Atypical mycobacterial infection Health Article

Definition

Atypical mycobacterial infection is an illness caused by a type of mycobacterium other than tuberculosis.

Alternative Names

Mycobacteria other than tuberculosis; Nontuberculous atypical mycobacterial disease

Causes, incidence, and risk factors

Atypical mycobacteria can cause a wide variety of infections such as abscesses, septic arthritis, and osteomyelitis (bone infection). They can also infect the lungs, lymph nodes, gastrointestinal tract, skin, and soft tissues.

There are many different species of mycobacterium other than tuberculosis (Mycobacterium tuberculosis). Some of the most common are listed below:

• Mycobacterium avium-intracellulare frequently affects AIDS patients and causes lung disease.
• Mycobacterium marinum cause skin infections and is also responsible for swimming pool granuloma.
• Mycobacterium ulcerans cause skin infections.
• Mycobacterium kansasii causes lung disease.

The rate of atypical mycobacterial infections is rare, but it is increasing as the AIDS population grows. Populations at risk include individuals who have lung disease and weakened immune systems (immunosuppression).

Symptoms

• Fever
• Weight loss
• Enlarged lymph glands
• Diarrhea
• Sweating, excessive -- night sweats
• Fatigue
• General discomfort, uneasiness or ill feeling (malaise)
• Cough
• Shortness of breath (dyspnea)
• Skin lesions
• Joint pain
• Bone pain

• Paleness
• Flank pain

Signs and tests

Tests to diagnose this infection may include:

• Blood culture
• Sputum culture
• Lymph node culture or biopsy
• Bone marrow culture
• Stool culture
• Chest x-ray or CT scan
• Culture - skin biopsy

Treatment

Treatment of the infection depends upon the specific type of infection. As many as four to six drugs may be used to treat some infections. Treatment may last 6 months to 2 years, possibly longer in those with weakened immune systems.

Certain lymph node infections and skin lesions can be surgically removed.

Expectations (prognosis)

The outcome depends upon the severity of the infection, the person's overall health, and their response to treatment.

Calling your health care provider

Call for an appointment with your health care provider if symptoms of an atypical mycobacterial infection develop. HIV-positive individuals who develop a cough, rapid breathing (tachypnea), shortness of breath, or other pulmonary symptoms should see their health care provider immediately.

Prevention

Use of azithromycin or clarithromycin in certain AIDS patients may help to prevent this infection.