In November 2016, an unprecedented epidemic thunderstorm asthma event in Victoria, Australia, resulted in many thousands of people developing breathing difficulties in a very short period of time. It caused ten deaths and created extreme demand across the Victorian health and emergency services. Because of the link between thunderstorm asthma and grass pollen allergies, a new early warning system for epidemic thunderstorm asthma (ETSA) risk was developed and operates during grass pollen season (October-December) each year. The warnings are delivered through a partnership between the Victorian Department of Health, the Bureau of Meteorology, the University of Melbourne, and AirHealth Lab.Value chain concepts were instrumental in the design of the warnings. Starting with the user needs, namely health sector preparedness and community safety, the partners worked backwards to determine the value chain of necessary capabilities (communication, risk assessment, hazard prediction, modelling, observations) and information flows that would be needed to provide a thunderstorm asthma warning service. This process highlighted gaps in knowledge of the hazard, and the need to develop capability to measure and predict grass pollen to support the thunderstorm asthma warnings. The value chain also helped define the partners’ roles and responsibilities in delivering the warnings.Focused effort by the partners enabled the thunderstorm asthma warning system to be implemented in time for the 2017 pollen season, accompanied by a full range of community, health and emergency sector awareness raising and education activities. The system uses a categorical risk-based approach, combining operational forecasting of gusty winds in severe thunderstorms with forecasts of high ambient grass pollen concentrations, which together generate the risk of epidemic thunderstorm asthma. This system now provides the first daily epidemic thunderstorm asthma risk warning service in the world that covers a wide area, and integrates into the health, ambulance and emergency management sector.At the end of each season the partners meet to review the performance of the warning system, including its ability to predict the hazard (i.e. the weather and grass pollen conditions associated with thunderstorm asthma risk) and the impact (unusually high numbers of people presenting to hospital emergency departments with asthma symptoms). The warnings show modest skill in discriminating between days with and without health impacts.This cyclical review process has led to continuous improvements in all aspects of the warnings system. These include more accurate grass pollen forecasts based on machine learning, progressive installation of automated pollen monitors to replace manual pollen counting, near real time detection of asthma spikes in hospital emergency departments based on natural language processing, and use of value-oriented metrics to tune the weather and grass pollen thresholds to optimize warning performance.

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.

When providing pollen forecasts to the community, there is a need to verify the accuracy of curated forecasts, but evaluation is not routinely reported. This study of the AusPollen Partnership compared multi-category grass pollen forecasts for up to six days ahead with daily airborne grass pollen concentrations measured in Brisbane, Canberra, Melbourne, and Sydney, Australia during four pollen seasons from 2016 to 2020. The accuracy of categorical grass pollen forecasts predicting grass pollen concentrations in the high and greater, or moderate and greater categories, were assessed as often applied in meteorology using Gerrity scores, equitable threat scores, false alarm ratios, success ratios, and probability of detection of correct category. The skill of grass pollen forecasts curated by aerobiologists were compared with two retrospectively calculated naïve reference forecast methods; climatology and persistence. For Brisbane and Melbourne, high or greater grass pollen levels occurred on average 32% and 22% of days, whereas for Canberra and Sydney, there were few high days, but moderate or greater pollen levels occurred on average 26% and 19% of days, respectively. Average annual Gerrity scores for curated forecasts of high or greater improved with experience from 0.20 to 0.66 in Brisbane, and from 0.39 to 0.55 in Melbourne between 2016 and 2019. Average Gerrity Scores for moderate or greater categories in Sydney were 0.45 and 0.43 in 2016 and 2018 respectively, and in Canberra were 0.34 and 0.41, in the same years. The skill of curated forecasts was usually better than persistence forecasts, but the accuracy of the curated forecasts decreased with longer lead times. Although persistence grass pollen forecasts consistently performed better than climatologies, persistence depends on previous day pollen concentrations being available. Short-term curated daily grass pollen forecasts of the AusPollen Partnership offer useful information for people with allergic rhinitis and asthma, to help facilitate behavioural change and reduce the health burden. There is a need in Australia to extend local pollen records through sustained pollen monitoring to track climate-related changes as well as improve reliability of daily pollen forecasts. Globally, continued evaluation will enable reporting of accurate pollen forecasts to community, clinicians and government stakeholders.

BACKGROUND: Grass pollen exposure is a risk factor for childhood asthma hospital attendances. However, its short-term influence on lung function, especially among those with other allergic conditions, has been less well-studied. OBJECTIVE: To investigate this association in a population-based sample of children. METHODS: Within the HealthNuts cohort, 641 children performed spirometry during the grass pollen season. Grass pollen concentration was considered on the day of testing (lag 0), up to 3 days before (lag 1-lag 3), and cumulatively (lag 0-3). We used linear regression to assess the relevant associations and examined potential interactions with current asthma, hay fever or eczema, and food allergy. RESULTS: Associations were observed only in children with allergic disease (P value for interaction <= 0.1). In children with food allergy, grass pollen concentration was associated with a lower ratio of forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC) and lower mid-forced expiratory flows (FEF25%-75%) at all lags (eg, at lag 2, FEV1/FVC z-score = -0.50 [95% CI -0.80 to -0.20] and FEF25%-75% z-score = -0.40 [-0.60 to -0.04] per 20 grains/m(3) pollen increase), and increased bronchodilator responsiveness (BDR) at lag 2 and lag 3 (eg, at lag 2, BDR [ (31 [95% CI -0.005 to 62] mL). In children with current asthma, increasing grass pollen concentration was associated with lower FEF25%-75% and increased BDR, whereas children with current hay fever or eczema had increased BDR only. CONCLUSIONS: A proactive approach needs to be enforced to manage susceptible children, especially those with food allergy, before highegrass pollen days. (C) 2022 American Academy of Allergy, Asthma & Immunology

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.

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 degrees 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.

BackgroundWhile 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. MethodsWe 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 & GE; 2 mm at age 1 year and & GE; 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. ResultsGrass pollen at lag 0-3 (every 20 grains/m(3) 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. ConclusionIncreasing 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.

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/m(3), 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.

Abstract Background Paediatric asthma-related readmissions significantly challenge public health systems. As evidence suggests readmissions are possibly associated with ambient grass pollen levels, we sought to determine the relationship between grass pollen exposure and the risk of readmission for asthma among children in Victoria, Australia. Methods The Victorian Admitted Episodes Dataset 1st July 1997–30th June 2009 was used to identify primary admissions with a principal diagnosis of asthma for children aged 2-18 years. Total sample size was 48,068 admissions. Readmissions were defined as a subsequent admission within 28 days of index discharge. Multiple semi-parametric Poisson Generalized Additive Models were used to assess associations between the grass pollen season and daily grass pollen counts (lagged and cumulative) with repeat admissions, while controlling for meteorological factors and air pollutants. Results Readmissions totalled to 2,152 (4.47% of all admissions). Mean daily readmissions were 1.44 times higher during the grass pollen season (95%CI 1.03-2.02). Pollen season was associated with readmission only for the youngest age group (2-5), incident rate ratio 1.99 (95%CI 1.26-3.14). Daily readmission was non-linearly associated with same day pollen counts only for the 13-18-year age group. Lag 2 pollen counts were non-linearly associated with all daily readmissions for boys in gender-stratified and younger age groups (2-5, 6-12) in age-stratified analysis. Conclusions Grass pollen exposure was associated with higher readmission rates for paediatric asthma. Key messages Younger children and boys with severe or poorly controlled asthma need to be assessed for preventive therapies before the grass pollen season to reduce the repeat admissions.

Nicotiana is found predominantly in the Americas and Australia, but also has representatives in Africa and the Pacific Islands. All native Australian Nicotiana species belong to section Suaveolentes. The number of species in this section is uncertain and subject to revision. An example of this uncertainty is the taxonomic status of a South Australian Nicotiana accession colloquially termed 'Corunna'. Here, we report sequences for nuclear and plastid markers for N. sp. Corunna (D.E.Symon 17088) and accessions of two other Australian species, N. burbidgeae and N. benthamiana. Phylogenetic comparison of these sequences with those of other members of Nicotiana places all three taxa in N. section Suaveolentes and shows that 'Corunna' represents a distinct phylogenetic lineage in a well supported clade along with N. goodspeedii, N. maritima, N. amplexicaulis and N. suaveolentes. Phenetic analysis of floral characters also supports recognition of N. sp. Corunna (D.E.Symon 17088) as a distinct species, which we describe here as Nicotiana paulineana Newbigin & P.M.Waterh., sp. nov. The enlarged molecular dataset described here contributes to a better understanding of taxonomic relationships within the section.

were in the 41–50 or 61–70 age range, with a female predominance. None had a twin sibling. Six respondents reported a family history of mastocytosis. Fifty-four (64%) reported onset of symptoms was linked to a stressful life event. Most reported being diagnosed between 41 to 50. Fifty-seven (68%) reported having consulted up to 5 doctors before the diagnosis was made. Of note, 6 respondents reported seeing more than 20 doctors to establish a diagnosis. A majority had consulted an immunologist/allergist or dermatologist. A final diagnosis of systemic mastocytosis was made in 59 cases, and cutaneous mastocytosis in 9 while 12 had both diagnoses. Alternative diagnoses given prior a final diagnosis include anxiety, fibromyalgia and allergies.

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).

The world’s most severe thunderstorm asthma event occurred in Melbourne, Australia on 21 November 2016, coinciding with the peak of the grass pollen season. The aetiological role of thunderstorms in these events is thought to cause pollen to rupture in high humidity conditions, releasing large numbers of sub-pollen particles (SPPs) with sizes very easily inhaled deep into the lungs. The humidity hypothesis was implemented into a three-dimensional atmospheric model and driven by inputs from three meteorological models. However, the mechanism could not explain how the Melbourne event occurred as relative humidity was very low throughout the atmosphere, and most available grass pollen remained within 40 m of the surface. Our tests showed humidity induced rupturing occurred frequently at other times and would likely lead to recurrent false alarms if used in a predictive capacity. We used the model to investigate a range of other possible pollen rupturing mechanisms which could have produced high concentrations of SPPs in the atmosphere during the storm. The mechanisms studied involve mechanical friction from wind gusts, electrical build up and discharge incurred during conditions of low relative humidity, and lightning strikes. Our results suggest that these mechanisms likely operated in tandem with one another, but the lightning method was the only mechanism to generate a pattern in SPPs following the path of the storm. If humidity induced rupturing cannot explain the 2016 Melbourne event, then new targeted laboratory studies of alternative pollen rupture mechanisms would be of considerable value to help constrain the parameterisation of the pollen rupturing process.

When many people develop asthma symptoms over a short period of time because of a combination of high concentrations of airborne allergens and strong thunderstorm outflows, this is known as epidemic thunderstorm asthma (ETSA).Worldwide, at least 22 ETSA events have been reported since 1983, with 10 occurring in southeastern Australia during late spring or early summer, when temperate grasses are flowering and there are high levels of airborne grass pollen (some of which may be ruptured into tiny allergenic starch granules and concentrated near ground level where they can affect the lower airways of susceptible people).Events have also been reported in the United Kingdom and other European countries, the Middle East, the United States, and Canada.

In November 2016, an unprecedented epidemic thunderstorm asthma event in Victoria, Australia, resulted in many thousands of people developing breathing difficulties in a very short period of time, including 10 deaths, and created extreme demand across the Victorian health services. To better prepare for future events, a pilot forecasting system for epidemic thunderstorm asthma (ETSA) risk has been developed for Victoria. The system uses a categorical risk-based approach, combining operational forecasting of gusty winds in severe thunderstorms with statistical forecasts of high ambient grass pollen concentrations, which together generate the risk of epidemic thunderstorm asthma. This pilot system provides the first routine daily epidemic thunderstorm asthma risk forecasting service in the world that covers a wide area, and integrates into the health, ambulance, and emergency management sector. Epidemic thunderstorm asthma events have historically occurred infrequently, and no event of similar magnitude has impacted the Victorian health system since. However, during the first three years of the pilot, 2017–19, two high asthma presentation events and four moderate asthma presentation events were identified from public hospital emergency department records. The ETSA risk forecasts showed skill in discriminating between days with and without health impacts. However, even with hindsight of the actual weather and airborne grass pollen conditions, some high asthma presentation events occurred in districts that were assessed as low risk for ETSA, reflecting the challenge of predicting this unusual phenomenon.

Background: Temperate grass (eg, ryegrass) pollen is a major driver of seasonal allergic rhinitis (SAR) and asthma risks, including thunderstorm asthma. Data for the effectiveness of temperate grass pollen allergen immunotherapy (AIT) in SAR patients from the southern hemisphere, who are frequently polysensitized to subtropical grass pollens, are limited. The 300 IR 5-grass pollen sublingual immunotherapy tablet (300 IR 5-grass SLIT) is known to be effective in polysensitized SAR patients with primary allergy to temperate grasses, however, the influence of polysensitization to subtropical grass pollen on treatment responses has yet to be specifically addressed. Key aims of this study were to measure patient treatment satisfaction during 300 IR 5-grass SLIT treatment and evaluate how polysensitization to subtropical grass pollens affects treatment responses. Methods: A prospective observational study was conducted in 63 patients (aged >= 5 years) in several temperate regions of Australia prescribed 300 IR 5-grass SLIT for SAR over 3 consecutive grass pollen seasons. Ambient levels of pollen were measured at representative sites. Patient treatment satisfaction was assessed using a QUARTIS questionnaire. Rhinoconjunctivitis Total Symptom Score (RTSS) and a Hodges-Lehmann Estimator analysis was performed to evaluate if polysensitization to subtropical grass pollen affected SAR symptom intensity changes during SLIT. Results: A diagnosis of ryegrass pollen allergy was nearly universal. There were 74.6% (47/63) polysensitized to subtropical and temperate grass pollens. There were 23.8% (15/63) monosensitized to temperate grass pollens. From the first pollen season, statistically significant improvements occurred in SAR symptoms compared with baseline in both monosensitized and polysensitized patients, particularly in those polysensitized (P = 0.0297). Improvements in SAR symptoms were sustained and similar in both groups in the second and third pollen seasons, reaching 70-85% improvement (P < 0.01). Polysensitized patients from both northerly and southerly temperate regions in Australia showed similar improvements. Grass pollen counts in both regions were consistently highest during springtime. Conclusions: 300 IR 5-grass SLIT is effective in a real-life setting in SAR patients in the southern hemisphere with primary allergy to temperate grass pollen and predominantly springtime grass pollen exposures. Importantly, SLIT treatment effectiveness was irrespective of the patient's polysensitization status to subtropical grass pollens.