Asthma Epidemics Research Articles

The Relationship between High-Presentation Asthma Days in Melbourne, Australia, and Modeled Thunderstorm Environments

Abstract Epidemic asthma events represent a significant risk to emergency services as well as the wider community. In southeastern Australia, these events occur in conjunction with relatively high amounts of grass pollen during the late spring and early summer, which may become concentrated in populated areas through atmospheric convergence caused by a number of physical mechanisms including thunderstorm outflow. Thunderstorm forecasts are therefore important for identifying epidemic asthma risk factors. However, the representation of thunderstorm environments using regional numerical weather prediction models, which are a key aspect of the construction of these forecasts, have not yet been systematically evaluated in the context of epidemic asthma events. Here, we evaluate diagnostics of thunderstorm environments from historical simulations of weather conditions in the vicinity of Melbourne, Australia, in relation to the identification of epidemic asthma cases based on hospital data from a set of controls. Skillful identification of epidemic asthma cases is achieved using a thunderstorm diagnostic that describes near-surface water vapor mixing ratio. This diagnostic is then used to gain insights on the variability of meteorological environments related to epidemic asthma in this region, including diurnal variations, long-term trends, and the relationship with large-scale climate drivers. Results suggest that there has been a long-term increase in days with high water vapor mixing ratio during the grass pollen season, with large-scale climate drivers having a limited influence on these conditions. Significance Statement We investigate the atmospheric conditions associated with epidemic thunderstorm asthma events in Melbourne, Australia, using historical model simulations of the weather. Conditions appear to be associated with high atmospheric moisture content, which relates to environments favorable for severe thunderstorms, but also potentially pollen rupturing as suggested by previous studies. These conditions are shown to be just as important as the concentration of grass pollen for a set of epidemic thunderstorm asthma events in this region. This means that weather model simulations of thunderstorm conditions can be incorporated into the forecasting process for epidemic asthma in Melbourne, Australia. We also investigate long-term variability in atmospheric conditions associated with severe thunderstorms, including relationships with the large-scale climate and long-term trends.

Epidemic thunderstorm asthma

Epidemic thunderstorm asthma

Breathing Easier in Australia: A Pilot Risk-Assessment System for Epidemic Thunderstorm-induced Asthma

Breathing Easier in Australia: A Pilot Risk-Assessment System for Epidemic Thunderstorm-induced Asthma

The impact of Vitamin D levels in predicting childhood asthma among Egyptian infants

Rationale: Ecologically, many of the patterns of vitamin D deficiency appear to be parallel to the patterns of the asthma epidemics. There are several Potential mechanisms for how vitamin D might decrease the disease severity of asthma and allergies. In this study, we tried to study the effect of serum vitamin D on the risk of development of childhood asthma by calculating Asthma predictive index (API) in relation to serum vitamin D levels.

Thunderstorm asthma in seasonal allergic rhinitis: The TAISAR study

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. We sought to identify risk factors for a history of TA and hospital presentation in a cohort of individuals with SAR. 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. 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. Clinical tests can identify risk of a history of TA in individuals with SAR and thereby inform patient-specific treatment recommendations.

How can air quality affect health?

Over recent years, Australians have been subject to an unprecedented number of environmental events materially and visibly affecting air quality, including thunderstorm asthma and bushfire smoke. There is increasing evidence that poor air quality adversely affects health with consequences for mortality and morbidity with measured particulates (PM2.5) in January 2019 frequently exceeding World Health Organization standards. Biological factors can also impact air quality with thunderstorm asthma epidemics evidence of a prime example, the 2016 event being associated with severe impacts on health services. Given these events, consideration needs to be given to environmental health literacy which will support individuals with pre-existing illness to recognise and mitigate as far as possible the effects of adverse air quality. Recognising the impact of poor air quality should also urge physicians to advocate for clean air as a necessity for good health.

Levels of Airborne Soybean Allergen (Gly m 1) in a Brazilian Soybean Production City: A Pilot Study.

Asthma epidemics have been shown to be related to where soybeans are loaded and handled, but data are scarce in the literature. This pilot study evaluated the levels of Gly m 1 in dust samples collected in Maringá, Brazil, a city with high soy production and processing. A dust impactor was used to collect seven isolated samples during 2015 and 2016. Samples were analyzed by an ELISA (enzyme-linked immunosorbent assay) detection method. Gly m 1 was found in all samples, ranging from 0.82–24.38 ng/m3 (median 2.41), regardless of the month or year evaluated. The levels of Gly m 1 were considered low, but the concentrations required to cause sensitization and symptoms are uncertain.

Diet: A Specific Part of the Western Lifestyle Pack in the Asthma Epidemic.

The Western lifestyle is a complex concept that includes the diet as the main axis of different factors which contribute to a detrimental effect on health, lower life expectancy and low quality-of-life. This type of diet is characterized by being high in calories, mainly provided by saturated fats, and rich in sugars that can lead to changes in immune cells and their responsiveness, by different mechanisms that have yet to be totally clarified. Inflammatory processes are perpetuated through different pathways, in which adipose tissue is a major factor. High fat stores in overweight and obesity accumulate energy but the endocrine function is also producing and releasing different bioactive compounds, adipokines, known to be pro-inflammatory and which play an important role in the pathogenesis of asthma. This review therefore explores the latest evidence regarding the adverse effect of the Western diet on adipose tissue inflammation and its causative effect on the asthma epidemic.

Thunderstorm Asthma Epidemic-A Systematic Review of the General Practice Perspective.

Thunderstorm asthma (TA) epidemics have been recognized globally as a rare phenomenon, producing a rapid surge of acute asthma presentations leading to an increased demand on emergency medical services and healthcare resources. General practitioners (GPs) are well placed in the community to contribute to healthcare during TA epidemics and similar disaster events. The aim of this review was to synthesize current evidence of the experiences of GPs during TA epidemics and similar surge events. A comprehensive systematic search of eleven electronic databases, including ancestry searching for peer-reviewed studies and grey literature published in English was conducted. Quantitative and qualitative study designs were included, and a quality assessment conducted. Of the 125 records identified, 16 were included for synthesis. During TA epidemics and surge events, GPs experience an increased demand for services, yet it is not known if general practice clinics experience resource limitations from this patient surge. While GPs express a willingness to help, few structures are in place to liaise, support and provide information to GPs during surge events. Following most surge/disaster events, no GP data is collected so it is not known how to improve coordination and communication between general practice services and emergency services. GPs have well-functioning adaptive management systems, and resources of space, supplies and staff thus the ability to increase surge capacity of their clinics.

Clinical Effects of Vitamin D on the Control of Bronchial Asthma-Is it Relevant?

Bronchial asthma is one of the most common chronic respiratory disease worldwide, and is characterised by different phenotypic variations. Acute exacerbations in bronchial asthma are common and leads to repeated hospitalisations leading to increase in direct costs of asthma and thus preventing exacerbations should be an important consideration. Vitamin D has an immunomodulatory action and its deficiency has been associated with asthma epidemics. We hereby critically review the clinical benefits of vitamin D in the control of bronchial asthma and in exacerbations.

Does early onset asthma increase childhood obesity risk? A pooled analysis of 16 European cohorts.

The parallel epidemics of childhood asthma and obesity over the past few decades have spurred research into obesity as a risk factor for asthma. However, little is known regarding the role of asthma in obesity incidence. We examined whether early-onset asthma and related phenotypes are associated with the risk of developing obesity in childhood.This study includes 21 130 children born from 1990 to 2008 in Denmark, France, Germany, Greece, Italy, The Netherlands, Spain, Sweden and the UK. We followed non-obese children at 3-4 years of age for incident obesity up to 8 years of age. Physician-diagnosed asthma, wheezing and allergic rhinitis were assessed up to 3-4 years of age.Children with physician-diagnosed asthma had a higher risk for incident obesity than those without asthma (adjusted hazard ratio (aHR) 1.66, 95% CI 1.18-2.33). Children with active asthma (wheeze in the last 12 months and physician-diagnosed asthma) exhibited a higher risk for obesity (aHR 1.98, 95% CI 1.31-3.00) than those without wheeze and asthma. Persistent wheezing was associated with increased risk for incident obesity compared to never wheezers (aHR 1.51, 95% CI 1.08-2.09).Early-onset asthma and wheezing may contribute to an increased risk of developing obesity in later childhood.

The pertussis hypothesis: Bordetella pertussis colonization in the etiology of asthma and diseases of allergic sensitization

Decades of peer reviewed evidence demonstrate that: 1)Bordetellapertussisand pertussis toxin are potent adjuvants, inducing asthma and allergic sensitization in animal models of human disease, 2)Bordetella pertussisoften colonizes the human nasopharynx, and is well documented in highly pertussis-vaccinated populations and 3) in children, a history of whooping cough increases the risk of asthma and allergic sensitization disease. We build on these observations with six case studies and offer a pertussis-based explanation for the rapid rise in allergic disease in former East Germany following the fall of the Berlin Wall; the current asthma, peanut allergy, and anaphylaxis epidemics in the United States; the correlation between the risk of asthma and gross national income per capita by country; the lower risk of asthma and allergy in children raised on farms; and the reduced risk of atopy with increased family size and later sibling birth order. To organize the evidence for the pertussis hypothesis, we apply the Bradford Hill criteria to the association between Bordetella pertussisand asthma and allergicsensitization disease. We propose that, contrary to conventional wisdom that nasopharyngealBordetella pertussiscolonizing infections are harmless, subclinicalBordetella pertussiscolonization is an important cause of asthma and diseases of allergic sensitization.

Mitochondrial Dysfunction Linking Obesity and Asthma.

The bidirectional epidemiological association between asthma and obesity is well known. Recent evidence suggests that there is an intersection of the pathophysiological molecular pathways leading to either obesity or asthma, at the level of mitochondria. This is not surprising, because mitochondria, beyond their roles as the metabolic powerhouses of the cell, serve as sensors of threats, regulators of stress signaling, and effectors of cytotoxicity. Reduced mitochondrial function and low metabolic activity are well-recognized features of obesity. Three distinct lines of experimental evidences connect mitochondrial dysfunction with asthma. First, asthma is associated with aberrant mitochondrial metabolism. Second, mitochondrial dysfunction may either induce asthma-like features or increase asthma severity. Third, mitochondria-targeted therapies appear effective in preventing or reversing asthma features. Importantly, mitochondrial dysfunction in airway epithelial cells appears to be a powerful trigger for airway remodeling that is independent of cellular inflammation. This is clinically relevant to the obese-asthma phenotype, with exaggerated symptoms despite apparently low levels of inflammation, and poor response to antiinflammatory treatment. In summary, mitochondrial dysfunction is a common thread tying together the twin epidemics of obesity and asthma. Environmental and lifestyle factors leading to primary mitochondrial dysfunction may be increasing the risk for either disease. Further, secondary mitochondrial dysfunction emerging from the pathogenesis of either obesity or asthma may increase the risk of the other. Mitochondrial health-centric strategies may be relevant to prevention and treatment of both obesity and asthma, and should be actively considered.

Thunderstorm and asthma outbreaks during pollen season

An increasing body of evidence shows the occurrence of asthma epidemics, sometimes also severe, during thunderstorms in the pollen season in various geographical zones. The main hypothesis explaining association between thunderstorms and asthma claims that thunderstorms can concentrate pollen grains at ground level; these grains may then release allergenic particles of respirable size in the atmosphere after their rupture by osmotic shock. During the first 20-30 minutes of a thunderstorm, patients suffering from pollen allergy may inhale a high concentration of the allergenic material dispersed into the atmosphere, which can, in turn, induce asthmatic reactions, often severe. Subjects without asthma symptoms but affected by seasonal rhinitis can also experience an asthma attack. All subjects affected by pollen allergy should be alerted to the danger of being outdoors during a thunderstorm in the pollen season, as such events may be an important cause of severe bronchial obstruction. Considering this background, it is useful to predict thunderstorms during pollen season and, thus, to prevent thunderstorm-related clinical event. However, it is also important to focus on therapy, and it is not sufficient that subjects at risk of asthma follow a correct therapy with bronchodilators, but they also need to inhale corticosteroids, using both in case of emergency.

Thunderstorm-related asthma: what happens and why.

The fifth report issued by the Intergovernmental Panel on Climate Change forecasts that greenhouse gases will increase the global temperature as well as the frequency of extreme weather phenomena. An increasing body of evidence shows the occurrence of severe asthma epidemics during thunderstorms in the pollen season, in various geographical zones. The main hypotheses explaining association between thunderstorms and asthma claim that thunderstorms can concentrate pollen grains at ground level which may then release allergenic particles of respirable size in the atmosphere after their rupture by osmotic shock. During the first 20-30 min of a thunderstorm, patients suffering from pollen allergies may inhale a high concentration of the allergenic material that is dispersed into the atmosphere, which in turn can induce asthmatic reactions, often severe. Subjects without asthma symptoms, but affected by seasonal rhinitis can also experience an asthma attack. All subjects affected by pollen allergy should be alerted to the danger of being outdoors during a thunderstorm in the pollen season, as such events may be an important cause of severe exacerbations. In light of these observations, it is useful to predict thunderstorms and thus minimize thunderstorm-related events.

Effects of Weight Loss on Airway Responsiveness in Obese Adults With Asthma: Does Weight Loss Lead to Reversibility of Asthma?

The growing epidemics of obesity and asthma are major public health concerns. Although asthma-obesity links are widely studied, the effects of weight loss on asthma severity measured by airway hyperresponsiveness (AHR) have received limited attention. The main study objective was to examine whether weight reduction reduces asthma severity in obese adults with asthma. In a prospective, controlled, parallel-group study, we followed 22 obese participants with asthma aged 18 to 75 years with a BMI ≥ 32.5 kg/m2 and AHR (provocative concentration of methacholine causing a 20% fall in FEV1 [PC20] < 16 mg/mL). Sixteen participants followed a behavioral weight reduction program for 3 months, and six served as control subjects. The primary outcome was change in AHR over 3 months. Changes in lung function, asthma control, and quality of life were secondary outcomes. At study entry, participant mean ± SD age was 44 ± 9 years, 95% were women, and mean BMI was 45.7 ± 9.2 kg/m2. After 3 months, mean weight loss was 16.5 ± 9.9 kg in the intervention group, and the control group had a mean weight gain of 0.6 ± 2.6 kg. There were significant improvements in PC20 (P = .009), FEV1 (P = .009), FVC (P = .010), asthma control (P < .001), and asthma quality of life (P = .003) in the intervention group, but these parameters remained unchanged in the control group. Physical activity levels also increased significantly in the intervention group but not in the control group. Weight loss in obese adults with asthma can improve asthma severity, AHR, asthma control, lung function, and quality of life. These findings support the need to actively pursue healthy weight-loss measures in this population.

An innate link between obesity and asthma

The concordant epidemics of asthma and obesity are both associated with inflammation, and obesity has been shown to be an independent risk factor for asthma. A new study in mice indicates that part of the immunological connection between obesity and asthma involves inflammasome activation and production of the cytokine interleukin-17 by innate lymphoid cells in the lung (pages 54–61).

Substance P antagonist improves both obesity and asthma in a mouse model

Evidence suggests a causal relationship between obesity and asthma; however, the underlying mechanisms remain unknown. Substance P (SP), involved in neurogenic inflammation by acting through its receptor NK1-R, seems to participate in obese-asthma phenotype in mice. To evaluate the effect of a selective substance P receptor antagonist on a mouse model of diet-induced obesity and asthma. Diet-induced obese Balb/c mice were sensitized and challenged with ovalbumin (OVA) and treated with a selective NK1-R antagonist or placebo. Serum glucose, insulin, IL-6, resistin, and OVA-specific IgE levels were quantified. A score for peribronchial inflammation in lung histology was used. Cells were counted in bronchoalveolar lavage fluid. Adipocyte sizes were measured. Ovalbumin-obese mice treated with NK1-R antagonist had lower weight (P=0.0002), reduced daily food intake (P=0.0021), reduced daily energy intake (P=0.0021), reduced surface adipocyte areas (P<0.0001), lower serum glucose (P=0.04), lower serum insulin (P=0.03), lower serum IL-(P=0.0022), lower serum resistin (P=0.0043), lower serum OVA-specific IgE (P=0.035), and lower peribronchial inflammation score (P<0.0001) than nontreated OVA-obese mice. We observed an interaction between obesity, allergen sensitization, and treatment with NK1-R antagonist for metabolic and systemic biomarkers, and for allergen sensitization and bronchial inflammation, showing a synergy between these variables. In an experimental model of obesity and asthma in mice, NK1-R blockade improved metabolic and systemic biomarkers, as well as allergen sensitization and bronchial inflammation. These positive effects support a common pathway in the obese-asthma phenotype and highlight SP as a target with potential clinical interest in the obese-asthma epidemics.

218 Thunderstorm-Related Asthma in Patients Sensitised to Olea Europaea Pollen

BackgroundAsthma exacerbation associated with thunderstorms has been reported in several countries. Common to all epidemics of thunderstorm-related asthma is a significant increase in atmospheric allergen load during and immediately after a thunderstorm. Sensitization to Alternaria species or to grass and parietaria pollens has been suggested to play a key role in thunderstorm-related asthma. The only reported event of thunderstorm-related asthma in Mediterranean area was attributed to sensitization to parietaria pollen.MethodsHere we describe a series of 20 patients who accessed to an Emergency Department in Puglia (Italy) for sudden and severe dispnoea between the 27th and the 28th of May 2010 (between 15:36 and 5:02), just after a violent thunderstorm which occurred after a very warm morning (mean atmospheric temperature: 29°C). All patients have been subsequently visited by an allergist and underwent a complete allergological work-up which included skin prick tests and a careful clinical history record. Data from atmospheric pollen count were recorded.ResultsIn the months between 10th of May and 10th of June 2010, a total of 86 accesses to same Emergency Department were recorded for asthma exacerbations, 20 of them during the studied day. Patients’ mean age was 44.25 ± 18.5 years (range: 9–81), 8/20 females, 2 smokers, 16 with a previous history of known respiratory allergy. All 20 patients were sensitized to Olea europaea pollen, 7 of which were monosensitized. Other sensitizations were: 10 patients to grass, 7 to parietaria, 5 to compositae, 5 to cypress, 5 to house dust mites, 3 to dog and 1 to cat danders. Mean atmospheric pollen count was 170 granules/m3 for Olea europaea and 60 granules/m3 for grass pollen.ConclusionsThis is, in our knowledge, the second thunderstorm-related asthma episode described in Mediterranean area and the first one in which sensitization to Olea europaea played a key-role. This result should focus the possibility that not only the increase of molds and grass pollen load after a thunderstorm may raise asthma exacerbations.

Rentrées des classes….retour de l’asthme

After schools open in September, epidemics of acute, sometimes severe, asthma begin, resulting in emergency room admissions for numerous pre-school and school-age children. Known as “September asthma epidemics”, they have been described in many countries (Canada, the USA, the United Kingdom, Australia, Finland, etc.) although they are still generally unknown in France, even though they have been described and reported there. They involve mainly school-aged children between 5 and 10 years of age. At the end of the summer, asthma control must be evaluated, and standard treatment reinforced if control is not optimal. It is then often necessary to re-start the basic treatment in children whose therapy had been stopped for the summer in order to improve global treatment compliance during the course of the coming year. In no case should a break in the basic therapy coincide with the return to school because of the risk of rapidly losing the benefit of the decreasing treatment.