Built Environment and SARS-CoV-2 Transmission in Long-Term Care Facilities: Cross-Sectional Survey and Data Linkage

OBJECTIVES

To describe the built environment in long-term care facilities (LTCF) and its association with introduction and transmission of SARS-CoV-2 infection.

DESIGN

Cross-sectional survey with linkage to routine surveillance data.

SETTING AND PARTICIPANTS

LTCFs in England caring for adults ≥65 years old, participating in the VIVALDI study (ISRCTN14447421) were eligible. Data were included from residents and staff.

METHODS

Cross-sectional survey of the LTCF built environment with linkage to routinely collected asymptomatic and symptomatic SARS-CoV-2 testing and vaccination data between September 1, 2020, and March 31, 2022. We used individual and LTCF level Poisson and Negative Binomial regression models to identify risk factors for 4 outcomes: incidence rate of resident infections and outbreaks, outbreak size, and duration. We considered interactions with variant transmissibility (pre vs post Omicron dominance).

RESULTS

A total of 134 of 151 (88.7%) LTCFs participated in the survey, contributing data for 13,010 residents and 17,766 staff. After adjustment and stratification, outbreak incidence (measuring infection introduction) was only associated with SARS-CoV-2 incidence in the community [incidence rate ratio (IRR) for high vs low incidence, 2.84; 95% CI, 1.85-4.36]. Characteristics of the built environment were associated with transmission outcomes and differed by variant transmissibility. For resident infection incidence, factors included number of storeys (0.64; 0.43-0.97) and bedrooms (1.04; 1.02-1.06), and purpose-built vs converted buildings (1.99; 1.08-3.69). Air quality was associated with outbreak size (dry vs just right 1.46; 1.00-2.13). Funding model (0.99; 0.99-1.00), crowding (0.98; 0.96-0.99), and bedroom temperature (1.15; 1.01-1.32) were associated with outbreak duration.

CONCLUSIONS AND IMPLICATIONS

We describe previously undocumented diversity in LTCF built environments. LTCFs have limited opportunities to prevent SARS-CoV-2 introduction, which was only driven by community incidence. However, adjusting the built environment, for example by isolating infected residents or improving airflow, may reduce transmission, although data quality was limited by subjectivity. Identifying LTCF built environment modifications that prevent infection transmission should be a research priority.

Shaping care home COVID-19 testing policy: a protocol for a pragmatic cluster randomised controlled trial of asymptomatic testing compared with standard care in care home staff (VIVALDI-CT)

INTRODUCTION

Care home residents have experienced significant morbidity, mortality and disruption following outbreaks of SARS-CoV-2. Regular SARS-CoV-2 testing of care home staff was introduced to reduce transmission of infection, but it is unclear whether this remains beneficial. This trial aims to investigate whether use of regular asymptomatic staff testing, alongside funding to reimburse sick pay for those who test positive and meet costs of employing agency staff, is a feasible and effective strategy to reduce COVID-19 impact in care homes.

METHODS AND ANALYSIS

The VIVALDI-Clinical Trial is a multicentre, open-label, cluster randomised controlled, phase III/IV superiority trial in up to 280 residential and/or nursing homes in England providing care to adults aged >65 years. All regular and agency staff will be enrolled, excepting those who opt out. Homes will be randomised to the intervention arm (twice weekly asymptomatic staff testing for SARS-CoV-2) or the control arm (current national testing guidance). Staff who test positive for SARS-CoV-2 will self-isolate and receive sick pay. Care providers will be reimbursed for costs associated with employing temporary staff to backfill for absence arising directly from the trial.The trial will be delivered by a multidisciplinary research team through a series of five work packages.The primary outcome is the incidence of COVID-19-related hospital admissions in residents. Secondary outcomes include the number and duration of outbreaks and home closures. Health economic and modelling analyses will investigate the cost-effectiveness and cost consequences of the testing intervention. A process evaluation using qualitative interviews will be conducted to understand intervention roll out and identify areas for optimisation to inform future intervention scale-up, should the testing approach prove effective and cost-effective. Stakeholder engagement will be undertaken to enable the sector to plan for results and their implications and to coproduce recommendations on the use of testing for policy-makers.

ETHICS AND DISSEMINATION

The study has been approved by the London-Bromley Research Ethics Committee (reference number 22/LO/0846) and the Health Research Authority (22/CAG/0165). The results of the trial will be disseminated regardless of the direction of effect. The publication of the results will comply with a trial-specific publication policy and will include submission to open access journals. A lay summary of the results will also be produced to disseminate the results to participants.

TRIAL REGISTRATION NUMBER

ISRCTN13296529.

The neurophysiological effect of NMDA-R antagonism of frontotemporal lobar degeneration is conditional on individual GABA concentration

There is a pressing need to accelerate therapeutic strategies against the syndromes caused by frontotemporal lobar degeneration, including symptomatic treatments. One approach is for experimental medicine, coupling neurophysiological studies of the mechanisms of disease with pharmacological interventions aimed at restoring neurochemical deficits. Here we consider the role of glutamatergic deficits and their potential as targets for treatment. We performed a double-blind placebo-controlled crossover pharmaco-magnetoencephalography study in 20 people with symptomatic frontotemporal lobar degeneration (10 behavioural variant frontotemporal dementia, 10 progressive supranuclear palsy) and 19 healthy age- and gender-matched controls. Both magnetoencephalography sessions recorded a roving auditory oddball paradigm: on placebo or following 10 mg memantine, an uncompetitive NMDA-receptor antagonist. Ultra-high-field magnetic resonance spectroscopy confirmed lower concentrations of GABA in the right inferior frontal gyrus of people with frontotemporal lobar degeneration. While memantine showed a subtle effect on early-auditory processing in patients, there was no significant main effect of memantine on the magnitude of the mismatch negativity (MMN) response in the right frontotemporal cortex in patients or controls. However, the change in the right auditory cortex MMN response to memantine (vs. placebo) in patients correlated with individuals' prefrontal GABA concentration. There was no moderating effect of glutamate concentration or cortical atrophy. This proof-of-concept study demonstrates the potential for baseline dependency in the pharmacological restoration of neurotransmitter deficits to influence cognitive neurophysiology in neurodegenerative disease. With changes to multiple neurotransmitters in frontotemporal lobar degeneration, we suggest that individuals' balance of excitation and inhibition may determine drug efficacy, with implications for drug selection and patient stratification in future clinical trials.

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.

Association between Shiga Toxin-Producing Escherichia coli O157:H7 stx Gene Subtype and Disease Severity, England, 2009-2019

Signs and symptoms of Shiga toxin–producing Escherichia coli (STEC) serogroup O157:H7 infection range from mild gastrointestinal to bloody diarrhea and hemolytic uremic syndrome (HUS). We assessed the association between Shiga toxin gene (stx) subtype and disease severity for »3,000 patients with STEC O157:H7 in England during 2009–2019. Odds of bloody diarrhea, HUS, or both, were significantly higher for patients infected with STEC O157:H7 possessing stx2a only or stx2a combined with other stx subtypes. Odds of severe signs/symptoms were significantly higher for isolates encoding stx2a only and belonging to sublineage Ic and lineage I/II than for those encoding stx2a only and belonging to sublineage IIb, indicating that stx2a is not the only driver causing HUS. Strains of STEC O157:H7 that had stx1a were also significantly more associated with severe disease than strains with stx2c only. This finding confounds public health risk assessment algorithms based on detection of stx2 as a predictor of severe disease.

Highly Pathogenic Clone of Shiga Toxin-Producing Escherichia coli O157:H7, England and Wales

We used whole-genome sequencing to investigate the evolutionary context of an emerging highly pathogenic strain of Shiga toxin–producing Escherichia coli (STEC) O157:H7 in England and Wales. A timed phylogeny of sublineage IIb revealed that the emerging clone evolved from a STEC O157:H7 stx-negative ancestor ≈10 years ago after acquisition of a bacteriophage encoding Shiga toxin (stx) 2a, which in turn had evolved from a stx2c progenitor ≈20 years ago. Infection with the stx2a clone was a significant risk factor for bloody diarrhea (OR 4.61, 95% CI 2.24–9.48; p<0.001), compared with infection with other strains within sublineage IIb. Clinical symptoms of cases infected with sublineage IIb stx2c and stx-negative clones were comparable, despite the loss of stx2c. Our analysis highlighted the highly dynamic nature of STEC O157:H7 Stx-encoding bacteriophages and revealed the evolutionary history of a highly pathogenic clone emerging within sublineage IIb, a sublineage not previously associated with severe clinical symptoms.

Estimating the burden of care home gastroenteritis outbreaks in England, 2014-2016

BACKGROUND

Outbreaks of infectious gastroenteritis in care homes are common, with norovirus a frequent cause. In England there is no co-ordinated national surveillance system. We aimed to estimate the burden of these outbreaks.

METHODS

Using a generalised linear mixed effects regression model we described the relationship between the observed number of care home outbreaks and covariates. Estimated model parameters were used to infer uplift in the number of outbreaks expected if all areas were subjected to enhanced surveillance. From this we then estimated the total burden of care home gastroenteritis outbreaks in this period.

RESULTS

We estimated a total of 14,146 care home gastroenteritis outbreaks in England during 2014-2016; this is 47% higher than the reported total and a rate of 32.4 outbreaks per 100 care homes per year. The median number of outbreaks from the model estimates was 31 (IQR 20-46) compared to 19 (IQR 12-34) reported from routine surveillance.

CONCLUSIONS

This estimated care home gastroenteritis burden in England indicates that current surveillance substantially underestimates the number of outbreaks, by almost half. Improving this surveillance could provide better epidemiological knowledge of the burden of norovirus to inform public health policy, particularly with the advent of norovirus vaccines.

Sociodemographic and clinical risk factors for paediatric typical haemolytic uraemic syndrome: retrospective cohort study

OBJECTIVES

Haemolytic uraemic syndrome (HUS) following Shiga toxin-producing Escherichia coli (STEC) infection is the the most common cause of acute renal failure among children in the UK. This study explored differential progression from STEC to HUS by social, demographic and clinical risk factors.

METHODS

We undertook a retrospective cohort study linking two datasets. We extracted data on paediatric STEC and HUS cases identified in the Public Health England National Enhanced Surveillance System for STEC and British Paediatric Surveillance Unit HUS surveillance from 1 October 2011 to 31 October 2014. Using logistic regression, we estimated the odds of HUS progression by risk factors.

RESULTS

1059 paediatric STEC cases were included in the study, of which 207 (19.55%, 95% CI 17% to 22%) developed HUS. In the fully adjusted model, the odds of progression to HUS were highest in those aged 1-4 years (OR 4.93, 95% CI 2.30 to 10.56, compared with 10-15 years), were infected with an Shiga toxin (stx) 2-only strain (OR 5.92, 95% CI 2.49 to 14.10), were prescribed antibiotics (OR 8.46, 95% CI 4.71 to 15.18) and had bloody diarrhoea (OR 3.56, 95% CI 2.04 to 6.24) or vomiting (OR 4.47, 95% CI 2.62 to 7.63), but there was no association with progression to HUS by socioeconomic circumstances or rurality.

CONCLUSION

Combining data from an active clinical surveillance system for HUS with the national enhanced STEC surveillance system suggests that 20% of diagnosed paediatric STEC infections in England resulted in HUS. No relationship was found with socioeconomic status or rurality of cases, but differences were demonstrated by age, stx type and presenting symptoms.

Estimating the Hospital Burden of Norovirus-Associated Gastroenteritis in England and Its Opportunity Costs for Nonadmitted Patients

Background

Norovirus places a substantial burden on healthcare systems, arising from infected patients, disease outbreaks, beds kept unoccupied for infection control, and staff absences due to infection. In settings with high rates of bed occupancy, opportunity costs arise from patients who cannot be admitted due to beds being unavailable. With several treatments and vaccines against norovirus in development, quantifying the expected economic burden is timely.

Methods

The number of inpatients with norovirus-associated gastroenteritis in England was modeled using infectious and noninfectious gastrointestinal Hospital Episode Statistics codes and laboratory reports of gastrointestinal pathogens collected at Public Health England. The excess length of stay from norovirus was estimated with a multistate model and local outbreak data. Unoccupied bed-days and staff absences were estimated from national outbreak surveillance. The burden was valued conventionally using accounting expenditures and wages, which we contrasted to the opportunity costs from forgone patients using a novel methodology.

Results

Between July 2013 and June 2016, 17.7% (95% confidence interval [CI], 15.6%‒21.6%) of primary and 23.8% (95% CI, 20.6%‒29.9%) of secondary gastrointestinal diagnoses were norovirus attributable. Annually, the estimated median 290000 (interquartile range, 282000‒297000) occupied and unoccupied bed-days used for norovirus displaced 57800 patients. Conventional costs for the National Health Service reached £107.6 million; the economic burden approximated to £297.7 million and a loss of 6300 quality-adjusted life-years annually.

Conclusions

In England, norovirus is now the second-largest contributor of the gastrointestinal hospital burden. With the projected impact being greater than previously estimated, improved capture of relevant opportunity costs seems imperative for diseases such as norovirus.

Correction to: Voriconazole-induced periostitis deformans: serial imaging in a patient with ANCA vasculitis

The original version of this paper unfortunately contained mistakes in the affiliations for all authors.

Voriconazole-induced periostitis deformans: serial imaging in a patient with ANCA vasculitis

OBJECTIVES

A 61-year-old with acute granulomatosis and polyangiitis developed Aspergillus fumigatus pneumonia after admission to the intensive care unit with a small bowel perforation. This occurred after immunosuppression (intravenous methylprednisolone, intravenous cyclophosphamide, and plasmapheresis) for his initial presentation with stage 3 acute kidney injury.

MATERIALS AND METHODS

The mycologist recommended long-term treatment with voriconazole after initial recovery.

RESULTS

After 7 months of treatment, the patient complained of joint pain and swelling in his hands. Radiographs, computed tomography, and single-photon emission computed tomography appearances were consistent with periostitis. A diagnosis of Voriconazole-induced periostitis deformans was made and the voriconazole was stopped. Plasma fluoride level was 278 μg/L (normal range < 50 μg/L). Discontinuation of voriconazole led to clinical improvement.

CONCLUSIONS

Periostitis deformans due to fluorosis is a rare complication of voriconazole treatment. The imaging in our case is unusually dramatic. We were able to track the evolution of periosteal reactions over serial imaging.

Non-invasive laminar inference with MEG: Comparison of methods and source inversion algorithms

Magnetoencephalography (MEG) is a direct measure of neuronal current flow; its anatomical resolution is therefore not constrained by physiology but rather by data quality and the models used to explain these data. Recent simulation work has shown that it is possible to distinguish between signals arising in the deep and superficial cortical laminae given accurate knowledge of these surfaces with respect to the MEG sensors. This previous work has focused around a single inversion scheme (multiple sparse priors) and a single global parametric fit metric (free energy). In this paper we use several different source inversion algorithms and both local and global, as well as parametric and non-parametric fit metrics in order to demonstrate the robustness of the discrimination between layers. We find that only algorithms with some sparsity constraint can successfully be used to make laminar discrimination. Importantly, local t-statistics, global cross-validation and free energy all provide robust and mutually corroborating metrics of fit. We show that discrimination accuracy is affected by patch size estimates, cortical surface features, and lead field strength, which suggests several possible future improvements to this technique. This study demonstrates the possibility of determining the laminar origin of MEG sensor activity, and thus directly testing theories of human cognition that involve laminar- and frequency-specific mechanisms. This possibility can now be achieved using recent developments in high precision MEG, most notably the use of subject-specific head-casts, which allow for significant increases in data quality and therefore anatomically precise MEG recordings.

Section

Analysis methods.

Classifications

Source localization: inverse problem; Source localization: other.

•

Laminar inferences can be made with MEG using both local and global fit metrics.

•

Source inversion algorithms with sparsity constraints performed best.

•

Classification is affected by patch size estimates, anatomy, and lead field strength.

The E-health Literacy Demands of Australia's My Health Record: A Heuristic Evaluation of Usability

Background

My Health Record is Australia's electronic personal health record system, which was introduced in July 2012. As of August 2017, approximately 21 percent of Australia's total population was registered to use My Health Record. Internationally, usability issues have been shown to negatively influence the uptake and use of electronic health record systems, and this scenario may particularly affect people who have low e-health literacy. It is likely that usability issues are negatively affecting the uptake and use of My Health Record in Australia.

Objective

To identify potential e-health literacy-related usability issues within My Health Record through a heuristic evaluation method.

Methods

Between September 14 and October 12, 2016, three of the authors conducted a heuristic evaluation of the two consumer-facing components of My Health Record-the information website and the electronic health record itself. These two components were evaluated against two sets of heuristics-the Health Literacy Online checklist and the Monkman Heuristics. The Health Literacy Online checklist and Monkman Heuristics are evidence-based checklists of web design elements with a focus on design for audiences with low health literacy. During this heuristic evaluation, the investigators individually navigated through the consumer-facing components of My Health Record, recording instances where the My Health Record did not conform to the checklist criteria. After the individual evaluations were completed, the investigators conferred and aggregated their results. From this process, a list of usability violations was constructed.

Results

When evaluated against the Health Literacy Online Checklist, the information website demonstrated violations in 12 of 35 criteria, and the electronic health record demonstrated violations in 16 of 35 criteria. When evaluated against the Monkman Heuristics, the information website demonstrated violations in 7 of 11 criteria, and the electronic health record demonstrated violations in 9 of 11 criteria. The identified violations included usability issues with the reading levels used within My Health Record, the graphic design elements, the layout of web pages, and a lack of images and audiovisual tools to support learning. Other important usability issues included a lack of translated resources, difficulty using accessibility tools, and complexity of the registration processes.

Conclusion

My Health Record is an important piece of technology that has the potential to facilitate better communication between consumers and their health providers. However, this heuristic evaluation demonstrated that many usability-related elements of My Health Record cater poorly to users at risk of having low e-health literacy. Usability issues have been identified as an important barrier to use of personal health records internationally, and the findings of this heuristic evaluation demonstrate that usability issues may be substantial barriers to the uptake and use of My Health Record.

Crimean-Congo hemorrhagic fever virus in livestock ticks and animal handler seroprevalence at an abattoir in Ghana

Background

Crimean-Congo Haemorrhagic Fever Virus (CCHFV) is a zoonotic virus transmitted by Ixodid ticks and causes Crimean-Congo hemorrhagic fever (CCHF) disease in humans with up to 50 % mortality rate.

Methods

Freshly slaughtered livestock at the Kumasi abattoir in the Ashanti Region of Ghana were examined for the presence of ticks once a month over a 6-month period from May to November 2011. The ticks were grouped into pools by species, sex, and animal source. CCHFV was detected in the ticks using reverse transcription PCR. Blood samples were collected from enrolled abattoir workers at initiation, and from those who reported fever in a preceding 30-day period during monthly visits 2–5 months after initiation. Six months after initiation, all participants who provided baseline samples were invited to provide blood samples. Serology was performed using enzyme linked immunosorbent assay (ELISA). Demographic and epidemiological data was also obtained from enrolled participants using a structured questionnaire.

Results

Of 428 freshly slaughtered animals comprising 130 sheep, 149 cattle, and 149 goats examined, 144 ticks belonging to the genera Ambylomma, Hyalomma and Boophilus were identified from 57 (13.3 %): 52 (34.9 %), 4 (3.1 %) and 1 (0.7 %) cattle, sheep and goat respectively. Of 97 tick pools tested, 5 pools comprising 1 pool of Hyalomma excavatum and 4 pools of Ambylomma variegatum, collected from cattle, were positive for CCHFV. Of 188 human serum samples collected from 108 abattoir workers, 7 (3.7 %) samples from 6 persons were anti-CCHF IgG positive with one of them also being CCHF IgM positive. The seroprevalence of CCHFV identified in this study was 5.7 %.

Conclusions

This study detected human exposure to CCHF virus in slaughterhouse workers and also identified the CCHF virus in proven vectors (ticks) of Crimean Congo hemorrhagic fever in Ghana. The CCHFV was detected only in ticks collected from cattle, one of the livestock known to play a role in the amplification of the CCHF virus.

Epidemiological and Microbiological Investigation of an Outbreak of Severe Disease from Shiga Toxin-Producing Escherichia coli O157 Infection Associated with Consumption of a Slaw Garnish

Investigating outbreaks of Shiga toxin-producing Escherichia coli (STEC) in England is a priority due to the potential severity of disease. However, there are often challenges in investigating outbreaks due to the small numbers of cases, poor patient recall, and low levels of bacteria that are challenging to detect in food samples using traditional laboratory culture techniques, and frequently a source is not identified. In September 2014, we investigated an STEC O157 outbreak associated with consuming a slaw garnish, and we report our findings here. Twenty confirmed cases were identified. Outbreak cases were interviewed, and menus reviewed to identify dishes consumed outside the home. Cases shared a history of eating meals at different chain restaurants. Analysis of menu items indicated shared consumption of slaw garnishes by 85.6% cases, although just 35.7% reported consuming them during interviews. Whole-genome sequencing linked cases where interpretation of the multilocus variable number tandem repeat analysis profile was obscured and indicated that the strain originated from a domestic (i.e., United Kingdom) source. Traceback identified that carrots and cabbages grown in the United Kingdom were the likely source of infection. Samples of products were examined, but STEC was not recovered. Epidemiological investigations linked the outbreak to consumption of a slaw garnish, which was poorly recalled by cases, and likely comprised of domestically produced raw vegetables. The causative organism was not isolated from food samples, and we conclude that future investigations should include sampling of animals and wildlife in the vicinity of farms where implicated produce is grown.

Surgical and postoperative events during permanent fistulation of sheep rumen by the Schalk and Amadon method

OBJECTIVE

To describe and report on the course of events during and after surgical fistulation of sheep rumen by the Schalk and Amadon method and on improvements to address current trends in animal health, care and welfare.

METHODS

A permanent re-entry fistula was created in 13 sheep using a method in which a fold of rumen is exteriorised and held by a metal clamp. Following surgery, sheep were monitored daily for any abnormalities for 4 weeks, then weekly for 6 months.

RESULTS

Permanent fistulation was achieved in all 13 sheep; 2 sheep had minor complications: one during the surgery (rumen perforation) and one on the day after surgery (slipping of the metal clamp), but both recovered within 48 h with treatment. Over the 4 weeks post-surgery, 7 sheep had mildly elevated rectal temperatures, which resolved with non-steroidal anti-inflammatory drugs, systemic antibiotics and/or topical antiseptic cream. There was an 8-day variation among sheep in the time from surgery to creation of the fistula.

CONCLUSION

Rumen fistulation of sheep by the Schalk and Amadon method, as described here, is a comparatively simple, safe and ethical procedure, with minimal effect on or complications for the animal.

Relationship between socioeconomic status and gastrointestinal infections in developed countries: a systematic review protocol

BACKGROUND

The association between low socioeconomic status (SES) and poor health is well documented in the existing literature. Nonetheless, evidence on the relationship between SES and gastrointestinal (GI) infections is limited, and the mechanisms underlying this relationship are not well understood with published studies pointing to conflicting results. This review aims to identify studies that investigate the relationship between SES and GI infections in developed countries, in order to assess the direction of the association and explore possible explanations for any differences in the risk, incidence or prevalence of GI infections across socioeconomic groups.

METHODS

Three systematic methods will be used to identify relevant literature: electronic database, reference list and grey literature searching. The databases MEDLINE, Scopus and Web of Science Core Collection will be searched using a broad range of search terms. Screening of the results will be performed by two reviewers using pre-defined inclusion and exclusion criteria. The reference lists of included studies will be searched, and Google will be used to identify grey literature. Observational studies reporting quantitative results on the prevalence or incidence of any symptomatic GI infections by SES, in a representative population sample from a member country of the Organisation for Economic Co-operation and Development (OECD), will be included. Data will be extracted using a standardised form. Study quality will be assessed using the Liverpool University Quality Assessment Tools (LQAT). A narrative synthesis will be performed including tabulation of studies for comparison.

DISCUSSION

This systematic review will consolidate the existing knowledge on the relationship between SES and GI infections. The results will help to identify gaps in the literature and will therefore provide an evidence base for future empirical studies to deepen the understanding of the relationship, including effective study design and appropriate data analysis methods. Ultimately, gaining insight into this relationship will help to inform policies to reduce any health inequalities identified.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015027231.

Heterologous expression of mitochondria-targeted microbial nitrilase enzymes increases cyanide tolerance in Arabidopsis

Anthropogenic activities have resulted in cyanide (CN) contamination of both soil and water in many areas of the globe. While plants possess a detoxification pathway that serves to degrade endogenously generated CN, this system is readily overwhelmed, limiting the use of plants in bioremediation. Genetic engineering of additional CN degradation pathways in plants is one potential strategy to increase their tolerance to CN. Here we show that heterologous expression of microbial nitrilase enzymes targeted to the mitochondria increases CN tolerance in Arabidopsis. Root length in seedlings expressing either a CN dihydratase from Bacillus pumilis or a CN hydratase from Neurospora crassa was increased by 45% relative in wild-type plants in the presence of 50 μm KCN. We also demonstrate that in contrast to its strong inhibitory effects on seedling establishment, seed germination of the Col-0 ecotype of Arabidopsis is unaffected by CN.

Randomised trial of software algorithm driven regional citrate anticoagulation versus heparin in continuous renal replacement therapy: the Filter Life in Renal Replacement Therapy pilot trial

OBJECTIVE

The effectiveness of continuous renal replacement therapy (CRRT) increases when unplanned circuit failure is prevented. Adequate anticoagulation is an important component. Although heparin is the predominating anticoagulant, calcium chelation with citrate is an alternative, but systemic calcium monitoring and supplementation increase the complexity of CRRT. We assessed efficacy and safety of citrate delivery via integrated software algorithms against an established regional heparin protocol.

DESIGN

Prospective computer randomisation allocated eligible patients to regional citrate or heparin between April and December 2012. Citrate fluids were Prismocitrate 18 mmol/L predilution and Prism0cal B22 dialysate. Hemosol B0 was the default fluid for heparin. The primary outcome was filter running time. Electively terminated circuits were censored. Intention-totreat (ITT) and per-protocol analyses were performed. Filter survival was compared by log-rank tests and hazard ratios were explored with a mixed-effects Cox model.

RESULTS

221 filters were analysed from 30 patients (of whom 19 were randomly allocated to citrate filters and 11 to heparin filters). Patients randomly allocated to citrate were older, sicker, with a higher male:female ratio, but of similar weight. Mortality was 37% in the citrate arm and 27% in the heparin arm. All deaths were attributed to underlying disease. Significant crossover occurred from the citrate arm to use of heparin. Median filter survival, by ITT, was not significantly different (citrate, 34 hours; heparin, 30.7 hours; P=0.58). Per-protocol survival favoured citrate (citrate, 42.1 hours; heparin, 24 hours; χ(2)=8.1; P=0.004). Considerable variation in filter life existed between patients, and between vascular access sites within patients. Safety end points were reached in one heparin and three citrate patients.

CONCLUSION

Although the per-protocol results favoured citrate when it was actually delivered, the significant crossover between treatment arms hampered more definitive conclusions. Until further studies support improved patient outcomes, increased complexity and complications suggest that anticoagulation choice be made using patient-specific indications.

A novel approach to analyzing concentration polarization of polysaccharide solutions

This paper describes a novel approach to analyzing the concentration polarization (CP) in the short-time constant flux filtration of polysaccharide solutions. With application of the pearl-necklace model based polymer solution permeability correlation, a transmembrane pressure (TMP) increase rate model was developed to relate the linear TMP increase rate measured in the short-time constant flux filtration to the solid concentration at the membrane surface, the polymer critical overlapping concentration, and the radius of gyration of the polymer molecules. Establishment of such a theoretical model allows analysis of the gelation propensity of the CP layer formed by polysaccharides based on the experimentally determined linear TMP increase rate.

Acute focal bacterial nephritis due to methicillin-resistant Staphylococcus aureus in an immunocompetent adult

Acute focal bacterial nephritis (AFBN) is a rare, acute focal infection of the renal parenchyma without liquefaction. The pathogenesis is thought to be due to hematogenous infection or ascending infection from the lower urinary tract. Escherichia coli has been the major pathogen isolated in prior cases, but other Gram-negative enteric pathogens and Staphylococcus aureus have been reported as well. It is well described in children and adults with diabetes and organ transplantation, but has not been previously reported in healthy adults. We report a case of an immunocompetent adult female who presented with a methicillin-resistant Staphylococcus aureus bacteremia after a skin and soft tissue infection that resulted in AFBN.

Outbreak of Shiga toxin-producing E. coli O157 associated with consumption of watercress, United Kingdom, August to September 2013

An increase in the number of cases of Shiga toxin-producing Escherichia coli O157 PT 2 stx2 infection was reported in the United Kingdom on 9 September 2013. Of the 19 cases, 13 were interviewed, of which 10 reported consuming watercress purchased from one retailer. The retailer recalled pre-packed bagged salads containing watercress on 12 September. The descriptive epidemiology was supported by a case–case study performed after control measures were implemented.

Cavum Vergae with Transient Loss of Conciousness in a Child: A Case Report and Brief Literature Review

Cavum vergae is a triangular fluid filled cavity posterior to foramen of Monro. They are seen in premature and term infants up to 2 months of age. It is of little clinical significance. Our patient is a 14year old girl with cavum vergae diagnosed with brain computed tomography and magnetic resonance imaging. These investigations were sequel to episodes of headache and one hour loss of consciousness with no antecedent complaints. Since no complicating evidence of hydrocephalus was seen, she was managed symptomatically. DOI: http://dx.doi.org/10.3126/ajms.v5i1.8107   Asian Journal of Medical Science Vol.5(1) 2014 pp.73-76

Skin effector memory T cells do not recirculate and provide immune protection in alemtuzumab-treated CTCL patients

Cutaneous T cell lymphoma (CTCL) is a cancer of skin-homing T cells with variants that include leukemic CTCL (L-CTCL), a malignancy of central memory T cells (T(CM)), and mycosis fungoides (MF), a malignancy of skin resident effector memory T cells (T(EM)). We report that low-dose alemtuzumab (αCD52) effectively treated patients with refractory L-CTCL but not MF. Alemtuzumab depleted all T cells in blood and depleted both benign and malignant T(CM) from skin, but a diverse population of skin resident T(EM) remained in skin after therapy. T cell depletion with alemtuzumab required the presence of neutrophils, a cell type frequent in blood but rare in normal skin. These data suggest that T(CM) were depleted because they recirculate between the blood and the skin, whereas skin resident T(EM) were spared because they are sessile and non-recirculating. After alemtuzumab treatment, skin T cells produced lower amounts of interleukin-4 and higher amounts of interferon-γ. Moreover, there was a marked lack of infections in alemtuzumab-treated L-CTCL patients despite the complete absence of T cells in the blood, suggesting that skin resident T(EM) can protect the skin from pathogens even in the absence of T cell recruitment from the circulation. Together, these data suggest that alemtuzumab may treat refractory L-CTCL without severely compromising the immune response to infection by depleting circulating T(CM) but sparing the skin resident T(EM) that provide local immune protection of the skin.

Problem based review: pleuritic chest pain

Pleuritic pain, a sharp discomfort near the chest wall exacerbated by inspiration is associated with a number of pathologies. Pulmonary embolus and infection are two common causes but diagnosis can often be challenging, both for experienced physicians and trainees. The underlying anatomy and pathophysiology of such pain and the most common aetiologies are presented. Clinical symptoms and signs that may arise alongside pleuritic pain are then discussed, followed by an introduction to the diagnostic tools such as the Wells’ score and current guidelines that can help to select the most appropriate investigation(s). Management of pulmonary embolism and other common causes of pleuritic pain are also discussed and highlighted by a clinical vignette.

Interleukin-16 as a marker of Sézary syndrome onset and stage

INTRODUCTION

Sézary syndrome is one of the most common forms of cutaneous T cell lymphoma (CTCL). It is characterized by skin infiltration of malignant T cells. We examined interleukin-16, a potent T cell chemoattractant and cell-cycle regulator, as a prospective marker of disease onset and stage.

METHODS

The correlation of total intracellular interleukin-16 and surface CD26 was studied by flow cytometry. Confocal microscopy was performed to determine localization of interleukin-16 at different stages of the disease. The levels of interleukin-16 in plasma and culture supernatants were examined by enzyme-linked immunoassay. Additionally, lymphocytes from stage IB patients were cultured in the presence of interleukin-16 alone and in combination with interleukin-15, and their ability to survive and proliferate was determined by cell counts and [3H]TdR incorporation.

RESULTS

The data indicate that loss of both nuclear and intracellular pro-interleukin-16 highly correspond to disease stage, with a concomitant increase in secreted mature interleukin-16 in both culture supernatants and patients' plasma that peaks at stage IB. Loss of intracellular interleukin-16 strongly corresponded to loss of surface CD26, which has been shown to occur with more advanced stage of CTCL. Nuclear translocation of pro-interleukin-16 was not observed in late stages of Sézary syndrome, indicating this loss is not reversible.

CONCLUSIONS

We propose that it is feasible to use plasma levels of IL-16 as a potential diagnostic marker of Sézary syndrome and to use loss of intracellular IL-16 as a prognostic indicator of disease severity and stage.

Root canal retreatment

Root canal therapy is not always successful and an increasing number of patients are requesting retreatment to address intra-radicular infection. The armamentarium available to assist the dentist, some of which is described in this article, has never been greater.

CLINICAL RELEVANCE

This paper discusses the causes of failure and reviews many of the techniques available to the practitioner to tackle the problem.

Fluticasone versus beclomethasone or budesonide for chronic asthma in adults and children

BACKGROUND

Beclomethasone dipropionate (BDP) and budesonide (BUD) are commonly prescribed inhaled corticosteroids for the treatment of asthma. Fluticasone propionate (FP) is newer agent with greater potency in in-vitro assays.

OBJECTIVES

To compare the efficacy and safety of Fluticasone to Beclomethasone or Budesonide in the treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trial register (January 2007) and reference lists of articles. We contacted trialists and pharmaceutical companies for additional studies and searched abstracts of major respiratory society meetings (1997 to 2006).

SELECTION CRITERIA

Randomised trials in children and adults comparing Fluticasone to either Beclomethasone or Budesonide in the treatment of chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed articles for inclusion and methodological quality. One reviewer extracted data. Quantitative analyses were undertaken using RevMan analyses 1.0.1.

MAIN RESULTS

Seventy-one studies (14,602 participants) representing 74 randomised comparisons met the inclusion criteria. Methodological quality was fair. Dose ratio 1:2: FP produced a significantly greater end of treatment FEV1 (0.04 litres (95% CI 0 to 0.07 litres), end of treatment and change in morning PEF, but not change in FEV1 or evening PEF. This applied to all drug doses, age groups, and delivery devices. No difference between FP and BDP/BUD were seen for trial withdrawals. FP led to fewer symptoms and less rescue medication use. When given at half the dose of BDP/BUD, FP led to a greater likelihood of pharyngitis. There was no difference in the likelihood of oral candidiasis. Plasma cortisol and 24 hour urinary cortisol was measured frequently but data presentation was limited. Dose ratio 1:1: FP produced a statistically significant difference in morning PEF, evening PEF, and FEV1 over BDP or BUD. The effects on exacerbations were mixed. There were no significant differences incidence of hoarseness, pharyngitis, candidiasis, or cough.

AUTHORS' CONCLUSIONS

Fluticasone given at half the daily dose of beclomethasone or budesonide leads to small improvements in measures of airway calibre, but it appears to have a higher risk of causing sore throat and when given at the same daily dose leads to increased hoarseness. There are concerns about adrenal suppression with Fluticasone given to children at doses greater than 400 mcg/day, but the randomised trials included in this review did not provide sufficient data to address this issue.

Holding chambers versus nebulisers for inhaled steroids in chronic asthma

BACKGROUND

Inhaled corticosteroids are available in the form of a suspension for nebulisation, although the role of this mode of therapy in the treatment of chronic asthma is still unclear.

OBJECTIVES

To assess the efficacy and safety of inhaled corticosteroids delivered via nebuliser versus holding chamber for the treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group Trial Register (1999) and reference lists of articles. We contacted the authors of studies and pharmaceutical companies for additional studies and hand-searched the British Journal of Clinical Research, European Journal of Clinical Research and major respiratory society meeting abstracts (1997-1999). Date of last search August 2005.

SELECTION CRITERIA

Randomised controlled trials comparing nebuliser to holding chamber in the delivery of inhaled corticosteroids for the treatment of chronic asthma. All age groups of patients were considered. Two reviewers assessed articles for inclusion; two reviewers independently assessed included studies for methodological quality.

DATA COLLECTION AND ANALYSIS

One reviewer extracted data; authors were contacted to clarify missing information. Quantitative analyses were undertaken using Review Manager 4.1 with MetaView 3.1.

MAIN RESULTS

Two studies were selected for inclusion (63 subjects), both concerned adults. An additional small study including 14 children was identified for the 2005 update. Methodological quality was variable. Due to design differences it was not appropriate to pool the studies. The single high quality study compared budesonide 2000-8000 mcg delivered via Pari Inhalier Boy jet nebuliser with inspiration-only inhalation to budesonide 1600 mcg via large volume spacer. The nebuliser delivery led to higher morning peak expiratory flow values (25 L/min p<0.01), higher evening values (30L/min, p<0.01), lower rescue beta2 agonist use and symptom scores compared to the holding chamber delivery.

AUTHORS' CONCLUSIONS

Budesonide in high dose delivered by the particular nebuliser used in the only double-blinded study that could be included in this review was more effective than budesonide 1600 mcg via a large volume spacer. However, it is not clear whether this was an effect of nominal dose delivered or delivery system. Cost, compliance and patient preference are important determinants of clinical effectiveness that still require further assessment. Future studies are needed to evaluate the relative effectiveness of inhaled corticosteroids delivered by different combinations of nebuliser/compressor compared to holding chamber. Moreover, further studies assessing these delivery methods are needed in infants and pre-school children, as these are groups that are likely to be considered for treatment with nebulised corticosteroids.

Eczema-like plaques secondary to enoxaparin

Low-molecular-weight heparins are used extensively in acute medicine. They are generally well tolerated but may cause a rare, eczema-like type IV hypersensitivity reaction. We report 3 cases of this eruption and speculate that it may be significantly under-reported due to misidentifying the causal drug, which may have serious consequences. We discuss treatment alternatives such as fondaparinux sodium, which may rarely cross-react.

Inhaled fluticasone versus inhaled beclomethasone or inhaled budesonide for chronic asthma in adults and children

BACKGROUND

Beclomethasone dipropionate (BDP) and budesonide (BUD) are commonly prescribed inhaled corticosteroids for the treatment of asthma. Fluticasone propionate (FP) is newer agent with greater potency in in-vitro assays.

OBJECTIVES

To compare the efficacy and safety of Fluticasone to Beclomethasone or Budesonide in the treatment of chronic asthma.

SEARCH STRATEGY

We searched the Cochrane Airways Group trial register (January 2004) and reference lists of articles. We contacted trialists and pharmaceutical companies for additional studies and searched abstracts of major respiratory society meetings (1997 to 2003).

SELECTION CRITERIA

Randomised trials in children and adults comparing Fluticasone to either Beclomethasone or Budesonide in the treatment of chronic asthma.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed articles for inclusion and methodological quality. One reviewer extracted data. Quantitative analyses were undertaken using RevMan analyses 1.0.1.

MAIN RESULTS

Fifty six studies (12, 119 participants) met the inclusion criteria. Methodological quality was variable. Dose ratio 1:2: FP produced a significantly greater FEV1 (0.14 litres, 95% Confidence Interval (CI) 0.06 to 0.22), morning PEF (11.10 L/min, 95%CI 3.12 to 19.09 L/min) and evening PEF (9.31 L/min, 95%CI 5.12 to 13.5 L/min). This applied to all drug doses, age groups, and delivery devices. No difference between FP and BDP/BUD were seen for trial withdrawals. Symptoms and rescue medication use were widely reported but few trials provided sufficient data for analysis. When given at half the dose of BDP/BUD, FP led to a greater likelihood of pharyngitis. There was no difference in the likelihood of oral candidiasis. Plasma cortisol and 24 hour urinary cortisol was measured frequently but data presentation was limited. Dose ratio 1:1: FP produced a statistically significant difference in am PEF (9.58 L/min (95% CI 5.20 to 13.97)), pm PEF (7.41 L/min (95% CI 2.61 to 12.22)), and FEV1 (0.09 L (0.02 to 0.17)). The effects on exacerbations were mixed. There was an increase in the incidence of hoarseness, but no significant difference in pharyngitis, candidiasis, or cough.

AUTHORS' CONCLUSIONS

Fluticasone given at half the daily dose of beclomethasone or budesonide leads to small improvements in measures of airway calibre, but it appears to have a higher risk of causing hoarseness when given at the same daily dose. Future studies should attempt to establish the relative efficacy of inhaled steroids delivered with CFC-free propellants.

Treatment of temporomandibular disorders by stabilising splints in general dental practice: results after initial treatment

INTRODUCTION

Little is known about how effective general dental practitioners (GDPs) are in treating temporomandibular disorders (TMD). The overall aim of this study was to compare the lower stabilising splint (SS) with a non-occluding control (CS) for the management of TMD in general dental practice.

METHOD

A total of 93 TMD patients attending 11 GDPs were randomly allocated to SS or CS. Diagnosis was according to International Headache Society Criteria. Outcome criteria included pain visual analogue scale (VAS), number of tender muscles, aggregate joint tenderness, inter-incisal opening, TMJ clicks and headaches. Splints were fitted one week after baseline and patients were followed-up every three weeks to three months; those not responding to CS after six weeks (< 50% VAS reduction) were crossed over to SS for a further three months.

RESULTS

Documentation was returned from nine GDPs for 72 patients (38 for SS, 34 for CS). At six weeks, mean improvements were noted for all outcome criteria, but less so for clicking. There were no significant differences between splints [chi(2)]. Seventeen CS patients had < 50% VAS reduction and were provided with SS in the cross-over group. CS patients with >50% VAS reduction were significantly younger than CS patients who crossed-over (ANOVA, p=0.009) and had significantly less diagnoses of TMJ clicking (chi(2), p<0.05). At the conclusion of the trial 16 patients were referred for specialist management: 11 non-responders (< 50% VAS reduction), one of whom needed occlusal adjustment and five responders also needing occlusal adjustment.

CONCLUSIONS

At six weeks SS gave similar relief to CS for all outcome criteria. Patients who crossed-over from CS to SS were more likely to be older and have clicking TMJs. At the end of treatment nine of 11 non-responders to SS had a diagnosis of disc displacement with reduction. However, 80% TMD patients were managed effectively by GDPs using splints for periods of up to five months.