Can We Use Lung Function Thresholds and Respiratory Symptoms to Identify Pre-Chronic Obstructive Pulmonary Disease? A Prospective, Population-based Cohort Study.

Rationale: The term "pre-chronic obstructive pulmonary disease" ("pre-COPD") refers to individuals at high risk of developing COPD who do not meet conventional spirometric criteria for airflow obstruction. New approaches to identifying these individuals are needed, particularly in younger populations. Objectives: To determine whether lung function thresholds and respiratory symptoms can be used to identify individuals at risk of developing COPD. Methods: The Tasmanian Longitudinal Health Study comprises a population-based cohort first studied in 1968 (at age 7 yr). Respiratory symptoms, pre- and post-bronchodilator (BD) spirometry, diffusing capacity, and static lung volumes were measured in a subgroup at age 45, and the incidence of COPD was assessed at age 53. For each lung function measure, z-scores were calculated using Global Lung Function Initiative references. The optimal threshold for best discrimination of COPD incidence was determined by the unweighted Youden index. Measurements and Main Results: Among 801 participants who did not have COPD at age 45, the optimal threshold for COPD incidence by age 53 was pre-BD FEV1/FVC z-score less than -1.264, corresponding to the lowest 10th percentile. Those below this threshold had a 36-fold increased risk of developing COPD over an 8-year follow-up period (risk ratio, 35.8; 95% confidence interval, 8.88 to 144), corresponding to a risk difference of 16.4% (95% confidence interval, 3.7 to 67.4). The sensitivity was 88%, and the specificity was 87%. Positive and negative likelihood ratios were 6.79 and 0.14, respectively. Respiratory symptoms, post-BD spirometry, diffusing capacity, and static lung volumes did not improve on the classification achieved by pre-BD FEV1/FVC alone. Conclusions: This is the first study, to our knowledge, to evaluate the discriminatory accuracy of spirometry, diffusing capacity, and static lung volume thresholds for COPD incidence in middle-aged adults. Our findings support the inclusion of pre-BD spirometry in the physiological definition of pre-COPD and indicate that pre-BD FEV1/FVC at the 10th percentile accurately identifies individuals at high risk of developing COPD in community-based settings.

Thunderstorm asthma in seasonal allergic rhinitis: The TAISAR study.

BACKGROUND: Asthma epidemics associated with thunderstorms have had catastrophic effects on individuals and emergency services. Seasonal allergic rhinitis (SAR) is present in the vast majority of people who develop thunderstorm asthma (TA), but there is little evidence regarding risk factors for TA among the SAR population. OBJECTIVE: We sought to identify risk factors for a history of TA and hospital presentation in a cohort of individuals with SAR. METHODS: This multicenter study recruited adults from Melbourne, Australia, with a past diagnosis of TA and/or self-reported SAR. Clinical information, spirometry results, white blood cell count, ryegrass pollen-specific (RGP-sp) IgE concentration, and fractional exhaled nitric oxide were measured to identify risk factors for a history of TA in individuals with SAR. RESULTS: From a total of 228 individuals with SAR, 35% (80 of 228) reported SAR only (the I-SAR group), 37% (84 of 228) reported TA symptoms but had not attended hospital for treatment (the O-TA group), and 28% (64 of 228) had presented to the hospital for TA (the H-TA group). All patients in the H-TA group reported a previous asthma diagnosis. Logistic regression analysis of factors associated with O-TA and H-TA indicated that lower FEV1 value and an Asthma Control Questionnaire score higher than 1.5 were associated with H-TA. Higher blood RGP-sp IgE concentration, eosinophil counts, and fractional exhaled nitric oxide level were significantly associated with both O-TA and H-TA. Receiver operating curve analysis showed an RGP-sp IgE concentration higher than 10.1 kU/L and a prebronchodilator FEV1 value of 90% or lower to be biomarkers of increased H-TA risk. CONCLUSION: Clinical tests can identify risk of a history of TA in individuals with SAR and thereby inform patient-specific treatment recommendations.

Grass pollen exposure is associated with higher readmission rates for pediatric asthma.

BACKGROUND: Pediatric asthma hospital readmission is a burden on the individual and costly for Australian hospitals. Grass pollen's role, a known trigger for asthma admissions, is unexamined in readmissions. We examined the association between grass pollen and pediatric asthma readmission. METHODS: The Victorian Admitted Episodes Dataset was used to identify all primary admissions with a principal diagnosis of asthma in children aged 2-18 years between 1997 and 2009. Readmissions were defined as subsequent admissions within 28 days of index admission discharge. Generalized additive models were used to assess associations between readmission, grass pollen season, and daily grass pollen counts, lagged and cumulative. Models were further stratified by sex and age group. RESULTS: Mean daily readmission was higher during grass pollen season than other times of the year, incidence rate ratio (IRR) 1.44 (95% CI, 1.03, 2.02) and for children aged 2-5 years, IRR 1.99 (1.26, 3.14). Same day grass pollen was nonlinearly associated with daily readmission for the 13-18 age group between 110 and 256 grains/m3 , p < .01. Lag 2 grass pollen was nonlinearly associated with daily readmissions overall (p = .03), boys (p = .01), and younger age groups 2-5 (p = .02) and 6-12 (p < .001). CONCLUSIONS: Grass pollen exposure was associated with higher readmission rates for pediatric asthma. Treatment plans prior to discharge could be implemented to reduce the likelihood of readmission by younger children during the pollen season.

The role of short-term grass pollen exposure in food skin-prick test reactivity, food allergy, and eczema flares in children.

BACKGROUND: While the relationship between pollen and respiratory allergies is well-documented, the role of short-term pollen exposure in food allergy and eczema flares has not previously been explored. We aimed to investigate these associations in a population-based sample of children. METHODS: We investigated 1- (n = 1108) and 6-year-old (n = 675) children in the grass pollen season from the HealthNuts cohort. Grass pollen concentrations were considered on the day of testing (lag 0), up to three days before (lag 1-lag 3) and cumulatively (lag 0-3). Associations between grass pollen and food skin-prick test reactivity (SPT ≥ 2 mm at age 1 year and ≥ 3 mm at age 6 years), eczema flares, challenge-confirmed food allergy, reaction threshold to oral food challenges (OFC), and serum food-specific IgE levels were analyzed using either logistic or quantile regression models. Atopy and family history of allergic disease were considered as potent effect modifiers. RESULTS: Grass pollen at lag 0-3 (every 20 grains/m3 increase) was associated with an up to 1.2-fold increased odds of food SPT reactivity and eczema flares in 6-year-olds. In 1-year-olds, the associations were only observed for peanut in those with a family history of food allergy. Increasing grass pollen concentrations were associated with a lower reaction threshold to OFC and higher serum IgE levels in peanut-allergic 1-year-olds only. CONCLUSION: Increasing grass pollen concentration was associated with increased risk of food SPT reactivity and eczema flares in children. The associations in peanut-allergic infants may be related to immune activation and/or peanut and grass pollen cross-reactivity leading to a lower reaction threshold.

The AusPollen partnership project: Allergenic airborne grass pollen seasonality and magnitude across temperate and subtropical eastern Australia, 2016-2020.

BACKGROUND: Allergic rhinitis affects half a billion people globally, including a fifth of the Australian population. As the foremost outdoor allergen source, ambient grass pollen exposure is likely to be altered by climate change. The AusPollen Partnership aimed to standardize pollen monitoring and examine broad-scale biogeographical and meteorological factors influencing interannual variation in seasonality of grass pollen aerobiology in Australia. METHODS: Daily airborne grass and other pollen concentrations in four eastern Australian cities separated by over 1700 km, were simultaneously monitored using Hirst-style samplers following the Australian Interim Pollen and Spore Monitoring Standard and Protocols over four seasons from 2016 to 2020. The grass seasonal pollen integral was determined. Gridded rainfall, temperature, and satellite-derived grassland sources up to 100 km from the monitoring site were analysed. RESULTS: The complexity of grass pollen seasons was related to latitude with multiple major summer-autumn peaks in Brisbane, major spring and minor summer peaks in Sydney and Canberra, and single major spring peaks occurring in Melbourne. The subtropical site of Brisbane showed a higher proportion of grass out of total pollen than more temperate sites. The magnitude of the grass seasonal pollen integral was correlated with pasture greenness, rainfall and number of days over 30 °C, preceding and within the season, up to 100 km radii from monitoring sites. CONCLUSIONS: Interannual fluctuations in Australian grass pollen season magnitude are strongly influenced by regional biogeography and both pre- and in-season weather. This first continental scale, Southern Hemisphere standardized aerobiology dataset forms the basis to track shifts in pollen seasonality, biodiversity and impacts on allergic respiratory diseases.

Women's attitude towards intimate partner violence and utilization of contraceptive methods and maternal health care services: an analysis of nationally representative cross-sectional surveys from four South Asian countries.

BACKGROUND: Intimate partner violence (IPV) adversely affects women's reproductive health outcomes but to what extent women's justification of IPV affects maternal health care service utilization is unexplored. METHODS: The secondary cross-sectional datasets from multiple indicator cluster surveys of Afghanistan, Bhutan, Nepal and Pakistan conducted between 2010 and 2015 were used. We used a generalized linear mixed model with random effects, at both cluster- and country-level, to determine the odds ratio of maternal health service utilization at the regional level and a multivariable logistic regression model adjusting for complex survey design at the country level. Interaction between women's justification of IPV and residential location, and linear trend in the utilization of maternal health care services associated with increasing levels of women's justification of IPV, were examined using the Likelihood Ratio Test (LRT). RESULTS: A total of 26,029 women aged 15-49 years, living with their partners and had a pregnancy outcome 2 years prior to the survey were included. Women justifying IPV were less likely to utilize contraceptive methods (aOR) = 0.86, 95% CI 0.84, 0.88), at-least one Antenatal Care (ANC) visit (aOR = 0.80, 95% CI 0.72, 0.88), four or more ANC services (aOR = 0.81, 95% CI 0.76, 0.86), institutional delivery (aOR = 0.87, 95% CI 0.80, 0.94) and Post-natal Care (aOR = 0.76, 95% CI 0.62, 0.95) services. A decreasing linear trend was observed for four or more ANC visits (LRT P = 0.96) and institutional delivery (LRT P = 0.80) with increasing levels of IPV justification. Women justifying IPV were less likely to have at least one ANC visit in urban (aOR 0.67, 95% CI 0.60, 0.75) compared to rural areas (aOR 0.83, 95% CI 0.73, 0.94). CONCLUSIONS: Women's justification of IPV was associated with decreased odds of utilizing a wide range of maternal health care services at the regional level. Although further research that may help establish a causal link is important before formulating public health interventions, our study indicates interventions targeting women's condoning attitude toward IPV, delivered sooner rather than later, could potentially help to improve women's utilization of essential maternal health care services in the South Asian region that comprises Afghanistan, Bhutan, Nepal, and Pakistan.

A single-case experimental evaluation of a new group-based intervention to enhance adjustment to life with acquired brain injury: VaLiANT (valued living after neurological trauma).

Adjustment to life with acquired brain injury (ABI) requires self-identity and behaviour to be updated, incorporating injury-related changes. Identifying and enabling new values-consistent behaviours could facilitate this process. We evaluated the feasibility, acceptability, and preliminary efficacy of VaLiANT, a new group intervention that aims to enhance "valued living" following ABI. We used a non-concurrent multiple baseline single-case experimental design (SCED) with an 8-week follow-up phase and randomization to multiple baseline lengths (5-7 weeks). Eight participants (50% women, aged 26-65; 4 Stroke, 3 Traumatic Brain Injury, 1 Epilepsy) attended eight group sessions with assessments before, during, and after the group. Target behaviour was valued living, assessed weekly by the Valued Living Questionnaire. Secondary outcomes included measures of wellbeing, mood, psychological acceptance, self-efficacy regarding ABI consequences, cognitive complaints, and intervention acceptability. Target behaviour was analysed through visual and statistical analysis while secondary outcome data were analysed via reliable change indices and descriptive statistics. Target behaviour data displayed no convincing patterns of improvement. Reliable improvements were found for most participants on secondary outcomes, particularly subjective wellbeing and anxiety. Intervention delivery was feasible with high acceptability ratings. Further investigation of VaLiANT is warranted, based on the feasibility and acceptability of intervention delivery and signals of efficacy identified across adjustment-related secondary outcomes.

The association between outdoor allergens - pollen, fungal spore season and high asthma admission days in children and adolescents.

Periods when asthma admissions peaks have serious implications for asthma sufferers and hospitals. We assessed the association between aeroallergen exposure and childhood asthma peak periods during two grass pollen seasons using the Melbourne Air Pollen Children and Adolescent Health (MAPCAH) study conducted in Melbourne, Australia. Two peak periods were identified. Effect modifications by atopy and sex were considered. All pollen 2 days prior was associated with increased odds of these peak periods. Same day fungal spores, but not pollen, were important. Grass at lag 2 was associated with increased odds 1.03 (95%CI 1.01, 1.05) as was the same day Alternaria 1.02 (1.00, 1.04) per spore/m3 for boys. In addition to pollen, fungal spores particularly Alternaria may result in days of high exacerbations during pollen seasons. Further guidance is needed to better prepare families/carers with information about the increased risk of asthma attacks in children prior to pollen seasons.

Role of psychological distress on long-term risky and heavy-episodic drinking patterns in major cities and rural and remote areas.

OBJECTIVE: Psychological distress and alcohol consumption are associated but few studies have focused on the association with problematic drinking in semi-urban and rural settings. In this study, we assessed the role of psychological distress on various measures of problematic drinking in urban, semi-urban and rural settings. DESIGN: Retrospective descriptive study Setting SETTING: National Drug Strategy Household Survey population health survey data PARTICIPANTS: 151,341 Australian residents MAIN OUTCOME MEASURES: Problematic alcohol consumption categorised as either heavy-episodic drinking (defined as drinking 5 or more standard drinks at least once in the last 12 months) or long-term risky drinking (defined as drinking more than 730 standard drinks in the past 12 months) was the outcome variables. Psychological distress was identified from the K10 questionnaire. Participants were grouped into area of residence: urban, semi-urban and rural. Sex differences were also explored. RESULTS: Poor-to-severe psychological distress was associated with higher odds of both long-term and heavy-episodic drinking. Being male alone increased the risk of both long-term and heavy-episodic drinking in all areas. When stratified by sex, being female and severe levels of psychological distress increased the risk of both long-term risky and heavy-episodic drinking. These risks were greater in non-urban environments. CONCLUSIONS: Poor mental health outcomes may exacerbate problematic drinking amongst females, especially those living in non-urban environments. Public health campaigns could both target these at-risk groups of females in non-urban settings and also account for the interplay between problematic drinking and mental health.

Outdoor pollen-related changes in lung function and markers of airway inflammation: A systematic review and meta-analysis.

BACKGROUND: Experimental challenge studies have shown that pollen can have early and delayed effects on the lungs and airways. Here, we qualitatively and quantitatively synthesize the evidence of outdoor pollen exposure on various lung function and airway inflammation markers in community-based studies. METHODS: Four online databases were searched: Medline, Web of Science, CINAHL and Google Scholar. The search strategy included terms relating to both exposure and outcomes. Inclusion criteria were human-based studies published in English that were representative of the community. Additionally, we only considered cross-sectional or short-term longitudinal studies which investigated pollen exposure by levels or season. Study quality assessment was performed using the Newcastle-Ottawa scale. Meta-analysis was conducted using random-effects models. RESULTS: We included 27 of 6551 studies identified from the search. Qualitative synthesis indicated associations between pollen exposure and predominantly type-2 inflammation in both the upper and lower airways, but little evidence for lung function changes. People with ever asthma and/or seasonal allergic rhinitis (SAR) were at higher risk of such airway inflammation. Meta-analysis confirmed a positive relationship between pollen season, eosinophilia and eosinophil cationic protein (ECP) in people with ever SAR but the results between studies were highly variable. Heterogeneity was reduced after further subgrouping by age, and the forest plots indicated that eosinophilic airway inflammation to outdoor pollen exposure increased with age. CONCLUSION: Among people with ever asthma and ever SAR, exposure to increased ambient pollen triggers type-2 upper and lower airway inflammation rather than a non-specific or innate inflammation. These findings can lead to the formulation of specific pollen immunotherapy for susceptible individuals. Future research should be directed towards investigating lagged associations and effect modifications using larger and more generalized populations. SYSTEMATIC REVIEW REGISTRATION: CRD42020146981 (PROSPERO).

Is short-term exposure to grass pollen adversely associated with lung function and airway inflammation in the community?

BACKGROUND: The association between grass pollen exposure and early markers of asthma exacerbations such as lung function changes and increase in airway inflammation is limited. We investigated the associations between short-term grass pollen exposure and lung function and airway inflammation in a community-based sample, and whether any such associations were modified by current asthma, current hay fever, pollen sensitization, age, and other environmental factors. METHODS: Cross-sectional and short-term analyses of data from the Melbourne Atopy Cohort Study (MACS) participants (n = 936). Lung function was assessed using spirometry. Airway inflammation was assessed by fractional exhaled nitric oxide (FeNO) and exhaled breath condensate pH and nitrogen oxides (NOx). Daily pollen counts were collected using a volumetric spore trap. The associations were examined by linear regression. RESULTS: Higher ambient levels of grass pollen 2 days before (lag 2) were associated with lower mid-forced expiratory flow (FEF25%-75% ) and FEV1 /FVC ratio (Coef. [95% CI] = -119 [-226, -11] mL/s and -1.0 [-3.0, -0.03] %, respectively) and also 3 days before (lag 3). Increased levels of grass pollen a day before (lag 1) were associated with increased FeNO (4.35 [-0.1, 8.7] ppb) and also at lag 2. Adverse associations between pollen and multiple outcomes were greater in adults with current asthma, hay fever, and pollen sensitization. CONCLUSION: Grass pollen exposure was associated with eosinophilic airway inflammation 1-2 days after exposure and airway obstruction 2-3 days after exposure. Adults and individuals with asthma, hay fever, and pollen sensitization may be at higher risk.

Brief intermittent pressure off-loading on skin microclimate in healthy adults - A descriptive-correlational pilot study.

AIM: This study examined microclimate changes to the skin as a result of pressure over a 1 h period. The results were compared to skin parameter results following brief consecutive off-loading of pressure-prone areas. DESIGN: A descriptive-correlational pilot study was undertaken. METHOD: A convenience sample of 41 healthy adults aged 18-60 years was recruited. Participants engaged in four 1 h data collection sessions. The sessions were conducted in both semi-recumbent and supine positions. Measures of erythema, melanin, stratum corneum hydration, and skin temperature were taken at pressure-prone areas at baseline and after 1 h in an uninterrupted method (continuous pressure-loading) and every 10 min in an interrupted method (brief off-loading). The Corneometer and Mexameter (Courage + Khazaka Electronics GMbH, 2013) and Exergen DermaTemp DT-1001 RS Infrared Thermographic Scanner (Exergen Corporation, 2008) provided a digital appraisal of skin parameters. Intraclass correlation coefficients (ICC) were calculated to indicate test-retest reliability and absolute agreement of results between the two methods. RESULTS: Strong agreement between the interrupted and uninterrupted method was observed with ICCs ranging from 0.72 to 0.99 (supine) and 0.62-0.99 (semi-recumbent). Endpoint measures tended to be higher compared to baseline measures for all skin parameters. Differences in skin parameters results by anatomical location were evident particularly for erythema and stratum corneum hydration; the elbows and heels yielded lower scores compared to the sacrum. Erythema had the most variation across methods. The supine and semi-recumbent positions had negligible effect on measured skin parameters. CONCLUSIONS: Minimal variation between skin parameter results indicates that brief off-loading in the interrupted method did not significantly change the outcomes; minor shifts in positioning do not alter changes to the skin from pressure. Skin parameters varied by anatomical location and changed over a 1 h period of pressure-loading. RELEVANCE TO CLINICAL PRACTICE: Biophysical techniques may be able to assist accurate assessment of skin microclimate and skin colour. As brief off-loading (interruptions) to enable skin parameter measurement does not alter skin readings, researchers can proceed with some confidence regarding the use of this protocol in future studies assessing skin parameters. This study data provides a library of cutaneous changes at pressure-prone areas of healthy adults and is expected to inform innovative approaches to pressure injury risk assessment.

Water, sanitation and hygiene practices associated with improved height-for-age, weight-for-height and weight-for-age z-scores among under-five children in Nepal.

BACKGROUND: Evidence of the influence of water, sanitation and hygiene (WASH) behaviors on childhood nutritional status is inconsistent. Few studies have examined their interactive effects. This study aimed to examine associations and interactions between WASH variables and preschool child undernutrition. METHODS: Data from a nationally representative sample of 2352 children assessed during the 2016 Nepal Demographic and Health Survey were analyzed by multi-variable linear regression to understand the association between height-for-age (HAZ), weight-for-height (WHZ) and weight-for-age (WAZ) z-scores and WASH variables. Interactions between WASH variables, sex and area of residence on childhood nutritional status were also examined. RESULTS: The mean z-score [standard deviation] for children's WAZ, HAZ and WHZ scores were - 1.33 [1.1], - 1.52 [1.3] and - 0.65 [1.1], respectively. A unit increase in cluster sanitation coverage was associated with an increase of 0.30 (95%CI: 0.12 to 0.48) for WAZ and 0.28 (95%CI: 0.001 to 0.56) for HAZ scores. Household water purification practice was associated with an increase of 0.24 (95%CI: 0.07 to 0.41) in WHZ score. Handwashing practice with water and soap was associated with an increase of 0.15 (95%CI: 0.04 to 0.25) in WAZ and 0.13 (95%CI: 0.01 to 0.24) in WHZ scores. The effect of water purification practice was higher for rural areas compared to urban settings for HAZ scores (p-value for interaction = 0.02). CONCLUSIONS: Consistent with findings from other countries in the South Asian region, findings of this study highlight the potential importance of good WASH practices, and therefore the potential of WASH interventions, to contribute to improved nutritional status in rural Nepal.

High ambient levels of grass, weed and other pollen are associated with asthma admissions in children and adolescents: A large 5-year case-crossover study.

BACKGROUND: Pollen is an important aeroallergen that triggers asthma exacerbations in children, but we know little about the impact of different pollen types in cities with varying climatic conditions and pollen seasons. OBJECTIVES: We aimed to assess the role of ambient level of different types of pollen on a large time series of child and adolescent asthma hospitalizations in Sydney, Australia. METHODS: Childhood asthma hospitalization and the daily ambient pollen concentrations of different species were collected in South-West Sydney. With a bidirectional case-crossover design, we fitted conditional logistic regression models to measure the associations between instantaneous and up to 3 days lagged effects of pollen concentrations on asthma hospitalizations after controlling for potential confounders and testing for interactions. RESULTS: A total of 2098 children, more boys (59.7%) and 2-5 years old (62.6%), were hospitalized due to asthma. The geometric mean concentration of Cupressus, 7.88 [5.02] grains/m3 , was the highest during the study period. The increase from 75th to 90th percentile of grass (OR = 1.037, 95% CI 1.005-1.070), weed other than Plantago species (OR = 1.053, 95% CI 1.009-1.098) and unclassified pollen (OR = 1.034, 95% CI 1.010-1.058) were significantly associated with the odds of asthma hospitalizations. Boys were at greater risk of asthma exacerbations associated with grass (OR = 1.046, 95% CI 1.003-1.090) and unclassified pollen (OR = 1.041, 95% CI 1.010-1.073). There was evidence of effect modification by age groups for Cupressus, conifer, total tree and total pollen. CONCLUSIONS: Although boys are more vulnerable to grass pollen, weed, and other pollen are also important triggers of asthma exacerbations in all children and adolescents. These findings are important for urban green space planning and the development of pollen monitoring systems for families with children at risk of asthma exacerbations during peak pollen seasons.

Associations between outdoor fungal spores and childhood and adolescent asthma hospitalizations.

BACKGROUND: Childhood asthma is a significant public health problem and severe exacerbations can result in diminished quality of life and hospitalization. OBJECTIVE: We sought to examine the contribution of outdoor fungi to childhood and adolescent asthma hospitalizations. METHODS: The Melbourne Air Pollen Children and Adolescent study is a case-crossover study of 644 children and adolescents (aged 2-17 years) hospitalized for asthma. The Melbourne Air Pollen Children and Adolescent study collected individual data on human rhinovirus infection and sensitization to Alternaria and Cladosporium and daily counts of ambient concentrations of fungal spores, pollen, and air pollutants. Conditional logistic regression models were used to assess associations with increases in spore counts while controlling for potential confounding and testing interactions. RESULTS: Exposure to Alternaria (adjusted odds ratio [aOR], 1.07; 95% CI, 1.03-1.11), Leptosphaeria (aOR, 1.05; 95% CI, 1.02-1.07), Coprinus (aOR, 1.04; 95% CI, 1.01-1.07), Drechslera (aOR, 1.03; 95% CI, 1.00-1.05), and total spores (aOR, 1.05; 95% CI, 1.01-1.09) was significantly associated with child asthma hospitalizations independent of human rhinovirus infection. There were significant lagged effects up to 3 days with Alternaria, Leptosphaeria, Cladosporium, Sporormiella, Coprinus, and Drechslera. Some of these associations were significantly greater in participants with Cladosporium sensitization. CONCLUSIONS: Exposures to several outdoor fungal spore taxa, including some not reported in previous research, are associated with the risk of child and adolescent asthma hospitalization, particularly in individuals sensitized to Cladosporium. We need further studies to examine cross-reactivity causing asthma exacerbations. Identifying sensitization to multiple fungal allergens in children with asthma could support the design and implementation of more effective strategies to prevent asthma exacerbations.

The role of outdoor fungi on asthma hospital admissions in children and adolescents: A 5-year time stratified case-crossover analysis.

BACKGROUND: Some fungal spores can trigger asthma exacerbation but knowledge of which outdoor fungal spores contribute to asthma hospitalisation is limited. OBJECTIVES: To examine the role of outdoor fungal spores in child and adolescent asthma hospitalisations. METHODS: We conducted a bi-directional time-stratified case-crossover study of child and adolescent asthma hospitalisations over 5 years. Conditional logistic regression assessed the role of 20 fungi taxa (Same day [L0] and lagged [L1-3]) adjusted for maximum temperature, humidity and grass pollen. Strata specific effects were explored if there was evidence of effect modification by age, sex, air pollutants or grass pollen. Non-linear effects examined with Generalized Additive Models. RESULTS: Of 2098 children hospitalised for asthma, 60% were boys; mean age was 5.5±3.7 years. Fungal spore counts peaked during warm months. Regression models found weak associations with Coprinus [L0,L1: OR=1.03, 1.01-1.06], Periconia [L0: OR=1.03, 1.001-1.07] and Chaetomium [L2: OR=1.08, 1.0-1.2]. Sex appeared to act as an effect modifier with girls having stronger associations with Cladosporium, Coprinus and total fungi. Older adolescent (14-18 years) hospitalisation was significantly associated with Coprinus and Ustilago/smuts. Air pollutants and grass pollen did not appear to act as effect modifiers. Non-linearity was not detected. CONCLUSION: There may be associations between some outdoor fungal spores and asthma hospitalisations. Further research needed to explore whether these findings can be replicated; and examine whether fungal sensitisation and/or human rhinovirus infections are associated with stronger effects. If findings are replicated, then the need to develop predictive models for fungal spore distribution and levels may become more important.

Effect of season of birth on cord blood IgE and IgE at birth: A systematic review and meta-analysis.

BACKGROUND: Elevated cord blood IgE is important on the pathway to allergic disease. The association between season of birth and infant cord blood IgE is not well-established. Study findings differ on which birth season is associated with higher cord blood IgE risk and its magnitude. We conducted a systematic review and meta-analysis of studies on season of birth and cord blood IgE. METHODS: We searched Medline, Web of Science, Scopus and ProQuest Health databases, and reviewed reference lists of articles that met the inclusion criteria. All included studies measured IgE as a binary variable using various cut-off values. We performed multivariate-random-effects meta-analysis to handle an exposure with multiple categories of Season of Birth. RESULTS: Our search identified 275 records and 10 had sufficient data to be included in a meta-analysis. Relative to summer, winter birth had the greatest odds of high IgE (≥ 0.1IU/ml), meta-analysis OR = 1.24 (95%CI: 1.01-1.52). A similar OR, was found for IgE ≥ 0.5 IU/ml, OR = 1.30 (95%CI: 0.99-1.71). CONCLUSIONS: A winter season of birth was associated with statistically significant higher odds of elevated cord blood IgE at cut-off ≥ 0.1IU/ml but borderline at cut-off ≥ 0.5IU/ml. This winter effect is likely to be a marker for a range of other environmental exposures during specific stages of pregnancy, such as aeroallergen exposures, maternal infections and vitamin D levels. Further research is required to support our finding and to identify the exact mechanisms that lead to the winter season of birth effect on circulating IgE levels, as this may have implications for allergic disease prevention.

Sensitization to milk, egg and peanut from birth to 18 years: A longitudinal study of a cohort at risk of allergic disease.

BACKGROUND: Longitudinal data on the natural history of food sensitization beyond early childhood are scarce. We aimed to investigate the natural history of milk, egg and peanut sensitization from infancy to 18 years and assess whether early food sensitization predicted adolescent food allergy. METHODS: Sensitization to cow's milk, hen's egg and peanut was measured by skin prick testing at ages 6 months, 1, 2, 12 and 18 years in a high-risk allergy birth cohort (n = 620). Generalized additive models investigated interactions with sex, eczema and aeroallergen sensitization in infancy. Logistic regression assessed the relationships between early food sensitization and adolescent sensitization and probable food allergy up to 18 years. RESULTS: The prevalence of egg and peanut sensitization peaked at 12 months, while milk sensitization peaked at both 1 and 12 years. Boys with early eczema had the highest prevalences of milk and egg sensitization throughout follow-ups. However, neither sex nor eczema influenced the prevalence of peanut sensitization over time. New onset food sensitization beyond the age of 2 was observed in 7% of participants. Food sensitization at 12 months was associated with increased risk of adolescent food sensitization and adolescent probable food allergy, with sensitization to more than one food allergen had the strongest predictor. CONCLUSIONS: Food sensitization prevalence is highest in infancy and declines after 12 months of age. Boys with early-life eczema have the highest prevalence of milk and egg sensitization. Food sensitization at 12 months can predict children at greater risk of adolescent sensitization and probable food allergy at 12 and 18 years.

Regional and seasonal variation in airborne grass pollen levels between cities of Australia and New Zealand.

Although grass pollen is widely regarded as the major outdoor aeroallergen source in Australia and New Zealand (NZ), no assemblage of airborne pollen data for the region has been previously compiled. Grass pollen count data collected at 14 urban sites in Australia and NZ over periods ranging from 1 to 17 years were acquired, assembled and compared, revealing considerable spatiotemporal variability. Although direct comparison between these data is problematic due to methodological differences between monitoring sites, the following patterns are apparent. Grass pollen seasons tended to have more than one peak from tropics to latitudes of 37°S and single peaks at sites south of this latitude. A longer grass pollen season was therefore found at sites below 37°S, driven by later seasonal end dates for grass growth and flowering. Daily pollen counts increased with latitude; subtropical regions had seasons of both high intensity and long duration. At higher latitude sites, the single springtime grass pollen peak is potentially due to a cooler growing season and a predominance of pollen from C3 grasses. The multiple peaks at lower latitude sites may be due to a warmer season and the predominance of pollen from C4 grasses. Prevalence and duration of seasonal allergies may reflect the differing pollen seasons across Australia and NZ. It must be emphasized that these findings are tentative due to limitations in the available data, reinforcing the need to implement standardized pollen-monitoring methods across Australasia. Furthermore, spatiotemporal differences in grass pollen counts indicate that local, current, standardized pollen monitoring would assist with the management of pollen allergen exposure for patients at risk of allergic rhinitis and asthma.