| Clinical Features |
Dependent on organism and site of infection, but usually chronic and progressive clinical course. Infections with these organisms frequently occur in persons who have some form of immunodeficiency (e.g., HIV-infection) or other chronic antecedent illness. |
| Etiologic Agent |
Mycobacterium avium complex and M. kansasii (usually associated with pneumonia or disseminated infection) are the leading causes of nontuberculous mycobacterial infections in humans. Other causes include M. malmoense, M. simiae, M.szulgai, M. xenopi (associated with pneumonia); M.scrofulaceum (associated with lymphadenitis); M. abscessus, M. chelonae, M. haemophilum, M. ulcerans (skin and soft tissue infections). In some areas of the tropics, Buruli ulcer disease caused by infection with M.ulcerans is a common cause of severe morbidity and disability. |
| Incidence |
Not nationally reportable. Incidence of nontuberculous mycobacteria in the United States is unknown. |
| Sequelae |
Chronic, untreatable infections are common. Cutaneous infections may require surgical excision. Extensive therapy of long duration frequently is required. |
| Transmission |
Many of these agents are ubiquitous and are found in soil, food, water, and animals. Most infections appear to be acquired by ingestion, aspiration, or inoculation of the organisms from these natural sources. |
| Risk Groups |
Immunocompromised persons (e.g., persons with HIV infection) or other chronic antecedent illness are at increased risk for acquiring nontuberculous infections. |
| Surveillance |
Active population-based surveillance for M.avium complex infections is conducted in the Atlanta, Georgia, and Houston, Texas, metropolitan areas as part of a special study to monitor the emergence of drug resistance. There is also laboratory-based surveillance through state public health laboratories using the Public Health Laboratory Information System (PHLIS). |
| Trends |
M. avium complex infections are decreasing among HIV-infected persons in the United States. The incidence of Buruli ulcer, caused by M.ulcerans, is increasing in several tropical West African countries. |
| Challenges |
Delineate the mode of transmission and variations in host susceptibility for mycobacterial species. Determine effective therapy using new drug regimens. |
| Opportunities |
Elimination of M. avium complex as an important cause of opportunistic infection among HIV-infected persons in the United States. Control and prevention of Buruli ulcer in areas of high endemicity. |
