Aspergillus is a type of fungus (a spore-forming mold) commonly found both outdoors and indoors throughout the World. It grows on plants, soil, rotting vegetable matter, household dust, building materials, and food items.
Most people breathe in Aspergillus spores every day without getting sick. But people with weakened immune systems or lung diseases are at a higher risk of developing health problems from Aspergillus exposure. This includes allergic reactions, infections of the lungs, worsening asthma, and infections of other organs.
These diseases can range from mild to life-threatening.
The group of diseases caused by this mold is referred to as aspergillosis.
It has many forms:
• Allergic Aspergillus sinusitis
• Aspergilloma
• Chronic pulmonary aspergillosis
• Invasive aspergillosis
• Cutaneous aspergillosis
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| Aspergillosis |
Signs and Symptoms of Aspergillosis
The different types of aspergillosis can cause different symptoms.
Symptoms of ABPA are similar to those of asthma:
• Shortness of breath
• Cough
Brown or dark mucous (also known as sputum)
Fever in rare cases
Symptoms of allergic Aspergillus sinusitis include the following:
• Runny nose
• Headache
• Reduced ability to smell
Aspergilloma, also known as “fungus ball” in reference to the clump that can grow in a cavity in your lung, has these symptoms:
• Coughing up blood
• Shortness of breath
These are the symptoms of chronic pulmonary aspergillosis:
• Cough
• Coughing up blood
• Fatigue
• Shortness of breath
Invasive aspergillosis tends to occur in people who are already sick from another medical condition or have impaired immunity due to a condition or treatment such as chemotherapy, so it can be challenging to determine which symptoms are related to an Aspergillus infection. That said, symptoms of invasive aspergillosis in the lungs include the following:
• Chest pain
• Cough
• Coughing up blood
• Shortness of breath
Symptoms of cutaneous aspergillosis, which is rare, include red to purplish plaques or papules.
Causes and Risk Factors of Aspergillosis
In most cases, aspergillosis is caused by a type of mold called Aspergillus fumigatus. (There are 180 species of Aspergillus, fewer than 40 of which are known to cause infections in people.)
In addition to being found on dead leaves, compost piles, and decaying vegetable matter, this mold is also known to grow on starchy foods like potatoes or bread, stored grains,and even on spices.
• Most people develop this infection by inhaling mold spores. Infection can also develop when spores enter the body through a cut or open wound.
• Having certain health conditions increases your risk of developing aspergillosis. ABPA is more likely to occur in individuals who have asthma or cystic fibrosis.
• Forms of chronic pulmonary aspergillosis are more likely to occur in individuals who have had a previous lung disease, including tuberculosis and chronic obstructive pulmonary disease, or a disorder that can affect the lungs, like sarcoidosis.
People who have had lung surgery in the past — for example, for lung cancer or a collapsed lung — can also develop this form of the disease.
• Invasive aspergillosis affects people who have weakened immune systems (such as those who've had a stem cell transplant or organ transplant), are undergoing chemotherapy for cancer, or getting high doses of corticosteroids.
• Aspergillomas usually affect people who have other lung diseases that form cavities, such as tuberculosis.
• Other conditions that can increase the risk of developing aspergillosis include using contaminated medical equipment near or in open wounds, and having a traumatic injury to the skin.
Diagnosis
Diagnosing aspergillosis can be difficult because symptoms can be similar to other lung conditions. Your healthcare provider will rely on your medical history, risk factors, symptoms, physical examinations, and lab tests in making a diagnosis.
One or more of the following tests may be used to pinpoint the cause of your symptoms:
• Respiratory secretion (sputum) test, in which a sample of your sputum is stained with a dye and checked for the presence of Aspergillus filaments
• Tissue and blood tests, which may help confirm ABPA
Biopsy of tissues from your lungs or sinuses and blood tests, to confirm invasive aspergillosis
Prognosis of Aspergillus Infection
Allergic forms of aspergillosis such as ABPA and allergic Aspergillus sinusitis typically heal with treatment and are generally not life-threatening.
• Invasive aspergillosis is a serious infection and can be a major cause of mortality in immunocompromised people. According to the Centers for Disease Control and Prevention (CDC), one study found that the one-year survival for people who had invasive aspergillosis was 59 percent among solid organ transplant recipients.
• Another study found a survival rate of 25 percent among stem cell transplant recipients.
• In addition, many of these patients relapse. Over long-term therapy, the fungi may develop resistance to some antifungals.
Duration of Aspergillosis
The duration of the diseases varies depending on underlying health issues, the severity or site of infection, and type of disease.
Allergic forms, like ABPA, may require steroid and antifungal treatment for a few months, possibly longer.
Invasive pulmonary aspergillosis may require treatment with an antifungal medication for at least 6 to 12 weeks. Severe forms may require lifelong treatment and monitoring to control the disease.
Treatment and Medication Options for Aspergillosis
In addition to early diagnosis, early treatment is critical in managing aspergillosis. Depending on the type of disease, you may have the following treatments:
Observation
If you have a simple, single aspergilloma, it often doesn't require treatment; you may instead be monitored with follow-up chest X-rays or CT scans. If your condition progresses, your physician may recommend antifungal medication.
Oral Corticosteroids
ABPA may be treated with antifungal medications combined with corticosteroids to decrease the use of steroids, improve lung function, and prevent existing asthma or cystic fibrosis from worsening. Prednisone (Deltasone), prednisolone (Orapred), and methylprednisolone (Medrol) are some examples.
Antifungal Medications
These drugs are the standard treatment for invasive pulmonary aspergillosis. These medications include voriconazole (VFEND) and amphotericin B (Amphocin, Fungizone).
Surgery
Antifungal medications don’t penetrate an aspergilloma very effectively so surgery may be used to remove the fungal mass when an aspergilloma causes bleeding in the lungs.
Arterial Embolization
This procedure can be used to temporarily stop bleeding caused by an aspergilloma.
Prevention of Aspergillus Infection
The type of mold that causes most forms of aspergillosis, Aspergillus fumigatus, is common in our environment. Fortunately, everyday exposure is rarely a problem for people with healthy immune systems. When mold spores are inhaled by a healthy individual, the immune system surrounds and destroys them.
• People with weakened immune systems, who are at a greater risk of infection, can take a few steps to help prevent illness:
• Avoid activities that include close contact with soil or dust, such as yard work or gardening. If you do these activities, especially if you handle soil, moss, or manure, wear shoes, long pants, and a long-sleeved shirt.
• Clean any cuts or skin abrasions well with soap and water, especially if they've been exposed to soil or dust.
• Use antifungal medication. Your doctor might prescribe medication to prevent aspergillosis if you're at a high risk for developing invasive aspergillosis (for example, if you’ve had an organ transplant or a stem cell transplant).
• Test for early infection. Blood tests to detect invasive aspergillosis may help some high-risk patients.
Complications of Aspergillosis
Depending on the type of infection, aspergillosis can cause a variety of serious complications.
Aspergillomas and invasive aspergillosis can cause severe bleeding in your lungs, which can be fatal.
The most serious complication of invasive aspergillosis is the spread of the infection to other parts of your body, especially the brain, heart, and kidneys. Invasive aspergillosis spreads rapidly and may be fatal.
Research and Statistics: Who Has Aspergillosis?
• It's difficult to determine the exact number of cases because aspergillosis is not a reportable infection in the United States, since it is not contagious.
• It can potentially affect individuals of any age, and mild cases may go undiagnosed.
• According to the CDC, ABPA likely affects between 1 and 15 percent of people with cystic fibrosis.
• One study found that worldwide 2.5 percent of adults with asthma also have ABPA. Of these approximately 4.8 million people, an estimated 400,000 also have chronic pulmonary aspergillosis (CPA).
• An estimated 1.2 million people worldwide have CPA after having tuberculosis, and over 70,000 people are estimated to have CPA as a complication of sarcoidosis.
• Aspergillosis has been reported all over the world. According to the National Organization for Rare Disorders (NORD), chronic pulmonary aspergillosis is estimated to affect about 3 million people worldwide.
Related Conditions of Aspergillosis
Severe asthma with fungal sensitization (SAFS) is a condition related to ABPA. With SAFS, asthma is severe in the presence of an allergy to Aspergillus or other molds, but only mild symptoms of Aspergillus infection are detected.
Mucormycosis is a general term for a group of uncommon infections caused by a fungus and specifically refers to a mold infection. As with aspergillosis, these infections are usually acquired when spores are inhaled or, less commonly, enter through a cut in the skin.
