Aspergillosis: A Secondary Complication in COVID-19
Dr. Rajiv R Sahay, CIAQP, FIAS, Laboratory Director
Aspergillus is a rapidly growing fungi that produce pigmented colonies of a green, yellow, brown, or black shade within ten days when incubated at 25°C (77°F). This mold is very common worldwide and is reported both from indoor and outdoor environments. It can be isolated from air, plants, foodstuffs, soil, sand beaches, caves, and mines, activated sludge, mangrove swamps, freshwater, compost, animal dung, silage, fodder, and cotton fabrics in the tropics. Some species are thermotolerant (50°C), some species are allergenic, and other species produce powerful mycotoxins. They are one of the most common causes of systemic fungal disease in humans and animals causing primarily acute or chronic respiratory tract infections.
Aspergillosis is an infection caused by a common mold known as Aspergillus which triggers allergic reactions and can develop as a mild to serious lung infection that affects the respiratory system. People with weakened immune systems or are suffering from lung diseases are at a higher risk of developing complications due to Aspergillus. The main route of exposure is through the respiratory system. The signs and symptoms of aspergillosis infection varies depending on the exposure and severity of illness. Initially, it may not exhibit any symptoms, but it may produce a mild cough. When Aspergillus invades the lungs of persons with certain chronic lung (pulmonary) conditions, such as emphysema, tuberculosis, or advanced sarcoidosis; the fungal filaments can occupy the air spaces (cavities) caused by these diseases and form a tangled mass known as aspergilloma.
In more severe forms of the infection, it affects and spreads rapidly from the lungs to the brain, heart, kidneys, or skin and is commonly known as invasive aspergillosis. Signs and symptoms may vary depending on the organs affected, although some important symptoms due to invasive aspergillosis includes fever and chills, a cough that brings up blood (hemoptysis), shortness of breath, chest or joint pain, headaches or eye symptoms, skin lesions, and others. Besides the lungs, Aspergillus can also infect the sinuses which may cause stuffy nose, fever, facial pain, and headaches etc.
Aspergillosis and COVID-19
People with the following conditions are at a higher risk of developing aspergillosis: weakened immune system, lower white blood cell levels, lung cavities, asthma or cystic fibrosis, and others.
It has been reported in many studies that patients with COVID-19 caused by Sever Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) have been reported with Aspergillus as a co-infectious agent. COVID-19 associated pulmonary aspergillosis (CAPA) is reported in patients based on the presence of the fungal antigen β-D-glucan (fungal marker) in their serum. The rate of CAPA varies between 4% to 35%. COVID-19 may be an underlying risk of pulmonary aspergillosis, even in patients not previously known to be immunosuppressed. In COVID-19 patients, diagnostics for Aspergillus and other agents that may cause respiratory ailments should be considered. This will minimize the risk of fungal and other agents to prevent putative invasive pulmonary aspergillosis in COVID-19 patients.
The air-borne Aspergillus, which may cause aspergillosis is a major threat to immunocompromised or COVID-19 suffering patients. The spores of Aspergillus are widely distributed and transported in environment due to their air-borne nature (conidia size, etc.).
Recent developments in IAQ technologies are helpful in minimizing the risk of aspergillosis, especially those caused by aerially transmitted Aspergillus spores. Periodical and routine maintenance of HVAC (Heating, Ventilation and Air Conditioning) and air-conveyance systems is effective not only in minimizing the risk of conidial dispersal, but also in identifying the environmental conditions that may also be responsible for the growth and dispersal of Aspergillus within an environment. Building health checks and diagnostic evaluations are important tools for assessing the overall Aspergillus incidence within facilities including, hospitals, healthcare facilities, residential, commercial and other types of building. To minimize the risk of aspergillosis in midst of the COVID-19 pandemic, proactive and reactive environmental sampling with advanced IAQ technology is encouraged for identifying Aspergillus and other particulates which may be linked to environmental Aspergillus infection.
For more information on Aspergillus or Environmental Coronavirus Testing please contact EDLab today.