What is Aspergillosis: Types, Causes, Symptoms, Treatment, Prognosis, Prevention

Fungal infections are not something which is unheard of. Majority of the times, fungal infections occur on the skin, or within moist cavities like mouth or vagina. Fungal infections can cause quite a bit of discomfort, but are generally not considered a serious problem. However, there are certain people who are at risk for serious complications as a result of fungal infections. One of such serious fungal infections is Aspergillosis.

Aspergillosis is one of a fungal infection, which is caused by a species of molds known as Aspergillus. This mold has the potential to cause different types of medical conditions in the human body; however, Aspergillus is commonly associated with respiratory symptoms as the fungal spores enter the human body via inhalation. In people having a weak immune system these Aspergillus spores spread to other parts of body through blood and cause various problems and diseases. People with a healthy immune system are able to provide sufficient defense against aspergillosis and do not develop this fungal infection, aspergillosis, when they get exposed to Aspergillus spores. However, about 1 in 4 asthma patients test positive for the Aspergillus antigen. All in all, it is rare to find a severe case of aspergillosis and is seen in patients who are immune compromised.

Depending on a host of factors, aspergillosis can manifest in different ways which consist of immune sensitivity, affecting the strength of the immune system along with other diseases of the lungs. Types of aspergillosis are:

Allergic Bronchopulmonary Aspergillosis (ABPA): In this type of aspergillosis, the fungi Aspergillus colonize in the lower airways and lead to a hypersensitivity reaction.

Chronic Necrotizing Pulmonary Aspergillosis (CNPA): This form of Aspergillosis is less common and is primarily seen in individuals with a weak immune system and people having lung diseases, such as COPD. CNPA damages the lung tissue.

Aspergilloma: This is a fungal ball, which develops in the cavity in the tissue of the lungs. These cavities often develop because of pre-existing diseases of the lungs, such as sarcoidosis or tuberculosis.

Invasive Aspergillosis: This type of Aspergillosis is the most severe type. Invasive Aspergillosis enters the blood vessels and can spread all over the body. Invasive Aspergillosis is more inclined to develop in patients who have undergone organ transplantation or who are suffering from AIDS.

There are different types of Aspergillus fungi which cause Aspergillosis and some of the common ones responsible for disease in humans include: Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus and Aspergillus terreus. 

Other than these, there are multiple types of Aspergillus fungi, which however cause only minority of diseases. Aspergillus is found in many places in the human habitat, such as in plants, trees, compost, rotting leaves, air conditioning, insulating material, carpets, heating systems, dust and bedding. However, only minority of individuals who have inhaled the mold spores get any disease.

Aspergillosis can affect anybody; however, individuals with weak immune system are at greater risk for developing this disease and people with a strong immune system are able to fight this disease. Other risk factors for Aspergillosis include lung tissue damage or any pre-existing lung disease. Factors or conditions which increase the risk for Aspergillosis are:

• Organ and bone marrow transplantation.
• AIDS.
• Asthma.
• Chemotherapy.
• Prolonged use of steroids.
• Tuberculosis.
• Cystic fibrosis.
• Sarcoidosis.
• Chronic obstructive pulmonary disease (COPD).

Aspergillosis is not a contagious condition and does not pass from person to person.

Symptoms of Aspergillosis depend on the part of the body which is affected. Lungs and lower airways are more prone to developing Aspergillosis, which is why aspergillosis displays various respiratory symptoms such as: Cough, shortness of breath, wheezing, blood in sputum, loss of smell, nasal congestion or runny nose.

Non-respiratory symptoms of aspergillosis that can be seen, especially with invasive aspergillosis are: Fever, headaches, unintentional weight loss, chest pain, skin sores, visual disturbances and bone pain.

The early stages of certain types of aspergillosis may not exhibit symptoms and symptoms of aspergillosis may not be noticeable if other more common conditions are present.

Antifungal medication is given for treating aspergillosis. However, this does not always cure severe types of aspergillosis; especially when treatment is delayed in invasive aspergillosis. In such cases, Antifungal medication is combined with other medications to treat aspergillosis. In case of aspergilloma, patient may also need surgery. The type of antifungal drug used depends on the type of aspergillosis and consists of:

Amphotericin B for treating all the types of aspergillosis.

Itraconazole for treating Aspergilloma, allergic bronchopulmonary aspergillosis and sometimes chronic necrotizing pulmonary aspergillosis.

Caspofungin for treating invasive aspergillosis and chronic necrotizing pulmonary aspergillosis.

Isavuconazole for treating invasive aspergillosis.

Voriconazole for treating invasive aspergillosis and chronic necrotizing pulmonary aspergillosis.

Posaconazole for treating invasive aspergillosis.

Prednisone which is a steroid is used for treating inflammation present in allergic bronchopulmonary aspergillosis. Use of steroids should be limited in patients who have been using steroids for a long period of time and patients with weak immune system. Using steroids for long periods of time, especially in high doses, further weakens the immune system and increases the risk of aspergillosis.

In case of aspergilloma and allergic bronchopulmonary aspergillosis, the prognosis is good. In case of chronic necrotizing pulmonary aspergillosis, and especially when the treatment is delayed, the prognosis is less than good. Prognosis for patients with invasive aspergillosis is poor, especially if the treatment is delayed and if the patient also has pre-existing health conditions, such as HIV/AIDS. The prognosis worsens if the patient has resistance to certain groups of antifungal medicines.

Antifungal medicines can be used in patients who have known risk factors to prevent aspergillosis. As Aspergillosis is not a contagious condition there is no need to prevent exposure to infected patients. Prevention of Aspergillosis can be achieved with reduction to fungi with the use of protective wear like face masks when handling soil or working on a construction site. These preventative measures are more important in individuals with a weak immune system and who have other risk factors.

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