Considerations for the use of inhaled antibiotics for Pseudomonas aeruginosa in people with cystic fibrosis receiving CFTR modulator therapy

The major cause of mortality in people with cystic fibrosis (pwCF) is progressive lung disease characterised by acute and chronic infections, the accumulation of mucus, airway inflammation, structural damage and pulmonary exacerbations. The prevalence of Pseudomonas aeruginosa rises rapidly in the teenage years, and this organism is the most common cause of chronic lung infection in adults with cystic fibrosis (CF). It is associated with an accelerated decline in lung function and premature death. New P. aeruginosa infections are treated with antibiotics to eradicate the organism, while chronic infections require long-term inhaled antibiotic therapy. The prevalence of P. aeruginosa infections has decreased in CF registries since the introduction of CF transmembrane conductance regulator modulators (CFTRm), but clinical observations suggest that chronic P. aeruginosa infections usually persist in patients receiving CFTRm. This indicates that pwCF may still need inhaled antibiotics in the CFTRm era to maintain long-term control of P. aeruginosa infections. Here, we provide an overview of the changing perceptions of P. aeruginosa infection management, including considerations on detection and treatment, the therapy burden associated with inhaled antibiotics and the potential effects of CFTRm on the lung microbiome. We conclude that updated guidance is required on the diagnosis and management of P. aeruginosa infection. In particular, we highlight a need for prospective studies to evaluate the consequences of stopping inhaled antibiotic therapy in pwCF who have chronic P. aeruginosa infection and are receiving CFTRm. This will help inform new guidelines on the use of antibiotics alongside CFTRm.

Determinants of multidrug-resistant tuberculosis among adults undergoing treatment for tuberculosis in Tigray Region, Ethiopia: a case-control study

BACKGROUND

Multidrug-resistant tuberculosis is a type of tuberculosis that is resistant to at least the first-line antituberculosis drugs namely, rifampicin and isoniazid. However, most of these studies were limited only to a single hospital. Therefore, this study aimed to identify the determinants of multidrug-resistant tuberculosis among adults undergoing treatment for tuberculosis in the Tigray region of Ethiopia.

METHODS

Hospital-based unmatched case-control study was conducted from 1 April 2019 to 30 June 2019. A simple random sampling method was used to select the required sample size. Variables at a p value less than 0.25 in bivariate analysis were entered into a multivariable analysis to identify the determinant factors of multidrug-resistant tuberculosis. Finally, the level of significance was declared at p<0.05.

RESULTS

Rural residence (adjusted OR (AOR) 2.54; 95% CI 1.34 to 4.83), HIV (AOR 4.5; 95% CI 1.4 to 14.2), relapse (AOR 3.86; 95% CI 1.98 to 7.5), return after lost follow-up (AOR 6.29; 95% CI 1.64 to 24.2), treatment failure (AOR 5.87; 95% CI 1.39 to 24.8) were among the determinants of multidrug-resistant tuberculosis.

CONCLUSION

Rural residence, HIV, relapses, return after lost follow-up and treatment failure were the identified determinant factors of multidrug-resistance tuberculosis.

Lack of racial and ethnic disparities in mortality in minority patients hospitalised with COVID-19 in a mid-Atlantic healthcare system

INTRODUCTION

In the USA, minoritised communities (racial and ethnic) have suffered disproportionately from COVID-19 compared with non-Hispanic white communities. In a large cohort of patients hospitalised for COVID-19 in a healthcare system spanning five adult hospitals, we analysed outcomes of patients based on race and ethnicity.

METHODS

This was a retrospective cohort analysis of patients 18 years or older admitted to five hospitals in the mid-Atlantic area between 4 March 2020 and 27 May 2022 with confirmed COVID-19. Participants were divided into four groups based on their race/ethnicity: non-Hispanic black, non-Hispanic white, Latinx and other. Propensity score weighted generalised linear models were used to assess the association between race/ethnicity and the primary outcome of in-hospital mortality.

RESULTS

Of the 9651 participants in the cohort, more than half were aged 18-64 years old (56%) and 51% of the cohort were females. Non-Hispanic white patients had higher mortality (p<0.001) and longer hospital length-of-stay (p<0.001) than Latinx and non-Hispanic black patients.

DISCUSSION

In this large multihospital cohort of patients admitted with COVID-19, non-Hispanic black and Hispanic patients did not have worse outcomes than white patients. Such findings likely reflect how the complex range of factors that resulted in a life-threatening and disproportionate impact of incidence on certain vulnerable populations by COVID-19 in the community was offset through admission at well-resourced hospitals and healthcare systems. However, there continues to remain a need for efforts to address the significant pre-existing race and ethnicity inequities highlighted by the COVID-19 pandemic to be better prepared for future public health emergencies.

Respiratory-related deaths and associated factors in Alicho-Weriro district, southern Ethiopia: verbal autopsy data analysis

BACKGROUND

Respiratory diseases disproportionately affect people living in resource-limited settings. However, obtaining information that explains respiratory-related deaths has been difficult, mainly due to a lack of medical certification of death and the fact that most deaths occur outside of health institutions. This study aimed to determine the proportion of respiratory-related deaths and identify associated factors in Alicho-Weriro district, southern Ethiopia, using the verbal autopsy method.

METHODS

A community-based cross-sectional study was conducted from April to June 2022. All deceased people in the study area from January 2020 to December 2021 were included in the study. Trained physicians ascertained the cause of death from verbal autopsy data that were collected using a pre-tested and modified WHO-designed questionnaire. The binary logistic regression models were used to identify factors associated with respiratory-related deaths.

RESULTS

Respiratory-related deaths accounted for 25% of the deaths from all causes, with 20.8% of male and 29.5% of female deaths. Of which, 9.7% were from tuberculosis, 8.3% were from asthma and 6.2% were from acute lower-respiratory tract infections. Moreover, being female (adjusted OR, AOR: 3.3; 95% CI: (1.75 to 6.22)), age 50-64 years (AOR: 9.3; 95% CI: (1.16 to 73.90)), age above 64 years (AOR: 8.9; 95% CI: (1.130 to 70.79)), family size of five persons or more (AOR: 1.9; 95% CI: (1.15 to 3.29)), smoking (AOR: 3.9; 95% CI: (1.86 to 8.35)), using wood and/or animal dung for household cooking (AOR: 6.6; 95% CI: (1.92 to 22.59)) and poor house ventilation (AOR: 3.1; 95% CI: (1.75 to 5.38)) were significantly associated with increased odds of dying from respiratory-related diseases.

CONCLUSION

This study has determined that about a quarter of deaths from all causes were due to respiratory diseases, mainly tuberculosis, asthma and acute lower respiratory tract infections. Therefore, interventions to reduce this burden should focus on supporting early case detection and treatment, promoting healthy lifestyles, exercising women's equality at the household level and improving housing conditions.

Comparative effectiveness of sotrovimab versus no treatment in non-hospitalised high-risk COVID-19 patients in north west London: a retrospective cohort study

BACKGROUND

We assessed the effectiveness of sotrovimab vs no early COVID-19 treatment in highest-risk COVID-19 patients during Omicron predominance.

METHODS

Retrospective cohort study using the Discover dataset in North West London. Included patients were non-hospitalised, aged ≥12 years and met ≥1 National Health Service highest-risk criterion for sotrovimab treatment. We used Cox proportional hazards models to compare HRs of 28-day COVID-19-related hospitalisation/death between highest-risk sotrovimab-treated and untreated patients. Age, renal disease and Omicron subvariant subgroup analyses were performed.

RESULTS

We included 599 sotrovimab-treated patients and 5191 untreated patients. Compared with untreated patients, the risk of COVID-19 hospitalisation/death (HR 0.50, 95% CI 0.24, 1.06; p=0.07) and the risk of COVID-19 hospitalisation (HR 0.43, 95% CI 0.18, 1.00; p=0.051) were both lower in the sotrovimab-treated group; however, statistical significance was not reached. In the ≥65 years and renal disease subgroups, sotrovimab was associated with a significantly reduced risk of COVID-19 hospitalisation, by 89% (HR 0.11, 95% CI 0.02, 0.82; p=0.03) and 82% (HR 0.18, 95% CI 0.05, 0.62; p=0.007), respectively.

CONCLUSIONS

Risk of COVID-19 hospitalisation in sotrovimab-treated patients aged ≥65 years and with renal disease was significantly lower compared with untreated patients. Overall, risk of hospitalisation was also lower for sotrovimab-treated patients, but statistical significance was not reached.

Respiratory syncytial virus: A new era

Respiratory syncytial virus (RSV) is a major public health problem that has undergone significant changes in recent years. First of all, it has become easier to diagnose with highly reliable and rapidly available confirmatory tests. This has led to a better understanding of its epidemiology and RSV has gone from being a disease of the pediatric age group, severe only in infants and immunosuppressed children, to being a common disease in people of all ages, particularly important in patients of advanced age or with immunosuppressive diseases. Recent therapeutic and prophylactic advances, both with long-lasting monoclonal antibodies and vaccines, are another reason for satisfaction. For these reasons, the COVID and Emerging Pathogens Committee of the Illustrious Official College of Physicians of Madrid (ICOMEM) has considered it pertinent to review this subject in the light of new knowledge and new resources for dealing with this infection. We have formulated a series of questions that we believe will be of interest not only to members of the College but also to any non-expert in this subject, with a particular focus on the situation of RSV infection in Spain.

Human mesenchymal stromal cells inhibit Mycobacterium avium replication in clinically relevant models of lung infection

INTRODUCTION

Novel therapeutic strategies are urgently needed for Mycobacterium avium complex pulmonary disease (MAC-PD). Human mesenchymal stromal cells (MSCs) can directly inhibit MAC growth, but their effect on intracellular bacilli is unknown. We investigated the ability of human MSCs to reduce bacterial replication and inflammation in MAC-infected macrophages and in a murine model of MAC-PD.

METHODS

Human monocyte-derived macrophages (MDMs) were infected with M. avium Chester strain and treated with human bone marrow-derived MSCs. Intracellular and extracellular colony-forming units (CFUs) were counted at 72 hours. Six-week-old female balb/c mice were infected by nebulisation of M. avium Chester. Mice were treated with 1×106 intravenous human MSCs or saline control at 21 and 28 days post-infection. Lungs, liver and spleen were harvested 42 days post-infection for bacterial counts. Cytokines were quantified by ELISA.

RESULTS

MSCs reduced intracellular bacteria in MDMs over 72 hours (median 35% reduction, p=0.027). MSC treatment increased extracellular concentrations of prostaglandin E2 (PGE2) (median 10.1-fold rise, p=0.002) and reduced tumour necrosis factor-α (median 28% reduction, p=0.025). Blocking MSC PGE2 production by cyclo-oxygenase-2 (COX-2) inhibition with celecoxib abrogated the antimicrobial effect, while this was restored by adding exogenous PGE2. MSC-treated mice had lower pulmonary CFUs (median 18% reduction, p=0.012), but no significant change in spleen or liver CFUs compared with controls.

CONCLUSION

MSCs can modulate inflammation and reduce intracellular M. avium growth in human macrophages via COX-2/PGE2 signalling and inhibit pulmonary bacterial replication in a murine model of chronic MAC-PD.

Risk factors for pulmonary tuberculosis recurrence, relapse and reinfection: a systematic review and meta-analysis

BACKGROUND

The rate of pulmonary tuberculosis (TB) recurrence is substantial. Identifying risk factors can support the development of prevention strategies.

METHODS

We retrieved studies published between 1 January 1980 and 31 December 2022 that assessed factors associated with undifferentiated TB recurrence, relapse or reinfection. For factors reported in at least four studies, we performed random-effects meta-analysis to estimate a pooled relative risk (RR). We assessed heterogeneity, risk of publication bias and certainty of evidence.

RESULTS

We included 85 studies in the review; 81 documented risk factors for undifferentiated recurrence, 17 for relapse and 10 for reinfection. The scope for meta-analyses was limited given the wide variety of factors studied, inconsistency in control for confounding and the fact that only few studies employed molecular genotyping. Factors that significantly contributed to moderately or strongly increased pooled risk and scored at least moderate certainty of evidence were: for undifferentiated recurrence, multidrug resistance (MDR) (RR 3.49; 95% CI 1.86 to 6.53) and fixed-dose combination TB drugs (RR 2.29; 95% CI 1.10 to 4.75) in the previous episode; for relapse, none; and for reinfection, HIV infection (RR 4.65; 95% CI 1.71 to 12.65). Low adherence to treatment increased the pooled risk of recurrence 3.3-fold (95% CI 2.37 to 4.62), but the certainty of evidence was weak.

CONCLUSION

This review emphasises the need for standardising methods for TB recurrence research. Actively pursuing MDR prevention, facilitating retention in treatment and providing integrated care for patients with HIV could curb recurrence rates. The use of fixed-dose combinations of TB drugs under field conditions merits further attention.

PROSPERO REGISTRATION NUMBER

CRD42018077867.

Hospitalisations and fatality due to respiratory diseases according to a national database in Brazil: a longitudinal study

BACKGROUND

Respiratory diseases (RDs) cause millions of hospitalisations and deaths worldwide, resulting in economic and social impacts. Strategies for health promotion and disease prevention based on the epidemiological profile of the population may reduce hospital costs.

AIM

To characterise hospitalisations and deaths due to RDs in Brazilian adults above 20 years old between 2008 and 2021.

METHODS

This ecological study used secondary data of hospitalisations and deaths due to RDs from the Hospital Information System of the Brazilian Unified Health System between 2008 and 2021. Data were grouped according to region, age group and sex. The period was divided into first (2008-2011), second (2012-2015) and third (2016-2019) quadrennia and one biennium (2020-2021), and all data were analysed using the GraphPad Prism; statistical significance was set at p<0.05.

RESULTS

A total of 9 502 378 hospitalisations due to RDs were registered between 2008 and 2021. The south and southeast regions presented the highest hospitalisation and fatality rate, respectively, in the age group ≥80 years with no significant differences between sexes. Also, RDs caused 1 170 504 deaths, with a national fatality rate of 12.32%.

CONCLUSION

RDs affected the Brazilian population and impaired the health system, especially the hospital environment. The south/southeast regions were the most affected, and the ageing process contributed to the increased incidence of RDs.

Indirect impact of childhood 13-valent pneumococcal conjugate vaccine (PCV13) in Canadian older adults: a Canadian Immunization Research Network (CIRN) retrospective observational study

BACKGROUND

13-valent pneumococcal conjugate vaccine (PCV13) has been part of publicly funded childhood immunisation programmes in Ontario and British Columbia (BC) since 2010. We assessed the indirect impact of infant PCV13 programmes on invasive pneumococcal disease (IPD) and all-cause pneumonia hospitalisation in older adults (aged ≥65 years) using a retrospective observational study.

METHODS

We extracted monthly IPD and all-cause pneumonia cases from laboratory and health administrative databases between January 2005 and December 2018. Using a quasi-experimental difference-in-differences design, we calculated the ratio of risk ratios (RRRs) using incidence rates of IPD or all-cause pneumonia cases before (pre-PCV13 period) and after (PCV13 period) 2010 with rates of fractures as controls.

RESULTS

The rates of all IPD or PCV serotype-specific IPD for older adults in both Ontario and BC did not change in 8 years after childhood PCV13 programme implementation. All-cause pneumonia increased in Ontario (RRR 1.38, 95% CI 1.11 to 1.71) but remained unchanged in BC.

CONCLUSIONS

Indirect community protection of older adults from hospitalisation with pneumococcal disease stalled despite maturation of childhood PCV13 vaccination programmes in two Canadian provinces.

Quantifying non-adherence to anti-tuberculosis treatment due to early discontinuation: a systematic literature review of timings to loss to follow-up

BACKGROUND

The burden of non-adherence to anti-tuberculosis (TB) treatment is poorly understood. One type is early discontinuation, that is, stopping treatment early. Given the implications of early discontinuation for treatment outcomes, we undertook a systematic review to estimate its burden, using the timing of loss to follow-up (LFU) as a proxy measure.

METHODS

Web of Science, Embase and Medline were searched up to 14 January 2021 using terms covering LFU, TB and treatment. Studies of adults (≥ 18 years) on the standard regimen for drug-sensitive TB reporting the timing of LFU (WHO definition) were included. A narrative synthesis was conducted and quality assessment undertaken using an adapted version of Downs and Black. Papers were grouped by the percentage of those who were ultimately LFU who were LFU by 2 months. Three groups were created: <28.3% LFU by 2 months, ≥28.3-<38.3%, ≥38.3%). The percentage of dose-months missed due to early discontinuation among (1) those LFU, and (2) all patients was calculated.

RESULTS

We found 40 relevant studies from 21 countries. The timing of LFU was variable within and between countries. 36/40 papers (90.0%) reported the percentage of patients LFU by the end of 2 months. 31/36 studies (86.1%) reported a higher than or as expected percentage of patients becoming LFU by 2 months. The percentage of dose-months missed by patients who became LFU ranged between 37% and 77% (equivalent to 2.2-4.6 months). Among all patients, the percentage of dose-months missed ranged between 1% and 22% (equivalent to 0.1-1.3 months).

CONCLUSIONS

A larger than expected percentage of patients became LFU within the first 2 months of treatment. These patients missed high percentages of dose months of treatment due to early discontinuation. Interventions to promote adherence and retain patients in care must not neglect the early months of treatment.

PROSPERO REGISTRATION NUMBER

CRD42021218636.

Lower airway microbiota in COPD and healthy controls

BACKGROUND

The lower airway microbiota in patients with chronic obstructive pulmonary disease (COPD) are likely altered compared with the microbiota in healthy individuals. Information on how the microbiota is affected by smoking, use of inhaled corticosteroids (ICS) and COPD severity is still scarce.

METHODS

In the MicroCOPD Study, participant characteristics were obtained through standardised questionnaires and clinical measurements at a single centre from 2012 to 2015. Protected bronchoalveolar lavage samples from 97 patients with COPD and 97 controls were paired-end sequenced with the Illumina MiSeq System. Data were analysed in QIIME 2 and R.

RESULTS

Alpha-diversity was lower in patients with COPD than controls (Pielou evenness: COPD=0.76, control=0.80, p=0.004; Shannon entropy: COPD=3.98, control=4.34, p=0.01). Beta-diversity differed with smoking only in the COPD cohort (weighted UniFrac: permutational analysis of variance R2=0.04, p=0.03). Nine genera were differentially abundant between COPD and controls. Genera enriched in COPD belonged to the Firmicutes phylum. Pack years were linked to differential abundance of taxa in controls only (ANCOM-BC (Analysis of Compositions of Microbiomes with Bias Correction) log-fold difference/q-values: Haemophilus -0.05/0.048; Lachnoanaerobaculum -0.04/0.03). Oribacterium was absent in smoking patients with COPD compared with non-smoking patients (ANCOM-BC log-fold difference/q-values: -1.46/0.03). We found no associations between the microbiota and COPD severity or ICS.

CONCLUSION

The lower airway microbiota is equal in richness in patients with COPD to controls, but less even. Genera from the Firmicutes phylum thrive particularly in COPD airways. Smoking has different effects on diversity and taxonomic abundance in patients with COPD compared with controls. COPD severity and ICS use were not linked to the lower airway microbiota.

Challenging the gold standard: the limitations of molecular assays for detection of Mycobacterium tuberculosis heteroresistance

OBJECTIVES

Heteroresistant infections are defined as infections in which a mixture of drug-resistant and drug-susceptible populations are present. In Mycobacterium tuberculosis (M. tb), heteroresistance poses a challenge in diagnosis and has been linked with poor treatment outcomes. We compared the analytical sensitivity of molecular methods, such as GeneXpert and whole genome sequencing (WGS) in detecting heteroresistance when compared with the 'gold standard' phenotypic assay: the agar proportion method (APM).

METHODS

Using two rounds of proficiency surveys with defined monoresistant BCG strains and mixtures of susceptible/resistant M. tb, we determined the limit of detection (LOD) of known resistance associated mutations.

RESULTS

The LOD for rifampin-R (RIF-R) detection was 1% using APM, 60% using GeneXpert MTB/RIF, 10% using GeneXpert MTB/RIF Ultra and 10% using WGS. While WGS could detect mutations beyond those associated with RIF resistance, the LOD for these other mutations was also 10%. Additionally, we observed instances where laboratories did not report resistance in the majority population, yet the mutations were present in the raw sequence data.

CONCLUSION

The gold standard APM detects minority resistant populations at a lower proportion than molecular tests. Mycobacterium bovis BCG strains with defined resistance and extracted DNA from M. tb provided concordant results and can serve in quality control of laboratories offering molecular testing for resistance. Further research is required to determine whether the higher LOD of molecular tests is associated with negative treatment outcomes.

Impact of different corticosteroids on severe community-acquired pneumonia: a systematic review and meta-analysis

OBJECTIVES

Randomised controlled trials (RCTs) have demonstrated conflicting results regarding the effects of corticosteroids on the treatment of severe community-acquired pneumonia (CAP). We aimed to investigate the efficacy and safety of different corticosteroids on patients who were hospitalised for severe CAP.

METHODS

We performed a systematic search through PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus from inception to May 2023. The primary outcome was all-cause mortality. Data analysis was performed using a random-effects model.

RESULTS

A total of 10 RCTs comprising 1962 patients were included. Corticosteroids were associated with a lower rate of all-cause mortality (risk ratio (RR), 0.70 (95% CI 0.54 to 0.90); I2=0.00%). When stratified into different corticosteroid types, hydrocortisone was associated with an approximately 50% lower mortality risk (RR, 0.48 (95% CI 0.32 to 0.72); I2=0.00%). However, dexamethasone, methylprednisolone or prednisolone were not associated with an improvement in mortality. Furthermore, hydrocortisone was associated with a reduction in the rate of mechanical ventilation, acute respiratory distress syndrome, shock and duration of intensive care unit stay. These trends were not observed for dexamethasone, methylprednisolone or prednisolone. Corticosteroids were not associated with an increased risk of adverse events including gastrointestinal bleeding, secondary infection or hyperglycaemia.

CONCLUSIONS

The use of hydrocortisone, but not other types of corticosteroids, was associated with a reduction in mortality and improvement in pneumonia outcomes among patients hospitalised with severe CAP.PROSPERO registration numberCRD42023431360.

Association of indicators of extensive disease and rifampin-resistant tuberculosis treatment outcomes: an individual participant data meta-analysis

BACKGROUND

Indicators of extensive disease-acid fast bacilli (AFB) smear positivity and lung cavitation-have been inconsistently associated with clinical rifampin-resistant/multidrug-resistant tuberculosis (RR/MDR-TB) outcomes. We evaluated the association of these indicators with end-of-treatment outcomes.

METHODS

We did an individual participant data meta-analysis of people treated for RR/MDR-TB with longer regimens with documented AFB smear and chest radiography findings. We compared people AFB smear-negative without cavities to people: (1) smear-negative with lung cavities; (2) smear-positive without lung cavities and (3) AFB smear-positive with lung cavities. Using multivariable logistic regression accounting for demographic, treatment and clinical factors, we calculated adjusted ORs (aOR) for any unfavourable outcome (death, lost to follow-up, failure/recurrence), and mortality and treatment failure/recurrence alone.

RESULTS

We included 5596 participants; included participants significantly differed from excluded participants. Overall, 774 (13.8%) were AFB smear-negative without cavities, 647 (11.6%) only had cavities, 1424 (25.4%) were AFB smear-positive alone and 2751 (49.2%) were AFB smear-positive with cavities. The median age was 37 years (IQR: 28-47), 3580 (64%) were male and 686 (12.5%) had HIV. Compared with participants AFB smear-negative without cavities, aOR (95% CI) for any unfavourable outcome was 1.0 (0.8 to 1.4) for participants smear-negative with lung cavities, 1.2 (0.9 to 1.5) if smear-positive without cavities and 1.6 (1.3 to 2.0) if AFB smear-positive with lung cavities. Odds were only significantly increased for mortality (1.5, 95% CI 1.1 to 2.1) and failure/recurrence (2.2, 95% CI 1.5 to 3.3) among participants AFB smear-positive with lung cavities.

CONCLUSION

Only the combination of AFB smear-positivity and lung cavitation was associated with unfavourable outcomes, suggesting they may benefit from stronger regimens.

Adherence to application technique of inhaled corticosteroid in patients with asthma and COVID-19 improves outcomes

BACKGROUND

Inhaled corticosteroids have been widely reported as a preventive measure against the development of severe forms of COVID-19 not only in patients with asthma.

METHODS

In 654 Czech and Slovak patients with asthma who developed COVID-19, we investigated whether the correct use of inhaler containing corticosteroids was associated with a less severe course of COVID-19 and whether this had an impact on the need for hospitalisation, measurable lung functions and quality of life (QoL).

RESULTS

Of the studied cohort 51.4% had moderate persistent, 29.9% mild persistent and 7.2% severe persistent asthma. We found a significant adverse effect of poor inhaler adherence on COVID-19 severity (p=0.049). We also observed a lower hospitalisation rate in patients adequately taking the inhaler with OR of 0.83. Vital capacity and forced expiratory lung volume deterioration caused by COVID-19 were significantly reversed, by approximately twofold to threefold, in individuals who inhaled correctly.

CONCLUSION

Higher quality of inhalation technique of corticosteroids measured by adherence to an inhaled medication application technique (A-AppIT) score had a significant positive effect on reversal of the vital capacity and forced expiratory lung volume in 1 s worsening (p=0.027 and p<0.0001, respectively) due to COVID-19. Scoring higher in the A-AppIT was also associated with significantly improved QoL. All measured variables concordantly and without exception showed a positive improvement in response to better adherence. We suggest that corticosteroids provide protection against the worsening of lungs in patients with COVID-19 and that correct and easily assessable adherence to corticosteroids with appropriate inhalation technique play an important role in preventing severe form of COVID-19.

Tracheostomy in children is associated with neutrophilic airway inflammation

BACKGROUND

Tracheostomies in children are associated with significant morbidity, poor quality of life, excess healthcare costs and excess mortality. The underlying mechanisms facilitating adverse respiratory outcomes in tracheostomised children are poorly understood. We aimed to characterise airway host defence in tracheostomised children using serial molecular analyses.

METHODS

Tracheal aspirates, tracheal cytology brushings and nasal swabs were prospectively collected from children with a tracheostomy and controls. Transcriptomic, proteomic and metabolomic methods were applied to characterise the impact of tracheostomy on host immune response and the airway microbiome.

RESULTS

Children followed up serially from the time of tracheostomy up to 3 months postprocedure (n=9) were studied. A further cohort of children with a long-term tracheostomy were also enrolled (n=24). Controls (n=13) comprised children without a tracheostomy undergoing bronchoscopy. Long-term tracheostomy was associated with airway neutrophilic inflammation, superoxide production and evidence of proteolysis when compared with controls. Reduced airway microbial diversity was established pre-tracheostomy and sustained thereafter.

CONCLUSIONS

Long-term childhood tracheostomy is associated with a inflammatory tracheal phenotype characterised by neutrophilic inflammation and the ongoing presence of potential respiratory pathogens. These findings suggest neutrophil recruitment and activation as potential exploratory targets in seeking to prevent recurrent airway complications in this vulnerable group of patients.

Observational cohort study protocol: neutrophil function and energetics in adults with pneumonia and sepsis - Pneumonia Metabolism in Ageing (PUMA)

INTRODUCTION

Community-acquired pneumonia has high mortality and is associated with significant healthcare costs. In older adults with community-acquired pneumonia neutrophil dysfunction has been identified and is associated with poor outcomes for patients. Immunometabolism is a rapidly developing field which links immune cell function to metabolism. This study aims to explore neutrophil metabolism in community-acquired pneumonia.

METHODS AND ANALYSIS

Pneumonia Metabolism in Ageing study is a prospective observational study recruiting older adults hospitalised with community-acquired pneumonia to examine neutrophil function and metabolic status. Controls will be older adults with no acute illness. The primary endpoint is neutrophil chemotaxis.

ETHICS AND DISSEMINATION

The study has ethical approval from the Research Ethics Committee Wales, reference 19/WA/0299. This study involves participants who may lack the capacity to consent to research involvement, in this situation, personal or professional assent will be sought. The results from this study will be submitted for publication in peer-reviewed journals and disseminated at local and international conferences.

Impact of the Syrian conflict and forced displacement on respiratory health: an analysis of primary data from a humanitarian organisation

BACKGROUND

Despite a decade of conflict, there has been little exploration of respiratory health in Syria, notwithstanding the known impacts of conflict on lung health. Our aim is to explore the burden and trends of respiratory consultations in Syrian American Medical Society (SAMS) facilities in northwest Syria through an ecological analysis.

METHODS

We performed a retrospective review of routinely collected data relating to respiratory presentations in SAMS' facilities between March 2017 and June 2020; we compared data by facility type, infectious versus non-infectious aetiologies and age.

RESULTS

Data were available for 5 058 864 consultations, of which 1 228 722 (24%) were respiratory presentations, across 22 hospitals, 22 primary healthcare centres, 3 mobile clinics and 1 polyclinic. The median number of respiratory consultations per month was 30 279 (IQR: 25 792-33 732). Key findings include: 73% of respiratory consultations were for children; respiratory presentations accounted for up to 38% of consultations each month, seasonal variation was evident; respiratory tract infections accounted for 91% of all respiratory presentations. A steep decrease in consultations occurred between the end of 2019 (160 000) and the first quarter of 2020 (90 000), correlating with an escalation of violence in Idlib governorate.

CONCLUSION

This study presents the largest quantitative analysis of respiratory data collected during the Syrian conflict. It supports the need for improved measures to aid the prevention, diagnosis and management of respiratory conditions during conflict as well as further research to explore the impact of conflict on respiratory health.

Acute respiratory distress syndrome: potential of therapeutic interventions effective in treating progression from COVID-19 to treat progression from other illnesses-a systematic review

BACKGROUND

Acute respiratory distress syndrome (ARDS) is the most severe form of lung injury, rendering gaseous exchange insufficient, leading to respiratory failure. Despite over 50 years of research on the treatment of ARDS when developed from illnesses such as sepsis and pneumonia, mortality remains high, and no robust pharmacological treatments exist. The progression of SARS-CoV-2 infections to ARDS during the recent global pandemic led to a surge in the number of clinical trials on the condition. Understandably, this explosion in new research focused on COVID-19 ARDS (CARDS) rather than ARDS when developed from other illnesses, yet differences in pathology between the two conditions mean that optimal treatment for them may be distinct.

AIM

The aim of the present work is to assess whether new therapeutic interventions that have been developed for the treatment of CARDS may also hold strong potential in the treatment of ARDS when developed from other illnesses. The study objectives are achieved through a systematic review of clinical trials.

RESULTS

The COVID-19 pandemic led to the identification of various therapeutic interventions for CARDS, some but not all of which are optimal for the management of ARDS. Interventions more suited to CARDS pathology include antithrombotics and biologic agents, such as cytokine inhibitors. Cell-based therapies, on the other hand, show promise in the treatment of both conditions, attributed to their broad mechanisms of action and the overlap in the clinical manifestations of the conditions. A shift towards personalised treatments for both CARDS and ARDS, as reflected through the increasing use of biologics, is also evident.

CONCLUSIONS

As ongoing CARDS clinical trials progress, their findings are likely to have important implications that alter the management of ARDS in patients that develop the condition from illnesses other than COVID-19 in the future.

Inhalation devices and inhaled corticosteroids particle size influence on severe pneumonia in patients with chronic obstructive pulmonary disease: a nationwide cohort study

BACKGROUND

Inhaled corticosteroids (ICSs) are associated with an increased risk of pneumonia among patients with chronic obstructive pulmonary disease (COPD). The introduction of extrafine particle ICS has aimed to improve the distribution of medicine in the airways by altering deposition within the lungs, potentially affecting efficacy and side effects. It remains unclear if extrafine particle ICS administration alters the risk of pneumonia compared with standard particle size ICS.

METHODS

An observational cohort study including all Danish COPD outpatients receiving ICS from 2010 to 2017. The primary outcome was pneumonia hospitalisation in the different ICS particle dosing regimens. The primary analysis was an adjusted Cox proportional hazards model. For sensitivity analysis, a subgroup analysis of patients receiving spray devices was done. Further, we created a propensity score matched cohort, in which we matched for the same covariates as adjusted for in the main analysis.

RESULTS

A total of 35 691 patients were included of whom 1471 received extrafine particle ICS. Among these patients, 4657 were hospitalised due to pneumonia. Patients with COPD receiving extrafine particle ICS had a lower risk of hospitalisation due to pneumonia compared with patients receiving standard particle size ICS in our primary analysis (HR 0.75; 95% CI 0.63 to 0.89; p=0.002), subgroup analysis (HR 0.54; 95% CI 0.45 to 0.65; p<0.0001) and the propensity-matched population (HR 0.72; 95% CI 0.60 to 0.87; p=0.0006).

INTERPRETATION

The use of extrafine particle ICS administration was associated with a lower risk of pneumonia hospitalisation in patients with COPD compared with those who received standard size treatment.

Inhaled corticosteroids and risk of lower respiratory tract infection with Moraxella catarrhalis in patients with chronic obstructive pulmonary disease

BACKGROUND

Use of inhaled corticosteroids (ICS) is common in patients with chronic obstructive pulmonary disease (COPD) and has been associated with an increased risk of pneumonia. Moraxella catarrhalis is one of the most common bacterial causes of infectious exacerbation in COPD. Currently, to our knowledge, no studies have investigated if ICS increases the risk of lower respiratory tract infection with M. catarrhalis in patients with COPD.

OBJECTIVE

To investigate if accumulated ICS use in patients with COPD, is associated with a dose-dependent risk of infection with M. catarrhalis.

METHODS

This observational cohort study included 18 870 persons with COPD who were registered in The Danish Register of COPD. Linkage to several nationwide registries was performed.Exposure to ICS was determined by identifying all prescriptions for ICS, redeemed within 365 days prior to study entry. Main outcome was a lower respiratory tract sample positive for M. catarrhalis. For the main analysis, a Cox multivariate regression model was used.We defined clinical infection as admission to hospital and/or a redeemed prescription for a relevant antibiotic, within 7 days prior to 14 days after the sample was obtained.

RESULTS

We found an increased, dose-dependent, risk of a lower respiratory tract sample with M. catarrhalis among patients who used ICS, compared with non-users. For low and moderate doses of ICS HR was 1.65 (95% CI 1.19 to 2.30, p=0.003) and 1.82 (95% CI 1.32 to 2.51, p=0.0002), respectively. In the group of patients with highest ICS exposure, the HR of M. catarrhalis was 2.80 (95% CI 2.06 to 3.82, p<0.0001). Results remained stable in sensitivity analyses. 87% of patients fulfilled the criteria for clinical infection, and results remained unchanged in this population.

CONCLUSION

Our study shows a dose-dependent increased risk of infection with M. catarrhalis associated to ICS exposure.

Cross-sectional study evaluating the impact of SARS-CoV-2 variants on Long COVID outcomes in UK hospital survivors

OBJECTIVES

COVID-19 studies report on hospital admission outcomes across SARS-CoV-2 waves of infection but knowledge of the impact of SARS-CoV-2 variants on the development of Long COVID in hospital survivors is limited. We sought to investigate Long COVID outcomes, aiming to compare outcomes in adult hospitalised survivors with known variants of concern during our first and second UK COVID-19 waves, prior to widespread vaccination.

DESIGN

Prospective observational cross-sectional study.

SETTING

Secondary care tertiary hospital in the UK.

PARTICIPANTS

This study investigated Long COVID in 673 adults with laboratory-positive SARS-CoV-2 infection or clinically suspected COVID-19, 6 weeks after hospital discharge. We compared adults with wave 1 (wildtype variant, admitted from February to April 2020) and wave 2 patients (confirmed Alpha variant on viral sequencing (B.1.1.7), admitted from December 2020 to February 2021).

OUTCOME MEASURES

Associations of Long COVID presence (one or more of 14 symptoms) and total number of Long COVID symptoms with SARS-CoV-2 variant were analysed using multiple logistic and Poisson regression, respectively.

RESULTS

322/400 (wave 1) and 248/273 (wave 2) patients completed follow-up. Predictors of increased total number of Long COVID symptoms included: pre-existing lung disease (adjusted count ratio (aCR)=1.26, 95% CI 1.07, 1.48) and more COVID-19 admission symptoms (aCR=1.07, 95% CI 1.02, 1.12). Weaker associations included increased length of inpatient stay (aCR=1.02, 95% CI 1.00, 1.03) and later review after discharge (aCR=1.00, 95% CI 1.00, 1.01). SARS-CoV-2 variant was not associated with Long COVID presence (OR=0.99, 95% CI 0.24, 4.20) or total number of symptoms (aCR=1.09, 95% CI 0.82, 1.44).

CONCLUSIONS

Patients with chronic lung disease or greater COVID-19 admission symptoms have higher Long COVID risk. SARS-CoV-2 variant was not predictive of Long COVID though in wave 2 we identified fewer admission symptoms, improved clinical trajectory and outcomes. Addressing modifiable factors such as length of stay and timepoint of clinical review following discharge may enable clinicians to move from Long COVID risk stratification towards improving its outcome.

Randomised controlled trial of perinatal vitamin D supplementation to prevent early-onset acute respiratory infections among Australian First Nations children: the 'D-Kids' study protocol

INTRODUCTION

Globally, acute respiratory infections (ARIs) are a leading cause of childhood morbidity and mortality. While ARI-related mortality is low in Australia, First Nations infants are hospitalised with ARIs up to nine times more often than their non-First Nations counterparts. The gap is widest in the Northern Territory (NT) where rates of both acute and chronic respiratory infection are among the highest reported in the world. Vitamin D deficiency is common among NT First Nations neonates and associated with an increased risk of ARI hospitalisation. We hypothesise that perinatal vitamin D supplementation will reduce the risk of ARI in the first year of life.

METHODS AND ANALYSIS

'D-Kids' is a parallel (1:1), double-blind (allocation concealed), randomised placebo-controlled trial conducted among NT First Nations mother-infant pairs. Pregnant women and their babies (n=314) receive either vitamin D or placebo. Women receive 14 000 IU/week or placebo from 28 to 34 weeks gestation until birth and babies receive 4200 IU/week or placebo from birth until age 4 months. The primary outcome is the incidence of ARI episodes receiving medical attention in the first year of life. Secondary outcomes include circulating vitamin D level and nasal pathogen prevalence. Tertiary outcomes include infant immune cell phenotypes and challenge responses. Blood, nasal swabs, breast milk and saliva are collected longitudinally across four study visits: enrolment, birth, infant age 4 and 12 months. The sample size provides 90% power to detect a 27.5% relative reduction in new ARI episodes between groups.

ETHICS AND DISSEMINATION

This trial is approved by the NT Human Research Ethics Committee (2018-3160). Study outcomes will be disseminated to participant families, communities, local policy-makers, the broader research and clinical community via written and oral reports, education workshops, peer-reviewed journals, national and international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12618001174279.

Bagasse dust exposure and chronic respiratory symptoms among workers in the Metehara and Wonji sugar factories in Ethiopia: a longitudinal study design

BACKGROUND

Ethiopia's sugar factories are growing by creating job opportunities for thousands of workers with varying educational, professional and socioeconomic backgrounds. These sugar factories are a source of several hazards that severely harm the workers' health. In this context, there is inconclusive evidence on the level of bagasse dust exposure and chronic respiratory health symptoms. This study aimed to assess the degree of bagasse dust exposure and chronic respiratory health symptoms.

METHODS

In this longitudinal study, five workstations were selected for dust sampling. A stratified random sampling technique was used to select 1043 participants. We measured the dust intensity using a calibrated handheld real-time dust monitor once a month for 5 months, totalling 50 dust samples. Chronic respiratory symptoms were assessed using the American Thoracic Society's respiratory symptoms questionnaire.

RESULTS

A 1 hour time-weighted average of bagasse dust intensity in the boiler, power turbine and evaporation plant was 8.93 mg/m3, 8.88 mg/m3 and 8.68 mg/m3, respectively. This corresponded to an exposure level to bagasse dust of 85.52% (95% CI 83.2% to 87.6%). The level of chronic respiratory health symptoms was 60.6% (95% CI 59.2% to 61.9%). The most common respiratory symptoms were wheezing (96.8%), coughing (89.7%) and breathlessness (80.9%). The identified risk factors were lack of dust control technology (β= 0.64, 95% CI 0.53 to 0.75), not practising wet spray (β = 0.27, 95% CI 0.21 to 0.41) and not wearing proper respiratory protection devices (β = 0.12, 95% CI 0.30 to 0.56).

CONCLUSIONS

Bagasse dust exposure and respiratory health abnormalities were worrying concerns. The absence of dust control technologies and no practice of wet spraying elevated the level of exposure. Not wearing proper respiratory protection gear increased the odds of having respiratory abnormalities. Hence, the use of mechanical solutions to stop dust emissions at their sources and the wearing of proper respiratory protection gear are highly advised.

Dysfunctional breathing symptoms, functional impact and quality of life in patients with long COVID-19: a prospective case series

BACKGROUND

Dysfunctional breathing is increasingly recognised after SARS-CoV-2 infection, but the associated symptoms, functional impact and quality of life have not been systematically studied.

METHODS

This study describes a prospective case series of 48 patients with dysfunctional breathing based on compatible symptoms and an abnormal breathing pattern during cardiopulmonary exercise testing. Patients with underlying disease that could explain these symptoms were excluded. Median time from COVID-19 to evaluation was 212 (IQR 121) days. Self-administered questionnaires, including the Nijmegen questionnaire, Short-Form (36) Health Survey (SF-36), Hospital Anxiety and Depression Scale, modified Medical Research Council scale, post-COVID-19 Functional Scale, and specific long COVID symptoms, were the outcome measures.

RESULTS

On average, mean V'O₂ was preserved. Pulmonary function tests were within limits of normality. Hyperventilation, periodic deep sighs/erratic breathing and mixed types of dysfunctional breathing were diagnosed in 20.8%, 47.1% and 33.3% of patients, respectively. After dyspnoea, the five most frequent symptoms using the Nijmegen scale with a cut-off of ≥3 were faster/deeper breathing (75.6%), palpitations (63.8%), sighs (48.7%), unable to breathe deeply (46.3%) and yawning (46.2%). Median Nijmegen and Hospital Anxiety and Depression Scale scores were 28 (IQR 20) and 16.5 (IQR 11), respectively. SF-36 scores were lower than the reference value.

CONCLUSIONS

Long COVID patients with dysfunctional breathing have a high burden of symptoms, functional impact and a low quality of life, despite no or negligible organic damage.

Global variability of influenza activity and virus subtype circulation from 2011 to 2023

BACKGROUND

Although decreased influenza activity has been reported in many countries during the COVID-19 pandemic, it remains unknown how global influenza activity has changed. We described the global variability of influenza activity and virus subtype circulation from 2011 to 2023 to prepare for the potential influenza outbreak with the control of the COVID-19 pandemic.

METHODS

Influenza virological surveillance data between 2011 and 2023 were obtained from the WHO-FluNet database. We first calculated and compared the influenza activity before and during the COVID-19 pandemic. For countries whose influenza activity has recovered, we also described changes in the duration of influenza epidemics. We then determined the proportion of influenza cases caused by the different influenza virus types.

RESULTS

In total, 73 countries with 2.17 million influenza cases were included. In the early stage of the COVID-19 pandemic, decreased influenza activity was observed in all WHO regions. In 2022 and 2023, rebound in influenza activity was observed in all WHO regions, especially in Western Pacific Region. At the same time, a change in the duration of the influenza epidemic was observed in several Southern Hemisphere countries. Moreover, in all WHO regions, few B/Yamagata viruses were detected during the COVID-19 pandemic.

CONCLUSIONS

Lack of exposure to influenza will diminish population immunity and increase the severity of large epidemics on a future global resurgence. Ongoing monitoring of the changes in the duration of the influenza epidemic and circulation subtypes should be the focus of future work.

Surveillance towards preventing paediatric incidence of respiratory syncytial virus attributable respiratory tract infection in primary and secondary/tertiary healthcare settings in Merseyside, Cheshire and Bristol, UK

INTRODUCTION

Respiratory syncytial virus (RSV) is a common respiratory virus, particularly affecting children, and can cause respiratory infections such as croup and bronchiolitis. The latter is a leading cause of paediatric hospitalisation within the UK. Children <3 years of age and/or with underlying health conditions are more vulnerable to severe RSV infection.There are currently limited data on the incidence of laboratory-confirmed RSV, particularly within primary care settings and outside the typical 'RSV season', which in the Northern hemisphere tends to coincide with winter months. There is also a lack of data on the health economic impact of RSV infection on families and healthcare systems.This observational surveillance study aims to collect data on the incidence of laboratory-confirmed RSV-attributable respiratory tract infection (RTI) in children aged <3 years presenting to primary, secondary or tertiary care; it also aims to estimate the health economic and quality of life impact of RSV-attributable infection in this cohort. Such data will contribute to informing public health strategies to prevent RSV-associated infection, including use of preventative medications.

METHODS AND ANALYSIS

Parents/carers of children <3 years of age with RTI symptoms will consent for a respiratory sample (nasal swab) to be taken. Laboratory PCR testing will assess for the presence of RSV and/or other pathogens. Data will be obtained from medical records on demographics, comorbidities, severity of infection and hospitalisation outcomes. Parents will complete questionnaires on the impact of ongoing infection symptoms at day 14 and 28 following enrolment. The primary outcome is incidence of laboratory-confirmed RSV in children <3 years presenting to primary, secondary or tertiary care with RTI symptoms leading to health-seeking behaviours. Recruitment will be carried out from December 2021 to March 2023, encompassing two UK winter seasons and intervening months.

ETHICS AND DISSEMINATION

Ethical approval has been granted (21/WS/0142), and study findings will be published as per International Committee of Medical Journal Editors' guidelines.

C reactive protein utilisation, a biomarker for early COVID-19 treatment, improves lenzilumab efficacy: results from the randomised phase 3 'LIVE-AIR' trial

OBJECTIVE

COVID-19 severity is correlated with granulocyte macrophage colony-stimulating factor (GM-CSF) and C reactive protein (CRP) levels. In the phase three LIVE-AIR trial, lenzilumab an anti-GM-CSF monoclonal antibody, improved the likelihood of survival without ventilation (SWOV) in COVID-19, with the greatest effect in participants having baseline CRP below a median of 79 mg/L. Herein, the utility of baseline CRP to guide lenzilumab treatment was assessed.

DESIGN

A subanalysis of the randomised, blinded, controlled, LIVE-AIR trial in which lenzilumab or placebo was administered on day 0 and participants were followed through Day 28.

PARTICIPANTS

Hospitalised COVID-19 participants (N=520) with SpO2 ≤94% on room air or requiring supplemental oxygen but not invasive mechanical ventilation.

INTERVENTIONS

Lenzilumab (1800 mg; three divided doses, q8h, within 24 hours) or placebo infusion alongside corticosteroid and remdesivir treatments.

MAIN OUTCOME MEASURES

The primary endpoint was the time-to-event analysis difference in SWOV through day 28 between lenzilumab and placebo treatments, stratified by baseline CRP.

RESULTS

SWOV was achieved in 152 (90%; 95% CI 85 to 94) lenzilumab and 144 (79%; 72 to 84) placebo-treated participants with baseline CRP <150 mg/L (HR: 2.54; 95% CI 1.46 to 4.41; p=0.0009) but not with CRP ≥150 mg/L (HR: 1.04; 95% CI 0.51 to 2.14; p=0.9058). A statistically significant interaction between CRP and lenzilumab treatment was observed (p=0.044). Grade ≥3 adverse events with lenzilumab were comparable to placebo in both CRP strata. No treatment-emergent serious adverse events were attributed to lenzilumab.

CONCLUSION

Hospitalised hypoxemic patients with COVID-19 with baseline CRP <150 mg/L derived the greatest clinical benefit from treatment with lenzilumab.

TRIAL REGISTRATION NUMBER

NCT04351152; ClinicalTrials.gov.

Single-arm, open-labelled, safety and tolerability of intrabronchial and nebulised bacteriophage treatment in children with cystic fibrosis and Pseudomonas aeruginosa

INTRODUCTION

Cystic fibrosis (CF) is a multisystem condition that is complicated by recurrent pulmonary infections requiring aggressive antibiotic treatment. This predisposes the patient to complications such as sensorineural hearing loss, renal impairment, hypersensitivity and the development of antibiotic resistance. Pseudomonas aeruginosa is one of the more common organisms which cause recurrent infections and result in greater morbidity and mortality in people living with CF. Bacteriophages have been identified as a potential alternative or adjunct to antibiotics. We hypothesise that bacteriophage therapy is a safe and well-tolerated treatment in children with CF infected with P. aeruginosa infection in their airways.

METHODS

This single-arm, open-labelled, non-randomised trial will run for a maximum period of 36 months with up to 10 participants. Adolescents (≥12 years and <18 years of age) who continue to shed P.aeruginosa (within 3 months of enrolment) despite undergoing eradication therapy previously, will be considered for this trial. Non-genetically modified bacteriophages that have demonstrated obligate lytic activity against each of the study participants' P. aeruginosa strains will be selected and prepared according to a combination of established protocols (isolation, purification, sterility testing and packaging) to achieve close to good manufacturing practice recommendations. The selected bacteriophage will be administered endo-bronchially first under direct vision, followed by two times a day nebulisation for 7 days in addition to standard CF treatment (intravenous antibiotics, physiotherapy to be completed as inpatient for 10-14 days). Safety and tolerability will be defined as the absence of (1) fever above 38.5°C occurring within 1 hour of the administration of the nebulised bacteriophage, (2) a 10% decline in spirometry (forced expiratory volume in 1 s %) measured preadministration and postadministration of the first dose of nebulised bacteriophage. Clinical reviews including repeat sputum cultures and spirometry will be performed at 3, 6, 9 and 12 months following bacteriophage treatment.

ETHICS AND DISSEMINATION

Our clinical trial is conducted in accordance with (1) good clinical practice, (2) Australian legislation, (3) National Health and Medical Research Council guidelines for the ethical conduct of research.

TRIAL REGISTRATION NUMBER

Australia and New Zealand Clinical Trial Registry (ACTRN12622000767707).

Mendelian randomisation of eosinophils and other cell types in relation to lung function and disease

RATIONALE

Eosinophils are associated with airway inflammation in respiratory disease. Eosinophil production and survival is controlled partly by interleukin-5: anti-interleukin-5 agents reduce asthma and response correlates with baseline eosinophil counts. However, whether raised eosinophils are causally related to chronic obstructive pulmonary disease (COPD) and other respiratory phenotypes is not well understood.

OBJECTIVES

We investigated causality between eosinophils and: lung function, acute exacerbations of COPD, asthma-COPD overlap (ACO), moderate-to-severe asthma and respiratory infections.

METHODS

We performed Mendelian randomisation (MR) using 151 variants from genome-wide association studies of blood eosinophils in UK Biobank/INTERVAL, and respiratory traits in UK Biobank/SpiroMeta, using methods relying on different assumptions for validity. We performed multivariable analyses using eight cell types where there was possible evidence of causation by eosinophils.

MEASUREMENTS AND MAIN RESULTS

Causal estimates derived from individual variants were highly heterogeneous, which may arise from pleiotropy. The average effect of raising eosinophils was to increase risk of ACO (weighted median OR per SD eosinophils, 1.44 (95%CI 1.19 to 1.74)), and moderate-severe asthma (weighted median OR 1.50 (95%CI 1.23 to 1.83)), and to reduce forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and FEV1 (weighted median estimator, SD FEV1/FVC: -0.054 (95% CI -0.078 to -0.029), effect only prominent in individuals with asthma).

CONCLUSIONS

Broad consistency across MR methods may suggest causation by eosinophils (although of uncertain magnitude), yet heterogeneity necessitates caution: other important mechanisms may be responsible for the impairment of respiratory health by these eosinophil-raising variants. These results could suggest that anti-IL5 agents (designed to lower eosinophils) may be valuable in treating other respiratory conditions, including people with overlapping features of asthma and COPD.

Pulmonary sequelae in 2-year-old children after hospitalisation for respiratory syncytial virus lower respiratory tract infection during infancy: an observational study

BACKGROUND

Respiratory syncytial virus (RSV) is the most common cause of hospitalisation for lower respiratory tract infection (LRTI) in children. RSV LRTI during early childhood may increase susceptibility to recurrent wheezing and asthma.

RESEARCH QUESTION

The aim of this study was to describe the pulmonary sequelae at 1 and 2 years of age following RSV LRTI hospitalisation during the first year of life in term infants.

STUDY DESIGN AND METHODS

A longitudinal case-control study was undertaken from April 2016 to December 2019. Cases constituted children hospitalised with PCR-confirmed RSV LRTI during infancy and controls were children not previously hospitalised with LRTI. A questionnaire detailing environmental and medical history, as well as a modified International Study of Asthma and Allergies (ISAAC) questionnaire, was administered, and pulmonary function testing, including oscillometry, tidal breath flow-volume loops and multiple breath wash-out, was performed, at one and two years of age.

RESULTS

One (n=308) and two-year-old (n=214) cases were more likely than one (n=292) and two-year-old (n=209) controls to have experienced clinical pulmonary symptoms, including wheezing ((55% vs 24%; p<0.001) and (61% vs 16%; p<0.001)), received treatment for wheezing ((17 vs 8%; p<0.001) and (51 vs 6%; p<0.001)) and had any admissions for wheezing ((31 vs 6%; p<0.001) and (46 vs 1.4%; p<0.001)) or any LRTI ((24 vs 2%; p<0.001) and (32 vs 1.4%; p<0.001)), after the initial RSV hospitalisation. RSV LRTI during infancy was associated with an increase in airway resistance by two years (22.46 vs 20.76 hPa.s.l^-1 (p=0.022)), along with a decrease in compliance at both one (-4.61 vs -3.09 hPa.s/l (p<0.001)) and two years (-0.99 vs 0.33 hPa.s/l¹ (p<0.001)). There was an increased work of breathing at one year, but this was no longer present at two years.

INTERPRETATION

RSV LRTI during infancy in cases was associated with more clinical and pulmonary function sequelae through to two years of age.

Protein arginine N-methyltransferase 4 (PRMT4) contributes to lymphopenia in experimental sepsis

BACKGROUND

One hallmark of sepsis is the reduced number of lymphocytes, termed lymphopenia, that occurs from decreased lymphocyte proliferation or increased cell death contributing to immune suppression. Histone modification enzymes regulate immunity by their epigenetic and non-epigenetic functions; however, the role of these enzymes in lymphopenia remains elusive.

METHODS

We used molecular biological approaches to investigate the high expression and function of a chromatin modulator protein arginine N-methyltransferase 4 (PRMT4)/coactivator-associated arginine methyltransferase 1 in human samples from septic patients and cellular and animal septic models.

RESULTS

We identified that PRMT4 is elevated systemically in septic patients and experimental sepsis. Gram-negative bacteria and their derived endotoxin lipopolysaccharide (LPS) increased PRMT4 in B and T lymphocytes and THP-1 monocytes. Single-cell RNA sequencing results indicate an increase of PRMT4 gene expression in activated T lymphocytes. Augmented PRMT4 is crucial for inducing lymphocyte apoptosis but not monocyte THP-1 cells. Ectopic expression of PRMT4 protein caused substantial lymphocyte death via caspase 3-mediated cell death signalling, and knockout of PRMT4 abolished LPS-mediated lymphocyte death. PRMT4 inhibition with a small molecule compound attenuated lymphocyte death in complementary models of sepsis.

CONCLUSIONS

These findings demonstrate a previously uncharacterised role of a key chromatin modulator in lymphocyte survival that may shed light on devising therapeutic modalities to lessen the severity of septic immunosuppression.

Understanding the risk of transmission of respiratory viral infections in childcare centres: protocol for the DISeases TrANsmission in ChildcarE (DISTANCE) multicentre cohort study

INTRODUCTION

Childcare centre is considered a high-risk setting for transmission of respiratory viruses. Further evidence is needed to understand the risk of transmission in childcare centres. To this end, we established the DISeases TrANsmission in ChildcarE (DISTANCE) study to understand the interaction among contact patterns, detection of respiratory viruses from environment samples and transmission of viral infections in childcare centres.

METHODS AND ANALYSIS

The DISTANCE study is a prospective cohort study in multiple childcare centres of Jiangsu Province, China. Study subjects will be childcare attendees and teaching staff of different grades. A range of information will be collected from the study subjects and participating childcare centres, including attendance, contact behaviours (collected by onsite observers), respiratory viral infection (weekly respiratory throat swabs tested by multiplex PCR), presence of respiratory viruses on touch surfaces of childcare centres and weekly follow-up survey on respiratory symptoms and healthcare seeking among subjects tested positive for any respiratory viruses. Detection patterns of respiratory viruses from study subjects and environment samples, contact patterns, and transmission risk will be analysed by developing statistical and mathematical models as appropriate. The study has been initiated in September 2022 in 1 childcare centre in Wuxi City, with a total of 104 children and 12 teaching staff included in the cohort; data collection and follow-up is ongoing. One more childcare centre in Nanjing City (anticipated to include 100 children and 10 teaching staff) will start recruitment in 2023.

ETHICS AND DISSEMINATION

The study has received ethics approval from Nanjing Medical University Ethics Committee (No. 2022-936) and ethics approval from Wuxi Center for Disease Control and Prevention Ethics Committee (No. 2022-011). We plan to disseminate the study findings mainly through publications in peer-reviewed journals and presentations in academic conferences. Aggregated research data will be shared freely to researchers.

Reduced lung function and health-related quality of life after treatment for pulmonary tuberculosis in Gambian children: a cross-sectional comparative study

BACKGROUND

Post-tuberculosis (post-TB) lung disease is an under-recognised consequence of pulmonary tuberculosis (pTB). We aimed to estimate the prevalence of residual lung function impairment and reduced health-related quality of life (HRQoL) in children after pTB treatment completion.

METHODS

We conducted a cross-sectional comparative study of children aged less than 15 years at TB diagnosis who had completed treatment for pTB at least 6 months previously with a comparator group of age-matched children without a history of pTB. Symptoms, spirometry and HRQoL measured with PedsQL scale were collected. Variables associated with lung function impairment were identified through logistic regression models.

RESULTS

We enrolled 68 post-TB cases (median age 8.9 (IQR 7.2-11.2) years) and 91 children in the comparison group (11.5 (8.0-13.7) years). Spirometry from 52 (76.5%) post-TB cases and 89 (94.5%) of the comparison group met the quality criteria for acceptability and repeatability. Lung function impairment was present in 20/52 (38.5%) post-TB cases and 15/86 (17.4%) in the comparison group, p=0.009. Previous pTB and a history of chronic cough were significantly associated with the presence of lung function impairment (p=0.047 and 0.006 respectively). Forced expiratory volume in 1 s (FEV₁), forced vital capacity (FVC) and FEV₁/FVC z-scores were significantly lower in the post-TB cases compared with the comparison group (p= <0.001, 0.014 and <0.001, respectively). The distribution of the self-reported physical health score, and parent-reported physical, emotional, psychological, social and total HRQoL scores were significantly lower in the post-TB cases compared with the comparison group.

CONCLUSIONS

Previous TB in children is associated with significantly impaired lung function and HRQoL.

Review of the British Thoracic Society Winter Meeting 2021, 24-26 November 2021

The Winter Meeting of the British Thoracic Society (BTS) is a platform for the latest clinical and scientific research in respiratory medicine. This review summarises the key symposia and presentations from the BTS Winter Meeting 2021 held online due to the COVID-19 pandemic.

Chest radiograph-based artificial intelligence predictive model for mortality in community-acquired pneumonia

Background

Chest radiograph (CXR) is a basic diagnostic test in community-acquired pneumonia (CAP) with prognostic value. We developed a CXR-based artificial intelligence (AI) model (CAP AI predictive Engine: CAPE) and prospectively evaluated its discrimination for 30-day mortality.

Methods

Deep-learning model using convolutional neural network (CNN) was trained with a retrospective cohort of 2235 CXRs from 1966 unique adult patients admitted for CAP from 1 January 2019 to 31 December 2019. A single-centre prospective cohort between 11 May 2020 and 15 June 2020 was analysed for model performance. CAPE mortality risk score based on CNN analysis of the first CXR performed for CAP was used to determine the area under the receiver operating characteristic curve (AUC) for 30-day mortality.

Results

315 inpatient episodes for CAP occurred, with 30-day mortality of 19.4% (n=61/315). Non-survivors were older than survivors (mean (SD)age, 80.4 (10.3) vs 69.2 (18.7)); more likely to have dementia (n=27/61 vs n=58/254) and malignancies (n=16/61 vs n=18/254); demonstrate higher serum C reactive protein (mean (SD), 109 mg/L (98.6) vs 59.3 mg/L (69.7)) and serum procalcitonin (mean (SD), 11.3 (27.8) μg/L vs 1.4 (5.9) μg/L). The AUC for CAPE mortality risk score for 30-day mortality was 0.79 (95% CI 0.73 to 0.85, p<0.001); Pneumonia Severity Index (PSI) 0.80 (95% CI 0.74 to 0.86, p<0.001); Confusion of new onset, blood Urea nitrogen, Respiratory rate, Blood pressure, 65 (CURB-65) score 0.76 (95% CI 0.70 to 0.81, p<0.001), respectively. CAPE combined with CURB-65 model has an AUC of 0.83 (95% CI 0.77 to 0.88, p<0.001). The best performing model was CAPE incorporated with PSI, with an AUC of 0.84 (95% CI 0.79 to 0.89, p<0.001).

Conclusion

CXR-based CAPE mortality risk score was comparable to traditional pneumonia severity scores and improved its discrimination when combined.

Trends and health burden of hospitalized acute respiratory infections and impact of Haemophilus influenza immunization in a Tunisian university hospital: a twelve-year study

BACKGROUND

We aimed to describe the episodes and trends of admissions for community-acquired Respiratory Infections (RI) over a 12-year period and to assess the impact of Haemophilus influenza type b (Hib) vaccine on RI admissions in children aged up to 3 years.

METHODS

We conducted a twelve-year retrospective observational study on all community-acquired RI admitted to Fattouma Bourguiba Hospital in Monastir Governorate (Tunisia) from 1 January 2002 to 31 December 2013. RI cases were selected from the Regional Registry of Hospital Morbidity. Data were coded according to ICD-10. To assess the impact of the Hib vaccine, three cohorts were defined based on vaccine status (unvaccinated cohort, first vaccinated cohort (VC) by monovalent form and second VC by pentavalent combination).

RESULTS

Admissions for RI represented 17.6% (CI95%: 17.3-18.1) of all communicable diseases hospitalizations (n = 6 061/34 289). The crude incidence rates (CIR) per 100,000 inh were 24.2 for upper RI (URI) and 77.5 and for Lower RI (LRI) (p < 0.0001). Pneumonias represented 53.9% of LRI. Sex-ratio (male/female) was 1.12 for URI and 1.64 for LRI (p < 0.0001). At admission, the median age was 22 years (IQR: 3-52). Admission for Pneumonia increased significantly during study period (slope 'b' = 5.16; p < 0.0001) especially in children up to 5 years old (slope 'b' = 5.53) and in elderly (slope 'b' = 2.13). Among children up to 3 years old, the CIRs per 100,000 for Hib pneumonia admission were 11.6 in Non-Vaccinated Cohort (NVC), 10.6 in Vaccinated Cohort (VC) by protocol 1 (Hib Vaccine monovalent) and 0.80 in VC by protocol 2 (pentavalent vaccine combination).The relative risk reduction was 99% for protocol 2 (p < 0.001).

CONCLUSION

Admissions for RI in a  tertiary level hospital were common with an increasing trend. The Hib immunization program, in particular the pentavalent combination, has had a positive impact on the reduction of related acute diseases.

Severe respiratory viral infection induces procalcitonin in the absence of bacterial pneumonia

INTRODUCTION

Procalcitonin expression is thought to be stimulated by bacteria and suppressed by viruses via interferon signalling. Consequently, during respiratory viral illness, clinicians often interpret elevated procalcitonin as evidence of bacterial coinfection, prompting antibiotic administration. We sought to evaluate the validity of this practice and the underlying assumption that viral infection inhibits procalcitonin synthesis.

METHODS

We conducted a retrospective cohort study of patients hospitalised with pure viral infection (n=2075) versus bacterial coinfection (n=179). The ability of procalcitonin to distinguish these groups was assessed. In addition, procalcitonin and interferon gene expression were evaluated in murine and cellular models of influenza infection.

RESULTS

Patients with bacterial coinfection had higher procalcitonin than those with pure viral infection, but also more severe disease and higher mortality (p<0.001). After matching for severity, the specificity of procalcitonin for bacterial coinfection dropped substantially, from 72% to 61%. In fact, receiver operating characteristic curve analysis showed that procalcitonin was a better indicator of multiple indices of severity (eg, organ failures and mortality) than of coinfection. Accordingly, patients with severe viral infection had elevated procalcitonin. In murine and cellular models of influenza infection, procalcitonin was also elevated despite bacteriologic sterility and correlated with markers of severity. Interferon signalling did not abrogate procalcitonin synthesis.

DISCUSSION

These studies reveal that procalcitonin rises during pure viral infection in proportion to disease severity and is not suppressed by interferon signalling, in contrast to prior models of procalcitonin regulation. Applied clinically, our data suggest that procalcitonin represents a better indicator of disease severity than bacterial coinfection during viral respiratory infection.

Respiratory Testing and Hospital Outcomes in Asymptomatic Infants Undergoing Heart Surgery

Respiratory viral infections in infants undergoing congenital heart surgery lead to prolonged intubation time, hospital (HLOS) and cardiac intensive care unit length of stay (CICU LOS). The objective of this study was to evaluate the prevalence of respiratory viruses using molecular testing in otherwise healthy infants presenting for low complexity heart surgery, and to evaluate the impact of a positive viral screen and study questionnaire on post-surgical HLOS, CICU LOS, intubation time, respiratory complications, and oxygen therapy at home discharge. Sixty-nine infants (1 month to 1 year) undergoing cardiac surgery from November to May of the years 2012 to 2014 were prospectively enrolled, surveyed and tested. We compared the outcomes of positive molecular testing and positive study questionnaire to test negative subjects. We also evaluated the predictive value of study questionnaire in identification of viruses by molecular testing. Of the 69 enrolled infants, 58 had complete information available for analysis. 17 (30%) infants tested positive by molecular testing for respiratory pathogens. 38 (65%) had a "positive" questionnaire. Among the 20 viruses detected, Human Rhinovirus was the most common 12 (60%). Seven (12%) of the 58 patients developed respiratory symptoms following surgery prompting molecular testing. Four of these tested positive for a respiratory virus post-surgically. Neither positive molecular testing nor a positive questionnaire prior to surgery was associated with greater post-operative HLOS, CICU LOS, intubation time, respiratory complications, or use of oxygen at discharge compared to negative testing. The questionnaire poorly predicted positive molecular testing. Routine screening for respiratory viruses in asymptomatic infants may not be an effective strategy to predict infants at risk of post-operative complications.

Introducing the new BTS Guideline: Management of non-tuberculous mycobacterial pulmonary disease (NTM-PD)

The new BTS Guidelines for the management of non-tuberculous mycobacterial pulmonary disease combine the best available evidence with expert consensus to generate a set of pragmatic Guidelines, published as a supplement to this issue of Thorax, to assist in the management of these challenging infections.

Late mortality after acute hypoxic respiratory failure

BACKGROUND

Acute hypoxic respiratory failure (AHRF) is associated with significant acute mortality. It is unclear whether later mortality is predominantly driven by pre-existing comorbid disease, the acute inciting event or is the result of AHRF itself.

METHODS

Observational cohort study of elderly US Health and Retirement Study (HRS) participants in fee-for-service Medicare (1998-2012). Patients hospitalised with AHRF were matched 1:1 to otherwise similar adults who were not currently hospitalised and separately to patients hospitalised with acute inciting events (pneumonia, non-pulmonary infection, aspiration, trauma, pancreatitis) that may result in AHRF, here termed at-risk hospitalisations. The primary outcome was late mortality-death in the 31 days to 2 years following hospital admission.

RESULTS

Among 15 075 HRS participants, we identified 1268 AHRF and 13 117 at-risk hospitalisations. AHRF hospitalisations were matched to 1157 non-hospitalised adults and 1017 at-risk hospitalisations. Among patients who survived at least 30 days, AHRF was associated with a 24.4% (95%CI 19.9% to 28.9%, p<0.001) absolute increase in late mortality relative to adults not currently hospitalised and a 6.7% (95%CI 1.7% to 11.7%, p=0.01) increase relative to adults hospitalised with acute inciting event(s) alone. At-risk hospitalisation explained 71.2% of the increased odds of late mortality, whereas the development of AHRF itself explained 28.8%. Risk for death was equivalent to at-risk hospitalisation beyond 90 days, but remained elevated for more than 1 year compared with non-hospitalised controls.

CONCLUSIONS

In this national sample of older Americans, approximately one in four survivors with AHRF had a late death not explained by pre-AHRF health status. More than 70% of this increased risk was associated with hospitalisation for acute inciting events, while 30% was associated with hypoxemic respiratory failure.

Differential lower airway dendritic cell patterns may reveal distinct endotypes of RSV bronchiolitis

RATIONALE

The pathogenesis of respiratory syncytial virus (RSV) bronchiolitis in infants remains poorly understood. Mouse models implicate pulmonary T cells in the development of RSV disease. T cell responses are initiated by dendritic cells (DCs), which accumulate in lungs of RSV-infected mice. In infants with RSV bronchiolitis, previous reports have shown that DCs are mobilised to the nasal mucosa, but data on lower airway DC responses are lacking.

OBJECTIVE

To determine the presence and phenotype of DCs and associated immune cells in bronchoalveolar lavage (BAL) and peripheral blood samples from infants with RSV bronchiolitis.

METHODS

Infants intubated and ventilated due to severe RSV bronchiolitis or for planned surgery (controls with healthy lungs) underwent non-bronchoscopic BAL. Immune cells in BAL and blood samples were characterised by flow cytometry and cytokines measured by Human V-Plex Pro-inflammatory Panel 1 MSD kit.

MEASUREMENTS AND MAIN RESULTS

In RSV cases, BAL conventional DCs (cDCs), NK T cells, NK cells and pro-inflammatory cytokines accumulated, plasmacytoid DCs (pDCs) and T cells were present, and blood cDCs increased activation marker expression. When stratifying RSV cases by risk group, preterm and older (≥4 months) infants had fewer BAL pDCs than term born and younger (<4 months) infants, respectively.

CONCLUSIONS

cDCs accumulate in the lower airways during RSV bronchiolitis, are activated systemically and may, through activation of T cells, NK T cells and NK cells, contribute to RSV-induced inflammation and disease. In addition, the small population of airway pDCs in preterm and older infants may reveal a distinct endotype of RSV bronchiolitis with weak antiviral pDC responses.