Aspergillosis is the name of a group of conditions caused by a fungal mould called aspergillus.
It usually affects the respiratory system (windpipe, sinuses and lungs), but it can spread to anywhere in the body.
Depending on a number of factors, the symptoms of aspergillosis can vary in severity from mild wheezing to coughing up blood. Someone with a weakened immune system is at greater risk of being more severely affected.
What causes aspergillosis?
Aspergillosis is caused by breathing in small spores of aspergillus mould. Most people's immune systems will quickly isolate and destroy the mould before it can spread to their lungs.
However, a person with damaged lungs or a weakened immune system is more likely to develop aspergillosis after breathing in aspergillus spores.
Aspergillosis isn't contagious and can't be passed between people or animals.
Read more about the causes of aspergillosis.
When to see your GP
You should contact your GP immediately if you have symptoms that suggest you may have an infection, such as a fever or persistent coughing, and:
- you're taking medication to suppress your immune system (immunosuppressants) after an organ or bone marrow transplant
- you have a condition known to weaken the immune system, such as cancer
Your GP will check your symptoms and carry out a physical examination. Further tests will be needed to confirm a diagnosis if they think you may have aspergillosis. The type of tests you'll have will depend on the type of aspergillosis suspected.
Read more about diagnosing aspergillosis.
Types of aspergillosis
There are four main types of aspergillosis in the lungs. They are:
- allergic bronchopulmonary aspergillosis (ABPA) and severe asthma with fungal sensitisation (SAFS)
- chronic pulmonary aspergillosis (CPA), including aspergilloma
- invasive pulmonary aspergillosis (IPA)
- aspergillus bronchitis and tracheobronchitis
There are also a number of other types of aspergillosis, including aspergillus sinusitis, postoperative aspergillosis, and fungal keratitis. This topic concentrates on the four main types that affect the lungs.
Allergic bronchopulmonary aspergillosis and severe asthma with fungal sensitisation
Allergic bronchopulmonary aspergillosis (ABPA) is caused by an allergic reaction to the spores of the aspergillus mould. It's the mildest form of aspergillosis.
ABPA usually affects people with asthma or other respiratory disorders, such as cystic fibrosis, tuberculosis or chronic obstructive pulmonary disorder (COPD).
Globally, ABPA affects around 2.5% of adults with asthma (4.8 million out of 193 million). It's estimated that severe asthma with fungal sensitisation (SAFS) affects 3.25 to 13 million adults worldwide, depending on the frequency of severe asthma (5 to 20% of all people with asthma).
Both ABPA and SAFS can be treated with antifungal medication.
Chronic pulmonary aspergillosis
Chronic pulmonary aspergillosis (CPA) is a long-term lung infection. Aspergillus fumigatus is usually the species of fungal mould responsible. Most people with CPA have an underlying lung condition.
If you have CPA, you may also have an aspergilloma (a fungal ball found in a single lung cavity). Aspergillomas are common in people with cystic fibrosis or cavities (spaces) in their lungs. Coughing up blood is a common symptom.
If there are cavities in the lungs but no fungal ball, the condition is known as chronic cavitary pulmonary aspergillosis.
Pulmonary aspergillosis can cause the lungs to become permanently scarred if it isn't treated.
Invasive pulmonary aspergillosis
Invasive pulmonary aspergillosis (IPA) usually only affects people with lowered immunity, such as those who have received a bone marrow transplant or cancer treatment, or those with HIV or AIDS. It's the most serious type of aspergillosis.
If you have IPA, it's likely you will have a raised temperature (slightly increased, but not necessarily to the level of a fever) as well as lung symptoms, such as a cough, chest pain or breathlessness, that can't be treated with normal antibiotics.
In people with a severely weakened immune system, the fungus can spread through the bloodstream from the lungs to the brain, eyes, heart or kidneys. This is very serious and can be life threatening if it's not diagnosed and treated quickly. Hospitalisation and treatment with antifungal medication will be needed.
IPA is estimated to occur in:
- 5 to 13% of people who've had a bone marrow transplant
- 5 to 25% of people who've had a heart or lung transplant
- 10 to 20% of people who've had high-dose radiotherapy or chemotherapy for leukaemia (cancer of the blood cells)
Aspergillus bronchitis and tracheobronchitis
Aspergillus bronchitis and tracheobronchitis is a rarer type of aspergillosis infection that affects the tracheobronchial tree (the structure that forms the airways that supply air to the lungs, made up of the trachea, bronchi and bronchioles).
Some experts have suggested that the term "tracheobronchitis" should also cover cases where the trachea or bronchi are inflamed, where there is excess mucus production and where aspergillus is the only source of infection.
However, because of the large number of possible clinical features in such cases, there's currently no definitive classification of this type of aspergillosis.
Allergic bronchopulmonary aspergillosis (ABPA) is usually treated with steroid medications to prevent an allergic response. However, if ABPA reoccurs, a long-term course of steroids may be required as well as itraconazole antifungal therapy.
SAFS also improves with steroids and antifungal therapy, although omalizumab may also be helpful.
Chronic pulmonary aspergillosis and aspergilloma, and aspergillus bronchitis and tracheobronchitis, can be treated with antifungal medications taken for long periods. In some cases, surgery may be needed to remove the infection from the lungs.
Invasive pulmonary aspergillosis (IPA) can also be treated with intravenous antifungal medication, but it's difficult to treat. In most people, voriconazole is the best initial therapy.
The infection can spread very quickly, and someone who develops IPA is usually already very ill. Around 50% of people don't respond to treatment and die from the condition.
Read more about how aspergillosis is treated.
It's almost impossible to avoid the aspergillus fungus completely, but there are precautions you can take to prevent aspergillosis.
If you have asthma, a weakened immune system, or a history of lung disease, you should avoid places where the aspergillus fungus is likely to be, such as:
- compost heaps
- grain stores
- rotting vegetation
- piles of dead leaves
- marshland and bogs
If you have a weakened immune system, you may also be advised to take extra precautions, such as wearing a face mask and taking antifungal medicines. This may be the case if you're having chemotherapy, you've recently had an organ transplant, or you're taking high doses of corticosteroid medication.
Read more about preventing aspergillosis.