COVID-19 vaccine safety in Scotland - background rates of adverse events of special interest

OBJECTIVES

Mass COVID-19 vaccination commenced in December 2020 in Scotland. Monitoring vaccine safety relies on accurate background incidence rates (IRs) for health outcomes potentially associated with vaccination. This study aimed to quantify IRs in Scotland of adverse events of special interest (AESI) potentially associated with COVID-19 vaccination.

STUDY DESIGN AND METHODS

IRs and 95% confidence intervals (CIs) for 36 AESI were calculated retrospectively for the pre-COVID-19 pandemic period (01 January 2015-31 December 2019) and the COVID-19 pandemic period (01 April 2020-30 November 2020), with age-sex stratification, and separately by calendar month and year. Incident cases were determined using International Classification of Diseases-10th Revision (ICD-10)-coded hospitalisations.

RESULTS

Prepandemic population-wide IRs ranged from 0.4 (0.3-0.5 CIs) cases per 100,000 person-years (PYRS) for neuromyelitis optica to 478.4 (475.8-481.0 CIs) cases per 100,000 PYRS for acute renal failure. Pandemic population-wide IRs ranged from 0.3 (0.2-0.5 CIs) cases per 100,000 PYRS for Kawasaki disease to 483.4 (473.2-493.7 CIs) cases per 100,000 PYRS for acute coronary syndrome. All AESI IRs varied by age and sex. Ten AESI (acute coronary syndrome, acute myocardial infarction, angina pectoris, heart failure, multiple sclerosis, polyneuropathies and peripheral neuropathies, respiratory failure, rheumatoid arthritis and polyarthritis, seizures and vasculitis) had lower pandemic than prepandemic period IRs overall. Only deep vein thrombosis and pulmonary embolism had a higher pandemic IR.

CONCLUSION

Lower pandemic IRs likely resulted from reduced health-seeking behaviours and healthcare provision. Higher IRs may be associated with SARS-CoV-2 infections. AESI IRs will facilitate future vaccine safety studies in Scotland.

"Turning up the heat": Role of neurotrophic batokines in the postnatal maturation and remodelling of brown adipose tissue in deer mice

Activation of brown adipose tissue (BAT) thermogenesis impacts energy balance and must be tightly regulated. Several neurotrophic factors, expressed in BAT of adult laboratory rodents, have been implicated in remodelling the sympathetic neural network to enhance thermogenesis (e.g., NGF, NRG4 and S100b). Here, we compare for the first time the relative roles of three neurotropic 'batokines' in establishing/remodelling innervation during postnatal development and adult cold stress. We used lab-reared P. maniculatus, which rely heavily on BAT-based thermogenesis for survival in the wild, beginning between postnatal days (P) 8 and 10. BAT sympathetic innervation was enhanced from P6-10, and exogenous NGF, NRG4, and S100b stimulated neurite outgrowth from P6 sympathetic neurons. Endogenous BAT protein stores and/or gene expression of NRG4, S100b, and calsyntenin-3ß (which regulates S100b secretion), remained high and constant during development. However, endogenous NGF was low and ngf mRNA was undetectable. Conditioned media (CM) from cultured P10 BAT slices stimulated neurite outgrowth from sympathetic neurons in vitro that was inhibited by antibodies against all three growth factors. P10 CM had significant amounts of secreted NRG4 and S100b protein, but not NGF. By contrast, BAT slices from cold-acclimated adults released significant amounts of all three factors relative to thermoneutral controls. These data suggest that while neurotrophic batokines regulate sympathetic innervation in vivo, their relative contributions differ depending on life stage. They also provide novel insight into the regulation of BAT remodelling and BAT's secretory role, which are both critical to our understanding of mammalian energy homeostasis.

Reducing control noise in gravitational wave detectors with interferometric local damping of suspended optics

Control noise is a limiting factor in the low-frequency performance of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). In this paper, we model the effects of using new sensors called Homodyne Quadrature Interferometers (HoQIs) to control the suspension resonances. We show that if we were to use HoQIs, instead of the standard shadow sensors, we could suppress resonance peaks up to tenfold more while simultaneously reducing the noise injected by the damping system. Through a cascade of effects, this will reduce the resonant cross-coupling of the suspensions, allow for improved stability for feed-forward control, and result in improved sensitivity of the detectors in the 10-20 Hz band. This analysis shows that improved local sensors, such as HoQIs, should be used in current and future detectors to improve low-frequency performance.

Using Early Exam Results to Predict Online MLS Program Success

Introduction/Objective

The objective of this effort is to demonstrate the impact of early didactic exam results for potential early intervention for students in an online medical laboratory science bridge program.

Methods/Case Report

For this study, we took retrospective data of 299 students from 2018 to 2021 who took MLSC 4312, Hematology, in their first semester. We then analyzed their first exam score and then used this data to evaluate its potential use as an early predictor of overall student success in both this course and the program. Specifically, the exam one score in the course was used to evaluate progression to the second semester, graduation, UAMS GPA, and ASCP Board of Certification total score and Hematology sub-score. Descriptive statistics and 2-sample T-tests were calculated using Number Cruncher Statistical System. Fisher’s exact test was performed using Graphpad software.

Results (if a Case Study enter NA)

Of the 296 students whose records were examined, 49 scored below a 76% on Hematology exam 1. 247 students scored above 75%.35 students who scored below 76% progressed to the second semester and of those, 33 (94.2%) graduated on time. 14 students were dismissed from the program after the first semester. The overall graduation rate of students who started the program and scored less than 76% on the first hematology exam was 67%. Of the 247 students who scored above 76% on exam 1, 229 (93%) progressed to the second semester and of those, 214 graduated on time (93.4%). 18 of these students were dismissed from the program. The overall graduation rate of students who started the program and scored greater than 76% on the first hematology exam was 86.70%. The overall ASCP Board of Certification pass rate was almost 19 percent higher, 81.7% vs. 62.9% in those who scored greater than 76% on the first hematology exam. Each of the comparisons was statistically significant (P=<0.05) using a 2-sample T-test or Fisher’s exact test as appropriate.

Conclusion

This study revealed the importance of doing well on the first major didactic exam in the Medical Laboratory Sciences program. Students who score < 76% on their first exam fail to progress to the second semester at four times the rate of those who score >76%. In addition, those who score <76% and progress fail the ASCP Board of Certification Exam at almost double the rate of those who score >76% on the first hematology exam. In the future, we will reach out earlier and offer targeted help to these students.

Quantitative EEG (qEEG) guided transcranial magnetic stimulation (TMS) treatment for depression and anxiety disorders: An open, observational cohort study of 210 patients

BACKGROUND

Major depression and anxiety disorders represent a substantial burden of morbidity. Neither antidepressant medication nor psychological interventions are fully effective, the former beset with side effects, interactions and compliance issues, and the latter requiring patient engagement, effort and a degree of psychological mindedness. Both treatments are lengthy. TMS by contrast is virtually free of side effects and compliance issues, relatively brief, and requires no patient effort. Nevertheless, remission rates are only about 1 in 3 with standard left frontal rapid (rTMS) stimulation, and up to 30 treatment sessions may be required. Our aim was to improve the effectiveness of TMS treatment using bespoke as opposed to standard left frontal rTMS, including theta burst stimulation (TBS).

METHODS

210 male and female patients were treated: regions and frequencies of TMS were guided by quantitative EEG analysis (qEEG) to elicit recognisable phenotypes, neuromarkers integral to the genesis of major depression and anxiety disorder, dictating treatment parameters.

RESULTS

98 patients (47%) achieved at least 50% reduction in Hamilton depression rating scale scores, while a further 60 (29%) patients achieved a 30-50% reduction, over a mean of 7.03 ± 0.3 treatment sessions. Theta burst stimulation (TBS) almost halved treatment time within session compared to rTMS. The effect size (Cohen's d) for both treatments was large (>0.8) with rTMS at 1.43 (1.16-1.70) and TBS at 1.87 (1.48-2.25).

CONCLUSIONS

qEEG guided TMS treatment is a safe and effective treatment in depression and anxiety disorders.

Investigating the association between COVID-19 vaccination and care home outbreak frequency and duration

OBJECTIVES

At the end of 2020, many countries commenced a vaccination programme against SARS-CoV-2. Public health authorities aim to prevent and interrupt outbreaks of infectious disease in social care settings. We aimed to investigate the association between the introduction of the vaccination programme and the frequency and duration of COVID-19 outbreaks in Northern Ireland (NI).

STUDY DESIGN

We undertook an ecological study using routinely available national data.

METHODS

We used Poisson regression to measure the relationship between the number of RT-PCR confirmed COVID-19 outbreaks in care homes, and as a measure of community COVID-19 prevalence, the Office for National Statistics COVID-19 Infection Survey estimated the number of people testing positive for COVID-19 in NI. We estimated the change in this relationship and estimated the expected number of care home outbreaks in the absence of the vaccination programme. A Cox proportional hazards model estimated the hazard ratio of a confirmed COVID-19 care home outbreak closure.

RESULTS

Care home outbreaks reduced by two-thirds compared to expected following the introduction of the vaccination programme, from a projected 1625 COVID-19 outbreaks (95% prediction interval 1553-1694) between 7 December 2020 and 28 October 2021 to an observed 501. We estimated an adjusted hazard ratio of 2.53 of the outbreak closure assuming a 21-day lag for immunity.

CONCLUSIONS

These findings describe the association of the vaccination with a reduction in outbreak frequency and duration across NI care homes. This indicates probable reduced harm and disruption from COVID-19 in social care settings following vaccination. Future research using individual level data from care home residents will be needed to investigate the effectiveness of the vaccines and the duration of their effects.

The 3-D Skills Model: a Randomised Controlled Pilot Study Comparing a Novel 1-1 Near-Peer Teaching Model to a Formative OSCE with Self-regulated Practice

INTRODUCTION

Near-peer teaching is a popular pedagogical teaching tool, with well-recognised benefits for students and tutors. There are multiple existing models to structure these interventions, but it is often unclear how they translate to academic attainment. We designed a novel near-peer teaching model that expands on previous research.

METHODS

Our model was piloted in a formative Objective Structured Clinical Examination (OSCE) setting, trialled on 22 pre-clinical medical students to establish feasibility, acceptability and descriptive outcomes that could inform the design of a larger study. Students were randomly assigned to intervention or control cohorts. Each cohort undertook 5 min formative OSCE assessments with either 3 additional minutes of structured teaching or 3 min of self-regulated practice before reattempting the first OSCE station. Checklist marking sheets for 1^st and 2^nd sittings were collected by independent external markers, in addition to a global assessment rating in which we used the Borderline Regression Method to establish the station pass mark.

RESULTS

A quantitative and qualitative result analysis was performed, demonstrating that students gained on average 3 additional marks after teaching with this model. Students and student-tutors reported increased confidence, high course satisfaction and evidence of reflective practice.

DISCUSSION

We established acceptability and feasibility outcomes. The descriptive outcomes will support the design of a larger, adequately powered study required to demonstrate translation to summative exam performance.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s40670-021-01369-w.

Assessing and rationalizing the performance of Hessian update schemes for reaction path Hamiltonian rate calculations

The reaction path Hamiltonian (RPH) can be used to calculate chemical reaction rate constants, going beyond transition-state theory in taking account of recrossing by providing an approximation to the dynamic transmission coefficient. However, the RPH necessitates the calculation of the Hessian matrix at a number of points along the minimum energy path; the associated computational cost stands as a bottleneck in RPH calculations, especially if one is interested in using high-accuracy electronic structure methods. In this work, four different Hessian update schemes (symmetric rank-1, Powell-symmetric Broyden, Bofill, and TS-BFGS updates) are assessed to see whether or not they reliably reproduce calculated transmission coefficients for three different chemical reactions. Based on the reactions investigated, the symmetric rank-1 Hessian update was the least appropriate for RPH construction, giving different transmission coefficients from the standard analytical Hessian approach, as well as inconsistent frequencies and coupling properties. The Bofill scheme, the Powell-symmetric Broyden scheme, and the TS-BFGS scheme were the most reliable Hessian update methods, with transmission coefficients that were in good agreement with those calculated by the standard RPH calculations. The relative accuracy of the different Hessian update schemes is further rationalized by investigating the approximated Coriolis and curvature coupling terms along the reaction-path, providing insight into when these schemes would be expected to work well. Furthermore, the associated computational cost associated with the RPH calculations was substantially reduced by the tested update schemes. Together, these results provide useful rules-of-thumb for using Hessian update schemes in RPH simulations.

National population prevalence of antibodies to SARS-CoV-2 among pregnant women in Scotland during the second wave of the COVID-19 pandemic: a prospective national serosurvey

OBJECTIVES

This study aimed to determine SARS-CoV-2 seroprevalence among pregnant women in the Scottish population during the second wave of the COVID-19 pandemic.

STUDY DESIGN

Prospective national serosurvey.

METHODS

We tested 13,428 residual samples retrieved from pregnant women participating in the first trimester combined ultrasound and biochemical screening for fetal trisomy across Scotland for SARS-CoV-2 antibodies over a 6-month period from November 2020 to April 2021. Seroprevalence estimates were adjusted for the sensitivity and specificity of the assays and weighted to reference populations.

RESULTS

Seroprevalence rates in the antenatal samples significantly increased from 5.5% (95% confidence interval [CI] 4.7%-6.5%) in the 5-week period up to and including International Organization for Standardization (ISO) Week 51 (w/b Monday 14 December 2020) to 11.3% (95% CI 10.1%-12.6%) in the 5-week period up to and including ISO Week 14 (w/b Monday 5 April 2021). Increasing seroprevalence trends across the second wave were observed among all age groups.

CONCLUSIONS

By the end of the second wave of the COVID-19 pandemic, approximately one in 10 women tested around the end of the first trimester of pregnancy had antibodies to SARS-CoV-2, suggesting that the vast majority were still susceptible to COVID-19 as they progressed to the later stages of pregnancy, when risks from infection are elevated for both mother and baby.

Cost-effectiveness of bariatric surgery and non-surgical weight management programmes for adults with severe obesity: a decision analysis model

OBJECTIVES

To determine the most cost-effective weight management programmes (WMPs) for adults, in England with severe obesity (BMI ≥ 35 kg/m2), who are more at risk of obesity related diseases.

METHODS

An economic evaluation of five different WMPs: 1) low intensity (WMP1); 2) very low calorie diets (VLCD) added to WMP1; 3) moderate intensity (WMP2); 4) high intensity (Look AHEAD); and 5) Roux-en-Y gastric bypass (RYGB) surgery, all compared to a baseline scenario representing no WMP. We also compare a VLCD added to WMP1 vs. WMP1 alone. A microsimulation decision analysis model was used to extrapolate the impact of changes in BMI, obtained from a systematic review and meta-analysis of randomised controlled trials (RCTs) of WMPs and bariatric surgery, on long-term risks of obesity related disease, costs, quality adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) measured as incremental cost per QALY gained over a 30-year time horizon from a UK National Health Service (NHS) perspective. Sensitivity analyses explored the impact of long-term weight regain assumptions on results.

RESULTS

RYGB was the most costly intervention but also generated the lowest incidence of obesity related disease and hence the highest QALY gains. Base case ICERs for WMP1, a VLCD added to WMP1, WMP2, Look AHEAD, and RYGB compared to no WMP were £557, £6628, £1540, £23,725 and £10,126 per QALY gained respectively. Adding a VLCD to WMP1 generated an ICER of over £121,000 per QALY compared to WMP1 alone. Sensitivity analysis found that all ICERs were sensitive to the modelled base case, five year post intervention cessation, weight regain assumption.

CONCLUSIONS

RYGB surgery was the most effective and cost-effective use of scarce NHS funding resources. However, where fixed healthcare budgets or patient preferences exclude surgery as an option, a standard 12 week behavioural WMP (WMP1) was the next most cost-effective intervention.

Impact of healthcare-associated infection on length of stay

BACKGROUND

Increased length of stay (LOS) for patients is an important measure of the burden of healthcare-associated infection (HAI).

AIM

To estimate the excess LOS attributable to HAI.

METHODS

This was a one-year prospective incidence study of HAI observed in one teaching hospital and one general hospital in NHS Scotland as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. All adult inpatients with an overnight stay were included. HAI was diagnosed using European Centres for Disease Prevention and Control definitions. A multi-state model was used to account for the time-varying nature of HAI and the competing risks of death and discharge.

FINDINGS

The excess LOS attributable to HAI was 7.8 days (95% confidence interval (CI): 5.7-9.9). Median LOS for HAI patients was 30 days and for non-HAI patients was 3 days. Using a simple comparison of duration of hospital stay for HAI cases and non-cases would overestimate the excess LOS by 3.5 times (27 days compared with 7.8 days). The greatest impact on LOS was due to pneumonia (16.3 days; 95% CI: 7.5-25.2), bloodstream infections (11.4 days; 5.8-17.0) and surgical site infection (SSI) (9.8 days; 4.5-15.0). It is estimated that 58,000 bed-days are occupied due to HAI annually.

CONCLUSION

A reduction of 10% in HAI incidence could make 5800 bed-days available. These could be used to treat 1706 elective patients in Scotland annually and help reduce the number of patients awaiting planned treatment. This study has important implications for investment decisions in infection prevention and control interventions locally, nationally, and internationally.

Bed-days and costs associated with the inpatient burden of healthcare-associated infection in the UK

BACKGROUND

Healthcare-associated infection (HAI) is associated with increased morbidity and mortality resulting in excess costs.

AIM

To investigate the impact of all types of HAI on the inpatient cost of HAI using different approaches.

METHODS

The incidence, types of HAI, and excess length of stay were estimated using data collected as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. Scottish NHS reference costs were used to estimate unit costs for bed-days. Variable (cash) costs associated with infection prevention and control (IPC) measures and treatment were calculated for each HAI type and overall. The inpatient cost of HAI is presented in terms of bed-days lost, bed-day costs, and cash costs.

FINDINGS

In Scotland 58,010 (95% confidence interval: 41,730-74,840) bed-days were estimated to be lost to HAI during 2018/19, costing £46.4 million (19m-129m). The total annual cost in the UK is estimated to be £774 million (328m-2,192m). Bloodstream infection and pneumonia were the most costly HAI types per case. Cash costs are a small proportion of the total cost of HAI, contributing 2.4% of total costs.

CONCLUSION

Reliable estimates of the cost burden of HAI management are important for assessing the cost-effectiveness of IPC programmes. This unique study presents robust economic data, demonstrating that HAI remains a burden to the UK NHS and bed-days capture the majority of inpatient costs. These findings can be used to inform the economic evaluation and decision analytic modelling of competing IPC programmes at local and national level.

Epidemiology of healthcare-associated infection reported from a hospital-wide incidence study: considerations for infection prevention and control planning

BACKGROUND

The measure of disease frequency most widely used to report healthcare-associated infection (HAI) is the point-prevalence survey. Incidence studies are rarely performed due to time and cost constraints; they show which patients are affected by HAI, when and where, and inform planning and design of infection prevention and control (IPC) measures.

AIM

To determine the epidemiology of HAI within a general and a teaching hospital in Scotland.

METHODS

A prospective observational incidence study was undertaken for one year from April 2018 using data collected as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. A novel, robust approach was undertaken, using record linkage to national administrative data to provide full admission and discharge information. Cases were recorded if they met international HAI definitions.

FINDINGS

Incidence of HAI for the combined hospitals was 250 HAI cases per 100,000 acute occupied bed-days (AOBD). Highest frequency was in urinary tract (51.2 per 100,000 AOBD), bloodstream (44.7), and lower respiratory tract infection (42.2). The most frequently reported organisms were Escherichia coli, Staphylococcus aureus, and norovirus. Incidence of HAI was higher in older people and emergency cases. There was an increase in the rate of HAI in summer months (pneumonia, respiratory, surgical, and gastrointestinal infection) and in winter months norovirus gastrointestinal infection (P < 0.0001). The highest incidence specialties were intensive care, renal medicine, and cardiothoracic surgery. HAI occurred at a median of 9 days (interquartile range: 4-19) after admission. Incidence data were extrapolated to provide an annual national estimate of HAI in NHS Scotland of 7437 (95% confidence interval: 7021-7849) cases.

CONCLUSION

This study provides a unique overview of incidence of HAI and identifies the burden of HAI at the national level for the first time. Understanding the incidence in different clinical settings, at different times, will allow targeting of IPC measures to those patients who would benefit the most.

Personalized infection prevention and control: identifying patients at risk of healthcare-associated infection

BACKGROUND

Few healthcare-associated infection (HAI) studies focus on risk of HAI at the point of admission. Understanding this will enable planning and management of care with infection prevention at the heart of the patient journey from the point of admission.

AIM

To determine intrinsic characteristics of patients at hospital admission and extrinsic events, during the two years preceding admission, that increase risk of developing HAI.

METHODS

An incidence survey of adults within two hospitals in NHS Scotland was undertaken for one year in 2018/19 as part of the Evaluation of Cost of Nosocomial Infection (ECONI) study. The primary outcome measure was developing any HAI using recognized case definitions. The cohort was derived from routine hospital episode data and linkage to community dispensed prescribing data.

FINDINGS

The risk factors present on admission observed as being the most significant for the acquisition of HAI were: being treated in a teaching hospital, increasing age, comorbidities of cancer, cardiovascular disease, chronic renal failure and diabetes; and emergency admission. Relative risk of developing HAI increased with intensive care unit, high-dependency unit, and surgical specialties, and surgery <30 days before admission and a total length of stay of >30 days in the two years to admission.

CONCLUSION

Targeting patients at risk of HAI from the point of admission maximizes the potential for prevention, especially when extrinsic risk factors are known and managed. This study proposes a new approach to infection prevention and control (IPC), identifying those patients at greatest risk of developing a particular type of HAI who might be potential candidates for personalized IPC interventions.

SARS-CoV-2 Positivity in Asymptomatic-Screened Dental Patients

Enhanced community surveillance is a key pillar of the public health response to coronavirus disease 2019 (COVID-19). Asymptomatic carriage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a potentially significant source of transmission, yet remains relatively poorly understood. Disruption of dental services continues with significantly reduced capacity. Ongoing precautions include preappointment and/or at appointment COVID-19 symptom screening and use of enhanced personal protective equipment (PPE). This study aimed to investigate SARS-CoV-2 infection in dental patients to inform community surveillance and improve understanding of risks in the dental setting. Thirty-one dental care centers across Scotland invited asymptomatic-screened patients aged over 5 y to participate. Following verbal consent and completion of sociodemographic and symptom history questionnaire, trained dental teams took a combined oropharyngeal and nasal swab sample using standardized Viral Transport Medium-containing test kits. Samples were processed by the Lighthouse Lab and patients informed of their results by SMS/email with appropriate self-isolation guidance in the event of a positive test. All positive cases were successfully followed up by the national contact tracing program. Over a 13-wk period (from August 3, 2020, to October 31, 2020), 4,032 patients, largely representative of the population, were tested. Of these, 22 (0.5%; 95% CI, 0.5%-0.8%) tested positive for SARS-CoV-2. The positivity rate increased over the period, commensurate with uptick in community prevalence identified across all national testing monitoring data streams. To our knowledge, this is the first report of a COVID-19 testing survey in asymptomatic-screened patients presenting in a dental setting. The positivity rate in this patient group reflects the underlying prevalence in community at the time. These data are a salient reminder, particularly when community infection levels are rising, of the importance of appropriate ongoing infection prevention control and PPE vigilance, which is relevant as health care team fatigue increases as the pandemic continues. Dental settings are a valuable location for public health surveillance.

Informing the public health response to COVID-19: a systematic review of risk factors for disease, severity, and mortality

BACKGROUND

Severe Acute Respiratory Syndrome coronavirus-2 (SARS-CoV-2) has challenged public health agencies globally. In order to effectively target government responses, it is critical to identify the individuals most at risk of coronavirus disease-19 (COVID-19), developing severe clinical signs, and mortality. We undertook a systematic review of the literature to present the current status of scientific knowledge in these areas and describe the need for unified global approaches, moving forwards, as well as lessons learnt for future pandemics.

METHODS

Medline, Embase and Global Health were searched to the end of April 2020, as well as the Web of Science. Search terms were specific to the SARS-CoV-2 virus and COVID-19. Comparative studies of risk factors from any setting, population group and in any language were included. Titles, abstracts and full texts were screened by two reviewers and extracted in duplicate into a standardised form. Data were extracted on risk factors for COVID-19 disease, severe disease, or death and were narratively and descriptively synthesised.

RESULTS

One thousand two hundred and thirty-eight papers were identified post-deduplication. Thirty-three met our inclusion criteria, of which 26 were from China. Six assessed the risk of contracting the disease, 20 the risk of having severe disease and ten the risk of dying. Age, gender and co-morbidities were commonly assessed as risk factors. The weight of evidence showed increasing age to be associated with severe disease and mortality, and general comorbidities with mortality. Only seven studies presented multivariable analyses and power was generally limited. A wide range of definitions were used for disease severity.

CONCLUSIONS

The volume of literature generated in the short time since the appearance of SARS-CoV-2 has been considerable. Many studies have sought to document the risk factors for COVID-19 disease, disease severity and mortality; age was the only risk factor based on robust studies and with a consistent body of evidence. Mechanistic studies are required to understand why age is such an important risk factor. At the start of pandemics, large, standardised, studies that use multivariable analyses are urgently needed so that the populations most at risk can be rapidly protected.

REGISTRATION

This review was registered on PROSPERO as CRD42020177714 .

Rugby league ball carrier injuries: The relative importance of tackle characteristics during the European Super League

Rugby league carries a high injury incidence with 61% of injuries occurring at tackles. The ball carrier has a higher injury incidence than the defender, therefore understanding mechanisms occurring during injurious tackles are important. Given the dynamic, open nature of tackling, characteristics influencing tackle outcome likely encompass complex networks of dependencies. This study aims to identify important classifying characteristics of the tackle related to ball carrier injurious and non-injurious events in rugby league and identify the characteristics capability to correctly classify those events. Forty-one ball carrier injuries were identified and 205 matched non-injurious tackles were identified as controls. Each case and control were analysed retrospectively through video analysis. Random forest models were built to (1) filter tackle characteristics possessing relative importance for classifying tackles resulting in injurious/non-injurious outcomes and (2) determine sensitivity and specificity of tackle characteristics to classify injurious and non-injurious events. Six characteristics were identified to possess relative importance to classify injurious tackles. This included 'tackler twisted ball carrier's legs when legs were planted on ground', 'the tackler and ball carrier collide heads', 'the tackler used body weight to tackle ball carrier', 'the tackler has obvious control of the ball carrier' 'the tackler was approaching tackle sub-maximally' and 'tackler's arms were below shoulder level, elbows were flexed'. The study identified tackle characteristics that can be modified in attempt to reduce injury. Additional injury data are needed to establish relationship networks of characteristics and analyse specific injuries. Sensitivity and specificity results of the random forest were 0.995 and 0.525.

First-dose ChAdOx1 and BNT162b2 COVID-19 vaccines and thrombocytopenic, thromboembolic and hemorrhagic events in Scotland

Reports of ChAdOx1 vaccine-associated thrombocytopenia and vascular adverse events have led to some countries restricting its use. Using a national prospective cohort, we estimated associations between exposure to first-dose ChAdOx1 or BNT162b2 vaccination and hematological and vascular adverse events using a nested incident-matched case-control study and a confirmatory self-controlled case series (SCCS) analysis. An association was found between ChAdOx1 vaccination and idiopathic thrombocytopenic purpura (ITP) (0-27 d after vaccination; adjusted rate ratio (aRR) = 5.77, 95% confidence interval (CI), 2.41-13.83), with an estimated incidence of 1.13 (0.62-1.63) cases per 100,000 doses. An SCCS analysis confirmed that this was unlikely due to bias (RR = 1.98 (1.29-3.02)). There was also an increased risk for arterial thromboembolic events (aRR = 1.22, 1.12-1.34) 0-27 d after vaccination, with an SCCS RR of 0.97 (0.93-1.02). For hemorrhagic events 0-27 d after vaccination, the aRR was 1.48 (1.12-1.96), with an SCCS RR of 0.95 (0.82-1.11). A first dose of ChAdOx1 was found to be associated with small increased risks of ITP, with suggestive evidence of an increased risk of arterial thromboembolic and hemorrhagic events. The attenuation of effect found in the SCCS analysis means that there is the potential for overestimation of the reported results, which might indicate the presence of some residual confounding or confounding by indication. Public health authorities should inform their jurisdictions of these relatively small increased risks associated with ChAdOx1. No positive associations were seen between BNT162b2 and thrombocytopenic, thromboembolic and hemorrhagic events.

Enhanced surveillance of COVID-19 in Scotland: population-based seroprevalence surveillance for SARS-CoV-2 during the first wave of the epidemic

Objectives

The impact of the COVID-19 pandemic in Scotland has been amongst the most severe in Europe. Serological surveillance is critical to determine the overall extent of infection across populations and to inform the public health response. This study aimed to estimate the proportion of people who have antibodies to SARS-CoV-2 (‘seroprevalence’) in the general population of Scotland and to see if this changes over time.

Study design/Methods

Between International Organization for Standardization (ISO) week 17 (i.e. week commencing 20th April) and ISO week 25 (week commencing 15 June), 4751 residual blood samples were obtained from regional biochemistry laboratories in six participating regional health authority areas covering approximately 75% of the Scottish population. Samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies using the LIAISON®SARS-CoV-2 S1/S2 IgG assay (DiaSorin, Italy). Seroprevalence rates were adjusted for the sensitivity and specificity of the assay using Bayesian methods.

Results

The combined adjusted seroprevalence across the study period was 4.3% (95% confidence interval: 4.2%–4.5%). The proportion varied each week between 1.9% and 6.8% with no difference in antibody positivity by age, sex or geographical area.

Conclusions

At the end of the first wave of the COVID-19 pandemic, only a small fraction of the Scottish population had antibodies to SARS-CoV-2. Control of COVID-19 requires the ability to detect asymptomatic and mild infections that would otherwise remain undetected through existing surveillance systems. This is important to determine the true number of infections within the general population which, in turn, can help to understand transmission, inform control measures and provide a denominator for the estimation of severity measures such as the proportion of infected people who have been hospitalised and/or have died.

Examining metastatic behavior within 3D bioprinted vasculature for the validation of a 3D computational flow model

Understanding the dynamics of circulating tumor cell (CTC) behavior within the vasculature has remained an elusive goal in cancer biology. To elucidate the contribution of hydrodynamics in determining sites of CTC vascular colonization, the physical forces affecting these cells must be evaluated in a highly controlled manner. To this end, we have bioprinted endothelialized vascular beds and perfused these constructs with metastatic mammary gland cells under physiological flow rates. By pairing these in vitro devices with an advanced computational flow model, we found that the bioprinted analog was readily capable of evaluating the accuracy and integrated complexity of a computational flow model, while also highlighting the discrete contribution of hydrodynamics in vascular colonization. This intersection of these two technologies, bioprinting and computational simulation, is a key demonstration in the establishment of an experimentation pipeline for the understanding of complex biophysical events.

Cost burden of Clostridioides difficile infection to the health service: A retrospective cohort study in Scotland

BACKGROUND

Clostridioides difficile infection (CDI) is associated with high healthcare demands and related costs.

AIM

To evaluate the healthcare and economic burden of CDI in hospitalized patients with community- (HOCA-CDI) or hospital-associated CDI (HOHA-CDI) in the National Health Service in Scotland.

METHODS

A retrospective cohort study was conducted, examining data between August 2010 and July 2013 from four patient-level Scottish datasets, linked to death data. Data examined included prior antimicrobial prescriptions in the community, hospitalizations, length of stay and mortality. Each CDI case was matched to three hospital-based controls on the basis of age, gender, hospital and date of admission. Descriptive economic evaluations were based on bed-day costs for different types of wards.

FINDINGS

Overall, 3304 CDI cases were included in the study. CDI was associated with additional median lengths of stay of 7.2 days for HOCA-CDI and 12.0 days for HOHA-CDI compared with their respective, matched controls. The 30-day mortality rate was 6.8% for HOCA-CDI and 12.4% for HOHA-CDI. Overall, recurrence within 90 days of the first CDI episode occurred in 373/2740 (13.6%) survivors. The median additional expenditure for each initial CDI case compared with matched controls was £1713. In the 6 months after the index hospitalization, the cost associated with a CDI case was £5126 higher than for controls.

CONCLUSION

Using routinely collected national data, we demonstrated the substantial burden of CDI on healthcare services, including lengthy hospital stays and readmissions, which increased the costs of managing patients with CDI compared with matched controls.

A systematic review of UK-based long-term nonsurgical interventions for people with severe obesity (BMI ≥35 kg m-2 )

Introduction

The aim of this project was to systematically review UK evidence on the effectiveness of long‐term (≥12 months) weight management services (WMSs) for weight loss and weight maintenance for adults (≥16 years) with severe obesity (body mass index ≥35 kg m⁻²), who would generally be eligible for Tier 3 services.

Methods

Four data sources were searched from 1999 to October 2018.

Results

Our searches identified 20 studies, mostly noncomparative studies: 10 primary care interventions, nine in secondary care specialist weight management clinics and one commercial setting intervention. A programme including a phase of low energy formula diet (810–833 kcal day⁻¹) showed the largest mean (SD) weight change at 12 months of –12.4 (11.4) kg for complete cases, with 25.3% dropout. Limitations or differences in evaluation and reporting (particularly for denominators), unclear dropout rates, and differences between participant groups in terms of comorbidities and psychological characteristics, made comparisons between WMSs and inferences challenging.

Conclusions

There is a persistent and clear need for guidance on long‐term weight data collection and reporting methods to allow comparisons across studies and services for participants with severe obesity. Data could also include quality of life, clinical outcomes, adverse events, costs and economic outcomes. A randomised trial comparison of National Health Service Tier 3 services with commercial WMSs would be of value.

The microstructure of laminin-111 compensates for dystroglycan loss in mammary epithelial cells in downstream expression of milk proteins

Laminin-111 (Ln-1), an extracellular matrix (ECM) glycoprotein found in the basement membrane of mammary gland epithelia, is essential for lactation. In mammary epithelial cells (MECs), dystroglycan (Dg) is believed to be necessary for polymerization of laminin-111 into networks., thus we asked whether correct polymerization could compensate for Dg loss. Artificially polymerized laminin-111 and the laminin-glycoprotein mix Matrigel, both formed branching, spread networks with fractal dimensions from 1.7 to 1.8, whereas laminin-111 in neutral buffers formed small aggregates without fractal properties (a fractal dimension of 2). In Dg knockout cells, either polymerized laminin-111 or Matrigel readily attached to the cell surface, whereas aggregated laminin-111 did not. In contrast, polymerized and aggregated laminin-111 bound similarly to Dg knock-ins. Both polymerized laminin-111 and Matrigel promoted cell rounding, clustering, formation of tight junctions, and expression of milk proteins, whereas aggregated Ln-1 did not attach to cells or promote functional differentiation. These findings support that the microstructure of Ln-1 networks in the basement membrane regulates mammary epithelial cell function.

Residual effect of community antimicrobial exposure on risk of hospital onset healthcare-associated Clostridioides difficile infection: a case-control study using national linked data

BACKGROUND

Associations between antimicrobial exposure in the community and community-associated Clostridioides difficile infection (CA-CDI) are well documented but associations with healthcare-associated CDI (HA-CDI) are less clear. This study estimates the association between antimicrobial prescribing in the community and HA-CDI.

METHODS

A matched case-control study was conducted by linking three national patient level datasets covering CDI cases, community prescriptions and hospitalizations. All validated cases of HA-CDI (August 2010 to July 2013) were extracted and up to three hospital-based controls were matched to each case on the basis of gender, age, hospital and date of admission. Conditional logistic regression was applied to estimate the association between antimicrobial prescribing in the community and HA-CDI. A sensitivity analysis was conducted to consider the impact of unmeasured hospital antimicrobial prescribing.

RESULTS

Nine-hundred and thirty unique cases of HA-CDI with onset in hospital and no hospital discharge in the 12 weeks prior to index admission were linked with 1810 matched controls. Individuals with prior prescription of any antimicrobial in the community had an odds ratio (OR) = 1.41 (95% confidence interval (CI) 1.13-1.75) for HA-CDI compared with those without. Individuals exposed to high-risk antimicrobials (cephalosporins, clindamycin, co-amoxiclav or fluoroquinolones) had an OR = 1.86 (95% CI: 1.33-2.59). After accounting for the likely impact of unmeasured hospital prescribing, the community exposure, particulary to high-risk antimicrobials, was still associated with elevated HA-CDI risk.

CONCLUSIONS

Community antimicrobial exposure is an independent risk factor for HA-CDI and should be considered as part of the risk assessment of patients developing diarrhoea in hospital.

Estimating excess length of stay due to healthcare-associated infections: a systematic review and meta-analysis of statistical methodology

BACKGROUND

Healthcare-associated infection (HCAI) affects millions of patients worldwide. HCAI is associated with increased healthcare costs, owing primarily to increased hospital length of stay (LOS) but calculating these costs is complicated due to time-dependent bias. Accurate estimation of excess LOS due to HCAI is essential to ensure that we invest in cost-effective infection prevention and control (IPC) measures.

AIM

To identify and review the main statistical methods that have been employed to estimate differential LOS between patients with, and without, HCAI; to highlight and discuss potential biases of all statistical approaches.

METHODS

A systematic review from 1997 to April 2017 was conducted in PubMed, CINAHL, ProQuest and EconLit databases. Studies were quality-assessed using an adapted Newcastle-Ottawa Scale (NOS). Methods were categorized as time-fixed or time-varying, with the former exhibiting time-dependent bias. Two examples of meta-analysis were used to illustrate how estimates of excess LOS differ between different studies.

FINDINGS

Ninety-two studies with estimates on excess LOS were identified. The majority of articles employed time-fixed methods (75%). Studies using time-varying methods are of higher quality according to NOS. Studies using time-fixed methods overestimate additional LOS attributable to HCAI. Undertaking meta-analysis is challenging due to a variety of study designs and reporting styles. Study differences are further magnified by heterogeneous populations, case definitions, causative organisms, and susceptibilities.

CONCLUSION

Methodologies have evolved over the last 20 years but there is still a significant body of evidence reliant upon time-fixed methods. Robust estimates are required to inform investment in cost-effective IPC interventions.

The Lysosomal Granule Membrane Protein, Lamp-2, Is also Present in Platelet Dense Granule Membranes

Lysosomal Associated Membrane Protein-2 (LAMP-2) is an inherent component of lysosomal granule membranes in diverse cell types, including platelets. We examined platelets for evidence of LAMP-2 in dense granule membranes as CD63 has previously been shown to be present in both lysosomal and dense granule membranes. Immunological techniques were used to examine the localization of LAMP-2 in control platelets and those from an individual with Hermansky-Pudlak syndrome (HPS), a condition characterised by platelet dense granule deficiency. Immunoblotting studies demonstrated that LAMP-2 was enriched in a dense granule preparation. Flow cytometry of thrombin-stimulated control platelets was consistent with biphasic surface expression of LAMP-2. The early expression was accompanied by dense granule, but minimal lysosomal granule, release. The late expression was accompanied by additional lysosomal granule release only. Thrombin stimulation of HPS platelets showed only late, lysosome-associated LAMP-2 expression. Immunoelectron microscopy indicated the presence of LAMP-2 in the membranes of serotonin-containing granules as identified by an anti-serotonin polyclonal antibody. These data indicate that LAMP-2 is present in the membranes of platelet dense granules in addition to lysosomal granules, and has a similar distribution to CD63.

Is there an association between airborne and surface microbes in the critical care environment?

BACKGROUND

There are few data and no accepted standards for air quality in the intensive care unit (ICU). Any relationship between airborne pathogens and hospital-acquired infection (HAI) risk in the ICU remains unknown.

AIM

First, to correlate environmental contamination of air and surfaces in the ICU; second, to examine any association between environmental contamination and ICU-acquired staphylococcal infection.

METHODS

Patients, air, and surfaces were screened on 10 sampling days in a mechanically ventilated 10-bed ICU for a 10-month period. Near-patient hand-touch sites (N = 500) and air (N = 80) were screened for total colony count and Staphylococcus aureus. Air counts were compared with surface counts according to proposed standards for air and surface bioburden. Patients were monitored for ICU-acquired staphylococcal infection throughout.

FINDINGS

Overall, 235 of 500 (47%) surfaces failed the standard for aerobic counts (≤2.5 cfu/cm²). Half of passive air samples (20/40: 50%) failed the 'index of microbial air' contamination (2 cfu/9 cm plate/h), and 15/40 (37.5%) active air samples failed the clean air standard (<10 cfu/m³). Settle plate data were closer to the pass/fail proportion from surfaces and provided the best agreement between air parameters and surfaces when evaluating surface benchmark values of 0-20 cfu/cm². The surface standard most likely to reflect hygiene pass/fail results compared with air was 5 cfu/cm². Rates of ICU-acquired staphylococcal infection were associated with surface counts per bed during 72h encompassing sampling days (P = 0.012).

CONCLUSION

Passive air sampling provides quantitative data analogous to that obtained from surfaces. Settle plates could serve as a proxy for routine environmental screening to determine the infection risk in ICU.

Results from the third Scottish National Prevalence Survey: is a population health approach now needed to prevent healthcare-associated infections?

BACKGROUND

Healthcare-associated infections (HCAIs) are a major public health concern and a significant cause of morbidity and mortality. A robust and current evidence base that is specific to local, national and Europe-wide settings is necessary to inform the development of strategies to reduce HCAI and contain antimicrobial resistance.

AIM

To measure the prevalence of HCAI and antimicrobial prescribing and identify key priority areas for interventions to reduce the burden of infection.

METHODS

A national rolling point-prevalence survey (PPS) in National Health Service (NHS) acute, NHS non-acute, NHS paediatric, and independent hospitals was carried out between September and November 2016 using the European Centre for Disease Prevention and Control protocol designed for the European PPS.

FINDINGS

The prevalence of HCAI was 4.6%, 2.7%, and 3.2% in acute adults, paediatric and non-acute patient groups, respectively. The most frequent HCAI types reported in adult patients were urinary tract infection and pneumonia. The prevalence of antimicrobial prescribing was 35.7%, 29.3%, and 13.8% in acute adults, paediatric, and non-acute patient groups, respectively. Respiratory, skin and soft tissue, gastrointestinal, and urinary tract infections were the most common infections being treated at the time of survey.

CONCLUSION

HCAI continues to be a public health concern in Scotland. Urinary tract infection and pneumonia continue to place a significant burden on patients and on healthcare delivery, including those that develop in the community and require hospital admission. A broader population health approach which focuses on reducing the risk of infection upstream would reduce these infections in both community and hospital settings.

Hospital usage of TOXBASE in Great Britain: Temporal trends in accesses 2008 to 2015

AIM

To examine temporal trends in accesses to the UK's National Poison Information Service's TOXBASE database in Britain.

METHODS

Generalized additive models were used to examine trends in daily numbers of accesses to TOXBASE from British emergency departments between January 2008 and December 2015. Day-of-the-week, seasonality and long-term trends were analysed at national and regional levels (Wales, Scotland and the nine English Government Office Regions).

RESULTS

The long-term trend in daily accesses increases from 2.8 (95% confidence interval (CI): 2.6-3.0) per user on 1 January 2008 to 4.6 (95% CI: 4.3-4.9) on 31 December 2015, with small but significant differences in population-corrected accesses by region ( p < 0.001). There are statistically significant seasonal and day of the week patterns ( p < 0.001) across all regions. Accesses are 18% (95% CI: 14-22%) higher in summer than in January and at the weekend compared to weekdays in all regions; there is a 7.5% (95% CI: 6.1-8.9%) increase between Friday and Sunday.

CONCLUSIONS

There are consistent in-year patterns in access to TOXBASE indicating potential seasonal patterns in poisonings in Britain, with location-dependent rates of usage. This novel descriptive work lays the basis for future work on the interaction of TOXBASE use with emergency admission of patients into hospital.

A mixed-methods evaluation of adherence to preventive treatment among child tuberculosis contacts in Indonesia

BACKGROUND

Tuberculosis (TB) can be prevented using isoniazid preventive therapy (IPT) among child contacts. However, the benefits of IPT depend on adherence to at least 6 months of daily treatment. A greater understanding of the barriers to and facilitators of adherence to IPT in resource-poor settings is required to optimise the benefits.

METHODS

We prospectively evaluated adherence to IPT and its associated factors among child contacts (age 0-5 years) eligible for IPT. We undertook in-depth interviews with care givers and a focus group discussion with health care workers, which were thematically analysed to explore barriers to and facilitators of adherence from the perspective of both care givers and health workers.

RESULTS

Of 99 eligible children, 49 (49.5%) did not complete 6 months of IPT. Children whose care giver collected their IPT medications from primary health centres were more likely to have incomplete adherence than those who collected them from hospitals (aOR 2.9, 95%CI 1.1-7.8). Thematic analyses revealed major barriers to and facilitators of adherence: regimen-related, care giver-related and health care-related factors, social support and access. Many of these factors are readily modifiable.

CONCLUSION

Providing information about IPT and improving accessibility for care givers to receive IPT at the primary health care facility should be priorities to facilitate implementation.

Improving electroconvulsive therapy practice through audit

Recent studies have highlighted deficiencies in ECT service delivery. This audit was set up to monitor and improve the ECT administered in a large psychiatric service. In the first phase of the audit Information was collected regarding stimulus adjustment in response to brief seizures. This highlighted inconsistencies In clinical practice and an education programme was instigated to correct these deficiencies and to bring practice into line with the Royal College of Psychiatrists guidelines. A repeat audit was performed and a marked improvement in the quality of stimulus adjustment was shown.

The APTT Response of Pregnant Plasma to Unfractionated Heparin

Pregnancy is associated with a physiological increase in coagulation factors and heparin binding proteins; both can affect the activated partial thromboplastin time (APTT) in response to unfractionated heparin (UFH) invalidating the use of a non-pregnant APTT therapeutic range. We compared the anticoagulant response of UFH added in vitro to the plasma of 13 pregnant (third trimester) and 15 nonpregnant women to determine whether the measured APTT and antifactor Xa activities are lower in pregnancy. Increasing concentrations of UFH were added to platelet-poor plasma from each subject and the APTT and anti-factor Xa activity were measured. The amount of UFH which was reversibly bound and neutralised by plasma heparin binding proteins was assessed by comparing the anti-factor Xa activity before and after addition of low affinity heparin (LAH). Fibrinogen, von Willebrand factor antigen (vWF Ag) and factor VIII levels, were also measured. The APTT response, assessed by the slope of the regression line of log APTT versus added heparin concentration, was attenuated in pregnant plasma (0.76 s/U/mL versus 1.2 s/U/mL, p = 0.005) and was highly correlated to increased non-specific plasma protein binding (47% versus 35% p <0.01) and increased fibrinogen (5.1g/L versus 2.8 g/L, p <0.01) and factor VIII activity (2.7 U/mL versus 1.2 U/mL, p <0.01). Thus, to achieve the same heparin level, pregnant women require higher daily doses of UFH than non-pregnant women. However, if UFH dose adjustments during the third trimester are based upon a non-pregnant APTT therapeutic range, systematic overdosing of pregnant women will result, possibly increasing the risk of bleeding and osteoporosis.

The impact of human papillomavirus type on colposcopy performance in women offered HPV immunisation in a catch-up vaccine programme: a two-centre observational study

OBJECTIVE

To determine whether human papillomavirus (HPV) immunisation has affected the prevalence of HPV genotypes and colposcopic features of cervical intraepithelial neoplasia (CIN) in young women referred for colposcopy.

DESIGN

A two-centre observational study including vaccinated and unvaccinated women.

SETTING

Colposcopy clinics serving two health regions in Scotland, UK.

POPULATION

A total of 361 women aged 20-25 years attending colposcopy following an abnormal cervical cytology result at routine cervical screening.

METHODS

Cervical samples were obtained from women for HPV DNA genotyping and mRNA E6/E7 expression of HPV 16, 18, 31, 33, and 45. Demographic data, cytology, and histology results and colposcopic features were recorded. Chi-square analysis was conducted to identify associations between vaccine status, HPV genotypes, and colposcopic features.

MAIN OUTCOME MEASURES

Colposcopic features, HPV genotypes, mRNA expression, and cervical histology.

RESULTS

The prevalence of HPV 16 was significantly lower in the vaccinated group (8.6%) compared with the unvaccinated group (46.7%) (P = 0.001). The number of cases of CIN2+ was significantly lower in women who had been vaccinated (P = 0.006). The HPV vaccine did not have a statistically significant effect on commonly recognised colposcopic features, but there was a slight reduction in the positive predictive value (PPV) of colposcopy for CIN2+, from 74% (unvaccinated) to 66.7% (vaccinated).

CONCLUSIONS

In this group of young women with abnormal cytology referred to colposcopy, HPV vaccination via a catch-up programme reduced the prevalence of CIN2+ and HPV 16 infection. The reduced PPV of colposcopy for the detection of CIN2+ in women who have been vaccinated is at the lower acceptable level of the UK national cervical screening programme guidelines.

TWEETABLE ABSTRACT

Reduction of hrHPV positivity and CIN in immunised women consistent with lower PPV of colposcopy for CIN2+.

Investigating anthelmintic efficacy against gastrointestinal nematodes in cattle by considering appropriate probability distributions for faecal egg count data

The Faecal Egg Count Reduction Test (FECRT) is the most widely used field-based method for estimating anthelmintic efficacy and as an indicator of the presence of anthelmintic resistant nematodes in cattle, despite never having been validated against the gold standard of controlled slaughter studies. The objectives of this study were to assess the normality of cattle faecal egg count (FEC) data and their transformed versions, since confidence intervals used to aid the interpretation of the FECRT, are derived from data assumed to be normally distributed, and violation of this assumption could potentially lead to the misclassification of anthelmintic efficacy. Further, probability distributions and associated parameters were evaluated to determine those most appropriate for representing cattle FEC data, which could be used to estimate percentage reductions and confidence limits. FEC data were analysed from 2175 cattle on 52 farms using a McMaster method at two different diagnostic sensitivities (30 and 15 eggs per gram (epg)) and a sensitive centrifugal flotation technique (SCFT) with a sensitivity of 1 epg. FEC data obtained from all egg count methods were found to be non-normal even upon transformation; therefore, it would be recommended that confidence or credible intervals be generated using either a Bootstrapping or Bayesian approach, respectively, since analyses using these frameworks do not necessarily require the assumption of normality. FEC data obtained using the SCFT method were best represented by distributions associated with the negative binomial and hence arithmetic means could be used in FECRT calculations.

Where FEC data were obtained with less sensitive counting techniques (i.e. McMaster 30 or 15 epg), zero-inflated distributions and their associated central tendency were the most appropriate and would be recommended to use, i.e. the arithmetic group mean divided by the proportion of non-zero counts present; otherwise apparent anthelmintic efficacy could be misrepresented.

•

Efficacy can be misrepresented if inappropriate central tendencies are used in calculations.

•

Sensitivity of counting technique used influences the distributions of best representation.

•

Confidence intervals assuming normality of data would not be recommended to use with FEC data.

Examining the association between surface bioburden and frequently touched sites in intensive care

BACKGROUND

Critical care patients are at increased risk of infection. Near-patient surfaces act as reservoirs of microbial soil, which may contain pathogens.

AIM

To correlate soil levels with hand-touch frequency of near-patient sites in an intensive care unit (ICU).

METHODS

Five sites around each bed in a 10-bed ICU were screened for total microbial soil (cfu/cm²) and Staphylococcus aureus every month for 10 months. Selected sites were infusion pump and cardiac monitor, left and right bedrails, and bed table. Ten 1 h covert audits of hand-touch frequency of these sites were performed in order to provide an average hand-touch count, which was modelled against soil levels obtained from microbiological screening.

FINDINGS

Seven of 10 staphylococci were found in conjunction with gross contamination of a specific site (P=0.005) and the same proportion from three most frequently touched sites (bedrails and bed table). There was a linear association between four sites demonstrating gross microbial contamination (>12 cfu/cm²) and mean number of hand-touch counts (P=0.08). The bed table was handled most but was not the most contaminated site. We suspected that customary placement of alcohol gel containers on bed tables may have reduced microbiological yield. Removing the gel container from one table confirmed its inhibitory effect on microbial contamination after rescreening (19% vs 50% >12 cfu/cm²: P=0.007).

CONCLUSION

Surface bioburden at near-patient sites in ICU is associated with hand-contact frequencies by staff and visitors. This supports the need for targeted hygienic cleaning in a high-risk healthcare environment.

An evaluation of chest X-ray in the context of community-based screening of child tuberculosis contacts

BACKGROUND

There are no published data on the critical review of chest X-ray (CXR) findings of children in the context of community-based contact screening.

OBJECTIVES

To describe the quality, findings and inter-observer agreement of CXRs in child TB contacts in Indonesia.

METHODS

We performed antero-posterior (AP) and lateral CXR in children who had had close contact with a pulmonary TB case. The CXRs were interpreted independently by four reviewers.

RESULTS

A total of 530 CXRs of 265 children were reviewed. Most (63%) of the children were asymptomatic at the time of CXR. Only 60% of the CXRs were reported as moderate to good quality by all reviewers, and inter-observer agreement on quality was slight to moderate (weighted κ = 0.16-0.35) for AP view. The majority of the CXRs were reported as normal (range 65-77%), with fair to moderate inter-observer agreement (κ = 0.25-0.46). Hilar lymphadenopathy (6-16%) was the most common CXR abnormality reported with poor inter-observer agreement (κ = -0.03 to 0.25).

CONCLUSION

The CXRs of child TB contacts investigated in the community were characterised by low quality, low agreement and low yield. Our findings support guidelines that CXR is not routinely indicated in asymptomatic child TB contacts in this setting.

A Comparison of Five Brief Screening Tools for HIV-Associated Neurocognitive Disorders in the USA and South Africa

Screening for HIV-associated neurocognitive disorders (HAND) is important to improve clinical outcomes. We compared the diagnostic sensitivity and specificity of the mini-mental state examination, International HIV dementia scale (IHDS), Montreal cognitive assessment, Simioni symptom questionnaire and cognitive assessment tool-rapid version (CAT-rapid) to a gold standard neuropsychological battery. Antiretroviral-experienced participants from Cape Town, South Africa, and Baltimore, USA, were recruited. The sensitivity and specificity of the five tools, as well as those of the combined IHDS and CAT-rapid, were established using 2 × 2 contingency tables and ROC analysis. More than a third (65165) had symptomatic HAND. In detecting HIV-D, the CAT-Rapid had good sensitivity (94 %) and weak specificity (52 %) (cut-point ≤10), while the IHDS showed fair sensitivity (68 %) and good specificity (86 %) (cut-point ≤10). The combined IHDS and CAT-rapid showed excellent sensitivity and specificity for HIV-D at a cut-off score of ≤16 (out of 20; 89 and 82 %). No tool was adequate in screening for any HAND. The combination IHDS and CAT-rapid tool appears to be a good screener for HIV-D but is only fairly sensitive and poorly specific in screening for any HAND. Screening for milder forms of HAND continues to be a clinical challenge.

Gut dendritic cell activation links an altered colonic microbiome to mucosal and systemic T-cell activation in untreated HIV-1 infection

HIV-1-associated disruption of intestinal homeostasis is a major factor contributing to chronic immune activation and inflammation. Dendritic cells (DCs) are crucial in maintaining intestinal homeostasis, but the impact of HIV-1 infection on intestinal DC number and function has not been extensively studied. We compared the frequency and activation/maturation status of colonic myeloid DC (mDC) subsets (CD1c(+) and CD1c(neg)) and plasmacytoid DCs in untreated HIV-1-infected subjects with uninfected controls. Colonic mDCs in HIV-1-infected subjects had increased CD40 but decreased CD83 expression, and CD40 expression on CD1c(+) mDCs positively correlated with mucosal HIV-1 viral load, with mucosal and systemic cytokine production, and with frequencies of activated colon and blood T cells. Percentage of CD83(+)CD1c(+) mDCs negatively correlated with frequencies of interferon-γ-producing colon CD4(+) and CD8(+) T cells. CD40 expression on CD1c(+) mDCs positively associated with abundance of high prevalence mucosal Prevotella copri and Prevotella stercorea but negatively associated with a number of low prevalence mucosal species, including Rumminococcus bromii. CD1c(+) mDC cytokine production was greater in response to in vitro stimulation with Prevotella species relative to R. bromii. These findings suggest that, during HIV infection, colonic mDCs become activated upon exposure to mucosal pathobiont bacteria leading to mucosal and systemic immune activation.