Aspergillosis is a term used for a range of infections caused by a fungal mould called aspergillus.
Aspergillosis usually affects the lungs, but can spread to almost anywhere in the body.
The infection can range from being mild to life-threatening. Symptoms range from mild wheezing to coughing up blood.
Aspergillosis usually only affects people with pre-existing health conditions, as most healthy people have natural immunity to it.
Types of aspergillosis
There are four main types of aspergillosis:
- allergic bronchopulmonary aspergillosis,
- aspergilloma,
- chronic necrotizing aspergillosis, and
- invasive pulmonary aspergillosis.
The four types are described below.
Allergic bronchopulmonary aspergillosis (ABPA)
Allergic bronchopulmonary aspergillosis (ABPA) is caused by an allergic reaction to spores of fungus mould. It is the mildest form of aspergillosis.
ABPA usually affects people with asthma or cystic fibrosis (an inherited condition where the lungs get plugged up with mucus).
Symptoms include coughing, wheezing and a worsening of asthma symptoms.
Aspergilloma
In aspergilloma, aspergillus fungi enter the lungs and group together to form a dense knot of fungi, called a fungal ball.
Aspergilloma usually only affects people who have a pre-existing lung condition, such as TB, which means that they have cavities (spaces) or damage in their lungs.
Coughing up blood is one of the most common symptoms of aspergilloma. The medical term for coughing up blood is haemoptysis.
Chronic necrotizing aspergillosis (CNA)
Chronic necrotizing aspergillosis (CNA) is a slow spreading, chronic (long-lasting) infection of the lungs by the aspergillus fungus.
CNA usually only affects people with a pre-existing lung condition, or people who have a weakened immune system, as a result of conditions, such as diabetes, liver disease or chronic alcohol abuse (an excessive amount of alcohol can weaken the immune system).
Invasive pulmonary aspergillosis (IPA)
Invasive pulmonary aspergillosis (IPA) is a common infection in people with severely weakened immune systems due to illness or taking immunosuppressants. IPA is the most serious form of aspergillosis.
IPA is a fungal infection in the lungs that then spreads rapidly through the body. The infection can spread to the blood, brain, heart and kidneys.
IPA usually only affects people with a severely weakened immune system, such as:
- people with end-stage HIV,
- people who are undergoing high-dose chemotherapy, and
- people taking medication to suppress their immune system (immunosuppressants) because they have had an organ or bone marrow transplant.
IPA is a medical emergency that requires hospitalisation and prompt treatment with injections of anti-fungal medication.
How common is aspergillosis?
Allergic bronchopulmonary aspergillosis (ABPA)
ABPA is estimated to affect 0.25–0.8% of people with mild to moderate asthma, and 7% of people with cystic fibrosis.
In cases of more severe asthma that can only be controlled with steroid medication, it is estimated that 7–10% of people will have ABPA.
Aspergilloma
Aspergilloma is a common condition in people who have cystic fibrosis or cavities in their lungs.
Chronic necrotizing aspergillosis (CNA)
Chronic necrotizing aspergillosis (CNA) is thought to be a rare condition, but there is little available data to estimate exactly how many people develop CNA. If the symptoms of CNA are mild, it can go undiagnosed during life.
Invasive pulmonary aspergillosis (IPA)
IPA is estimated to occur in 5–13% of people who have had a bone marrow transplant, 5–25% of people who with a heart or lung transplant and 10–20% of people who undergo high-dose radiotherapy for leukaemia (cancer of the blood cells).
Outlook
The outlook for ABPA is good as most people take steroid medications to prevent the allergic response. However, if ABPA reoccurs, a long-term course of steroids may be required.
The outlook for aspergilloma and CNA is fair. Both can be treated with anti-fungal medications. In some cases, surgery may be required to remove the infection from the lungs. This carries an associated risk of complications, particularly in people whose lungs are already damaged.
There is also a risk that the symptom of haemoptysis (coughing up blood) may become life-threatening, and require emergency surgery to stop the source of the bleeding.
Even though IPA can be treated with anti-fungal medication, the outlook is poor. The infection can spread very quickly, and someone who develops IPA is usually already very ill. An estimated 50% of people do not respond to treatment and die from the condition.
Lungs
Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
Immune system
The immune system is the body's defence system, which helps protect it from disease, bacteria and viruses.
Allergic
An allergen is a substance that reacts with the body's immune system and causes an allergic reaction.
Wheezing
Wheezing is the whistling sound made during breathing when the airways are blocked or compressed.
Abscess
An abscess is a lump containing pus, which is made by the body during infection.
Chemotherapy
Chemotherapy is a treatment of an illness or disease with a chemical substance, e.g. in the treatment of cancer.
Kidneys
Kidneys are a pair of bean-shaped organs located at the back of the abdomen, which remove waste and extra fluid from the blood and pass them out of the body as urine.
Heart
The heart is a muscular organ that pumps blood around the body.
Brain
The brain controls thought, memory and emotion. It sends messages to the body controlling movement, speech and senses.