Teresa Mitakakis

Personal exposure to allergenic pollen and mould spores in inland New South Wales, Australia

In inland NSW, Australia, allergic sensitization to the fungi Alternaria and Cladosporium and to pollen is common and an important risk factor for asthma.

Natural exposure to Alternaria spores induces allergic rhinitis symptoms in sensitized children.

Allergic rhinitis is associated with exposure to inhaled allergens. Allergic sensitization to the fungus Alternaria is common, especially in warm climates, but the relevance of sensitization to Alternaria in the generation of rhinitis has not been elucidated. The aim of this study was to determine whether natural exposure to Alternaria induces rhinoconjuctivitis symptoms in Alternaria‐sensitized children. Symptoms of rhinoconjuctivitis in 132 atopic (measured by skin prick tests) children (aged 7–12 years) in inland New South Wales Australia were measured using parent‐completed questionnaires in summer and winter 1998. Airborne concentrations of Alternaria spores and grass pollen were measured throughout the study period using a Burkard volumetric trap. The relation between airborne concentrations of Alternaria spores and symptoms of rhinoconjunctivitis was examined using Wilcoxons matched pairs signed ranked test and generalized estimating equations. The proportion of children atopic to Alternaria reporting symptoms of rhinitis was significantly higher in the summer, when airborne concentrations of Alternaria were high, than in the winter, when airborne concentrations were low (66.2% vs. 38.2% for nasal symptoms at night, p = 0.0001, 70.6% vs. 51.52% for nasal symptoms during the day, p = 0.02). The proportion of children using anti‐allergic treatment was also higher in summer than in winter (anti‐allergic medication for the nose 39.7% vs. 17.7%, p = 0.0003). A strong correlation between airborne concentrations of grass pollen and Alternaria was found (R = 0.94, p < 0.001). However, when all children atopic to ryegrass were excluded from the analyses, significant associations between symptoms and season remained. We conclude that exposure to Alternaria spores may be an important cause of allergic rhinoconjunctivitis.

The effect of local cropping activities and weather on the airborne concentration of allergenic Alternaria spores in rural Australia

Atopy to the fungus Alternaria is strongly associated with respiratory disease. The prevalences of asthma and of allergy to Alternaria are high amongst children living in rural towns of south-eastern Australia. In such towns, airborne allergenic spores have been proposed to arise from nearby crops, but this has not been tested and crops are unlikely to be the only sources of Alternaria . We sought to identify sources and factors that influence concentrations of spores of Alternaria detected in rural towns. Over two years, we sampled spores in two towns (Wagga Wagga and Moree, New South Wales, Australia), in nearby wheat and cotton crops during harvesting and control periods, in a cotton gin and a grain shed. Alternaria was present in both towns throughout the study, and above the crops, at the gin and grain shed. Daily and annual concentrations were amongst the highest recorded worldwide and peaks persisted for six months in Wagga Wagga and ten months in Moree. Crop maturation affected the spore load in the air more than the actual days of harvest. Regression analysis showed that the overall spore concentrations above towns correlated with those above crops. Variables of rainfall and maximum temperature correlated with concentrations in both towns, and additionally wind direction in Wagga Wagga. In conclusion, crops and produce handling released spores into the air that reached nearby rural towns, with peaks in spore concentrations following warm temperatures and recent rainfall.

Four methods of sampling for dust mite allergen: differences in ‘dust’

Background: Measurement of exposure to the dust mite allergen Der p 1 is important in asthma research and is potentially useful in managing asthma. As no single measure can capture all characteristics of an exposure, it is important to recognize differences in the available methods of measuring exposure to Der p 1.

Particulate masks and non‐powdered gloves reduce latex allergen inhaled by healthcare workers

Background Although allergy to latex is a well‐characterized phenomenon, some hospitals continue to provide staff with powdered latex gloves as an option to low‐ or non‐powdered gloves.

Reliability of measures of spores of Alternaria and pollen concentrations in air over two towns in rural Australia

We examined the reliability of measurements from a single Burkard volumetric trap to represent the distribution of airborne concentrations of spores of Alternaria and pollen across two towns in rural Australia. Each town was sampled with three traps, sited 2.0 to 4.9 km apart, simultaneously. Substantial intra-class correlation coefficients (ICC) were observed between all three sites (ICC∼0.52, 95% CI 0.30-0.71 to 0.76, 95% CI 0.61-0.87) when counts of pollen and Alternaria spores were relatively high. The correlation was poor when counts were low. Highly variable distributions of cypress pollen were found to be location dependent. We further compared two central lengthwise microscopic traverses of Burkard trap samples collected daily over one year. Correlation was strong for Alternaria spores (ICC∼0.95, 95% CI 0.94-0.96), grass pollen (ICC∼0.94, 95% CI 0.91-0.96) and total non-grass pollen (ICC∼0.91, 95% CI 0.89-0.93). We conclude that a single central traverse of a Burkard trap sample collected at one location provides an acceptable measure of the concentrations of spores of Alternaria and grass pollen across the two rural towns when counts are relatively high. The measure is less reliable when counts are low.

Evidence for the genetic control of immunoglobulin E reactivity to the allergens of Alternaria alternata

Background The fungus Alternaria alternata contains potent allergens, and sensitization to these allergens is associated with a high risk of respiratory disease. The influence of genetic regulation on sensitization to Alternaria is unknown.

Predictors of house-dust-mite allergen concentrations in dry regions in Australia

Background: House‐dust‐mite allergen content differs between houses and is thought to be a function of the housing characteristics and furnishing choices that affect indoor microclimate and mite proliferation. The importance of these features may differ with regional climates.