Nocardia infection
Nocardiosis
Nocardia infection (nocardiosis) is a disorder that affects the lungs, brain, or skin. In otherwise healthy people, it may occur as a local infection. But in people with weakened immune systems, it may spread throughout the body.
Antigens are large molecules (usually proteins) on the surface of cells, viruses, fungi, bacteria, and some non-living substances such as toxins, chemicals, drugs, and foreign particles. The immune system recognizes antigens and produces antibodies that destroy substances containing antigens.
Causes
Nocardia infection is caused by a bacterium. It usually starts in the lungs. It may spread to other organs, most often the brain and the skin. It may also involve the kidneys, joints, heart, eyes, and bones.
Nocardia bacteria are found in soil around the world. You can get the disease by breathing in dust that has the bacteria. You can also get the disease if soil containing nocardia bacteria gets into an open wound.
You are more likely to get this infection if you have long-term (chronic) lung disease or a weakened immune system, which can occur with transplants, cancer, HIV/AIDS, and long-term use of steroids.
Symptoms
Symptoms vary and depend on the organs involved.
If in the lungs, symptoms may include:
- Chest pain when breathing (may occur suddenly or slowly)
- Coughing up blood
- Fever
- Night sweats
- Weight loss
If in the brain, symptoms may include:
If the skin is affected, symptoms may include:
- Skin breakdown and a draining tract (fistula)
- Ulcers or nodules with infection sometimes spreading along lymph nodes
Some people with nocardia infection have no symptoms.
Exams and Tests
The health care provider will examine you and ask about your symptoms.
Nocardia infection is diagnosed using tests that identify the bacteria (Gram stain, modified acid-fast staining or culture). For example, for an infection in the lung, a sputum culture may be done.
Depending on the part of the body infected, testing may involve taking a tissue sample by:
- Brain biopsy
- Lung biopsy
- Skin biopsy
Treatment
You will need to take antibiotics for 6 months to a year or longer. You may need more than one antibiotic.
Surgery may be done to drain pus that has collected in the skin or tissues (abscess).
Outlook (Prognosis)
How well you do depends on your overall health and the parts of the body involved. Infection that affects many areas of the body is hard to treat, and some people may not be able to recover.
Possible Complications
Complications of nocardia infections depend on how much of the body is involved.
- Certain lung infections may lead to scarring and long-term (chronic) shortness of breath.
- Skin infections may lead to scarring or disfigurement.
- Brain abscesses may lead to loss of neurological function.
When to Contact a Medical Professional
Contact your provider if you have any symptoms of this infection. They are nonspecific symptoms that can have many other causes.
References
Chen SC-A, Watts MR, Maddocks S, Sorrell TC. Nocardia species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 253.
Southwick FS. Nocardiosis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 314.
Version Info
Last reviewed on: 12/4/2022
Reviewed by: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
