Murine MHC-Deficient Nonobese Diabetic Mice Carrying Human HLA-DQ8 Develop Severe Myocarditis and Myositis in Response to Anti-PD-1 Immune Checkpoint Inhibitor Cancer Therapy

Myocarditis has emerged as an immune-related adverse event of immune checkpoint inhibitor (ICI) cancer therapy associated with significant mortality. To ensure patients continue to safely benefit from life-saving cancer therapy, an understanding of fundamental immunological phenomena underlying ICI myocarditis is essential. We recently developed the NOD-cMHCI/II-/-.DQ8 mouse model that spontaneously develops myocarditis with lower mortality than observed in previous HLA-DQ8 NOD mouse strains. Our strain was rendered murine MHC class I and II deficient using CRISPR/Cas9 technology, making it a genetically clean platform for dissecting CD4+ T cell-mediated myocarditis in the absence of classically selected CD8+ T cells. These mice are highly susceptible to myocarditis and acute heart failure following anti-PD-1 ICI-induced treatment. Additionally, anti-PD-1 administration accelerates skeletal muscle myositis. Using histology, flow cytometry, adoptive transfers, and RNA sequencing analyses, we performed a thorough characterization of cardiac and skeletal muscle T cells, identifying shared and unique characteristics of both populations. Taken together, this report details a mouse model with features of a rare, but highly lethal clinical presentation of overlapping myocarditis and myositis following ICI therapy. This study sheds light on underlying immunological mechanisms in ICI myocarditis and provides the basis for further detailed analyses of diagnostic and therapeutic strategies.

Association between lung function and dyspnoea and its variation in the multinational Burden of Obstructive Lung Disease (BOLD) study

BACKGROUND

Dyspnoea is a common symptom of respiratory disease. However, data on its prevalence in general populations and its association with lung function are limited and are mainly from high-income countries. The aims of this study were to estimate the prevalence of dyspnoea across several world regions, and to investigate the association of dyspnoea with lung function.

METHODS

Dyspnoea was assessed, and lung function measured in 25,806 adult participants of the multinational Burden of Obstructive Lung Disease study. Dyspnoea was defined as ≥2 on the modified Medical Research Council (mMRC) dyspnoea scale. The prevalence of dyspnoea was estimated for each of the study sites and compared across countries and world regions. Multivariable logistic regression was used to assess the association of dyspnoea with lung function in each site. Results were then pooled using random-effects meta-analysis.

RESULTS

The prevalence of dyspnoea varied widely across sites without a clear geographical pattern. The mean prevalence of dyspnoea was 13.7 % (SD=8.2 %), ranging from 0 % in Mysore (India) to 28.8 % in Nampicuan-Talugtug (Philippines). Dyspnoea was strongly associated with both spirometry restriction (FVC

CONCLUSION

The prevalence of dyspnoea varies substantially across the world and is strongly associated with lung function impairment. Using the mMRC scale in epidemiological research should be discussed.

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Key Words

• Breathlessness
• Dyspnoea
• Lung function
• Spirometry

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Affiliation(s)

A Müller Ludwig Boltzmann Institute for Lung Health, Vienna, Austria; Care and Public Health Research Institute, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands.
E F Wouters Ludwig Boltzmann Institute for Lung Health, Vienna, Austria; Sigmund Freud University, Faculty of Medicine, Vienna, Austria; Department of Respiratory Medicine, Maastricht University Medical Center, Maastricht, the Netherlands
P Koul Department of Pulmonary Medicine, Sheri Kashmir Institute of Medical Sciences, Srinagar, India
T Welte Department of Respiratory Medicine/Infectious Disease, Member of the German Centre for Lung Research, Hannover School of Medicine, Hannover, Germany
I Harrabi Faculté de Médecine, Sousse, Tunisia
A Rashid RCSI and UCD Malaysia Campus, Penang, Malaysia
L C Loh RUMC, Penang, Malaysia
M Al Ghobain King Abdullah International Medical Research Center, King Saud ben Abdulaziz University for Health Science, Riyadh, Saudi Arabia
A Elsony The Epidemiological Laboratory, Khartoum, Sudan
R Ahmed The Epidemiological Laboratory, Khartoum, Sudan
J Potts National Heart and Lung Institute, Imperial College London, London, UK
K Mortimer University of Cambridge, Cambridge, UK; Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
F Rodrigues Pulmonology Department, Lisbon North Hospital Centre, Lisbon, Portugal; Institute of Environmental Health, Associate Laboratory TERRA, Lisbon Medical School, Lisbon University, Lisbon, Portugal
S N Paraguas Philippine College of Chest Physicians, Manila, Philippines
S Juvekar KEM Hospital Research Centre, Pune, India
D Agarwal KEM Hospital Research Centre, Pune, India
D Obaseki Department of Medicine, Obafemi Awolowo University, Nigeria; Faculty of Medicine, University of British Columbia, Canada
T Gislason Faculty of Medicine, University of Iceland, Reykjavik, Iceland; Department of Sleep, Landspitali - The National University Hospital of Iceland, Reykjavik, Iceland
T Seemungal Faculty of Medical Sciences, University of West Indies, St Augustine, Trinidad and Tobago
A A Nafees Aga Khan University, Karachi, Pakistan
C Jenkins Woolcock Institute of Medical Research, Sydney, Australia
H B Dias Escola Superior de Tecnologia da Saúde de Lisboa, Politecnico de Lisboa, Lisbon, Portugal
F M E Franssen Department of Respiratory Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Research and Development, Ciro, Horn, the Netherlands
M Studnicka Department of Pulmonary Medicine, Paracelsus Medical University, Salzburg, Austria
C Janson Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
H H Cherkaski Faculty of Medicine, University Badji Mokhtar, Annaba, Algeria
M El Biaze Department of Respiratory Medicine, Faculty of Medicine, Mohammed Ben Abdellah University, Fes, Morocco
P A Mahesh Department of Respiratory Medicine, JSS Medical College and Hospital, Mysore, Karnataka, India
J Cardoso Pulmonology Department, Centro Hospitalar Universitário de Lisboa Central, Lisboa, Portugal; NOVA Medical School, Nova University Lisbon, Lisboa, Portugal
P Burney National Heart and Lung Institute, Imperial College London, London, UK
S Hartl Ludwig Boltzmann Institute for Lung Health, Vienna, Austria; Sigmund Freud University, Faculty of Medicine, Vienna, Austria
D J A Janssen Care and Public Health Research Institute, Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands; Department of Research and Development, Ciro, Horn, the Netherlands
A F S Amaral National Heart and Lung Institute, Imperial College London, London, UK; NIHR Imperial Biomedical Research Centre, London, UK

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Sporadic bovine encephalopathy caused by Chlamydia pecorum secondary to bovine viral diarrhoea virus infection in calves in South Australia

BACKGROUND

Despite bovine viral diarrhoea virus and Chlamydia pecorum being important endemic diseases of cattle, there are limited reports of theirco-occurrence.

CASE REPORT

Several 12-18-week-old, weaned Hereford calves presented with ill-thriftiness and neurological signs on a mixed cattle and sheep farm in South Australia in July 2021. Immune suppression resulting from transient infection with bovine viral diarrhoea virus (BVDV) is implicated in predisposing to infection with Chlamydia pecorum, the causative agent of sporadic bovine encephalopathy (SBE). Chlamydia spp. are difficult to culture in vitro or definitively identify based on current standard molecular based tests. In this case, diagnosis was confirmed by immunohistochemistry.

CONCLUSION

To the authors' knowledge, this case report is the first to document BVDV transient infection occurring in conjunction with SBE. Given the current high prevalence of BVDV on Australian farms, such co-infections may have significant future clinical relevance. This case also highlights the need for appropriate tests, such as immunohistochemistry to demonstrate the causative organism in histological lesions and thus reduce the occurrence of false negative diagnosis.

Advancing gender inclusivity for Two-Spirit, trans, nonbinary and other gender-diverse blood and plasma donors

BACKGROUND AND OBJECTIVES

Two-Spirit, trans, nonbinary and other gender-diverse (2STGD) donors face challenges in donation. While many blood operators aim to address these challenges, to date, no empirical study with these donors has been conducted to guide their efforts. This paper reports 2STGD donors' views on a two-step approach asking donors their gender and sex assigned at birth (SAAB), and expanding gender options in donor registration.

MATERIALS AND METHODS

A qualitative community-based study was conducted with 2STGD donors (n = 85) in Canada. Semi-structured, in-depth interviews were conducted from July to October 2022, audio-recorded and transcribed. Data were analysed using a thematic analytic framework.

RESULTS

Participants were divided on their views of a two-step approach asking gender and SAAB. Themes underlying views in favour of this approach included the following: demonstrating validation and visibility, and treating 2STGD donors and cisgender donors alike. Themes underlying views not in favour or uncertain included potential for harm, compromising physical safety, and invalidation. All participants were in favour of expanding gender options if blood operators must know donors' gender.

CONCLUSION

Results indicate that a two-step approach for all donors is not recommended unless the blood operator must know both a donor's gender and SAAB to ensure donor and/or recipient safety. Gender options should be expanded beyond binary options. Ongoing research and evidence synthesis are needed to determine how best to apply donor safety measures to nonbinary donors.

What works in advocating for food advertising policy change across an english region - a realist evaluation

BACKGROUND

With increasing recognition of the role of commercial determinants of health, local areas in England have sought to restrict the advertising of products high in fat, salt and sugar (HFSS) on council-owned spaces, as part of wider strategies to reduce obesity. While there is some evidence of the impact of such policy change on behaviour, little is known about what works in the process of implementing this policy change.

METHODS

Guided by a realist evaluation framework that explores the interaction between context, mechanism and outcomes, this study aims to investigate the factors that influence the restriction of outdoor advertising of HFSS products in one region in England. It refines a programme theory co-produced with stakeholders from 14 local authorities within a region and uses multiple data sources from each area with an in-depth examination of four case study sites. Data sources include longitudinal realist interviews, focus groups and surveys with policy advocates and policy stakeholders. Data were analysed retroductively to understand the causal link between context, mechanism and outcomes.

RESULTS

Outcomes were driven by five dominant mechanisms: a strategic and staggered approach to stakeholder engagement, gathering intelligence, identifying policy champions, building relationships, reframing the issue; and two secondary mechanisms of amplifying the issue and increasing public will. These led to varied outcomes with no changes in formal policy position within the evaluation period but draft policy guidance in place and changes in political will demonstrated. Dominant context factors influencing change included having a named and resourced policy advocate in place supported by an external Community of Improvement and having existing aligned local objectives. Organisational complexity and change, financial concerns, lack of local examples, ideological positions and the pandemic were also influencing contextual factors.

CONCLUSION

Effecting policy change in this area requires the commitment of an extended period and the valuing of short-term policy outcomes, such as increasing political will. The importance of a resourced and well-supported policy advocate to lead this work is fundamental and the commercially sensitive nature of this policy change means that a complex interplay of mechanisms is required which may be dominated by a strategically staggered approach to stakeholder engagement.

Initial Experience with the Commercial Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The purpose of this study was to introduce a new commercial electron FLASH system that has the potential to become widely available for FLASH researchers globally. In this study, we first present the initial acceptance and commissioning tests for the FLASH system, and second, we highlight preliminary FLASH effect results from our cell studies.

MATERIALS/METHODS

A linear accelerator was converted into a commercial research platform with the FLASH Research Extension, enabling the generation of a powerful 16 MeV electron FLASH beam. The dosimetric and stability tests were conducted using various dosimeters (i.e., radiochromic film, optically stimulated luminescent dosimeters (OSLDs), and a plane-parallel ionization chamber). To evaluate the FLASH effect, normal and cancer cell lines were FLASH irradiated using different pulse repetition frequencies (PRF) of 18 pulses/s and 180 pulses/s.

RESULTS

The electron FLASH mode was able to generate over 1 Gy per pulse at the isocenter and a dose rate of up to 690 Gy/s near the accessory mount of the Linac gantry head. The charge collected by the plane-parallel ionization chamber at the highest PRF (i.e., 180 pulses/s) showed a linear relationship with the delivered number of pulses (i.e., 1 to 99 pulses) with a coefficient of determination (R2) of 0.9996. The absorbed dose measured using radiochromic film and OSLDs agreed within 3%, on average, and followed an inverse square law as the source-to-axis distance (SAD) varied for which the R2 values were 0.9972 and 0.9955 for radiochromic film and OSLDs, respectively. The profile of the FLASH beam was symmetrical but was not as flat as the conventional 16 MeV electron beam due to the use of a thinner custom scattering foil to reduce the degradation of the ultra-high dose rate. The depth-dose curve beyond the build-up region for the FLASH beam was similar to the conventional 16 MeV electron beam for which the range at 50% the maximum dose (R50) agreed within 0.5 mm. The FLASH beam output remained consistent over a 4-month period with a variation of 2.5%, on average. The FLASH sparing effect was observed in vitro for healthy human pancreatic cells. Furthermore, we observed that the highest PRF beam (180 pulses/s) was more effective at destroying pancreatic cancerous cells while minimizing damage to healthy cells compared to the lowest PRF beam (18 pulses/s).

CONCLUSION

The novel commercial FLASH Research Extension system was dosimetrically characterized for pre-clinical FLASH research, and preliminary in vitro results demonstrated the FLASH effect. Given the prevalence of linear accelerators, this new commercial system has the potential to greatly increase the access to FLASH research.

Commissioning and Initial Validation of Commercial Treatment Planning System for the Electron FLASH Research Extension

PURPOSE/OBJECTIVE(S)

The aim of this study was to investigate the feasibility of commissioning the 16 MeV electron FLASH beam in a commercial treatment planning system (TPS) for pre-clinical research purposes. The delivery system consisted of a new commercial solution for which a linear accelerator was modified into a FLASH Research Extension platform. Additionally, preliminary radiation biology results were highlighted to showcase the future use of this system.

MATERIALS/METHODS

To commission a commercial electron Monte Carlo (MC) for dose calculation of a 16 MeV FLASH beam in the TPS, radiochromic film was used to measure the vendor-required beam data, e.g., profiles and percent depth dose (PDD) curves for cone sizes of 6 × 6 cm2, 10 × 10 cm2, and 15 × 15 cm2 as well as an in-air profile for a 40 × 40 cm2 open field (no cone). Once the electron MC beam model was generated, additional measurements were collected for validation and compared against the calculated dose from the TPS. A treatment planning comparison between the newly commissioned FLASH beam and the conventional electron beam was conducted. Specifically, the dose-volume histograms (DVHs) for target volumes and organs at risk were investigated for skin cancer cases previously treated with conventional electron beams. Lastly, the FLASH dose distribution predicted by the electron MC for an in vitro cell study setup was validated with radiochromic film measurements, and initial radiobiology tests were conducted using FLASH and conventional dose-rate electron beams.

RESULTS

The electron MC calculated dose for the 16 MeV electron FLASH beam agreed with measured PDDs within 1% for all field sizes. The beam profile characteristics, such as penumbra, shape, and full width at half maximum, demonstrated good agreement with less than 0.5 mm difference between the TPS and measurements. There were noticeable differences in the profiles of large fields between the FLASH and conventional dose-rate beam models due to the more forward-peaked FLASH beam. For treatment planning, Regarding DVH, the FLASH dose-rate plan provided comparable plan quality to the conventional dose-rate plan, achieving adequate coverage for the target volumes and sparing the healthy organs and tissues. The electron MC dose prediction for the FLASH beam was also found to be in good agreement with the film measurements of the in vitro cell study setup. Furthermore, the FLASH beam was observed to be more effective with a 20 % increase in killing pancreatic cancer cells compared to the conventional dose rate.

CONCLUSION

The study successfully incorporated the 16 MeV electron FLASH Research Extension into the commercial TPS using electron Monte Carlo for dose calculation. This will be valuable for pre-clinical cell and animal studies. This research also enables FLASH treatment planning studies, a key component for the future implementation of FLASH into clinical care. Further research is necessary to incorporate the radiation biology effect of FLASH into the treatment planning system.

Immunohistochemical characteristics of local sites that trigger atrial arrhythmias in response to high-frequency stimulation

AIMS

The response to high frequency stimulation (HFS) is used to locate putative sites of ganglionated plexuses (GPs), which are implicated in triggering atrial fibrillation (AF). To identify topological and immunohistochemical characteristics of presumed GP sites functionally identified by HFS.

METHODS AND RESULTS

Sixty-three atrial sites were tested with HFS in four Langendorff-perfused porcine hearts. A 3.5 mm tip quadripolar ablation catheter was used to stimulate and deliver HFS to the left and right atrial epicardium, within the local atrial refractory period. Tissue samples from sites triggering atrial ectopy/AF (ET) sites and non-ET sites were stained with choline acetyltransferase (ChAT) and tyrosine hydroxylase (TH), for quantification of parasympathetic and sympathetic nerves, respectively. The average cross-sectional area (CSA) of nerves was also calculated. Histomorphometry of six ET sites (9.5%) identified by HFS evoking at least a single atrial ectopic was compared with non-ET sites. All ET sites contained ChAT-immunoreactive (ChAT-IR) and/or TH-immunoreactive nerves (TH-IR). Nerve density was greater in ET sites compared to non-ET sites (nerves/cm2: 162.3 ± 110.9 vs. 69.65 ± 72.48; P = 0.047). Overall, TH-IR nerves had a larger CSA than ChAT-IR nerves (µm2: 11 196 ± 35 141 vs. 2070 ± 5841; P < 0.0001), but in ET sites, TH-IR nerves were smaller than in non-ET sites (µm2: 6021 ± 14 586 vs. 25 254 ± 61 499; P < 0.001).

CONCLUSIONS

ET sites identified by HFS contained a higher density of smaller nerves than non-ET sites. The majority of these nerves were within the atrial myocardium. This has important clinical implications for devising an effective therapeutic strategy for targeting autonomic triggers of AF.

Microbiological Quality of Ready-to-Eat Salad Products Collected from Retail and Catering Settings in England during 2020 to 2021

ABSTRACT

Salad and other fresh produce were collected in England from retail and catering businesses during 2020 to 2021 and were tested for Salmonella, Shiga toxin-producing Escherichia coli (STEC), Listeria, Bacillus cereus, and E. coli. Of the 604 samples collected, 57% were from retail settings and 43% were from catering settings; 61% were either salad leaves or salad leaves mixed with other products. Equal numbers of samples were prepacked or loose, and 50% were refrigerated at the time of sampling. Combining results for all microbiological parameters, 84% were interpreted as satisfactory, 12% were interpreted as borderline, and 4% were interpreted as unsatisfactory. One sample (prepacked leaves, cucumber, and tomato from a caterer) was categorized as unacceptable and potentially injurious because of detection of STEC O76; no STEC from human infections in the United Kingdom matched this isolate. No Salmonella enterica was detected, but Listeria monocytogenes was recovered from 11 samples: 1 at 20 CFU/g and the remainder at <20 CFU/g. B. cereus was detected at borderline levels (103 to ≤105 CFU/g) in 9% of samples and at an unsatisfactory level (>105 CFU/g) in one sample. E. coli was detected in 3% of samples at borderline levels (20 to ≤102 CFU/g) and in 4% at unsatisfactory levels (>102 CFU/g). There was a significant association between detection of L. monocytogenes and borderline or unsatisfactory levels of E. coli. There were no specific risk profiles associated with products with the higher levels of B. cereus, STEC, or Listeria, but elevated levels of E. coli were predominantly confined to loose products from the United Kingdom collected from caterers in summer or autumn 2021 and may have resulted from relaxation of COVID-19 restrictions. Among the L. monocytogenes isolates, only one matched those from human cases and was recovered from a prepacked mixed salad from a catering business in 2021. This isolate was the same strain as that responsible for a multicountry outbreak (2015 to 2018) associated with Hungarian-produced frozen sweet corn; no link to the outbreak food chain was established.

HIGHLIGHTS

Suspected chlamydial foetal loss highlights the need for standardised on-farm protocols

Chlamydia psittaci is a recognised cause of late-term equine foetal loss and poses a zoonotic risk in Australia. However, a management strategy is lacking to protect at-risk humans handling infected aborted material and pregnant mares. This study proposes a protocol for approaching C. psittaci foetal loss after investigating four foetal losses that occurred on a horse stud in the Hunter Valley, Australia in 2021. Swabs from the foetal loss cases (n = 4), close contact mares (n = 59), and foals of the close contact mares (n = 33) were collected and tested for C. psittaci using both isothermal points of care and quantitative polymerase chain reaction (qPCR) laboratory-based testing. Genotyping was performed utilising C. psittaci multilocus sequence typing and ompA sequencing from C. psittaci positive pooled foetal and placental (n = 3) DNA. Foetal and placental samples from the four foetal loss cases were all positive for C. psittaci with 100% agreement between the isothermal swab testing on the farm and qPCR DNA testing at an external laboratory. Genotyping revealed the clonal and identical sequence type 24 (ST24) C. psittaci strains in all samples. C. psittaci was not detected in close contact with mares or their foals. There was no statistically significant difference in foal survival between the close contact mare groups that did and did not receive antimicrobial intervention (P > 0.05). The proposed protocol is intended to raise awareness and begin a discussion for guidelines around handling of chlamydial foetal loss cases in late pregnant mares which pose a zoonotic threat to farm workers and veterinarians.

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

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

British Journal of Surgery Society.

Lessons learned from the investigation and management of an outbreak of Shigella flexneri associated with a restaurant in London, 2019-2020

BACKGROUND

Foodborne outbreaks of Shigella flexneri infection are uncommon in the UK. In November 2019, the United Kingdom Health Security Agency investigated an outbreak of S. flexneri associated with a fast-food restaurant in London.

METHODS

Epidemiological investigations included case ascertainment and interviewing suspected cases using enhanced surveillance questionnaires. Whole-genome sequencing (WGS) was used for characterisation of human isolates. Environmental investigations included a review of food safety processes at the implicated restaurant, administration of exposure questionnaires and stool sampling of staff.

RESULTS

Between November 2019 and February 2020, 17 cases were confirmed as part of the outbreak by WGS in London. Among these, 15 were linked to the implicated restaurant. A review of the food safety processes at the restaurant was satisfactory. Despite initial suboptimal coverage of stool screening of staff, all staff members working at the restaurant during the sampling period were screened and an asymptomatic food handler tested positive for S.flexneri with the outbreak WGS profile. The individual underwent microbiological clearance, and no further cases were reported. It was not possible to confirm the direction of transmission for the community cases or the staff member.

CONCLUSION

We report an outbreak of S. flexneri in a fast-food restaurant in London with previous inspection ratings indicating good compliance with food safety and hygiene standards. WGS was crucial in identifying cases linked to the outbreak. This outbreak highlights the importance of prompt testing of food handlers in outbreaks suspected to be associated with food businesses.

Improving provider, patient and health systems outcomes: a qualitative analysis of Project ECHO

Background

Project ECHO (Extension for Community Healthcare Outcomes) is an internationally recognised tele-mentoring intervention that has been implemented in over 40 countries. The model connects specialist healthcare providers (hubs) with providers in primary and community practice (spokes), often in rural and isolated areas.

Objectives

Project ECHO aims to improve healthcare provider's skills, confidence and knowledge, and to create a community of practitioners using the hub and spoke model. Analysing interview data from 27 Project ECHO network leads and participants in Northern Ireland, this study sought to assess the impact of Project ECHO on improving provider, patient and health system outcomes.

Results

Having access to a specialist, a space to share experiences, and being able to disseminate up-to-date best practice were all cited as improving provider knowledge. Providers described improved outcomes for patients such as receiving a new treatment or an efficient referral. Providers reported being more confident in managing patients and thus were less likely to refer unnecessarily, and links between providers at primary and secondary levels being improved. ECHO was deemed an acceptable methodology in terms of format and in improving access to education and training by removing geographic barriers and reducing time barriers.

Conclusions

This is one of the first studies to qualitatively analyse outcomes across a number of different ECHO networks, and involving both health and social care networks. The results indicate the benefit of ECHO in improving provider, patient and healthcare outcomes. This has implications for future resourcing decisions, particularly within the context of COVID-19 in which virtual and online training is necessitated by social distancing requirements. This study has implications for wider international contexts in which ECHO may be piloted to address similar challenges.

Key messages

Participants across our study described Project ECHO as having a positive impact on provider, patient and health systems outcomes.

Project ECHO was described as an acceptable approach to training and education that improved access through removing geographic barriers.

Shiga toxin-producing Escherichia coli diagnosed by Stx PCR: assessing the public health risk of non-O157 strains

BACKGROUND

The implementation by diagnostic laboratories in England of polymerase chain reaction (PCR) to screen faecal specimens for Shiga toxin-producing Escherichia coli (STEC) has resulted in a significant increase in notifications mainly due to non-O157 strains. The purpose of this study was to develop an approach to public health risk assessment that prioritizes follow-up to cases caused by haemolytic uraemic syndrome (HUS) associated E. coli (HUSEC) strains and minimizes unnecessary actions.

METHODS

Epidemiological and microbiological data were prospectively collected from 1 November 2013 to 31 March 2017 and used to compare three risk assessment approaches.

RESULTS

A history of HUS/bloody diarrhoea/age under 6 years and faecal specimens positive for stx-predicted HUSEC with a diagnostic accuracy of 84% (95% CI; 81-88%). STEC isolated by Gastrointestinal Bacteria Reference Unit (GBRU) and stx2 and eae positive predicted HUSEC with a diagnostic accuracy of 99% (95% CI; 98-100%). Risk assessment combining these two tests predicts the most efficient use of resources, predicting that 18% (97/552) of cases would be eligible for follow-up at some stage, 16% (86/552) following local stx PCR results, 1% (7/552) following GBRU results of stx2 and eae status and 0.7% (4/552) following whole-genome sequencing. Follow-up could be stopped in 78% (76/97) of these cases, 97% (74/76) following second stage risk assessment.

CONCLUSIONS

This three-stage risk assessment approach prioritizes follow-up to HUSEC and minimizes unnecessary public health actions. We developed it into the algorithm for public health actions included in the updated PHE Guidance for management of STEC published in August 2018.

Cross-Priming Dendritic Cells Exacerbate Immunopathology After Ischemic Tissue Damage in the Heart

BACKGROUND

Ischemic heart disease is a leading cause of heart failure and despite advanced therapeutic options, morbidity and mortality rates remain high. Although acute inflammation in response to myocardial cell death has been extensively studied, subsequent adaptive immune activity and anti-heart autoimmunity may also contribute to the development of heart failure. After ischemic injury to the myocardium, dendritic cells (DC) respond to cardiomyocyte necrosis, present cardiac antigen to T cells, and potentially initiate a persistent autoimmune response against the heart. Cross-priming DC have the ability to activate both CD4+ helper and CD8+ cytotoxic T cells in response to necrotic cells and may thus be crucial players in exacerbating autoimmunity targeting the heart. This study investigates a role for cross-priming DC in post-myocardial infarction immunopathology through presentation of self-antigen from necrotic cardiac cells to cytotoxic CD8+ T cells.

METHODS

We induced type 2 myocardial infarction-like ischemic injury in the heart by treatment with a single high dose of the β-adrenergic agonist isoproterenol. We characterized the DC population in the heart and mediastinal lymph nodes and analyzed long-term cardiac immunopathology and functional decline in wild type and Clec9a-depleted mice lacking DC cross-priming function.

RESULTS

A diverse DC population, including cross-priming DC, is present in the heart and activated after ischemic injury. Clec9a-/- mice deficient in DC cross-priming are protected from persistent immune-mediated myocardial damage and decline of cardiac function, likely because of dampened activation of cytotoxic CD8+ T cells.

CONCLUSION

Activation of cytotoxic CD8+ T cells by cross-priming DC contributes to exacerbation of postischemic inflammatory damage of the myocardium and corresponding decline in cardiac function. Importantly, this provides novel therapeutic targets to prevent postischemic immunopathology and heart failure.

North American temperate conifer (Tsuga canadensis) reveals a complex physiological response to climatic and anthropogenic stressors

Rising atmospheric CO₂ (c_a) is expected to promote tree growth and lower water loss via changes in leaf gas exchange. However, uncertainties remain if gas-exchange regulation strategies are homeostatic or dynamical in response to increasing c_a, as well as evolving climate and pollution inputs. Using a suite of tree ring-based δ¹³C-derived physiological parameters (Δ¹³C, c_i, iWUE) and tree growth from a mesic, low elevation stand of canopy-dominant Tsuga canadensis in north-eastern USA, we investigated the influence of rising c_a, climate and pollution on, and characterised the dynamical regulation strategy of, leaf gas exchange at multidecadal scales. Isotopic and growth time series revealed an evolving physiological response in which the species shifted its leaf gas-exchange strategy dynamically (constant c_i; constant c_i/c_a; constant c_a - c_i) in response to rising c_a, moisture availability and site conditions over 111 yr. Tree iWUE plateaued after 1975, driven by greater moisture availability and a changing soil biogeochemistry that may have impaired a stomatal response. Results suggested that trees may exhibit more complex physiological responses to the changing environmental conditions over multidecadal periods, and complicating the parameterisation of Earth system models and the estimation of future carbon sink capacity and water balance in midlatitude forests and elsewhere.

Development of a pro-arrhythmic ex vivo intact human and porcine model: cardiac electrophysiological changes associated with cellular uncoupling

We describe a human and large animal Langendorff experimental apparatus for live electrophysiological studies and measure the electrophysiological changes due to gap junction uncoupling in human and porcine hearts. The resultant ex vivo intact human and porcine model can bridge the translational gap between smaller simple laboratory models and clinical research. In particular, electrophysiological models would benefit from the greater myocardial mass of a large heart due to its effects on far-field signal, electrode contact issues and motion artefacts, consequently more closely mimicking the clinical setting. Porcine (n = 9) and human (n = 4) donor hearts were perfused on a custom-designed Langendorff apparatus. Epicardial electrograms were collected at 16 sites across the left atrium and left ventricle. A total of 1 mM of carbenoxolone was administered at 5 ml/min to induce cellular uncoupling, and then recordings were repeated at the same sites. Changes in electrogram characteristics were analysed. We demonstrate the viability of a controlled ex vivo model of intact porcine and human hearts for electrophysiology with pharmacological modulation. Carbenoxolone reduces cellular coupling and changes contact electrogram features. The time from stimulus artefact to (-dV/dt)_max increased between baseline and carbenoxolone (47.9 ± 4.1–67.2 ± 2.7 ms) indicating conduction slowing. The features with the largest percentage change between baseline and carbenoxolone were fractionation + 185.3%, endpoint amplitude − 106.9%, S-endpoint gradient + 54.9%, S point − 39.4%, RS ratio + 38.6% and (-dV/dt)_max − 20.9%. The physiological relevance of this methodological tool is that it provides a model to further investigate pharmacologically induced pro-arrhythmic substrates.

Understanding the needs of carers in Vietnam and the development of online supportive resources

Issue

Informal carers provide an important and often overlooked role in the care of people with a cancer diagnosis. Our study sought to better understand carers needs and develop an online resource to help address the needs identified. There are not currently any widespread or embedded support services for cancer carers in Vietnam.

Description of the Problem

We conducted in-depth interviews and focus groups with both carers (n = 20) and healthcare providers (n = 22) to understand the needs and challenges of caring for someone with a cancer diagnosis. We discussed what resources would alleviate challenges and used these discussions to inform a process of co-designing an online resource. This process was modelled off a peer-led online resource intervention developed in the United Kingdom. This process of co-design is transferable to other contexts, and when adapted could help meet the needs of cancer carers in other lower and middle income countries.

Results

Carers in Vietnam reported (i) economic challenges of care; (ii) not being able to access facilities and secure accommodation when caring for inpatients; (iii) lack of information about cancer and nutrition; (iv) lacking emotional support; and (v) requiring training to support both the treatment and recovery of people under their care. Suggestions for content of an online resource included the need for contextually appropriate Vietnamese content, specific information on diet and nutrition, support in making decisions around treatment, and signposting for other services.

Lessons

Successful co-design of resources requires input from multiple key stakeholders. This is necessary to successful adapt and modify interventions for new contexts. Our process revealed new information about the roles and needs of carers, and enabled us to incorporate solutions to these needs within our online resource. Given the lack of other supportive services for carers, the development of such resources should be considered a priority.

Key messages

Cancer carers in Vietnam experience specific challenges including provision of nutrition, supporting navigation of hospital administration, and taking a central role in treatment decision-making. Co-designed online resources have the potential to support carers in providing relevant and appropriate information and signposting to other important services.

HIV-related tuberculosis: mortality risk in persons without vs. with culture-confirmed disease

BACKGROUND

Tuberculosis (TB) diagnosis in human immunodeficiency virus (HIV) positive persons is difficult, particularly in resource-limited settings. The relationship between TB culture status and mortality in HIV-positive persons treated for TB is unclear.

METHODS

We evaluated HIV-positive adults treated for TB at or after their first HIV clinic visit in Argentina, Brazil, Chile, Honduras, Mexico or Peru from 2000 to 2015. Anti-tuberculosis treatment included 2 months of isoniazid, rifampicin (RMP)/rifabutin (RBT), pyrazinamide ± ethambutol, followed by continuation phase treatment with isoniazid + RMP/RBT.

RESULTS

Of 759 TB-HIV patients, 238 (31%) were culture-negative, 228 (30%) had unknown culture status or did not undergo culture and 293 (39%) were culture-positive. The median CD4 at TB diagnosis was 96 (interquartile range 40-228); 636 (84%) received concurrent antiretroviral therapy (ART) and anti-tuberculosis treatment. There were 123 (16%) deaths: 90/466 (19%) with TB culture-negative, unknown or not performed vs. 33/293 (11%) who were TB culture-positive (P = 0.005). In Kaplan-Meier analysis, mortality in TB patients without culture-confirmed disease was higher (P = 0.002). In a Cox model adjusted for age, sex, CD4, ART timing, disease site and stratified by study site, mortality in persons without culture-confirmed TB was not significantly increased compared to those with culture-positive TB (hazard ratio 1.39, 95%CI 0.89-2.16, P = 0.15).

CONCLUSION

Most HIV-positive patients treated for TB did not have culture-confirmed TB, and mortality tended to be higher in patients without culture-confirmed disease, although the association was not statistically different after adjusting for other variables. Accurate TB diagnosis in HIV-positive persons is crucial.

An enhancer cluster controls gene activity and topology of the SCN5A-SCN10A locus in vivo

Mutations and variations in and around SCN5A, encoding the major cardiac sodium channel, influence impulse conduction and are associated with a broad spectrum of arrhythmia disorders. Here, we identify an evolutionary conserved regulatory cluster with super enhancer characteristics downstream of SCN5A, which drives localized cardiac expression and contains conduction velocity-associated variants. We use genome editing to create a series of deletions in the mouse genome and show that the enhancer cluster controls the conformation of a >0.5 Mb genomic region harboring multiple interacting gene promoters and enhancers. We find that this cluster and its individual components are selectively required for cardiac Scn5a expression, normal cardiac conduction and normal embryonic development. Our studies reveal physiological roles of an enhancer cluster in the SCN5A-SCN10A locus, show that it controls the chromatin architecture of the locus and Scn5a expression, and suggest that genetic variants affecting its activity may influence cardiac function.

A sensitive method for the recovery of Escherichia coli serogroup O55 including Shiga toxin-producing variants for potential use in outbreaks

AIM

Shiga toxin-producing Escherichia coli (STEC) cause bloody diarrhoea, kidney failure and occasionally death. However, identifying the source of infection caused by STEC other than serogroup O157 is hampered by the availability of sensitive methods for detecting these pathogens. In this study, we developed novel tools for detecting E. coli O55 that is potentially associated with human outbreaks.

METHODS AND RESULTS

Overall specificity of immuno-magnetic separation (IMS) beads coated with anti-O55 serum was good with exception of cross-reactivity with E. coli O22 and O23, which was eliminated using an O55-specific PCR. Limit of detection for E. coli O55 using O55-IMS beads in spiked cattle faeces was on average 50 CFU per ml (range 1-90), and improved to <10 CFU per ml using the O55-specific PCR, following IMS on samples enriched for 2 h with E. coli O55. Application of these tools to test cattle faeces collected on-farm allowed the isolation of O55:H19, which through whole genome sequencing was compared to STEC O55:H7 human outbreak strains.

CONCLUSION

These tools provide a sensitive method which could be used to screen samples for STEC O55, whether environmental or human clinical.

SIGNIFICANCE AND IMPACT OF THE STUDY

Several human outbreaks reported in England were caused by STEC O55:H7. Tools developed here could assist in identification of the environmental source for these isolates, which has not yet been established.

Assessment and Management of Medically Ill Patients who Refuse Life-Prolonging Treatments: Two Case Reports and Proposed Guidelines

Patients who have chosen to have treatment withdrawn because of debilitating conditions pose a special problem for palliative care. We report on two such patients: patient 1 refused amputation of a gangrenous leg and patient 2 refused food and hydration after a series of strokes. The management of these patients through the dying process is discussed and guidelines are suggested. The criteria for competency include both a general cognitive and psychiatric assessment as well as a specific evaluation of the patient's ability to make the treatment withdrawal decision. Treatable symptoms which impair the patient's quality of life and have an impact on the decision should be corrected. If a proxy decides to withdraw therapy in an incompetent patient, this decision should accord with the patient's known wishes and values as far as possible. The beneficence of the decision may be assessed according to the disease process, degree of suffering, and risks of accepting treatment. The complexity of these cases calls for a multidisciplinary approach, and the palliative care team should work in collaboration with the primary care treatment team.

Functional Outcome and Revision Rate Are Independent of Limb Alignment Following Oxford Medial Unicompartmental Knee Replacement

BACKGROUND

There is controversy about optimal limb alignment following knee replacement. An aim of using Oxford medial unicompartmental knee replacement (UKR) implants is to accurately restore normal ligament tension in the knee, thereby restoring normal kinematics. This return to normal tension typically results in a return to prearthritic alignment, which is frequently varus. The aim of this study was to investigate the relationship between postoperative limb alignment and postoperative patient-reported outcome and implant revision rate.

METHODS

We used a consecutive cohort of 891 knees with cemented Oxford medial UKR implants with a mean 10-year follow-up and recorded alignment. We grouped knees according to postoperative mechanical alignment as marked varus (estimated at 10°), mild varus (estimated at 5°), neutral, and valgus. The mean Oxford Knee Score (OKS) was calculated at 5 and 10 years postoperatively. Revision risk was assessed by survival analysis and component-time incidence rates.

RESULTS

Postoperatively, 67 (8%) of the 891 knees were in marked varus; 308 (35%), in mild varus; 508 (57%), in neutral; and 8 (1%), in valgus. The valgus group (8 knees) was too small for further analysis. The mean OKS (and standard deviation [SD]) at 10 years postoperatively was 41.7 ± 7 for marked varus, 40.5 ± 8 for mild varus, and 39.4 ± 9 for neutral alignment (p = 0.28). At 10 years, 92%, 85%, and 76% achieved a good or excellent OKS outcome, respectively (p = 0.02). Twelve-year survival rates were 93.3% for marked varus, 93.2% for mild varus, and 93.6% for neutral alignment, respectively (p = 0.53). Revision incidence rates per 100 component-years were 0.49 (95% confidence interval [CI], 0.2 to 1.5), 0.36 (95% CI, 0.2 to 0.7), and 0.54 (95% CI, 0.4 to 0.8), respectively, and were not significantly different (p = 0.53).

CONCLUSIONS

Marked postoperative varus mechanical alignment of an estimated 10° was present in 8%, and mild varus of about 5° was present in 35%. Increasing varus alignment was associated with an increasing percentage of good or excellent OKS outcomes, but otherwise there were no significant differences between alignment groups in patient-reported outcome or revision rate. These data support the standard operative technique for the Oxford UKR, which aims to restore ligament tension and therefore prearthritic alignment rather than neutral mechanical alignment.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Ten-year survival and seven-year functional results of cementless Oxford unicompartmental knee replacement: A prospective consecutive series of our first 1000 cases

BACKGROUND

Cementless fixation is an alternative to cemented unicompartmental knee replacement (UKR), with several advantages over cementation. This study reports the ten-year survival and seven-year clinical outcome of cementless Oxford unicompartmental knee replacement (OUKR).

METHODS

This prospective study describes the clinical outcome and survival of the first 1000 consecutive cementless medial OUKRs implanted at two centres for recommended indications.

RESULTS

The 10-year survival was 97% (CI 95%: 92-100%), with 25 knees being revised. The commonest reason for revision was progression of arthritis laterally, which occurred in nine knees, followed by primary dislocation of the bearing, which occurred in six knees. There were two dislocations secondary to trauma and a ruptured ACL, and two tibial plateau fractures. Although there were no definite cases of aseptic loosening, two early revisions were related to tibial fixation: one for pain and a radiolucent line and one for incomplete seating of the component with a radiolucent line. There were four revisions for pain, but the cause of the pain was uncertain: in one there was tibial overhang and in two there was patellofemoral degeneration, which possibly contributed to the pain. There were no deep infections. The mean OKS improved from 23 (SD 8) to 42 (SD 7) at a mean follow-up of 7.0 years (p < 0.001). There was no significant difference in survival or clinical outcome between the designer and independent centre.

CONCLUSIONS

The cementless OUKR is a safe and reproducible procedure with excellent 10-year survival and clinical results in the hands of both designer and independent surgeons.

Strengthening Screening and Detection Services for Breast Cancer in Vietnam

Background: The incidence of breast cancer has increased consistently in Vietnam over the past two decades. Data from 2012 indicates an increase from an age-standardized rate of 16.2 per 100,000 in 2002, to 23.0 per 100,000 in 2012. Despite this, and consistent studies indicating late diagnosis, there has been a lack of empirical studies on what breast cancer services exist and how they function across different levels of the Vietnamese health system. Aim: Our project sought to examine the accessibility, affordability, and appropriateness of breast cancer services in Vietnam with the objective of making recommendations to strengthen service delivery. Methods: The project used a mixed-methods approach, collecting data through self-administered questionnaires (n=69) and in-depth interviews (n=23) with health professionals working at facilities across all four levels of the Vietnamese health system (national, provincial, district, & commune). We completed in-depth interviews with women (n=12) diagnosed with breast cancer, focusing on their experiences of accessing and using services. Our study was located across three provinces, representing the northern, central, and southern regions of the country. Results: Our results show that screening activities for breast cancer in the community are not systematically organized or provided. There are no stand-alone screening campaigns for breast cancer and facility-based opportunistic screening is limited. There is scope for strengthening the primary and secondary levels of the Vietnamese health system to detect, diagnose and treat breast cancer. Increased autonomy and support for commune-level health stations to conduct screening activities, the systematic incorporation of opportunistic screening, and the extension of breast cancer-specific training for commune and district level health care staff are potential areas for strengthening. Conclusion: Our study suggests that there should be concerted efforts to implement the Ministry of Health's strategic objectives to decentralise and strengthen commune and district levels of the health system in relation to detection, diagnosis and treatment of breast cancer. No studies have been conducted that pilot interventions to provide systematic and comprehensive breast cancer services at the lower levels of the health system. Specific attention should be given to increasing autonomy and support for commune level health stations to conduct screening activities; for the systematic incorporation of opportunistic screening; and the extension of breast cancer-specific training for commune and district level health care staff.

An assessment of the microbiological quality and safety of raw drinking milk on retail sale in England

AIMS

This study aimed to review the microbiological results for raw drinking milk (RDM) samples submitted to Public Health England laboratories between 2014 and 2016 in order to produce up-to-date data on the microbiological safety of RDM and inform future risk assessments on its sale.

METHODS AND RESULTS

A total of 902 samples of RDM were collected from retail sale in England for microbiological examination. Overall, 454 of 770 samples (59·0%) taken for routine monitoring were of a satisfactory quality, whilst eight (1·0%) were 'unsatisfactory and potentially injurious to health' due to the presence of Shiga toxin-producing Escherichia coli, Campylobacter or elevated levels of Listeria monocytogenes or coagulase-positive staphylococci. In contrast, 16 of 114 (14·0%) of samples taken in follow-up to a previous unsatisfactory result and 5 of 18 (27·8%) of samples related to illness were potentially injurious. A total of 229 of 902 samples (25·4%) gave unsatisfactory results due to elevated aerobic colony counts and/or coliforms, whilst 139 of 902 samples (15·4%) were of borderline quality due to coagulase-positive staphylococci. Listeria monocytogenes was detected at levels of <100 CFU per ml in 66 of 902 samples (7·3%) and other Listeria species in 44 of 902 samples (4·9%).

CONCLUSIONS

Pathogens and/or indicators of poor hygiene were present in almost half of samples examined. Cows' milk samples gave a significantly greater proportion of unsatisfactory results compared to milk from other species (i.e. goat, sheep, buffalo, camel).

SIGNIFICANCE AND IMPACT OF THE STUDY

These results demonstrate the importance of maintaining strict controls on the production and sale of this product.

Shiga toxin-producing Escherichia coli (STEC) O157 outbreak associated with likely transmission in an inflatable home paddling pool in England, June 2017

In June 2017, an outbreak of Shiga toxin-producing Escherichia coli (STEC) O157 infection with phage type 21/28 and identical genotypic profiles involving three children from Staffordshire was reported. Two cases developed haemolytic uraemic syndrome (HUS). Person-to-person transmission via a shared inflatable home paddling pool was the most likely route of infection, following contamination by the first case. The source of infection in the first case was not identified. We recommend that individuals experiencing gastroenteritis should not bathe in paddling pools and that water should be changed at frequent intervals throughout the day to minimise the spread of infection.

Abstract P3-08-05: Validation of a nomogram for predicting recurrence among women with ductal carcinoma in situ and breast conserving surgery in an integrated health care system

Current management of ductal carcinoma in situ (DCIS) most often entails removing the lesion by breast-conserving surgery. Quantifying the risk of a patient's ipsilateral breast event (IBE) recurrence, either invasive cancer or DCIS, after breast conserving surgery remains a clinical concern. The aim of this study was to validate the Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram to predict IBE recurrence in patients from our institution.

Patients and Methods

We retrospectively identified 608 patients in the Kaiser Permanente Northwest integrated healthcare system with a diagnosis of DCIS who had undergone local excision from 1990 through 2007. We assessed the performance of the MSKCC nomogram for predicting IBE recurrence using measures of discrimination (how well risk scores separate those with and without the event) and calibration (agreement between predicted and observed risk). We calculated Harrell's C and R2D to provide estimates of discrimination. We calculated the calibration slope by performing a Cox regression using the prognostic index (PI; predicted log relative hazard based on the original Cox coefficients), with a slope not significantly different from 1 indicating no difference in discrimination from the development sample. We also examined discrimination by comparing the KM curves of 4 risk groups and in a Cox regression as a predictor, which were created using Cox's method (4 groups using the 16th, 50th, & 84th percentiles), as no risk groups were defined in the MSKCC development study. We examined whether there was model misfit by testing each predictor in a Cox regression with an offset of the PI. Finally, we assessed calibration by plotting the observed rates and associated 95% CIs against the predicted probabilities for groups based on 4 risk groups and octiles.

Results

The median follow-up time for the KPNW cohort was 125 months. The 10-year IBE recurrence rate was 9.5%, 95% CI [7.0%, 13.0%). Harrell's C was .70, which is comparable to what has been found in other validation studies. The PI accounted for 22% of variation in time (R2D =.22, 95% CI [.08, .38]). The test of the calibration slope provided no support that discrimination in this sample differs from the development study (LR χ2(1)=0.21, p=.65). An examination of the Kaplan-Meier curves among the risk groups showed good separation of the high risk group compared to the others, but little separation between the lowest two risk groups. None of the predictors demonstrated evidence for differential weighting from the MSKCC coefficients (p values ranged from .08 to .97). Calibration was good for the lowest, low, and moderate risk groups, but there was underprediction in the high risk group. When examining calibration using octiles, we found a similar pattern to that of other validation studies in which the highest octile had the furthest departure from perfect agreement.

Conclusion

The MSKCC nomogram for predicting IBE recurrence in patients with DCIS who were treated with local excision have some utility, and our results are consistent with other validation efforts. However, there is much potential to further increase the prediction of recurrence beyond what is possible with the MSKCC nomogram.

Citation Format: Leo MC, Francisco M, Jenkins C, Weinmann S. Validation of a nomogram for predicting recurrence among women with ductal carcinoma in situ and breast conserving surgery in an integrated health care system [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-08-05.

Molecular evidence to suggest pigeon-type Chlamydia psittaci in association with an equine foal loss

Chlamydia psittaci is an important avian pathogen with spillover from infected wild and domesticated birds also posing a risk to human health. We recently reported a case of C. psittaci equine placentitis associated with further spillover to humans. Molecular typing of this case revealed it belonged to the 6BC clade of C. psittaci, a globally distributed highly virulent set of strains, typically linked to infection spillover from parrots. Equine chlamydiosis associated with C. psittaci infection has previously been reported elsewhere in countries where parrots are not endemic, however, raising questions over the identity of infecting C. psittaci strains and the potential infection reservoirs. In this study, we describe the detection and molecular characterization of C. psittaci in a case of equine abortion in southern Queensland. Equine placenta and fresh liver and lung tissue from the necropsied foetus were positive by C. psittaci-specific qPCR. Chlamydia psittaci-specific multilocus sequence typing and ompA genotyping were used to further characterize the detected equine strains and an additional strain obtained from a dove from a different geographic region presenting with psittacosis. Molecular typing of this case revealed that the infecting equine strains were closely related to the C0sittaci detected in dove, all belonging to an evolutionary lineage of C. psittaci strains typically associated with infections of pigeons globally. This finding suggests a broader diversity of C. psittaci strains may be detected in horses and in association with reproductive loss, highlighting the need for an expansion of surveillance studies globally to understand the epidemiology of equine chlamydiosis and the associated zoonotic risk.

Ethical international recruitment

Right from the start of our international recruitment campaign the Department of Health was determined to ensure that international recruitment takes place using a planned and managed approach. Now, the UK leads the way in developing and implementing the types of international recruitment policies called for by the World Health Assembly.

APOL1, CDKN2A/CDKN2B, and HDAC9 polymorphisms and small vessel ischemic stroke

OBJECTIVE

Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) ischemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including the APOL1 G1 variants, with the occurrence of SVD ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study.

MATERIALS AND METHODS

Cases were consecutively recruited consenting adults (aged 18 years or older) with neuroimaging-confirmed first clinical stroke. Stroke-free controls were ascertained using a locally validated version of the Questionnaire for Verifying Stroke-Free Status (QVSFS). Logistic regression models adjusting for known vascular risk factors were fitted to assess the associations of the 23 SNPs in rigorously phenotyped cases (N = 154) of SVD ischemic stroke and stroke-free (N = 483) controls.

RESULTS

Apolipoprotein L1 (APOL1) rs73885319 (OR = 1.52; CI: 1.09-2.13, P-value = .013), rs2383207 in CDKN2A/CDKN2B (OR = 3.08; CI: 1.15-8.26, P -value = .026) and rs2107595 (OR = 1.70; CI: 1.12-2.60, P-value = .014) and rs28688791 (OR = 1.52; CI: 1.03-2.26, P-value = .036) in HDAC9 gene were associated with SVD stroke at 0.05 significance level. Polymorphisms in other genes did not show significant associations.

CONCLUSION

This is the first report of a specific association of APOL1 with a stroke subtype. Further research is needed to confirm these initial findings and deepen understanding of the genetics of stroke in people of African ancestry with possible implications for other ancestries as all humans originated from Africa.