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

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).

• 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

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