Aspergillosis

Aspergillosis
Pulmonary invasive aspergillosis in a person with interstitial pneumonia (autopsy material), using Grocott's methenamine silver stain
Pronunciation	/ˌæspərdʒɪlˈoʊsɪs/
Specialty	Infectious disease
Complications	Bleeding, systemic infection[1]
Causes	Aspergillus fungal infection
Frequency	14 million

Aspergillosis is a fungal infection of usually the lungs,^[2] caused by the genus Aspergillus, a common mould that is breathed in frequently from the air, but does not usually affect most people.^[3][4] It generally occurs in people with lung diseases such as asthma, cystic fibrosis or tuberculosis, or COVID-19 or those who are immunocompromized such as those who have had a stem cell or organ transplant or those who take medications such as steroids and some cancer treatments which suppress the immune system.^[2][5] Rarely, it can affect skin.^[5][6]

Aspergillosis occurs in humans, birds and other animals. Aspergillosis occurs in chronic or acute forms which are clinically very distinct. Most cases of acute aspergillosis occur in people with severely compromised immune systems such as those undergoing bone marrow transplantation.^[7] Chronic colonization or infection can cause complications in people with underlying respiratory illnesses, such as asthma,^[8] cystic fibrosis,^[9] sarcoidosis,^[10] tuberculosis, or chronic obstructive pulmonary disease.^[11] Most commonly, aspergillosis occurs in the form of chronic pulmonary aspergillosis (CPA), aspergilloma, or allergic bronchopulmonary aspergillosis (ABPA).^[12] Some forms are intertwined; for example ABPA and simple aspergilloma can progress to CPA.

Other, noninvasive manifestations include fungal sinusitis (both allergic in nature and with established fungal balls), otomycosis (ear infection), keratitis (eye infection), and onychomycosis (nail infection). In most instances, these are less severe, and curable with effective antifungal treatment.

The most frequently identified pathogens are Aspergillus fumigatus and Aspergillus flavus, ubiquitous organisms capable of living under extensive environmental stress. Most people are thought to inhale thousands of Aspergillus spores daily but without effect due to an efficient immune response. Invasive aspergillosis has a 20% mortality at 6 months.^[13] The major chronic, invasive, and allergic forms of aspergillosis account for around 600,000 deaths annually worldwide.^{[10][14][15][16][17]}