apply our method to synthetic and biological datasets to illustrate the concepts proposed and compare the performance of our framework to existing techniques.

CONCLUSIONS

Through the numerous extensions and variations presented here, we create a very flexible framework that can effectively handle objects of various topologies, multi-object complexes, open surfaces, and objects of complex geometry such as high-curvature regions or extremely thin features.

Prolonged exposure to arsenic in UK private water supplies: toenail, hair and drinking water concentrations

Chronic exposure to arsenic (As) in drinking water is an established cause of cancer and other adverse health effects. Arsenic concentrations >10 μg L(-1) were previously measured in 5% of private water supplies (PWS) in Cornwall, UK. The present study investigated prolongued exposure to As by measuring biomarkers in hair and toenail samples from 212 volunteers and repeated measurements of As in drinking water from 127 households served by PWS. Strong positive Pearson correlations (rp = 0.95) indicated stability of water As concentrations over the time period investigated (up to 31 months). Drinking water As concentrations were positively correlated with toenail (rp = 0.53) and hair (rp = 0.38) As concentrations - indicative of prolonged exposure. Analysis of washing procedure solutions provided strong evidence of the effective removal of exogenous As from toenail samples. Significantly higher As concentrations were measured in hair samples from males and smokers and As concentrations in toenails were negatively associated with age. A positive association between seafood consumption and toenail As and a negative association between home-grown vegetable consumption and hair As was observed for volunteers exposed to <1 As μg L(-1) in drinking water. These findings have important implications regarding the interpretation of toenail and hair biomarkers. Substantial variation in biomarker As concentrations remained unaccounted for, with soil and dust exposure as possible explanations.

Formulating and improving care while mitigating risk in a military Ebola virus disease treatment unit

This paper describes the development of the UK military's Ebola Virus Disease Treatment Unit (EVD TU) that was deployed to Sierra Leone as part of the UK response to the West African Ebola virus disease (EVD) epidemic in 2014 and 2015. It highlights specific challenges faced within this unique Field Hospital environment. The military EVD TU was initially established to provide confidence to international healthcare workers coming to Sierra Leone to assist in the international response to the EVD epidemic and formed a key part of the action plan by the UK's Department for International Development. It was designed and staffed to provide a high level of care to those admitted with suspected or confirmed EVD and was prepared to admit the first patient within 6 weeks of the original activation order by the Ministry of Defence. This article outlines the main hazards perceived at the outset of the operation and the methods used to mitigate the risk to the healthcare workers at the EVD TU. The article examines the mechanisms that enabled the hospital to respond positively to challenges that emerged during the deployment, while simultaneously reducing the risk to the healthcare workers involved in care delivery.

Urinary arsenic profiles reveal exposures to inorganic arsenic from private drinking water supplies in Cornwall, UK

Private water supplies (PWS) in Cornwall, South West England exceeded the current WHO guidance value and UK prescribed concentration or value (PCV) for arsenic of 10 μg/L in 5% of properties surveyed (n = 497). In this follow-up study, the first of its kind in the UK, volunteers (n = 207) from 127 households who used their PWS for drinking, provided urine and drinking water samples for total As determination by inductively coupled plasma mass spectrometry (ICP-MS) and urinary As speciation by high performance liquid chromatography ICP-MS (HPLC-ICP-MS). Arsenic concentrations exceeding 10 μg/L were found in the PWS of 10% of the volunteers. Unadjusted total urinary As concentrations were poorly correlated (Spearman's ρ = 0.36 (P < 0.001)) with PWS As largely due to the use of spot urine samples and the dominance of arsenobetaine (AB) from seafood sources. However, the osmolality adjusted sum, U-As(IMM), of urinary inorganic As species, arsenite (As(III)) and arsenate (As(V)), and their metabolites, methylarsonate (MA) and dimethylarsinate (DMA), was found to strongly correlate (Spearman's ρ: 0.62 (P < 0.001)) with PWS As, indicating private water supplies as the dominant source of inorganic As exposure in the study population of PWS users.

Caring for critically ill patients with ebola virus disease. Perspectives from West Africa

The largest ever Ebola virus disease outbreak is ravaging West Africa. The constellation of little public health infrastructure, low levels of health literacy, limited acute care and infection prevention and control resources, densely populated areas, and a highly transmissible and lethal viral infection have led to thousands of confirmed, probable, or suspected cases thus far. Ebola virus disease is characterized by a febrile severe illness with profound gastrointestinal manifestations and is complicated by intravascular volume depletion, shock, profound electrolyte abnormalities, and organ dysfunction. Despite no proven Ebola virus-specific medical therapies, the potential effect of supportive care is great for a condition with high baseline mortality and one usually occurring in resource-constrained settings. With more personnel, basic monitoring, and supportive treatment, many of the sickest patients with Ebola virus disease do not need to die. Ebola virus disease represents an illness ready for a paradigm shift in care delivery and outcomes, and the profession of critical care medicine can and should be instrumental in helping this happen.

Hydrodynamics of fossil fishes

From their earliest origins, fishes have developed a suite of adaptations for locomotion in water, which determine performance and ultimately fitness. Even without data from behaviour, soft tissue and extant relatives, it is possible to infer a wealth of palaeobiological and palaeoecological information. As in extant species, aspects of gross morphology such as streamlining, fin position and tail type are optimized even in the earliest fishes, indicating similar life strategies have been present throughout their evolutionary history. As hydrodynamical studies become more sophisticated, increasingly complex fluid movement can be modelled, including vortex formation and boundary layer control. Drag-reducing riblets ornamenting the scales of fast-moving sharks have been subjected to particularly intense research, but this has not been extended to extinct forms. Riblets are a convergent adaptation seen in many Palaeozoic fishes, and probably served a similar hydrodynamic purpose. Conversely, structures which appear to increase skin friction may act as turbulisors, reducing overall drag while serving a protective function. Here, we examine the diverse adaptions that contribute to drag reduction in modern fishes and review the few attempts to elucidate the hydrodynamics of extinct forms.

Root biomass production in populations of six rooted macrophytes in response to Cu exposure: intra-specific variability versus constitutive-like tolerance

Intra-specific variability of root biomass production (RP) of six rooted macrophytes, i.e. Juncus effusus, Phragmites australis, Schoenoplectus lacustris, Typha latifolia, Phalaris arundinacea, and Iris pseudacorus grown from clones, in response to Cu exposure was investigated. Root biomass production varied widely for all these macrophytes in control conditions (0.08 μM) according to the sampling site. Root biomass production of T. latifolia and I. pseudacorus in the 2.5-25 μM Cu range depended on the sampling location but not on the Cu dose in the growth medium. For P. australis, J. effusus, S. lacustris, and P. arundinacea, an intra-specific variability of RP depending on both the sampling location and the Cu-dose was evidenced. This intra-specific variability of RP depending on the sampling location and of Cu-tolerance for these last four species suggests that Cu constitutive tolerance for all rooted macrophytes is not a species-wide trait but it exhibits variability for some species.

Sex differences in recovery from PTSD in male and female interpersonal assault survivors

Men and women differ in exposure to trauma and the development of posttraumatic stress disorder (PTSD); however, research regarding sex differences in recovery from PTSD has been sparse. This study evaluated the treatment response trajectory for 69 male and female interpersonal assault survivors, using a modified Cognitive Processing Therapy (CPT) protocol that allowed survivors to receive up to18 sessions of CPT, with treatment end determined by therapy progress. Few sex differences were observed in trauma history, baseline PTSD and depressive severity, Axis I comorbidity, anger, guilt and dissociation. Women did report more sexual assault in adulthood and elevated baseline guilt cognitions, whereas men reported more baseline anger directed inward. Attrition and total number of sessions did not differ by sex. Over the course of treatment and follow-up, men and women demonstrated similar rates of change in PTSD and depressive symptoms. However, medium effect sizes on both of these primary outcomes at the 3-month follow-up assessment favored women. Several differences in the slope of change emerged on secondary outcomes such that women evidenced more rapid gains on global guilt, guilt cognitions, anger/irritability, and dissociation. Results suggest that male survivors may warrant additional attention to address these important clinical correlates.

Escherichia coli contamination and health aspects of soil and tomatoes (Solanum lycopersicum L.) subsurface drip irrigated with on-site treated domestic wastewater

Faecal contamination of soil and tomatoes irrigated by sprinkler as well as surface and subsurface drip irrigation with treated domestic wastewater were compared in 2007 and 2008 at experimental sites in Crete and Italy. Wastewater was treated by Membrane Bio Reactor (MBR) technology, gravel filtration or UV-treatment before used for irrigation. Irrigation water, soil and tomato samples were collected during two cropping seasons and enumerated for the faecal indicator bacterium Escherichia coli and helminth eggs. The study found elevated levels of E. coli in irrigation water (mean: Italy 1753 cell forming unit (cfu) per 100 ml and Crete 488 cfu per 100 ml) and low concentrations of E. coli in soil (mean: Italy 95 cfu g(-1) and Crete 33 cfu g(-1)). Only two out of 84 tomato samples in Crete contained E. coli (mean: 2700 cfu g(-1)) while tomatoes from Italy were free of E. coli. No helminth eggs were found in the irrigation water or on the tomatoes from Crete. Two tomato samples out of 36 from Italy were contaminated by helminth eggs (mean: 0.18 eggs g(-1)) and had been irrigated with treated wastewater and tap water, respectively. Pulsed Field Gel Electrophoresis DNA fingerprints of E. coli collected during 2008 showed no identical pattern between water and soil isolates which indicates contribution from other environmental sources with E. coli, e.g. wildlife. A quantitative microbial risk assessment (QMRA) model with Monte Carlo simulations adopted by the World Health Organization (WHO) found the use of tap water and treated wastewater to be associated with risks that exceed permissible limits as proposed by the WHO (1.0 × 10(-3) disease risk per person per year) for the accidental ingestion of irrigated soil by farmers (Crete: 0.67 pppy and Italy: 1.0 pppy). The QMRA found that the consumption of tomatoes in Italy was deemed to be safe while permissible limits were exceeded in Crete (1.0 pppy). Overall the quality of tomatoes was safe for human consumption since the disease risk found on Crete was based on only two contaminated tomato samples. It is a fundamental limitation of the WHO QMRA model that it is not based on actual pathogen numbers, but rather on numbers of E. coli converted to estimated pathogen numbers, since it is widely accepted that there is poor correlation between E. coli and viral and parasite pathogens. Our findings also stress the importance of the external environment, typically wildlife, as sources of faecal contamination.

Effect of lipids on insect cell growth and expression of recombinant proteins in serum-free medium

The lipid emulsion components of a serum-free insect cell medium were varied and evaluated for effects on cell growth and recombinant protein expression. The growth of High-Five(TM) cells was significantly affected by polyol Pluronic F-68 and Tween-80, but not by lipids. Pluronic was essential for cell growth, while Tween-80 was required to achieve maximum cell densities. A dose response effect was observed for Tween-80 with optimal cell growth at a concentration of 25 mg/l. Cholesterol had a minor effect on cell growth, but was essential for the expression of recombinant proteins. The expression of β-galactosidase (β-gal) was directly affected by cholesterol with optimal expression at a concentration of 5.4 mg/l. Vitamin E, important as an antioxidant to stabilize lipids, did not directly affect recombinant protein expression. Although lipids were not required for cell growth, the presence of lipids were required during the cell growth phase in order to achieve efficient infection with baculovirus. These studies help to define the important components, and range of concentrations, for lipid emulsions which can effectively replace serum in insect cell culture.

Quality Control of Diffusion Weighted Images

Diffusion Tensor Imaging (DTI) has become an important MRI procedure to investigate the integrity of white matter in brain in vivo. DTI is estimated from a series of acquired Diffusion Weighted Imaging (DWI) volumes. DWI data suffers from inherent low SNR, overall long scanning time of multiple directional encoding with correspondingly large risk to encounter several kinds of artifacts. These artifacts can be too severe for a correct and stable estimation of the diffusion tensor. Thus, a quality control (QC) procedure is absolutely necessary for DTI studies. Currently, routine DTI QC procedures are conducted manually by visually checking the DWI data set in a gradient by gradient and slice by slice way. The results often suffer from low consistence across different data sets, lack of agreement of different experts, and difficulty to judge motion artifacts by qualitative inspection. Additionally considerable manpower is needed for this step due to the large number of images to QC, which is common for group comparison and longitudinal studies, especially with increasing number of diffusion gradient directions. We present a framework for automatic DWI QC. We developed a tool called DTIPrep which pipelines the QC steps with a detailed protocoling and reporting facility. And it is fully open source. This framework/tool has been successfully applied to several DTI studies with several hundred DWIs in our lab as well as collaborating labs in Utah and Iowa. In our studies, the tool provides a crucial piece for robust DTI analysis in brain white matter study.

Cancer morbidity in British military veterans included in chemical warfare agent experiments at Porton Down: cohort study

OBJECTIVE

To determine cancer morbidity in members of the armed forces who took part in tests of chemical warfare agents from 1941 to 1989.

DESIGN

Historical cohort study, with cohort members followed up to December 2004.

DATA SOURCE

Archive of UK government research facility at Porton Down, UK military personnel records, and national death and cancer records.

PARTICIPANTS

All veterans included in the cohort study of mortality, excluding those known to have died or been lost to follow-up before 1 January 1971 when the UK cancer registration system commenced: 17,013 male members of the UK armed forces who took part in tests (Porton Down veterans) and a similar group of 16,520 men who did not (non-Porton Down veterans).

MAIN OUTCOME MEASURES

Cancer morbidity in each group of veterans; rate ratios, with 95% confidence intervals, adjusted for age group and calendar period.

RESULTS

3457 cancers were reported in the Porton Down veterans compared with 3380 cancers in the non-Porton Down veterans. While overall cancer morbidity was the same in both groups (rate ratio 1.00, 95% confidence interval 0.95 to 1.05), Porton Down veterans had higher rates of ill defined malignant neoplasms (1.12, 1.02 to 1.22), in situ neoplasms (1.45, 1.06 to 2.00), and those of uncertain or unknown behaviour (1.32, 1.01 to 1.73).

CONCLUSION

Overall cancer morbidity in Porton Down veterans was no different from that in non-Porton Down veterans.

Mortality in British military participants in human experimental research into chemical warfare agents at Porton Down: cohort study

OBJECTIVE

To investigate any long term effects on mortality in participants in experimental research related to chemical warfare agents from 1941 to 1989.

DESIGN

Historical cohort study. Data sources Archive of UK government research facility at Porton Down, UK military personnel records, and national death and cancer records. Participants 18,276 male members of the UK armed forces who had spent one or more short periods (median 4 days between first and last test) at Porton Down and a comparison group of 17,600 non-Porton Down veterans followed to 31 December 2004.

MAIN OUTCOME MEASURES

Mortality rate ratio of Porton Down compared with non-Porton Down veterans and standardised mortality ratio of each veteran group compared with the general population. Both ratios adjusted for age group and calendar period.

RESULTS

Porton Down veterans were similar to non-Porton Down veterans in year of enlistment (median 1951) but had longer military service (median 6.2 v 5.0 years). After a median follow-up of 43 years, 40% (7306) of Porton Down and 39% (6900) of non-Porton Down veterans had died. All cause mortality was slightly greater in Porton Down veterans (rate ratio 1.06, 95% confidence interval 1.03 to 1.10, P<0.001), more so for deaths outside the UK (1.26, 1.09 to 1.46). Of 12 cause specific groups examined, rate ratios in Porton Down veterans were increased for deaths attributed to infectious and parasitic (1.57, 1.07 to 2.29), genitourinary (1.46, 1.04 to 2.04), circulatory (1.07, 1.01 to 1.12), and external (non-medical) (1.17, 1.00 to 1.37) causes and decreased for deaths attributed to in situ, benign, and unspecified neoplasms (0.60, 0.37 to 0.99). There was no clear relation between type of chemical exposure and cause specific mortality. The mortality in both groups of veterans was lower than that in the general population (standardised mortality ratio 0.88, 0.85 to 0.90; 0.82, 0.80 to 0.84).

CONCLUSIONS

Mortality was slightly higher in Porton Down than non-Porton Down veterans. With lack of information on other important factors, such as smoking or service overseas, it is not possible to attribute the small excess mortality to chemical exposures at Porton Down.

Exposure to indoor mould and children's respiratory health in the PATY study

BACKGROUND

Living in a damp or mouldy home reportedly damages children's respiratory health, yet mould appears not to be a prominent risk factor in the public's perception. Analyses of data on over 58,000 children from the Pollution and the Young (PATY) study are presented. In this collaboration, researchers from 12 cross-sectional studies pooled their data to assess the effects of air quality on a spectrum of children's respiratory disorders.

METHOD

Original studies were conducted in Russia, North America and 10 countries in Eastern and Western Europe. Pooled analyses were restricted to children aged 6-12 years. Associations between visible mould reported in the household and a spectrum of eight respiratory and allergic symptoms were estimated within each study. Logistic regressions were used, controlling for individual risk factors and for study area. Heterogeneity between study-specific results and mean effects (allowing for heterogeneity) were estimated using meta-analysis.

RESULTS

Visible mould was reported by 13.9% of respondents in Russia, increasing to 39.1% in North America. Positive associations between exposure to mould and children's respiratory health were seen with considerable consistency across studies and across outcomes. Confounder-adjusted combined ORs ranged from 1.30 (95% CI 1.22 to 1.39) for "nocturnal cough" to 1.50 (1.31 to 1.73) for "morning cough". Evidence of stronger effects in more crowded households was statistically significant for only asthma and sensitivity to inhaled allergens. No consistent interactions between mould and age, sex or parental smoking were found.

CONCLUSION

Indoor mould exposure was consistently associated with adverse respiratory health outcomes in children living in these diverse countries.

Exposure to indoor mould and children's respiratory health in the PATY study

BACKGROUND

Living in a damp or mouldy home reportedly damages children's respiratory health, yet mould appears not to be a prominent risk factor in the public's perception. Analyses of data on over 58,000 children from the Pollution and the Young (PATY) study are presented. In this collaboration, researchers from 12 cross-sectional studies pooled their data to assess the effects of air quality on a spectrum of children's respiratory disorders.

METHOD

Original studies were conducted in Russia, North America and 10 countries in Eastern and Western Europe. Pooled analyses were restricted to children aged 6-12 years. Associations between visible mould reported in the household and a spectrum of eight respiratory and allergic symptoms were estimated within each study. Logistic regressions were used, controlling for individual risk factors and for study area. Heterogeneity between study-specific results and mean effects (allowing for heterogeneity) were estimated using meta-analysis.

RESULTS

Visible mould was reported by 13.9% of respondents in Russia, increasing to 39.1% in North America. Positive associations between exposure to mould and children's respiratory health were seen with considerable consistency across studies and across outcomes. Confounder-adjusted combined ORs ranged from 1.30 (95% CI 1.22 to 1.39) for "nocturnal cough" to 1.50 (1.31 to 1.73) for "morning cough". Evidence of stronger effects in more crowded households was statistically significant for only asthma and sensitivity to inhaled allergens. No consistent interactions between mould and age, sex or parental smoking were found.

CONCLUSION

Indoor mould exposure was consistently associated with adverse respiratory health outcomes in children living in these diverse countries.