Nocardiosis is a rare infection caused by the Nocardia asteroides bacterium. This type of bacteria can be found in the soil and water of regions around the world. People may become infected with this bacteria when they inhale it or when the bacteria enter an open wound. The infection can’t be spread from one person to another.
Nocardiosis most commonly occurs in the lungs, but it may spread to other areas of the body, such as the:
- digestive system
Though nocardiosis can develop in anyone, the condition is much more likely to affect people with very weak immune systems. An immune system may become compromised as a result of:
- lung disease
- a bone marrow or organ transplant
- the long-term use of steroid medications
In the United States, it’s estimated that 500 to 1,000 cases of nocardiosis occur each year. In about 60 percent of these cases, the infection is related to a weak immune system.
Since a Nocardia infection is usually slow to respond to treatment, it can be life-threatening for those with weakened immune systems, especially if diagnosis and treatment are delayed. It’s important to seek treatment as soon as symptoms develop. This can help prevent the infection from spreading and causing complications.
The symptoms will vary depending on the area of the body that has become infected.
Nocardiosis most commonly affects the lungs. If your lungs are infected, you may experience:
- a fever
- chest pain
- a cough
- night sweats
The skin is the second most commonly affected area. If your skin becomes infected with Nocardia bacteria, you may experience:
- open, seeping sores
- swollen lymph nodes
In some cases, the infection can spread to other parts of the body and cause varying symptoms.
If the infection spreads to your digestive system, you may experience:
- sudden weight loss
- abdominal swelling
If the infection spreads to your brain, you may experience:
Your doctor can diagnose this infection by performing various tests that check for the presence of N. asteroides bacteria. These tests may include the following:
- A chest X-ray is an imaging test that produces detailed images of the lungs.
- A bronchoscopy is a test in which your doctor uses a thin tube with an attached camera to view the lungs.
- A brain biopsy is a procedure that involves removing a small sample of abnormal brain tissue.
- A lung biopsy is a procedure that involves removing a small sample of abnormal lung tissue.
- A skin biopsy is a procedure that involves removing a small sample of abnormal skin cells.
- A sputum culture is a procedure that involves taking a small sample of mucus.
All cases of nocardiosis should be treated with long-term and low-dose antibiotics known as sulfonamides. Treatment typically lasts from six months to a year. However, more severe infections may require treatment for a longer period.
If you develop an abscess due to this infection, your doctor may recommend surgery to drain it.
A number of complications can arise from this infection. These vary depending on the area of the body that has become infected:
- A lung infection might lead to scarring or long-term shortness of breath.
- A skin infection might lead to disfigurement or scarring.
- A brain infection might lead to the loss of certain brain functions.
Your long-term outlook will largely depend on the area of the body that has become infected. The health and stability of your immune system will also play a role in how easily your symptoms can be treated.
In most cases, nocardiosis can be treated successfully with antibiotics, especially when treatment is received early. However, the infection can become life-threatening when multiple areas of the body become infected at the same time. It’s especially dangerous for people with weakened immune systems.