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''Mycobacterium avium-intracellulare'' infection (MAI),〔(Medscape Reference - Mycobacterium Avium-Intracellulare ) Author: Janak Koirala, MD, MPH, FACP, FIDSA; Chief Editor: Burke A Cunha, MD, Updated: Jan 12, 2011〕 also known as MAC (Mycobacterium Avium Complex), is an atypical mycobacterial infection which can occur in the later stages of AIDS. It can also affect people who do not have AIDS, and usually first presents as a persistent cough. It is typically treated with a series of three antibiotics for a period of at least six months. ''Mycobacterium avium'' and ''M. intracellulare'' (the ''M. a.'' complex - MAC) are saprotrophic organisms present in soil and water; entry into hosts is usually via the gastrointestinal tract, but also can be via the lungs. MAC can cause fevers, diarrhea, malabsorption, as well as loss of appetite and weight loss, and can disseminate to the bone marrow. Therapy for MAI is typically resistant to standard mycobacterial therapies. == Sources and symptoms == MAC bacteria are common in the environment and cause infection when inhaled or swallowed. Symptoms are reminiscent of tuberculosis (TB), and include fever, fatigue, and weight loss. Many patients will have anemia and neutropenia if bone marrow is involved. Pulmonary involvement is similar to TB, while diarrhea and abdominal pain are associated with gastrointestinal involvement. MAC bacteria should always be considered in a person with HIV infection presenting with diarrhea. Recently, ''M. avium'' has been found to deposit and grow in bathroom shower heads from which it may be easily aerosolized and inhaled.〔(Showerheads may harbor bacteria dangerous to some ) By RANDOLPH E. SCHMID, AP Science Writer Randolph E. Schmid, Ap Science Writer – Mon Sep 14, 9:19 pm ET〕 The various subspecies of ''M. avium'' are prevalent in different areas: * ''M. a. avium'' (MAA) primarily affects birds, but has also been found in ruminant mammals, especially deer. * ''M. a. paratuberculosis'' (MAP) causes paratuberculosis, or Johne's Disease, and also is usually found in mammals. MAI is common in immunocompromised individuals, including senior citizens and those suffering from HIV or cystic fibrosis. Bronchiectasis, the bronchial condition which causes unnatural enlargement of the bronchial tubes, is commonly found with MAI infection. Whether the bronchiectasis leads to the MAC infection or is the result of it is not always known.〔http://www.nejm.org/doi/full/10.1056/NEJMicm010899〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Mycobacterium avium-intracellulare infection」の詳細全文を読む スポンサード リンク
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