30 January 2025
The extensive use of azole fungicides (azoles), particularly in some agricultural and horticultural practices, can increase the risk of Aspergillus fungi developing resistance to essential antifungal treatments. This significant finding is highlighted in a report by the five EU health and environment agencies, with support from the European Commission’s Joint Research Centre (JRC). The Agencies collaborated under a One Health approach to address this growing threat.
For the first time, the five EU health and environment agencies – EFSA, ECDC, ECHA, EEA, and EMA[1]– supported by the JRC, reviewed how the use of azole substances outside human medicine affects public health.
Azole medicines are essential for treating aspergillosis, a serious infection caused by Aspergillus fungi. However, these fungi are increasingly becoming resistant to azole therapies, making treatment less effective.
Azole substances are widely used in plant protection products (‘pesticides’) to control fungal diseases in agriculture and horticulture, as veterinary medicines to treat fungal infections in animals, as biocides in wood preservatives, as industrial chemicals (e.g. intermediates and dyes), and in cosmetics (e.g. as anti-dandruff agents).
The joint report highlights that their broad use outside human medicine, particularly in agriculture, contributes to the risk of Aspergillus becoming azole-resistant. Exposure to environments where azole fungicides are used, such as agricultural sites and woodwork, can potentially increase the risk of infection with azole-resistant Aspergillus spp.
Data collected from EU/EEA countries (2010–2021) and included in the report detail the use of azole fungicides across Europe. Plant protection products account for most of the reported sales across all sectors.
One Health: main recommendations
Tackling azole resistance in Aspergillus requires cross-sectoral collaboration. The One Health approach brought together EU experts from human and veterinary medicine, agriculture and environmental sciences to review existing evidence, identify factors that promote azole resistance, and propose measures to prevent and control it.
Recognising the interconnected nature of this challenge, the Agencies’ experts recommended the following actions:
- Adding new specific requirements to the approval and authorisation processes for azole fungicides;
- Supporting research into and development of new fungicides with innovative mechanisms of action that do not lead to resistance to antifungal medicines used in human treatments;
- Following good agricultural and horticultural practices, properly storing organic waste, managing waste effectively, and using and disposing azole-treated products responsibly;
- Implementing effective waste management for wood treated with azole-based biocides;
- Collecting more data on the uses of azole-based fungicides and of azole-based antifungals;
- Further developing specific technical guidance and risk assessment methodologies to support regulatory decisions on the approval of azole substances and to mitigate the risk of azole resistance in Aspergillus;
- Conducting further research to address existing uncertainties.
The report reinforces the value of a One Health approach in addressing complex health threats like antifungal resistance. By continuing cross-disciplinary collaboration, we can strengthen surveillance, advance research, and implement effective measures to safeguard public health, animal health, and the environment.
[1] The following acronyms are used in this press release: EFSA (European Food Safety Authority), ECDC (European Centre for Disease Prevention and Control), ECHA (European Chemicals Agency), EEA (European Environment Agency), EMA (European Medicines Agency), JRC (the European Commission’s Joint Research Centre).
Links to science
Impact of the use of azole fungicides, other than as human medicines, on the development of azole‐resistant Aspergillus spp.