The genus Aspergillus was first described in 1729 by an Italian priest and biologist Pier Antonio Micheli. It got its name from its spore-forming structure that resembles an aspergillum (instrument used for sprinkling holy water during liturgical services). Aspergillus species are saprophytic (obtain food by absorbing dissolved organic material), asexual and filamentous fungi that are commonly found in soil, water, food items, decaying vegetation, and outside air. Some well-known Aspergillus species are Aspergillus niger (commonly known as black mould), Aspergillus fumigatus and Aspergillus flavus.
What makes Aspergillus thrive?
Aspergillus spp. are ubiquitous environmental moulds that grow and disperse microscopic spores (conidia) into the air in both long and short distances; when they encounter solid or liquid surfaces and the conditions are right, they are deposited and proceed to germinate. They can thrive in environments with high concentrations of oxygen, sugars, and moisture. Aspergillus spp. can also be characterised as oligotrophic where they can grow in nutrient poor environments for example, Aspergillus niger can be found growing on damp bathroom walls, fabrics, or even plastic products.
What can it cause?
Although it is impossible to avoid breathing in Aspergillus conidia every day, human beings have an effective immune system that prevents development of infections from Aspergillus conidia. When the immune system is weakened or compromised, Aspergillus spp. then have an opportunity to start growing within the body, thereby causing aspergillosis.
Aspergillosis is a spectrum of diseases caused by Aspergillus spp. ranging from invasive diseases where the fungus disseminates throughout the body to allergic responses. It is caused by inhaling Aspergillus conidia which affects the respiratory system causing symptoms such as wheezing, shortness of breath and coughing. Aspergillosis is not contagious from person to person.
Prevention & Control
For many years, health experts have warned of the dangers of drying damp clothes on radiators as this can encourage Aspergillus to grow. Areas in the home with excess moisture build-up such as the bathroom and the kitchen show a high potential for fungal growth – to prevent this, remember to open windows to allow air circulation. Taking antifungal medication is another measure of prevention if you are in a high-risk group for developing invasive aspergillosis. Last but not least, it is important to try and avoid areas with a lot of dust like construction and excavation sites.