Aspergillosis is the name of a group of conditions caused by a fungal mould called aspergillus.

Aspergillosis is caused by breathing in small spores of aspergillus mould. Most people’s immune systems will quickly isolate and destroy the mould before it can spread to their lungs.

However, a person with damaged lungs or a weakened immune system is more likely to develop aspergillosis after breathing in aspergillus spores.

Aspergillosis isn’t contagious and can’t be passed between people or animals. It is a common fungal infection that can affect people with structural lung disease, such as bronchiectasis or old TB cavities and immune deficiency.

Humid conditions and aspergillus

The mould Aspergillus thrives in humid conditions such as damp, warm conditions. Doctors have recently warned that wet washing dried indoors can pose a health threat for people with weakened immune systems.

Our advice is that although complete avoidance of moulds is difficult, people should be aware that household plants frequently carry mould, often visibly and that damp environments promote mould growth. To help prevent this try and keep your main living and sleeping space dry, as far as possible. If washing is dried inside, try to do this in a well-ventilated space or consider getting a dehumidifier.

This page was reviewed by Dr Matthew Buckland, Chair of our Medical Advisory Panel, August 2022.