First Fungal Spore Calendar Developed for Patients with Asthma, Allergies

A fungal spore calendar has been developed by University of Leicester researchers as a tool to allow patients with allergies and asthma to better manage their symptoms through seasonal awareness.¹

The calendar provides individuals with asthma and allergies the ability to note seasonal patterns related to airborne spores. The development of this calendar resulted from new research authored in part by Fiona A. Symon, from the department of respiratory sciences at the University of Leicester in the UK.

“We hope that the calendar becomes an invaluable resource for patients managing chronic respiratory conditions, who can use it as a tool to plan activities, manage symptoms, and, if needed, increase preventive measures during these high-risk seasons,” Symon said in a statement.²

Analysis and Findings

Through microscopy, the research team identified 23 fungal spores within daily air samples that had been gathered from 2007 - 2020 in Leicester. The team thus was able to formulate a spore calendar for the 9 most abundant spores: Alternaria, Tilletiopsis and Ustilago, Cladosporium, Didymella, Sporobolomyces, Leptosphaeria, Aspergillus/Penicillium type, and colored basidiospores.

The investigators highlighted the large degree of variability in concentrations of total spores and daily maximal peak concentrations across the course of their analysis, though they also found that temporal distributions had been consistent. The spore season was bimodal, with the main peak period being in the summer months, coinciding with the greatest variety of species, followed by a smaller peak in autumn, mainly due to basidiospore release.

Among those in their collected list, the research team noted that Cladosporium, Alternaria, and Aspergillus/Penicillium are known allergens. The remainder had been implicated in allergy and thunderstorm asthma circumstances.

The peak season for spores was shown to have a much slower decline than that of grass pollen, and this coincided with the steady decline in prescription for antihistamines. Such a conclusion suggests that fungal spores may have a role in late summer hay fever, a result seen for Cladosporium as well.

They looked at the months in which spores hit their peak concentrations, noting that in individual fungal genera, Ustilago, had been the first to reach its peak concentration level by June. This was then followed later by Tilletiopsis, Cladosporium, and Sporobolomyces, all of which hit their peak in July as well as August. Levels for Alternaria and Didymella rose in July and later hit their peak level in August.

The investigatiors found that colored basidiospore concentrations rose steadily over the course of the summer, without a peak until the months of autumn. Both Aspergillus/Penicillium type and Leptosphaeria were shown to be the earliest and longest spore seasons.

The primary meteorological factors affecting fungal spore concentrations were temperature and precipitation. "Wet weather" spores such as Tilletiopsis, Didymella, and Sporobolomyces, was shown to be associated with precipitation levels (P < .01). Spores known for "dry weather" such as Alternaria and Cladosporium had concentrations with a strong correlation to daily temperature (P < .01).

Over the 13-year period analyzed, the overall spore concentration displayed a statistically significant decline (P = .03), largely attributed to reductions in Sporobolomyces and Tilletiopsis (P = .03 and .05, respectively). This was also attributed to Didymella and Leptosphaeria decreases.

Such a decline in "wet weather" spore levels was linked to a notable decrease in daily levels of rain (R² = 0.3234, P = .04). The investigators highlighted the contrast with the noted concentrations of Alternaria and Cladosporium, which showed an upward trend.

Additionally, the number of days in each year when levels of Alternaria went past their allergenic thresholds also rose significantly (P = .02). The research team highlighted the implications this could have for allergy management and for clinical outcomes.

“In the UK, fungal allergies affect as many as 30% of hay fever sufferers and up to 70% of those with severe asthma, making fungal spores a significant health concern,” Symon said in a statement. “Through our analysis we discovered two main peaks in spore concentrations: a primary peak in the summer and a smaller, secondary peak in the autumn.”²

The spore calendar was said to be accessible through the University of Leicester's website.¹

References

1. ^{Symon, F.A., Anees-Hill, S., Satchwell, J., Fairs, A., Edwards, R., Wardlaw, A.J., Cuthbertson, L., Hansell, A.L. and Pashley, C.H. (2024), A fungal spore calendar for England: Analysis of 13 years of daily concentrations. Allergy. https://doi.org/10.1111/all.16356. Date accessed: November 13, 2024.}
2. ^{New Fungal Spore Calendar helps allergy and asthma sufferers plan for better health. University of Leicester. November 7, 2024. https://le.ac.uk/news/2024/november/fungal-calendar. Date accessed: November 13, 2024.}