P–265 Investigating the nanotoxicity of solid silica nanoparticles in gametes following in vitro exposure

Study question

Do solid silica nanoparticles qualify as a new research tool for the in vitro transfer of compounds into gametes prior to Assisted Reproductive Technology (ART).

Summary answer

Solid silica nanoparticles (SSNPs) could be used as an intra-gamete delivery system to deliver therapeutic biomolecules into gametes prior to ART.

What is known already

Sperm-mediated gene transfer (SMGT) results in the production of transgenic embryos; however, the success rate of this technique is low. Nanoparticles are an efficient intra-cellular delivery system in vitro. Naturally cell-secreted nanoparticles are involved in the development of gametes. Mesoporous silica nanoparticles have been shown to carry large amounts of compounds and to interact with gametes without toxic effects, thus providing an alternative to naturally secreted nanoparticles. However, this technique is associated with some limitations, such as the size of these nanoparticles. SSNPs can be synthesised on a smaller nanoscale, thus providing higher potential to penetrate gametes and delivering biomolecules.

Study design, size, duration

This was an experimental in vitro study that investigated the effects of SSNPs on the motility of boar sperm and the degeneration of hamster oocytes, as determined by ooplasm shrinkage.

Participants/materials, setting, methods

SSNPs (20 nm) were conjugated with fluorescein diacetate–5-maleimide (FDA5M), a fluorescent protein. FDA5M-labelled SSNPS were incubated with boar sperm (N = 3) at 10 and 30µg/ml/107 sperm for four-hours. Motility parameters were assessed by computer-assisted sperm analysis (CASA). Binding potential was evaluated by fluorescent microscopy. Hamster oocytes (7 oocytes/group) were incubated with FDA5M-labelled SSNPs at 100, 150, and 300µg/ml, for two-hours; ooplasm shrinkage was evaluated. Time/matched control sperm was incubated in phosphate-buffered saline and oocytes in KSOM.

Main results and the role of chance

Exposure to FDA5M-labelled SSNPs did not affect total or progressive sperm motility (P = 0.6735 and 0.9606, respectively), average-path velocity or straight-line velocity after 4-hours of incubation (P = 0.7459 and 0.8696, respectively) compared to controls. SSNPs at 10 µg/ml significantly increased sperm curvilinear velocity after 1-hour (P = 0.0495) and linearity and straightness after 4-hours (P = 0.0389 and 0.0312, respectively). SSNPs at 30 µg/ml significantly increased sperm linearity after 3- and 4-hours (P = 0.0384 and 0.005, respectively). The proportion of sperm showing green fluorescence was significantly higher in the 30µg/ml dose of SSNPs than the 10µg/ml dose after 4-hours (P < 0.00001). In oocytes, the zona pellucida remained morphologically intact and the ooplasm exhibited green fluorescence. The ooplasm of 42% of the oocytes at 300µg/ml showed ooplasm shrinkage (a sign of degeneration); no oocytes showed shrinkage at doses of 100 and 150µg/ml of SSNPs. The green fluorescence in the sperm head and the ooplasm indicated the ability of SSNPs to spontaneously interact non-invasively with these gametes either by surface association or by cell-internalisation. This could provide a safe and non-invasive intra-gamete delivery system for research purposes and clinical therapy. This system could be used to deliver specific agents into gametes prior to ART to improve outcomes.

Limitations, reasons for caution

The SSNPs are non-biodegradable; it remains unknown as to how gametes or embryos might react with SSNPs over long time periods. The nanotoxicity of SSNPs has not yet been investigated over the long term. SSNPs have still to be tested with embryos to evaluate their effect on embryonic development.

Wider implications of the findings: SSNPs could be functionalised to target the nucleus of mammalian gametes and embryos to act as a carrier for oligonucleotides and genes to correct chromosomal abnormalities and to provide genetic therapy in these gametes and embryos to treat hereditary diseases before intra-uterine transfer.

Trial registration number

Not applicable

Autism spectrum disorder in females with fragile X syndrome: a systematic review and meta-analysis of prevalence

BACKGROUND

Whilst up to 60% of males with fragile X syndrome (FXS) meet criteria for autism spectrum disorder (ASD), the prevalence and nature of ASD in females with FXS remains unclear.

METHOD

A systematic literature search identified papers reporting ASD prevalence and/or symptomatology in females with FXS.

RESULTS AND CONCLUSION

Meta-analysis suggested that rates of ASD for females with FXS are reliably higher than for females in the general population (a random effects model estimated weighted average prevalence at 14%, 95% CI 13-18%). Whilst papers highlighted a number of social and repetitive difficulties for females with FXS, characteristic profiles of impairment are not clear. Possible associations between ASD traits and IQ, and between ASD and levels of fragile X mental retardation protein, are suggested, but data are equivocal.

UpToDate versus DynaMed: a cross-sectional study comparing the speed and accuracy of two point-of-care information tools

Objective:

To compare the accuracy, time to answer, user confidence, and user satisfaction between UpToDate and DynaMed (formerly DynaMed Plus), which are two popular point-of-care information tools.

Methods:

A crossover study was conducted with medical residents in obstetrics and gynecology and family medicine at the University of Toronto in order to compare the speed and accuracy with which they retrieved answers to clinical questions using UpToDate and DynaMed. Experiments took place between February 2017 and December 2019. Following a short tutorial on how to use each tool and completion of a background survey, participants attempted to find answers to two clinical questions in each tool. Time to answer each question, the chosen answer, confidence score, and satisfaction score were recorded for each clinical question.

Results:

A total of 57 residents took part in the experiment, including 32 from family medicine and 25 from obstetrics and gynecology. Accuracy in clinical answers was equal between UpToDate (average 1.35 out of 2) and DynaMed (average 1.36 out of 2). However, time to answer was 2.5 minutes faster in UpToDate compared to DynaMed. Participants were also more confident and satisfied with their answers in UpToDate compared to DynaMed.

Conclusions:

Despite a preference for UpToDate and a higher confidence in responses, the accuracy of clinical answers in UpToDate was equal to those in DynaMed. Previous exposure to UpToDate likely played a major role in participants' preferences. More research in this area is recommended.

Reinforcing locally led solutions for universal health coverage: a logic model with applications in Benin, Namibia and Uganda

Development assistance for health programmes is often characterised as donor-led models with minimal country ownership and limited sustainability. This article presents new ways for low-income and middle-income countries to gain more control of their development assistance programming as they move towards universal health coverage (UHC). We base our findings on the experience of the African Collaborative for Health Financing Solutions (ACS), an innovative US Agency for International Development-funded project. The ACS project stems from the premise that the global health community can more effectively support UHC processes in countries if development partners change three long-standing paradigms: (1) time-limited projects to enhancing long-lasting processes, (2) fly-in/fly-out development support to leveraging and strengthening local and regional expertise and (3) static knowledge creation to supporting practical and co-developed resources that enhance learning and capture implementation experience. We assume that development partners can facilitate progress towards UHC if interventions follow five action steps, including (1) align to country demand, (2) provide evidence-based and tailored health financing technical support, (3) respond to knowledge and learnings throughout activity design and implementation, (4) foster multi-stakeholder collaboration and ownership and (5) strengthen accountability mechanisms. Since 2017, the ACS project has applied these five action steps in its implementing countries, including Benin, Namibia and Uganda. This article shares with the global health community preliminary achievements of implementing a unique, challenging but promising experience.

Cohort profile: DOLORisk Dundee: a longitudinal study of chronic neuropathic pain

PURPOSE

Neuropathic pain is a common disorder of the somatosensory system that affects 7%-10% of the general population. The disorder places a large social and economic burden on patients as well as healthcare services. However, not everyone with a relevant underlying aetiology develops corresponding pain. DOLORisk Dundee, a European Union-funded cohort, part of the multicentre DOLORisk consortium, was set up to increase current understanding of this variation in onset. In particular, the cohort will allow exploration of psychosocial, clinical and genetic predictors of neuropathic pain onset.

PARTICIPANTS

DOLORisk Dundee has been constructed by rephenotyping two pre-existing Scottish population cohorts for neuropathic pain using a standardised 'core' study protocol: Genetics of Diabetes Audit and Research in Tayside Scotland (GoDARTS) (n=5236) consisting of predominantly type 2 diabetics from the Tayside region, and Generation Scotland: Scottish Family Health Study (GS:SFHS; n=20 221). Rephenotyping was conducted in two phases: a baseline postal survey and a combined postal and online follow-up survey. DOLORisk Dundee consists of 9155 participants (GoDARTS=1915; GS:SFHS=7240) who responded to the baseline survey, of which 6338 (69.2%; GoDARTS=1046; GS:SFHS=5292) also responded to the follow-up survey (18 months later).

FINDINGS TO DATE

At baseline, the proportion of those with chronic neuropathic pain (Douleur Neuropathique en 4 Questions questionnaire score ≥3, duration ≥3 months) was 30.5% in GoDARTS and 14.2% in Generation Scotland. Electronic record linkage enables large scale genetic association studies to be conducted and risk models have been constructed for neuropathic pain.

FUTURE PLANS

The cohort is being maintained by an access committee, through which collaborations are encouraged. Details of how to do this will be available on the study website (http://dolorisk.eu/). Further follow-up surveys of the cohort are planned and funding applications are being prepared to this effect. This will be conducted in harmony with similar pain rephenotyping of UK Biobank.

758 Pre-Incisional Infiltration of Local Anaesthetic Is Associated with Reduced Intra-Operative Fentanyl Requirements and Lower Pain Scores in Recovery

Introduction

Effective pain management is a pivotal component of day-surgical pathways. Intra-operative regional infiltration of long-acting local anaesthetic (LA) has been shown to be efficacious in reducing post-operative pain after general anaesthesia, yet few studies have explored the optimal timing of its use.

Method

Patients undergoing day-case breast/general surgical operations under a single consultant surgeon were randomised to receive LA infiltration (Levobupivicaine) before the initial incision, or during wound closure. All patients were given a propofol-based general anaesthetic. Primary outcomes were intra-operative/post-operative fentanyl requirements, and numerical pain scores (at 1 and 3 hours post-operatively). The study ran from October 2019 but was suspended during the COVID-19 pandemic. Non-parametric statistical tests were used.

Results

25 patients were randomised. Those receiving pre-incisional LA had lower fentanyl requirements intra-operatively (mean; 150mcg vs 186mcg, p < 0.05) but similar requirements post-operatively. Mean pain scores were lower in the pre-incisional LA group at 1 hour (1.2 vs 2.3, p < 0.05) and 3 hours post-operatively (0.7 vs 1.3, p > 0.4).

Conclusions

Pre-incisional infiltration of LA led to a significantly reduced requirement for intra-operative fentanyl, and significantly lower pain scores at 1 hour post-operatively. Larger studies should interrogate this effect at individual procedure level and assess for differences in rates of chronic pain.

Immunisation Status of Children with Cerebral Palsy in Rural Bangladesh: Results from the Bangladesh Cerebral Palsy Register (BCPR)

BACKGROUND

Cerebral palsy (CP) is the most common cause of physical disability in childhood, with an estimated 17 million cases worldwide. There is limited data concerning the general health of this population and the immunisation status of children with CP is largely unknown.

OBJECTIVE

We aimed to assess the immunisation status of children with CP in rural Bangladesh and determine the predictors of non-immunisation.

METHODS

This study is part of the Bangladesh CP Register (BCPR) study; a population based CP register commenced in January 2015 in the Shahjadpur sub-district of Bangladesh. As part of BCPR registration, all children with CP in the catchment area were assessed by a paediatrician and their clinical and immunisation history were collected.

RESULTS

Between January and December 2015, 615 children with CP were registered on the BCPR. The median age of the children was 7.5 years, and 38.5% were female. 91.7% of those children had a BCG vaccine scar (as an objective marker for immunisation at birth). However, only 43.2% reported to have received the rubella vaccine during the 2014 national rubella immunisation campaign. Timing of CP diagnosis was found to be an independent predictor for immunisation uptake; those diagnosed before the age of 3 were more likely to have received the rubella vaccine (95% confidence interval [CI] 1.6 - 4.3, odds ratio [OR] 2.6, p <0.0001).

CONCLUSIONS

To the best of our knowledge, this is the first paper to use a formal CP register to examine the relationship between CP and immunisation status in a low or middle income country like Bangladesh. Our data suggest that more than half of children with CP in rural Bangladesh did not receive immunisation during a recent national campaign.

Aquatic contaminants in Solomon Islands and Vanuatu: Evidence from passive samplers and Microtox toxicity assessment

Water Quality issues in many Pacific countries are rising, with the increase in coastal populations and associated urban runoff but management requires contamination issues in the aquatic environment to be identified and prioritised. In Vanuatu and Solomon Islands there are few laboratories and resources to assess for the presence or impact of complex chemical contaminants. The extent and impact of chemical contamination of the marine and coastal environment is poorly described. Passive chemical samplers were used to measure a range of aquatic pollutants around the capital cities, Honiara (Solomon Islands) and Port Vila (Vanuatu). We detected a range of chemicals indicative of agricultural and industrial contamination and a few sites had concerning concentrations of specific hydrocarbons and pesticides. The rapid ecotoxicology test, Microtox, indicated toxic impacts in rivers, coastal sites and urban drains This work provides new data on chemical contamination and possible impacts of that contamination for both countries. The techniques could be applied widely across the region to generate critical data for environmental management, guide monitoring efforts and measure the impact of policy or land-use changes.

76 This is (Probably) Not the Frailty Solution You are Looking For: Utilisation of A Novel Stand-Alone Community-Based Ambulatory Care Unit

Introduction/Aim

Our organisation wished to expand its “Care Closer To Home” capability, especially for older and/or frail patients. Our novel Ambulatory Care Unit (ACU) in a community hospital, staffed by GPs & nurses, opened a year ago. The ACU has some Point of Care (POCT) diagnostics, access to plain-film radiography and OT/physio. During the planning of the unit,” acute frailty” was anticipated to be core business. We wished to determine whether this turned out to be the case.

Method

Interrogation of the ACU patient log (spreadsheet collated from Data Collection Forms) Dec 2018-Nov 2019.

Results

Conclusion/Discussion

Recording of CFS by ACU staff was poor, limiting the validity of our results. Nevertheless, it is obvious that most patients seen in our ACU are not frail, and do not require therapies input. Those that are frail, however, have an acceptable conversion-to-admission rate of 8.6%, comfortably below the national target (20%).

Barriers to greater utilisation of our service for frail patients may include lack of urgent but non-emergency transport options for the less mobile, lack of access to certain commonly-used tests (e.g. CT, troponin) and referrer anticipation of difficulty discharging the frail patient in crisis without a new or boosted care package and/or access to respite beds. These aspects of service planning need to be addressed if the potential utility of community-based units like ours for frail patients is to be maximised.

AAPS Perspective on the EURL Recommendation on the use of Non-Animal-Derived Antibodies

In May 2020, the EU Reference Laboratory for alternatives to animal testing (EURL ECVAM) published a recommendation report entitled "Recommendation on nonanimal-derived antibodies". In this report, the EURL ECVAM specifically states: "Therefore, taking into consideration the ESAC Opinion on the scientific validity of replacements for animal-derived antibodies, EURL ECVAM recommends that animals should no longer be used for the development and production of antibodies for research, regulatory, diagnostic and therapeutic applications. The provisions of Directive 2010/63/EU should be respected, and EU countries should no longer authorise the development and production of antibodies through animal immunisation, where robust, legitimate scientific justification is lacking." (1). Here, we are providing the American Association of Pharmaceutical Scientists (AAPS) opinion on the EURL ECVAM recommendation report. In brief, there has been a clear and strong progress in reduction of animal use in the drug discovery and development process, including significant reduction of animal use in production of antibody reagents. Yet, it is proposed that more data need to be generated, shared and discussed within the scientific community before a decision to implement the change to non-animal derived antibodies is made.

Developmental cell programs are co-opted in inflammatory skin disease

The skin confers biophysical and immunological protection through a complex cellular network established early in embryonic development. We profiled the transcriptomes of more than 500,000 single cells from developing human fetal skin, healthy adult skin, and adult skin with atopic dermatitis and psoriasis. We leveraged these datasets to compare cell states across development, homeostasis, and disease. Our analysis revealed an enrichment of innate immune cells in skin during the first trimester and clonal expansion of disease-associated lymphocytes in atopic dermatitis and psoriasis. We uncovered and validated in situ a reemergence of prenatal vascular endothelial cell and macrophage cellular programs in atopic dermatitis and psoriasis lesional skin. These data illustrate the dynamism of cutaneous immunity and provide opportunities for targeting pathological developmental programs in inflammatory skin diseases.

First-in-Human Randomized Study to Assess the Safety and Immunogenicity of an Investigational Respiratory Syncytial Virus (RSV) Vaccine Based on Chimpanzee-Adenovirus-155 Viral Vector-Expressing RSV Fusion, Nucleocapsid, and Antitermination Viral Proteins in Healthy Adults

Background

Respiratory syncytial virus (RSV) disease is a major cause of infant morbidity and mortality. This Phase I, randomized, observer-blind, placebo- and active-controlled study evaluated an investigational vaccine against RSV (ChAd155-RSV) using the viral vector chimpanzee-adenovirus-155, encoding RSV fusion (F), nucleocapsid, and transcription antitermination proteins.

Methods

Healthy 18–45-year-old adults received ChAd155-RSV, a placebo, or an active control (Bexsero) at Days (D) 0 and 30. An escalation from a low dose (5 × 10⁹ viral particles) to a high dose (5 × 10¹⁰ viral particles) occurred after the first 16 participants. Endpoints were solicited/unsolicited and serious adverse events (SAEs), biochemical/hematological parameters, cell-mediated immunogenicity by enzyme-linked immunospot, functional neutralizing antibodies, anti RSV-F immunoglobin (Ig) G, and ChAd155 neutralizing antibodies.

Results

There were 7 participants who received the ChAd155-RSV low dose, 31 who received the ChAd155-RSV high dose, 19 who received the placebo, and 15 who received the active control. No dose-related toxicity or attributable SAEs at the 1-year follow-up were observed. The RSV-A neutralizing antibodies geometric mean titer ratios (post/pre-immunization) following a high dose were 2.6 (D30) and 2.3 (D60). The ratio of the fold-rise (D0 to D30) in anti-F IgG over the fold-rise in RSV-A–neutralizing antibodies was 1.01. At D7 after the high dose of the study vaccine, the median frequencies of circulating B-cells secreting anti-F antibodies were 133.3/10⁶ (IgG) and 16.7/10⁶ (IgA) in peripheral blood mononuclear cells (PBMCs). The median frequency of RSV-F–specific interferon γ–secreting T-cells after a ChAd155-RSV high dose was 108.3/10⁶ PBMCs at D30, with no increase after the second dose.

Conclusions

In adults previously naturally exposed to RSV, ChAd155-RSV generated increases in specific humoral and cellular immune responses without raising significant safety concerns.

Clinical Trials Registration

NCT02491463.

Healthcare staff perceptions and misconceptions regarding antibody testing in the United Kingdom: implications for the next steps for antibody screening

BACKGROUND

Healthcare workers have been at increased risk of exposure, infection and serious complications from COVID-19. Antibody testing has been used to identify staff members who have been previously infected by SARS-CoV-2, and has been rolled out rapidly in the United Kingdom. A number of comment and editorial articles have been published that raise concerns about antibody testing in this context. We present perceptions of National Health Service (NHS) healthcare workers in relation to SARS-CoV-2 antibody testing.

METHODS

An electronic survey regarding perceptions towards SARS-CoV-2 antibody testing was distributed to all healthcare workers at a major NHS tertiary hospital following implementation of antibody testing.

RESULTS

In total, 560 healthcare workers completed the survey (80% female; 25% of Black and Minority Ethnic background; 58% from frontline clinical staff). Exploring whether they previously had COVID-19 was the primary reported reason for choosing to undergo antibody testing (85.2%). In case of a positive antibody test, 72% reported that they would feel relieved, whilst 48% felt that they would be happier to work in a patient-facing area. Moreover, 12% responded that a positive test would mean "social distancing is less important", with 34% of the responders indicating that in this case they would be both less likely to catch COVID-19 and happier to visit friends/relatives.

CONCLUSIONS

NHS staff members primarily seek out SARS-CoV-2 antibody testing for an appropriate reason. Based on our findings and given the lack of definite data regarding the extent of immunity protection from a positive SARS-CoV-2 antibody test, significant concerns may be raised regarding the reported interpretation by healthcare workers of positive antibody test results. This needs to be further explored and addressed to protect NHS staff and patients.

Tokophobia and fear of birth: a workshop consensus statement on current issues and recommendations for future research

Objective: To discuss and develop a statement on the current state of the evidence and opinion in Fear of Childbirth (FoC) and Tokophobia (Tocophobia), and to provide recommendations. Background: A group met in 2019 to discuss the state of clinical and academic knowledge relating to FoC/Tokophobia. Five key areas were agreed as the focus of the meeting. Methods: 12 internationally acknowledged experts, in this or a closely related area (e.g. PTSD) met to discuss their understanding of the evidence for FoC/ Tokophobia and current practice. The consensus described in this paper constitutes the expression of the general opinion of the participants and does not necessarily imply unanimity. Keys points: Work focussed on tokophobia is recent and there remains a wide range of issues, which were addressed in the workshop including complexity in defining prevalence, a theoretical lack of understanding, which creates challenge for robust assessment and the identification of risk factors. An improved aetiological and developmental understanding of the tokophobia is required to underpin appropriate, effective and evidence-based interventions. Evaluation of pathways of care and relevant interventions, should be a focus of future research. Conclusion: Significant gaps remain within the FoC/tokophobia knowledge base. Further research is necessary.

Recruiting men from across the socioeconomic spectrum via GP registers and community outreach to a weight management feasibility randomised controlled trial

Background

Men, particularly those living in disadvantaged areas, are less likely to participate in weight management programmes than women despite similar levels of excess weight. Little is known about how best to recruit men to weight management interventions. This paper describes patient and public involvement in pre-trial decisions relevant to recruitment and aims to report on recruitment to the subsequent men-only weight management feasibility trial, including the: i) acceptability and feasibility of recruitment; and ii) baseline sample characteristics by recruitment strategy.

Methods

Men with BMI ≥30 kg/m² and/or waist circumference ≥ 40 in. were recruited to the feasibility trial via two strategies; community outreach (venue information stands and word of mouth) and GP letters, targeting disadvantaged areas. Recruitment activities (e.g. letters sent, researcher venue hours) were recorded systematically, and baseline characteristics questionnaire data collated. Qualitative interviews (n = 50) were conducted three months post-recruitment. Analyses and reporting followed a complementary mixed methods approach.

Results

105 men were recruited within four months (community n = 60, GP letter n = 45). Community outreach took 2.3 recruiter hours per participant and GP letters had an opt-in rate of 10.2% (n = 90/879). More men were interested than could be accommodated. Most participants (60%) lived in more disadvantaged areas. Compared to community outreach, men recruited via GP letters were older (mean = 57 vs 48 years); more likely to report an obesity-related co-morbidity (87% vs 44%); and less educated (no formal qualifications, 32% vs 10%, degree educated 11% vs 41%). Recruitment strategies were acceptable, a sensitive approach and trusting relationships with recruiters valued, and the ‘catchy’ study name drew attention.

Conclusions

Targeted community outreach and GP letters were acceptable strategies that successfully recruited participants to a men-only weight management feasibility trial. Both strategies engaged men from disadvantaged areas, a typically underserved population. Using two recruitment strategies produced samples with different health risk profiles, which could add value to research where either primary or secondary prevention is of interest. Further work is required to examine how these strategies could be implemented and sustained in practice.

Trial registration

ClinicalTrials.gov: NCT03040518, 2nd February 2017.

Homologous and heterologous re-challenge with Salmonella Typhi and Salmonella Paratyphi A in a randomised controlled human infection model

Enteric fever is a systemic infection caused by Salmonella Typhi or Paratyphi A. In many endemic areas, these serovars co-circulate and can cause multiple infection-episodes in childhood. Prior exposure is thought to confer partial, but incomplete, protection against subsequent attacks of enteric fever. Empirical data to support this hypothesis are limited, and there are few studies describing the occurrence of heterologous-protection between these closely related serovars. We performed a challenge-re-challenge study using a controlled human infection model (CHIM) to investigate the extent of infection-derived immunity to Salmonella Typhi or Paratyphi A infection. We recruited healthy volunteers into two groups: naïve volunteers with no prior exposure to Salmonella Typhi/Paratyphi A and volunteers previously-exposed to Salmonella Typhi or Paratyphi A in earlier CHIM studies. Within each group, participants were randomised 1:1 to oral challenge with either Salmonella Typhi (104 CFU) or Paratyphi A (103 CFU). The primary objective was to compare the attack rate between naïve and previously challenged individuals, defined as the proportion of participants per group meeting the diagnostic criteria of temperature of ≥38°C persisting for ≥12 hours and/or S. Typhi/Paratyphi bacteraemia up to day 14 post challenge. The attack-rate in participants who underwent homologous re-challenge with Salmonella Typhi was reduced compared with challenged naïve controls, although this reduction was not statistically significant (12/27[44%] vs. 12/19[63%]; Relative risk 0.70; 95% CI 0.41-1.21; p = 0.24). Homologous re-challenge with Salmonella Paratyphi A also resulted in a lower attack-rate than was seen in challenged naïve controls (3/12[25%] vs. 10/18[56%]; RR0.45; 95% CI 0.16-1.30; p = 0.14). Evidence of protection was supported by a post hoc analysis in which previous exposure was associated with an approximately 36% and 57% reduced risk of typhoid or paratyphoid disease respectively on re-challenge. Individuals who did not develop enteric fever on primary exposure were significantly more likely to be protected on re-challenge, compared with individuals who developed disease on primary exposure. Heterologous re-challenge with Salmonella Typhi or Salmonella Paratyphi A was not associated with a reduced attack rate following challenge. Within the context of the model, prior exposure was not associated with reduced disease severity, altered microbiological profile or boosting of humoral immune responses. We conclude that prior Salmonella Typhi and Paratyphi A exposure may confer partial but incomplete protection against subsequent infection, but with a comparable clinical and microbiological phenotype. There is no demonstrable cross-protection between these serovars, consistent with the co-circulation of Salmonella Typhi and Paratyphi A. Collectively, these data are consistent with surveillance and modelling studies that indicate multiple infections can occur in high transmission settings, supporting the need for vaccines to reduce the burden of disease in childhood and achieve disease control. Trial registration NCT02192008; clinicaltrials.gov.

Human Salmonella Typhi exposure generates differential multifunctional cross-reactive T-cell memory responses against Salmonella Paratyphi and invasive nontyphoidal Salmonella

Objective

There are no vaccines for most of the major invasive Salmonella strains causing severe infection in humans. We evaluated the specificity of adaptive T memory cell responses generated after Salmonella Typhi exposure in humans against other major invasive Salmonella strains sharing capacity for dissemination.

Methods

T memory cells from eleven volunteers who underwent controlled oral challenge with wtS. Typhi were characterised by flow cytometry for cross‐reactive cellular cytokine/chemokine effector responses or evidence of degranulation upon stimulation with autologous B‐lymphoblastoid cells infected with either S. Typhi, Salmonella Paratyphi A (PA), S. Paratyphi B (PB) or an invasive nontyphoidal Salmonella strain of the S. Typhimurium serovar (iNTSTy).

Results

Blood T‐cell effector memory (T_EM) responses after exposure to S. Typhi in humans evolve late, peaking weeks after infection in most volunteers. Induced multifunctional CD4⁺ Th1 and CD8⁺ T_EM cells elicited after S. Typhi challenge were cross‐reactive with PA, PB and iNTSTy. The magnitude of multifunctional CD4⁺ T_EM cell responses to S. Typhi correlated with induction of cross‐reactive multifunctional CD8⁺ T_EM cells against PA, PB and iNTSTy. Highly multifunctional subsets and T central memory and T effector memory cells that re‐express CD45 (T_EMRA) demonstrated less heterologous T‐cell cross‐reactivity, and multifunctional Th17 elicited after S. Typhi challenge was not cross‐reactive against other invasive Salmonella.

Conclusion

Gaps in cross‐reactive immune effector functions in human T‐cell memory compartments were highly dependent on invasive Salmonella strain, underscoring the importance of strain‐dependent vaccination in the design of T‐cell‐based vaccines for invasive Salmonella.

Text messaging and financial incentives to encourage weight loss in men with obesity: the Game of Stones feasibility RCT

Background

In 2016, 26% of UK men were estimated to be obese. Systematic reviews suggest that few men engage in formal weight loss interventions that support weight reduction and improve health.

Objective

To co-produce, with patient and public involvement, an acceptable and feasible randomised controlled trial design to test a men-only weight management intervention.

Design

This was a two-phase feasibility study. Phase 1 was the development of intervention components, study procedures and materials including a discrete choice experiment with survey questions. Phase 2 was an individually randomised three-arm feasibility trial over 12 months. Qualitative interviews were conducted at 3 and 12 months.

Setting

The setting was two sites in Scotland that had disadvantaged urban and rural areas and differed in employment levels and ethnic groups.

Participants

In phase 1, 1045 men with obesity were recruited by Ipsos MORI (London, UK; www.ipsos.com/ipsos-mori/en-uk) to represent the UK population. In phase 2, 105 men with obesity were recruited in the community or through general practice obesity registers. Qualitative interviews were conducted with 50 men at 3 months and with 33 men at 12 months.

Interventions

The trial arms were narrative short message service (SMS) for 12 months (SMS only), financial endowment incentive informed by loss aversion and linked to achievement of weight loss targets plus narrative SMS for 12 months (SMS + I), and waiting list control group for 12 months followed by 3 months of an alternative SMS style developed based on feedback from men who had received the narrative SMS (control).

Main outcome measures

The main outcome measures were acceptability and feasibility of recruitment, retention, engagement, intervention components and trial procedures. Outcomes were assessed by examining procedural, quantitative and qualitative data at 3, 6 and 12 months.

Results

The most acceptable incentive strategy, based on the discrete choice experiment results, was to verify weight loss of 5% at 3 months, verify weight loss of 10% at 6 months and maintain weight loss of 10% at 12 months. Overall, 105 men with obesity from across the socioeconomic spectrum were successfully recruited to target, 59% of whom lived in more disadvantaged areas. Retention at 12 months was acceptable (74%) and was higher among individuals from disadvantaged areas. Narrative SMS were acceptable to many men, with a minority reporting negative reactions. Incentives were acceptable but were not the primary motivation for behaviour change. Twelve men in the incentive arm (33%) secured at least some money and three (8%) secured the full amount. Both intervention arms lost some weight, with greater weight loss in the arm that received SMS and incentives. The alternative SMS based on men’s feedback received no strong negative reactions.

Limitations

Fewer participants from the SMS + I arm (64%) completed the study at 12 months than did those in the SMS-only (79%) and control (83%) arms. The reasons for this difference were complex.

Conclusions

The men-only weight management intervention consisting of narrative SMS and financial incentives was acceptable and feasible, meeting the progression criteria for a full trial. Tailoring of SMS may improve acceptability and retention.

Future work

Minor refinements to the intervention components based on the study findings will be made prior to testing in a multisite definitive randomised controlled trial.

Trial registration

ClinicalTrials.gov NCT03040518.

Funding

This project was funded by the National Institute for Health Research (NIHR) Public Health Research programme and will be published in full in Public Health Research; Vol. 8, No. 11. See the NIHR Journals Library website for further project information.

A Community Development Program and Reduction in High-Cost Health Care Use

Adverse housing and neighborhood conditions influence child health. The Healthy Neighborhoods Healthy Families community development initiative was established in 2008 to address housing, education, employment, and other neighborhood-level, child health-influencing factors on the south side of Columbus, Ohio, with the goal of improving child health and well-being. In this article, we discuss the path from advocacy to outcomes analysis in this initiative and assess changes in high-cost health care use by children in the target area over the first decade of implementation. Change in health care use was measured by using a difference-in-differences approach comparing emergency department visits, inpatient stays, and inpatient length of stay in the intervention neighborhood and a propensity score-matched, pooled comparator neighborhood in the same city. The baseline and follow-up periods were August 2008 to July 2010 and August 2015 to July 2017, respectively. Findings from this analysis reveal that compared to 2 pooled comparison neighborhoods, the intervention neighborhood trended, nonsignificantly, toward greater decreases in inpatient stays and emergency department visits and smaller increases in length of stays. These results suggest that our community development activities may be influencing health care use outcomes, but in the early years of the intervention relative changes are modest and are variable based on the definition of the intervention and comparator neighborhoods. Lessons learned in expanding from advocacy to analysis include the importance of building multidisciplinary teams that can apply novel approaches to analysis, moderating expectations, and retaining focus on the broader social context.