Mycobacterium avium intracellulare

- saprophytic organism of low pathogenicity and ubiquitous in soil and water
- occurs in later stage of HIV infection when patient are profoundly immunosuppressed
- presents with fever, malaise, weight loss, anorexia, anemia (dissemination to bone marrow), diarrhea and malabsorption, generalised lymphadenopathy, tender hepatosplenomegaly
- in immunocompetent person, it causes pulmonary infection (Lady Windermere syndrome)
- diagnosis: culture from blood or bone marrow
- primary prophylaxis with azithromycin when CD4 count less than 50
- treatment: ethambutol, rifabutin and clarithromycin