Microbe of the Month: Alternaria
Classification Type: Fungi
Cultured from / Found in HVAC: Coiling Coils, Diffusers, Grilles, Filters, Drain Pans, Humidifiers
Noted Health Risks:
Pulmonary Diseases, Asthma, Allergies
There are over 250 known species of Alternaria. Alternaria is a genus of Deuteromycetes fungi. Alternaria species are known as major plant pathogens. They are also common allergens in humans, growing indoors and causing hay fever or hypersensitivity reactions that sometimes lead to asthma.
Alternaria is found both indoors and outdoors. Outside it can be seen in damp places such as on dead plant material, grass with dew and overwatered soil. These spores can spread indoors and be found in carpets, wallpaper, window frames and air conditioning systems.
Here are some health risks associated with Alternaria:
- Allergic reactions: Alternaria is a common outdoor mould and a known allergen. It can trigger allergic reactions in susceptible individuals, leading to symptoms such as sneezing, runny or congested nose, itchy or watery eyes, coughing, and wheezing. In some cases, it may exacerbate asthma symptoms. 
- Asthma: Exposure to Alternaria has been linked to the development or worsening of asthma symptoms in susceptible individuals. It can trigger asthma attacks, leading to wheezing, shortness of breath, chest tightness, and coughing. 
- Respiratory infections: In rare cases, individuals with weakened immune systems or pre-existing respiratory conditions may be at risk of developing respiratory infections caused by Alternaria. These infections can manifest as pneumonia or sinusitis. 
It's important to note that the health risks associated with Alternaria can vary depending on individual susceptibility, the amount and duration of exposure, and other factors. If you suspect that you have been exposed to Alternaria and are experiencing concerning symptoms, it is recommended to consult with a healthcare professional for proper evaluation and guidance.
 Rosenberg, M., & Patterson, R. (2005). Epidemiology of allergic rhinitis: clinical presentation. Journal of Allergy and Clinical Immunology, 115(2 Suppl), S460-S464. doi: 10.1016/j.jaci.2004.12.002  Kanchongkittiphon, W., Gaffin, J. M., & Phipatanakul, W. (2017). The indoor environment and inner-city childhood asthma: Addressing the allergens. Children (Basel, Switzerland), 4(7), 56. doi: 10.3390/children4070056  Thompson, G. R., & Patterson, T. F. (2016). Fungal disease in the setting of human immunodeficiency virus infection. Clinical Microbiology Reviews, 29(4), 806-822. doi: 10.1128/CMR.00058-15
Safe indoor air from a serviced HVAC system means a lower particle count and less breathing difficulties for occupants of the building. Clean-Air are IICRC mould remediation experts with the knowledge and experience to test, treat and eliminate serious mould-related risks within your HVAC system. If you have concerns about the air you are breathing, or would like an HVAC health check, contact our team today.