119 research outputs found
Long-term evolution of antigen repertoires among carried meningococci
Most studies of bacterial pathogen populations have been based on isolates collected from individuals with disease, or their contacts, over short time periods. For commensal organisms that occasionally cause disease, such as Neisseria meningitidis, however, the analysis of isolates from long-term asymptomatic carriage is necessary to elucidate their evolution and population structure. Here, we use mathematical models to analyse the structuring and dynamics of three vaccine-candidate antigens among carried meningococcal isolates collected over nearly 30 years in the Czech Republic. The data indicate that stable combinations of antigenic alleles were maintained over this time period despite evidence for high rates of recombination, consistent with theoretical models in which strong immune selection can maintain non-overlapping combinations of antigenic determinants in the presence of recombination. We contrast this antigenic structure with the overlapping but relatively stable combinations of the housekeeping genes observed among the same isolates, and use a novel network approach to visualize these relationships
Variations in the cost of formal and informal health care for patients with advanced chronic disease and refractory breathlessness: A cross-sectional secondary analysis
Background: Refractory breathlessness in advanced chronic disease leads to high levels of disability, anxiety and social isolation. These result in high health-resource use, although this is not quantified. Aims: To measure the cost of care for patients with advanced disease and refractory breathlessness and to identify factors associated with high costs. Design: A cross-sectional secondary analysis of data from a randomised controlled trial. Setting/participants: Patients with advanced chronic disease and refractory breathlessness recruited from three National Health Service hospitals and via general practitioners in South London. Results: Of 105 patients recruited, the mean cost of formal care was 3253 pound (standard deviation 3652) pound for 3 months. The largest contributions to formal-care cost were hospital admissions (>60%), and palliative care contributed 250% to 1,507 pound (standard deviation 9911) pound. Increased patient disability resulting from breathlessness was associated with high cost (629 pound per unit increase in disability score;p = 0.006). Increased breathlessness on exertion and the presence of an informal carer were also significantly associated with high cost. Patients with chronic obstructive pulmonary disease tended to have higher healthcare costs than other patients. Conclusion: Informal carers contribute significantly to the care of patients with advanced disease and refractory breathlessness. Disability resulting from breathlessness is an important clinical cost driver. It is important for policy makers to support and acknowledge the contributions of informal carers. Further research is required to assess the clinical- and cost-effectiveness of palliative care interventions in reducing disability resulting from breathlessness in this patient group
Physical Inactivity in Pulmonary Sarcoidosis
Purpose
Reduced physical activity in many chronic diseases is consistently associated with increased morbidity. Little is known about physical activity in sarcoidosis. The aim of this study was to objectively assess physical activity in patients with pulmonary sarcoidosis and investigate its relationship with lung function, exercise capacity, symptom burden, and health status.
Methods
Physical activity was assessed over one week in 15 patients with pulmonary sarcoidosis and 14 age-matched healthy controls with a tri-axial accelerometer (ActivPalᵀᴹ) and the International Physical Activity Questionnaire (IPAQ). All participants underwent pulmonary function tests, 6-minute walk test (6MWT) and completed the Fatigue Assessment Scale (FAS), Medical Research Council (MRC) Dyspnoea Scale and the King’s Sarcoidosis Questionnaire (KSQ).
Results
Patients with sarcoidosis had significantly lower daily step counts than healthy controls; mean(SD) 5624(1875) vs. 10429(2942) steps (p<0.01) and completed fewer sit-to-stand transitions each day (p=0.095). Only two patients (13%) self-reported undertaking vigorous physical activity (IPAQ) compared to half of healthy individuals (p<0.01). Daily step count was significantly associated with 6MWT distance in sarcoidosis (r=0.634, p=0.01), but not with forced vital capacity (r=0.290), fatigue (r=0.041), dyspnoea (r=-0.466) or KSQ health status (r=0.099-0.484). Time spent upright was associated with fatigue (r=-0.630, p=0.012) and health status (KSQ Lung scores r=0.524, p=0.045), and there was a significant correlation between the number of sit-to-stand transitions and MRC dyspnoea score (r=-0.527, p=0.044).
Conclusion
Physical activity is significantly reduced in sarcoidosis and is associated with reduced functional exercise capacity (6MWD). Fatigue, exertional symptoms and health status were more closely associated with time spent upright and the number of bouts of physical activity, as compared to step counts. Further studies are warranted to identify the factors that determine different physical activity profiles in sarcoidosis
Exercise-induced bronchoconstriction in athletes – A qualitative assessment of symptom perception
© 2016Background A poor relationship between perceived respiratory symptoms and objective evidence of exercise-induced bronchoconstriction (EIB) in athletes is often reported; however, the reasons for this disconnect remain unclear. The primary aim of this study was to utilise a qualitative-analytical approach to compare respiratory symptoms in athletes with and without objectively confirmed EIB. Methods Endurance athletes who had previously undergone bronchoprovocation test screening for EIB were divided into sub-groups, based on the presence or absence of EIB ± heightened self-report of dyspnoea: (i) EIB-Dys- (ii) EIB + Dys+ (iii) EIB + Dys- (iv) EIB-Dys+. All athletes underwent a detailed semi-structured interview. Results Twenty athletes completed the study with an equal distribution in each sub-group (n = 5). Thematic analysis of individual narratives resulted in four over-arching themes: 1) Factors aggravating dyspnoea, 2) Exercise limitation, 3) Strategies to control dyspnoea, 4) Diagnostic accuracy. The anatomical location of symptoms varied between EIB + Dys + athletes and EIB-Dys + athletes. All EIB-Dys + reported significantly longer recovery times following high-intensity exercise in comparison to all other sub-groups. Finally, EIB + Dys + reported symptom improvement following beta-2 agonist therapy, whereas EIB-Dys + deemed treatment ineffective. Conclusion A detailed qualitative approach to the assessment of breathlessness reveals few features that distinguish between EIB and non-EIB causes of exertional dyspnoea in athletes. Important differences that may provide value in clinical work-up include (i) location of symptoms, (ii) recovery time following exercise and (iii) response to beta-2 agonist therapy. Overall these findings may inform clinical evaluation and development of future questionnaires to aid clinic-based assessment of athletes with dyspnoea
Typing complex meningococcal vaccines to understand diversity and population structure of key vaccine antigens [version 1; referees: 2 approved]
Background: Protein-conjugate capsular polysaccharide vaccines can potentially control invasive meningococcal disease (IMD) caused by five (A, C, W, X, Y) of the six IMD-associated serogroups. Concerns raised by immunological similarity of the serogroup B capsule, to human neural cell carbohydrates, has meant that ‘serogroup B substitute’ vaccines target more variable subcapsular protein antigens. A successful approach using outer membrane vesicles (OMVs) as major vaccine components had limited strain coverage. In 4CMenB (Bexsero®), recombinant proteins have been added to ameliorate this problem. Methods: Here, scalable, portable, genomic techniques were used to investigate the Bexsero® OMV protein diversity in meningococcal populations. Shotgun proteomics identified 461 proteins in the OMV, defining a complex proteome. Amino acid sequences for the 24 proteins most likely to be involved in cross-protective immune responses were catalogued within the PubMLST.org/neisseria database using a novel OMV peptide Typing (OMVT) scheme. Results: Among these proteins there was variation in the extent of diversity and association with meningococcal lineages, identified as clonal complexes (ccs), ranging from the most conserved peptides (FbpA, NEISp0578, and putative periplasmic protein, NEISp1063) to the most diverse (TbpA, NEISp1690). There were 1752 unique OMVTs identified amongst 2492/3506 isolates examined by whole-genome sequencing (WGS). These OMVTs were grouped into clusters (sharing ≥18 identical OMVT peptides), with 45.3% of isolates assigned to one of 27 OMVT clusters. OMVTs and OMVT clusters were strongly associated with cc, genogroup, and Bexsero® antigen variants, demonstrating that combinations of OMV proteins exist in discrete, non-overlapping combinations associated with genogroup and Bexsero® Antigen Sequence Type. This highly structured population of IMD-associated meningococci is consistent with strain structure models invoking host immune selection. Conclusions: The OMVT scheme facilitates region-specific WGS investigation of meningococcal diversity and is an open-access, portable tool with applications for vaccine development, especially in the choice of antigen combinations, assessment and implementation
The Effect of Immune Selection on the Structure of the Meningococcal Opa Protein Repertoire
The opa genes of the Gram negative bacterium Neisseria meningitidis encode Opacity-associated outer membrane proteins whose role is to promote adhesion to the human host tissue during colonisation and invasion. Each meningococcus contains 3–4 opa loci, each of which may be occupied by one of a large number of alleles. We analysed the Opa repertoire structure in a large, well-characterised collection of asymptomatically carried meningococci. Our data show an association between Opa repertoire and meningococcal lineages similar to that observed previously for meningococci isolated from cases of invasive disease. Furthermore, these Opa repertoires exhibit discrete, non-overlapping structure at a population level, and yet low within-repertoire diversity. These data are consistent with the predictions of a mathematical model of strong immune selection upon a system where identical alleles may occupy different loci
Do guidelines influence breathlessness management in advanced lung diseases? A multinational survey of respiratory medicine and palliative care physicians
Background: Respiratory medicine (RM) and palliative care (PC) physicians’ management of chronic breathlessness in advanced chronic obstructive pulmonary disease (COPD), fibrotic interstitial lung disease (fILD) and lung cancer (LC), and the influence of practice guidelines was explored via an online survey. Methods: A voluntary, online survey was distributed to RM and PC physicians via society newsletter mailing lists. Results: 450 evaluable questionnaires (348 (77%) RM and 102 (23%) PC) were analysed. Significantly more PC physicians indicated routine use (often/always) of opioids across conditions (COPD: 92% vs. 39%, fILD: 83% vs. 36%, LC: 95% vs. 76%; all p < 0.001) and significantly more PC physicians indicated routine use of benzodiazepines for COPD (33% vs. 10%) and fILD (25% vs. 12%) (both p < 0.001). Significantly more RM physicians reported routine use of a breathlessness score (62% vs. 13%, p < 0.001) and prioritised exercise training/rehabilitation for COPD (49% vs. 7%) and fILD (30% vs. 18%) (both p < 0.001). Overall, 40% of all respondents reported reading non-cancer palliative care guidelines (either carefully or looked at them briefly). Respondents who reported reading these guidelines were more likely to: routinely use a breathlessness score (χ2 = 13.8; p < 0.001), use opioids (χ2 = 12.58, p < 0.001) and refer to pulmonary rehabilitation (χ2 = 6.41, p = 0.011) in COPD; use antidepressants (χ2 = 6.25; p = 0.044) and refer to PC (χ2 = 5.83; p = 0.016) in fILD; and use a handheld fan in COPD (χ2 = 8.75, p = 0.003), fILD (χ2 = 4.85, p = 0.028) and LC (χ2 = 5.63; p = 0.018). Conclusions: These findings suggest a need for improved dissemination and uptake of jointly developed breathlessness management guidelines in order to encourage appropriate use of existing, evidence-based therapies. The lack of opioid use by RM, and continued benzodiazepine use in PC, suggest that a wider range of acceptable therapies need to be developed and trialled
Prevalence of physical frailty, including risk factors, up to 1 year after hospitalisation for COVID-19 in the UK: a multicentre, longitudinal cohort study
BACKGROUND: The scale of COVID-19 and its well documented long-term sequelae support a need to understand long-term outcomes including frailty. METHODS: This prospective cohort study recruited adults who had survived hospitalisation with clinically diagnosed COVID-19 across 35 sites in the UK (PHOSP-COVID). The burden of frailty was objectively measured using Fried's Frailty Phenotype (FFP). The primary outcome was the prevalence of each FFP group-robust (no FFP criteria), pre-frail (one or two FFP criteria) and frail (three or more FFP criteria)-at 5 months and 1 year after discharge from hospital. For inclusion in the primary analysis, participants required complete outcome data for three of the five FFP criteria. Longitudinal changes across frailty domains are reported at 5 months and 1 year post-hospitalisation, along with risk factors for frailty status. Patient-perceived recovery and health-related quality of life (HRQoL) were retrospectively rated for pre-COVID-19 and prospectively rated at the 5 month and 1 year visits. This study is registered with ISRCTN, number ISRCTN10980107. FINDINGS: Between March 5, 2020, and March 31, 2021, 2419 participants were enrolled with FFP data. Mean age was 57.9 (SD 12.6) years, 933 (38.6%) were female, and 429 (17.7%) had received invasive mechanical ventilation. 1785 had measures at both timepoints, of which 240 (13.4%), 1138 (63.8%) and 407 (22.8%) were frail, pre-frail and robust, respectively, at 5 months compared with 123 (6.9%), 1046 (58.6%) and 616 (34.5%) at 1 year. Factors associated with pre-frailty or frailty were invasive mechanical ventilation, older age, female sex, and greater social deprivation. Frail participants had a larger reduction in HRQoL compared with before their COVID-19 illness and were less likely to describe themselves as recovered. INTERPRETATION: Physical frailty and pre-frailty are common following hospitalisation with COVID-19. Improvement in frailty was seen between 5 and 12 months although two-thirds of the population remained pre-frail or frail. This suggests comprehensive assessment and interventions targeting pre-frailty and frailty beyond the initial illness are required. FUNDING: UK Research and Innovation and National Institute for Health Research
Prevalence of physical frailty including risk factors up to one year after hospitalisation for COVID-19 in the UK: a multicentre, longitudinal cohort study
Background: The scale of COVID-19 and its well documented long-term sequelae support a need to understand long-term outcomes including frailty. Methods: This prospective cohort study recruited adults who had survived hospitalisation with clinically diagnosed COVID-19 across 35 sites in the UK (PHOSP-COVID). The burden of frailty was objectively measured using Fried's Frailty Phenotype (FFP). The primary outcome was the prevalence of each FFP group—robust (no FFP criteria), pre-frail (one or two FFP criteria) and frail (three or more FFP criteria)—at 5 months and 1 year after discharge from hospital. For inclusion in the primary analysis, participants required complete outcome data for three of the five FFP criteria. Longitudinal changes across frailty domains are reported at 5 months and 1 year post-hospitalisation, along with risk factors for frailty status. Patient-perceived recovery and health-related quality of life (HRQoL) were retrospectively rated for pre-COVID-19 and prospectively rated at the 5 month and 1 year visits. This study is registered with ISRCTN, number ISRCTN10980107. Findings: Between March 5, 2020, and March 31, 2021, 2419 participants were enrolled with FFP data. Mean age was 57.9 (SD 12.6) years, 933 (38.6%) were female, and 429 (17.7%) had received invasive mechanical ventilation. 1785 had measures at both timepoints, of which 240 (13.4%), 1138 (63.8%) and 407 (22.8%) were frail, pre-frail and robust, respectively, at 5 months compared with 123 (6.9%), 1046 (58.6%) and 616 (34.5%) at 1 year. Factors associated with pre-frailty or frailty were invasive mechanical ventilation, older age, female sex, and greater social deprivation. Frail participants had a larger reduction in HRQoL compared with before their COVID-19 illness and were less likely to describe themselves as recovered. Interpretation: Physical frailty and pre-frailty are common following hospitalisation with COVID-19. Improvement in frailty was seen between 5 and 12 months although two-thirds of the population remained pre-frail or frail. This suggests comprehensive assessment and interventions targeting pre-frailty and frailty beyond the initial illness are required. Funding: UK Research and Innovation and National Institute for Health Research
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