Gut microbiome signature and nasal lavage inflammatory markers in young people with asthma.

Background: Asthma is a complex disease and a severe global public health problem resulting from interactions between genetic background and environmental exposures. It has been suggested that gut microbiota may be related to asthma development; however, such relationships needs further investigation. Objective: This study aimed to characterize the gut microbiota as well as the nasal lavage cytokine profile of asthmatic and nonasthmatic individuals. Methods: Stool and nasal lavage samples were collected from 29 children and adolescents with type 2 asthma and 28 children without asthma in Brazil. Amplicon sequencing of the stool bacterial V4 region of the 16S rRNA gene was performed using Illumina MiSeq. Microbiota analysis was performed by QIIME 2 and PICRUSt2. Type 2 asthma phenotype was characterized by high sputum eosinophil counts and positive skin prick tests for house dust mite, cockroach, and/or cat or dog dander. The nasal immune marker profile was assessed using a customized multiplex panel. Results: Stool microbiota differed significantly between asthmatic and nonasthmatic participants (P = .001). Bacteroides was more abundant in participants with asthma (P < .05), while Prevotella was more abundant in nonasthmatic individuals (P < .05). In people with asthma, the relative abundance of Bacteroides correlated with IL-4 concentration in nasal lavage samples. Inference of microbiota functional capacity identified differential fatty acid biosynthesis in asthmatic compared to nonasthmatic subjects. Conclusion: The stool microbiota differed between asthmatic and nonasthmatic young people in Brazil. Asthma was associated with higher Bacteroides levels, which correlated with nasal IL-4 concentration.

Defining cases of asthma, eczema and allergic rhinitis using electronic health records in the Born in Bradford birth cohort.

Key Messages • In electronic health records, the accuracy of diagnostic codes to define outcomes can be uncertain • The accuracy can vary in different settings, doctors and practices, even with validated codes • We recommend definitions combining codes previously described and other codes available in the records.

Spontaneous Clearance of Vertically Acquired Hepatitis C Infection: Implications for Testing and Treatment.

BACKGROUND: Current guidelines recommend that infants born to women with hepatitis C virus (HCV) viremia be screened for HCV antibody at age 18 months and, if positive, referred for RNA testing at 3 years to confirm chronic infection. This policy is based, in part, on analyses that suggest that 25%-40% of vertically acquired HCV infections clear spontaneously within 4-5 years. METHODS: Data on 179 infants with HCV RNA and/or anti-HCV evidence of vertically acquired infection in 3 prospective European cohorts were investigated. Ages at clearance of infection were estimated taking account of interval censoring and delayed entry. We also investigated clearance in initially HCV RNA-negative infants in whom RNA was not detectable until after 6 weeks. RESULTS: Clearance rates were initially high then declined slowly. Apparently, many infections clear before they can be confirmed. An estimated 65.9% (95% credible interval [CrI], 50.1-81.6) of confirmed infections cleared by 5 years, at a median 12.4 (CrI, 7.1-18.9) months. If treatment were to begin at age 6 months, 18 months, or 3 years, at least 59.0% (CrI, 42.0-76.9), 39.7% (CrI, 17.9-65.9), and 20.9% (CrI, 4.6-44.8) of those treated would clear without treatment. In 7 (6.6%) confirmed infections, RNA was not detectable until after 6 weeks and not until after 6 months in 2 (1.9%). However, all such cases subsequently cleared. CONCLUSIONS: Most confirmed infection cleared by age 3 years. Treatment before age 3, if it was available, would avoid loss to follow-up but would result in substantial overtreatment.

An Ecological Study of COVID-19 Infection Rates within the UK Food and Drink Processing Industry.

OBJECTIVES: Food processing facilities represent critical infrastructure that have stayed open during much of the COVID-19 pandemic. Understanding the burden of COVID-19 in this sector is thus important to help reduce the potential for workplace infection in future outbreaks. METHODS: We undertook a workplace survey in the UK food and drink processing sector and collected information on workplace size, characteristics (e.g. temperature, ventilation), and experience with COVID-19 (e.g. numbers of positive cases). For each site, we calculated COVID-19 case rates per month per 1000 workers. We performed an ecological analysis using negative binomial regression to assess the association between COVID-19 rates and workplace and local risk factors. RESULTS: Respondents from 33 companies including 66 individual sites completed the survey. COVID-19 cases were reported from the start of the pandemic up to June 2021. Respondents represented a range of industry subgroups, including grain milling/storage (n = 16), manufacture of malt (n = 14), manufacture of prepared meals (n = 12), manufacture of beverages (n = 8), distilling (n = 5), manufacture of baked goods (n = 5), and other (n = 6), with a total of 15 563 workers across all sites. Average monthly case rates per 1000 workers ranged from 0.9 in distilling to 6.1 in grain milling/storage. Incidence rate ratios were partially attenuated after adjusting for several local and workplace factors, though risks for one subgroup (grain milling/storage) remained elevated. Certain local and workplace characteristics were related to higher infection rates, such as higher deprivation (5 km only), a lower proportion of remote workers, lower proportion of workers in close proximity, and higher numbers of workers overall. CONCLUSIONS: Our analysis suggests some heterogeneity in the rates of COVID-19 across sectors of the UK food and drink processing industry. Infection rates were associated with deprivation, the proportions of remote workers and workers in close proximity, and the number of workers.

Overall Vertical Transmission of Hepatitis C Virus, Transmission Net of Clearance, and Timing of Transmission.

BACKGROUND: It is widely accepted that the risk of hepatitis C virus (HCV) vertical transmission (VT) is 5%-6% in monoinfected women, and that 25%-40% of HCV infection clears spontaneously within 5 years. However, there is no consensus on how VT rates should be estimated, and there is a lack of information on VT rates "net" of clearance. METHODS: We reanalyzed data on 1749 children in 3 prospective cohorts to obtain coherent estimates of overall VT rate and VT rates net of clearance at different ages. Clearance rates were used to impute the proportion of uninfected children who had been infected and then cleared before testing negative. The proportion of transmission early in utero, late in utero, and at delivery was estimated from data on the proportion of HCV RNA positive within 3 days of birth, and differences between elective cesarean and nonelective cesarean deliveries. RESULTS: Overall VT rates were 7.2% (95% credible interval [CrI], 5.6%-8.9%) in mothers who were human immunodeficiency virus (HIV) negative and 12.1% (95% CrI, 8.6%-16.8%) in HIV-coinfected women. The corresponding rates net of clearance at 5 years were 2.4% (95% CrI, 1.1%-4.1%), and 4.1% (95% CrI, 1.7%-7.3%). We estimated that 24.8% (95% CrI, 12.1%-40.8%) of infections occur early in utero, 66.0% (95% CrI, 42.5%-83.3%) later in utero, and 9.3% (95% CrI, 0.5%-30.6%) during delivery. CONCLUSIONS: Overall VT rates are about 24% higher than previously assumed, but the risk of infection persisting beyond age 5 years is about 38% lower. The results can inform design of trials of interventions to prevent or treat pediatric HCV infection, and strategies to manage children exposed in utero.

Asthma inflammatory phenotypes on four continents: most asthma is non-eosinophilic.

BACKGROUND: Most studies assessing pathophysiological heterogeneity in asthma have been conducted in high-income countries (HICs), with little known about the prevalence and characteristics of different asthma inflammatory phenotypes in low-and middle-income countries (LMICs). This study assessed sputum inflammatory phenotypes in five centres, in Brazil, Ecuador, Uganda, New Zealand (NZ) and the United Kingdom (UK). METHODS: We conducted a cross-sectional study of 998 asthmatics and 356 non-asthmatics in 2016-20. All centres studied children and adolescents (age range 8-20 years), except the UK centre which involved 26-27 year-olds. Information was collected using questionnaires, clinical characterization, blood and induced sputum. RESULTS: Of 623 asthmatics with sputum results, 39% (243) were classified as eosinophilic or mixed granulocytic, i.e. eosinophilic asthma (EA). Adjusted for age and sex, with NZ as baseline, the UK showed similar odds of EA (odds ratio 1.04, 95% confidence interval 0.37-2.94) with lower odds in the LMICs: Brazil (0.73, 0.42-1.27), Ecuador (0.40, 0.24-0.66) and Uganda (0.62, 0.37-1.04). Despite the low prevalence of neutrophilic asthma in most centres, sputum neutrophilia was increased in asthmatics and non-asthmatics in Uganda. CONCLUSIONS: This is the first time that sputum induction has been used to compare asthma inflammatory phenotypes in HICs and LMICs. Most cases were non-eosinophilic, including in settings where corticosteroid use was low. A lower prevalence of EA was observed in the LMICs than in the HICs. This has major implications for asthma prevention and management, and suggests that novel prevention strategies and therapies specifically targeting non-eosinophilic asthma are required globally.

Availability and use of rapid diagnostic tests for the management of acute childhood infections in Europe: A cross-sectional survey of paediatricians.

BACKGROUND: Point-of-care-tests (POCTs) have been advocated to optimise care in patients with infections but their actual use varies. This study aimed to estimate the variability in the adoption of current POCTs by paediatricians across Europe, and to explore the determinants of variability. METHODS AND FINDINGS: A cross-sectional survey was conducted of hospital and primary care paediatricians, recruited through professional networks. Questions focused on the availability and use of currently available POCTs. Data were analysed descriptively and using Median Odds Ratio (MOR) to measure variation between countries. Multilevel regression modelling using changes in the area under the receiver operating characteristic curve of models were used to assess the contribution of individual or workplace versus country level factors, to the observed variation. The commonest POCT was urine dipsticks (UD) which were available to >80% of primary care and hospital paediatricians in 68% (13/19) and 79% (23/29) countries, respectively. Availability of all POCTs varied between countries. In primary care, the country (MOR) varied from 1.61 (95%CI: 1.04-2.58) for lactate to 7.28 (95%CI: 3.04-24.35) for UD. In hospitals, the country MOR varied from 1.37 (95%CI:1.04-1.80) for lactate to 11.93 (95%CI:3.35-72.23) for UD. Most paediatricians in primary care (69%, 795/1154) and hospital (81%, 962/1188) would use a diagnostic test in the case scenario of an infant with undifferentiated fever. Multilevel regression modelling showed that the country of work was more important in predicting both the availability and use of POCTs than individual or workplace characteristics. CONCLUSION: There is substantial variability in the adoption of POCTs for the management of acute infections in children across Europe. To inform future implementation of both existing and innovative tests, further research is needed to understand what drives the variation between countries, the needs of frontline clinicians, and the role of diagnostic tests in the management of acute childhood infections.

Transmission and Control of SARS-CoV-2 in the Food Production Sector: A Rapid Narrative Review of the Literature.

This review aimed to provide an overview of the literature assessing the extent of COVID-19 transmission in the food processing sector along with the risk factors associated with COVID-19 infection/mortality rates in this setting, and the preventive measures used to reduce transmission. An electronic search was conducted using scientific databases, including Web of Science, OVID, PubMed and MedRxiv. The search strategy identified 26 papers that met the inclusion criteria. Six of these studies were based in the UK and the country with the most papers was the USA, with a total of nine papers. Findings showed some evidence of a high transmission level of SARS-CoV-2 within some areas of the food production sector. Risk factors associated with the spread included ethnicity, poor ventilation, lack of social distancing and lack of sick pay. The preventative measures included/recommended were social distancing, testing, adequate ventilation, cleaning regimes and access to PPE. Additional research focusing on the food production sector could show the potential variations in transmission and risk between each sub-sector. Future research focusing on the application of various preventative measures and their efficacy by sub-sector would be beneficial, while further qualitative research could help provide in-depth information regarding knowledge gaps.

Factors predicting amoxicillin prescribing in primary care among children: a cohort study.

BACKGROUND: Antibiotic prescribing during childhood, most commonly for respiratory tract infections (RTIs), contributes to antimicrobial resistance, which is a major public health concern. AIM: To identify factors associated with amoxicillin prescribing and RTI consultation attendance in young children in primary care. DESIGN AND SETTING: Cohort study in Bradford spanning pregnancy to age 24 months, collected 2007-2013, linked to electronic primary care and air pollution data. METHOD: Amoxicillin prescribing and RTI consultation rates/1000 child-years were calculated. Mixed-effects logistic regression models were fitted with general practice (GP) surgery as the random effect. RESULTS: The amoxicillin prescribing rate among 2493 children was 710/1000 child-years during year 1 (95% confidence interval [CI] = 677 to 744) and 780/1000 (95% CI = 745 to 816) during year 2. During year 1, odds of amoxicillin prescribing were higher for boys (adjusted odds ratio [aOR] 1.36, 95% CI = 1.14 to 1.61), infants from socioeconomically deprived households (aOR 1.36, 95% CI = 1.00 to 1.86), and infants with a Pakistani ethnic background (with mothers born in the UK [aOR 1.44, 95% CI = 1.06 to 1.94] and outside [aOR 1.42, 95% CI = 1.07 to 1.90]). During year 2, odds of amoxicillin prescribing were higher for infants with a Pakistani ethnic background (with mothers born in the UK [aOR 1.46, 95% CI = 1.10 to 1.94] and outside [aOR 1.56, 95% CI = 1.19 to 2.04]) and those born <39 weeks gestation (aOR 1.20, 95% CI = 1.00 to 1.45). Additional risk factors included caesarean delivery, congenital anomalies, overcrowding, birth season, and childcare attendance, with GP surgery explaining 7%-9% of variation. CONCLUSION: Socioeconomic status and ethnic background were associated with amoxicillin prescribing during childhood. Efforts to reduce RTI spread in household and childcare settings may reduce antibiotic prescribing in primary care.

Excess mortality among essential workers in England and Wales during the COVID-19 pandemic.

BACKGROUND: Exposure to SARS-CoV-2, subsequent development of COVID-19 and death from COVID-19 may vary by occupation, and the risks may be higher for those categorised as 'essential workers'. METHODS: We estimated excess mortality by occupational group and sex separately for each month in 2020 and for the entire 12 months overall. RESULTS: Mortality for all adults of working age was similar to the annual average over the previous 5 years. Monthly excess mortality peaked in April, when the number of deaths was 54.2% higher than expected and was lowest in December when deaths were 30.0% lower than expected.Essential workers had consistently higher excess mortality than other groups throughout 2020. There were also large differences in excess mortality between the categories of essential workers, with healthcare workers having the highest excess mortality and social care and education workers having the lowest. Excess mortality also varied widely between men and women, even within the same occupational group. Generally, excess mortality was higher in men. CONCLUSIONS: In summary, excess mortality was consistently higher for essential workers throughout 2020, particularly for healthcare workers. Further research is needed to examine excess mortality by occupational group, while controlling for important confounders such as ethnicity and socioeconomic status. For non-essential workers, the lockdowns, encouragement to work from home and to maintain social distancing are likely to have prevented a number of deaths from COVID-19 and from other causes.

Occupation and COVID-19 mortality in England: a national linked data study of 14.3 million adults.

OBJECTIVES: To estimate occupational differences in COVID-19 mortality and test whether these are confounded by factors such as regional differences, ethnicity and education or due to non-workplace factors, such as deprivation or prepandemic health. METHODS: Using a cohort study of over 14 million people aged 40-64 years living in England, we analysed occupational differences in death involving COVID-19, assessed between 24 January 2020 and 28 December 2020.We estimated age-standardised mortality rates (ASMRs) per 100 000 person-years at risk stratified by sex and occupation. We estimated the effect of occupation on COVID-19 mortality using Cox proportional hazard models adjusted for confounding factors. We further adjusted for non-workplace factors and interpreted the residual effects of occupation as being due to workplace exposures to SARS-CoV-2. RESULTS: In men, the ASMRs were highest among those working as taxi and cab drivers or chauffeurs at 119.7 deaths per 100 000 (95% CI 98.0 to 141.4), followed by other elementary occupations at 106.5 (84.5 to 132.4) and care workers and home carers at 99.2 (74.5 to 129.4). Adjusting for confounding factors strongly attenuated the HRs for many occupations, but many remained at elevated risk. Adjusting for living conditions reduced further the HRs, and many occupations were no longer at excess risk. For most occupations, confounding factors and mediators other than workplace exposure to SARS-CoV-2 explained 70%-80% of the excess age-adjusted occupational differences. CONCLUSIONS: Working conditions play a role in COVID-19 mortality, particularly in occupations involving contact with patients or the public. However, there is also a substantial contribution from non-workplace factors.

Evidence for causal associations between prenatal and postnatal antibiotic exposure and asthma in children, England.

BACKGROUND: Higher risks of asthma have been observed in children with prenatal exposure to antibiotics and during early life compared with those who have not. However, the causality of such associations is unclear. OBJECTIVE: To assess whether exposure to antibiotics in early life had a causal effect in increasing the risk of asthma in children diagnosed at 5-8 years of life, and the impact in the target population. METHODS: Data were from electronic health records and questionnaires for children and their mothers in the Born in Bradford birth cohort. Exposure variables were prescriptions of systemic antibiotics to the mother during pregnancy (prenatal) and to the children at 0-24 months of life (postnatal). We assessed the association in 12,476 children with several approaches to deal with different sources of bias (triangulation): the interactions with mother's ethnicity, mode of delivery, and between prenatal and postnatal exposures; dose-response; and estimated the population attributable risk. RESULTS: There was an association between prenatal exposure at 7-27 days before the child's birth and asthma (adjusted OR = 1.40; 1.05, 1.87), but no association with the negative control exposure (before pregnancy) (adjusted OR = 0.99 (0.88, 1.12)). For postnatal exposure, the adjusted OR was 2.00 (1.71, 2.34), and for sibling analysis, it was 1.99 (1.00, 3.93). For postnatal exposure, the risk of asthma increased with the number of prescriptions. The observed effect of both exposures was lower among children with mothers of Pakistani ethnicity, but inconclusive (p > .25). The interaction between prenatal and postnatal exposures was also inconclusive (p = .287). The population attributable risk of postnatal exposure for asthma was 4.6% (0.1% for prenatal). CONCLUSIONS: We conclude that the associations between both late-pregnancy prenatal exposure to antibiotics and postnatal exposure to antibiotics and an increased risk of asthma are plausible and consistent with a causal effect.

Association between mode of delivery and body mass index at 4-5 years in White British and Pakistani children: the Born in Bradford birth cohort.

BACKGROUND: Globally, it is becoming more common for pregnant women to deliver by caesarean section (CS). In 2020, 31% of births in England were CS, surpassing the recommended prevalence of CS. Concerns have been raised regarding potential unknown consequences of this mode of delivery. Childhood adiposity is also an increasing concern. Previous research provides inconsistent conclusions on the association between CS and childhood adiposity. More studies are needed to investigate the consequences of CS in different populations and ethnicities. Therefore, this study investigates the association between mode of delivery and BMI, in children of 4-5 years and if this differs between White British (WB) and Pakistani ethnicities, in Bradford UK. METHODS: Data were obtained from the Born in Bradford (BiB) cohort, which recruited pregnant women at the Bradford Royal Infirmary, between 2007 and 2010. For these analyses, a sub-sample (n = 6410) of the BiB cohort (n = 13,858) was used. Linear regression models determined the association between mode of delivery (vaginal or CS) and BMI z-scores at 4-5 years. Children were categorised as underweight/healthy weight, overweight and obese, and logistic regression models determined the odds of adiposity. Effect modification by ethnicity was also explored. RESULTS: Multivariable analysis found no evidence for a difference in BMI z-score between children of CS and vaginal delivery (0.005 kg/m2, 95% CI = - 0.062-0.072, p = 0.88). Neither was there evidence of CS affecting the odds of being overweight (OR = 1.05, 95% CI = 0.86-1.28, p = 0.65), or obese (OR = 0.98, 95% CI = 0.74-1.29, p = 0.87). There was no evidence that ethnicity was an effect modifier of these associations (p = 0.97). CONCLUSION: Having CS, compared to a vaginal delivery, was not associated with greater adiposity in children of 4-5 years in this population. Concerns over CS increasing adiposity in children are not supported by the findings reported here using the BiB study population, of both WB and Pakistani families.

Respiratory syncytial virus in young children: community cohort study integrating serological surveys, questionnaire and electronic health records, Born in Bradford cohort, England, 2008 to 2013.

BackgroundBronchiolitis caused by respiratory syncytial virus (RSV) is a major cause of mortality and morbidity in infants.AimTo describe RSV epidemiology in children in the community in a high-income setting.MethodsWe used stored blood samples from the United Kingdom Born in Bradford cohort study that had been collected at birth, age 1 and 2 years old, tested for IgG RSV postfusion F antibody and linked to questionnaires and primary and hospital care records. We used finite mixture models to classify children as RSV infected/not infected according to their antibody concentrations at age 1 and 2 years. We assessed risk factors for primary RSV infection at each age using Poisson regression models.ResultsThe study cohort included 700 children with cord blood samples; 490 had additional blood samples taken at both ages 1 and 2 years old. Of these 490 children, 258 (53%; 95% confidence interval (CI): 48-57%) were first infected with RSV at age 1, 99 of whom (38%; 95% CI: 33-43%) had been in contact with healthcare during peak RSV season (November-January). Having older siblings, birth in October-June and attending formal childcare were associated with risk of RSV infection in infancy. By age 2, a further 164 of 490 children (33%; 95% CI: 29-38%) had been infected.ConclusionOver half of children experienced RSV infection in infancy, a further one third had evidence of primary RSV infection by age 2, and one in seven remained seronegative by their second birthday. These findings will inform future analyses to assess the cost-effectiveness of RSV vaccination programmes in high-income settings.

Occupational differences in COVID-19 incidence, severity, and mortality in the United Kingdom: Available data and framework for analyses.

There are important differences in the risk of SARS-CoV-2 infection and death depending on occupation. Infections in healthcare workers have received the most attention, and there are clearly increased risks for intensive care unit workers who are caring for COVID-19 patients. However, a number of other occupations may also be at an increased risk, particularly those which involve social care or contact with the public. A large number of data sets are available with the potential to assess occupational risks of COVID-19 incidence, severity, or mortality. We are reviewing these data sets as part of the Partnership for Research in Occupational, Transport, Environmental COVID Transmission (PROTECT) initiative, which is part of the National COVID-19 Core Studies. In this report, we review the data sets available (including the key variables on occupation and potential confounders) for examining occupational differences in SARS-CoV-2 infection and COVID-19 incidence, severity and mortality. We also discuss the possible types of analyses of these data sets and the definitions of (occupational) exposure and outcomes. We conclude that none of these data sets are ideal, and all have various strengths and weaknesses. For example, mortality data suffer from problems of coding of COVID-19 deaths, and the deaths (in England and Wales) that have been referred to the coroner are unavailable. On the other hand, testing data is heavily biased in some periods (particularly the first wave) because some occupations (e.g. healthcare workers) were tested more often than the general population. Random population surveys are, in principle, ideal for estimating population prevalence and incidence, but are also affected by non-response. Thus, any analysis of the risks in a particular occupation or sector (e.g. transport), will require a careful analysis and triangulation of findings across the various available data sets.

Metabolomics datasets in the Born in Bradford cohort.

Metabolomics is the quantification of small molecules, commonly known as metabolites. Collectively, these metabolites and their interactions within a biological system are known as the metabolome. The metabolome is a unique area of study, capturing influences from both genotype and environment. The availability of high-throughput technologies for quantifying large numbers of metabolites, as well as lipids and lipoprotein particles, has enabled detailed investigation of human metabolism in large-scale epidemiological studies. The Born in Bradford (BiB) cohort includes 12,453 women who experienced 13,776 pregnancies recruited between 2007-2011, their partners and their offspring. In this data note, we describe the metabolomic data available in BiB, profiled during pregnancy, in cord blood and during early life in the offspring. These include two platforms of metabolomic profiling: nuclear magnetic resonance and mass spectrometry. The maternal measures, taken at 26-28 weeks' gestation, can provide insight into the metabolome during pregnancy and how it relates to maternal and offspring health. The offspring cord blood measurements provide information on the fetal metabolome. These measures, alongside maternal pregnancy measures, can be used to explore how they may influence outcomes. The infant measures (taken around ages 12 and 24 months) provide a snapshot of the early life metabolome during a key phase of nutrition, environmental exposures, growth, and development. These metabolomic data can be examined alongside the BiB cohorts' extensive phenotype data from questionnaires, medical, educational and social record linkage, and other 'omics data.

Age at cytomegalovirus, Epstein Barr virus and varicella zoster virus infection and risk of atopy: The Born in Bradford cohort, UK.

BACKGROUND: The prevalence of allergic diseases has increased in recent decades, but the causes remain unclear. Changes in the epidemiology of childhood infections could have contributed, but the current evidence is inconclusive. This study aims to investigate whether age at cytomegalovirus (CMV), Epstein-Barr virus (EBV) or varicella zoster virus (VZV) infection is associated with the development of atopy. METHODS: A total of 2559 children were enrolled in the Born in Bradford Allergy and Infection Study. Serum samples collected at 12 and 24 months were tested for CMV-IgG, EBV-IgG and VZV-IgG for 1000 children to establish age at infection. Skin prick testing (SPT) was conducted at age 4 years. RESULTS: Serology and SPT results were available for 740 children. Of these, 135 (18%) were atopic. In girls, there was a strong association of CMV infection in the second year with increased odds of atopy (adjusted OR 4.38, 95% CI 1.87-10.29) but this was not observed in boys. Age at EBV or VZV infection was not associated with risk of atopy in unadjusted analysis, but there was effect modification by sex; girls infected with VZV in the second year of life had increased odds of atopy (adjusted OR 2.85, 95% CI 1.29-6.30). CONCLUSIONS: Our results highlight potential sex-specific effects of age at CMV infection and age at VZV infection on risk of atopy, which provide insight into the mechanisms involved in the development of atopy.

Understanding asthma phenotypes: the World Asthma Phenotypes (WASP) international collaboration.

The World Asthma Phenotypes (WASP) study started in 2016 and has been conducted in five centres, in the UK, New Zealand, Brazil, Ecuador and Uganda. The objectives of this study are to combine detailed biomarker and clinical information in order to 1) better understand and characterise asthma phenotypes in high-income countries (HICs) and low and middle-income countries (LMICs), and in high and low prevalence centres; 2) compare phenotype characteristics, including clinical severity; 3) assess the risk factors for each phenotype; and 4) assess how the distribution of phenotypes differs between high prevalence and low prevalence centres. Here we present the rationale and protocol for the WASP study to enable other centres around the world to carry out similar analyses using a standardised protocol. Large collaborative and integrative studies like this are essential to further our understanding of asthma phenotypes. The findings of this study will help elucidate the aetiological mechanisms of asthma and might potentially identify new causes and guide the development of new treatments, thereby enabling better management and prevention of asthma in both HICs and LMICs.

Cytomegalovirus, Epstein-Barr virus and varicella zoster virus infection in the first two years of life: a cohort study in Bradford, UK.

BACKGROUND: Cytomegalovirus (CMV), Epstein Barr virus (EBV) and varicella-zoster virus (VZV) are common herpesviruses frequently acquired in childhood, which establish persistent, latent infection and are likely to impact the developing immune system. Little is known about the epidemiology of CMV and EBV infections in contemporary UK paediatric populations, particularly whether age at infection differs by ethnic group. METHODS: Children enrolled in the Born in Bradford Allergy and Infection Study had a blood sample taken and a questionnaire completed at 12 and 24 months of age. Ordered logistic regression quantified associations between ethnicity and other risk factors and age at CMV/EBV/VZV infection (<12 months, 12-24 months, uninfected at 24 months). RESULTS: Pakistani children (n = 472) were more likely to be infected with CMV and EBV at a younger age than White British children (n = 391) (CMV: adjusted odds ratio (OR) 2.53, 95% confidence interval (CI) 1.47-4.33; EBV: adjusted OR 2.16, 95% CI 1.43-3.26). Conversely, Pakistani children had lower odds of being VZV infected in the second year than White British children (adjusted OR 0.57, 95% CI 0.33-0.97). There was a strong association between increasing birth order and later CMV infection in Pakistani children. CONCLUSIONS: We report large differences in CMV and EBV incidence in the first 2 years between Pakistani and White British children born in Bradford, which cannot be explained by differences in risk factors for infection. Our data will inform the optimum schedule for future CMV and EBV vaccination programmes.