What is Aspergillosis?

Diseases caused by the fungus Aspergillus are called aspergillosis. The severity of aspergillosis is determined by various factors, but one of the most important is a weakened immune system. Infections can effect any area of the body, but by far the most common are the lungs and sinuses. There are several distinct types of aspergillosis as described briefly below.

Aspergilloma and chronic pulmonary aspergillosis

In this disease the fungus - usually Aspergillus fumigatus -  grows within a cavity of the lung, which was previously damaged during another lung  illness such as tuberculosis or sarcoidosis. The spores penetrate the cavity and germinate, if a fungal ball forms within the cavity it is called an aspergilloma.

Any lung disease which causes cavities in a lung can leave a person open to developing an aspergilloma see underlying diseases.  In some people, cavities in the lung are formed by Aspergillus, and no fungal ball is present. The fungus secretes toxic and allergic products, which may make the person feel ill. The person affected may have no symptoms (especially early on). Weight loss, chronic cough, feeling rundown and tired are common symptoms. Coughing of blood (haemoptysis) can occur in up to 50-90% of affected people and can be severe.

Allergic bronchopulmonary aspergillosis (ABPA)

This is a condition, where a person develops an allergy to the spores of the Aspergillus moulds. Asthmatic patients can be allergic to Aspergillus spores - up to 5% of asthmatics might get this at some time during their lives.

ABPA is also common in cystic fibrosis patients, as they reach adulthood. The symptoms are similar to those of asthma: intermittent episodes of feeling unwell, coughing and wheezing.

Invasive aspergillosis

People with invasive aspergillosis usually have a fever and some lung symptoms (may be a cough, chest pain, discomfort or breathlessness) which do not respond to standard antibiotics. This condition is usually only diagnosed in a person with low defences such as a bone marrow transplant patient, following cancer treatment, or AIDS patients or major burns cases. There is also a rare inherited condition that gives people low immunity (chronic granulomatous disease) which puts affected people at moderate risk.

Chest X-rays and CT scans show abnormalities  and help to locate the disease. Bronchoscopy (inspection of the inside of the lung with a small tube inserted via the nose) is often used to help to confirm the diagnosis along with cultures and blood tests.

In people with particularly poor immune systems, the fungus can transfer from the lung through the blood stream to the brain or to other organs, including the eye, the heart, the kidneys and the skin. Usually this is a bad sign as the condition is more severe and the person is very ill. This condition can be fatal and the best chance of survival is with an early diagnosis and early treatment with antifungals.

Aspergillus sinusitis

Aspergillus disease can happen in the sinuses leading to Aspergillus sinusitis. Just as in the lungs, Aspergillus can cause the three diseases in the sinus - allergic sinusitis, a fungal ball or invasive sinus aspergillosis. The fungal ball caused by Aspergillus happens in a similar way to an aspergilloma. In those with normal immune systems, stuffiness of the nose, chronic headache or discomfort in the face is common.

When patients have damaged immune systems - if, for example they have had cancer or have had a bone marrow transplant - Aspergillus sinusitis is more serious. In these cases the sinusitis is a form of  invasive aspergillosis. The symptoms include fever, facial pain, nasal discharge and headaches. The diagnosis is made by finding the fungus in fluid or tissue from the sinuses and with scans.

Antifungal treatments

There are a number of antifungal drugs that are used to treat aspergillus infections - each type of aspergillosis may require different medication, this is described in more detail here, with patient information leaflets also available. The principle antifungal drugs used for the treatment of aspergillosis are Amphotericin B, Itraconazole, Voriconazole, Posaconazole, Caspofungin and Flucytosine. Some resistant strains of Aspergillus species have been identified so antifungal drug resistance is monitored alongside blood levels of a drug to check optimal dosing.