鸟分枝杆菌复合群（mycobacterium avium complex, MAC）感染具有多变的临床表现，包括慢性咳嗽、体重减轻和发热。
有肺部基础疾病、严重吸烟和过度饮酒的患者发病率升高。
HIV感染者CD4细胞数＜50个/μL时感染风险增加。
诊断非 HIV 感染者的肺疾病除了相符的临床症状和影像学表现之外，还需要从呼吸道分泌物中反复分离出病原体。
至少使用两种药物的联合治疗很重要。
鸟分枝杆菌复合群（mycobacterium avium complex, MAC）也叫鸟胞内分枝杆菌（mycobacterium avium-intracellulare, MAI），包含两种分枝杆菌：鸟分枝杆菌和胞内分枝杆菌。[1]Good RC. Opportunistic pathogens in the genus mycobacterium. Annu Rev Microbiol. 1985;39:347-69.
http://www.ncbi.nlm.nih.gov/pubmed/3904604?tool=bestpractice.com
尽管通过分子技术可鉴定出 MAC 分离株为鸟分枝杆菌或胞内分枝杆菌，[2]Saito H, Tomioka H, Sato K, et al. Identification of various serovar strains of Mycobacterium avium complex by using DNA probes specific for Mycobacterium avium and Mycobacterium intracellulare. J Clin Microbiol. 1990 Aug;28(8):1694-7.
http://jcm.asm.org/cgi/reprint/28/8/1694?view=long&pmid=2203807
http://www.ncbi.nlm.nih.gov/pubmed/2203807?tool=bestpractice.com
这样做没有预后或治疗优势。MAC 感染人体后通常引起 3 种疾病综合征：肺部疾病、颈部淋巴结炎或播散性疾病。[3]Rosenzweig DY. Pulmonary mycobacterial infections due to Mycobacterium intracellulare-avium complex. Chest. 1979 Feb;75(2):115-9.
http://www.ncbi.nlm.nih.gov/pubmed/421545?tool=bestpractice.com
[4]Wolinsky E. Mycobacterial lymphadenitis in children: a prospective study of 105 nontuberculous cases with long-term follow-up. Clin Infect Dis. 1995 Apr;20(4):954-63.
http://www.ncbi.nlm.nih.gov/pubmed/7795100?tool=bestpractice.com
[5]Horsburgh CR Jr, Mason UG, Farhi DC, et al. Disseminated infection with Mycobacterium avium-intracellulare: a report of 13 cases and a review of the literature. Medicine. 1985 Jan;64(1):36-48.
http://www.ncbi.nlm.nih.gov/pubmed/3880852?tool=bestpractice.com
还报道了第四种综合征，即与使用热浴盆相关的过敏性肺炎。[6]Rickman OB, Ryu JH, Fidler ME, et al. Hypersensitivity pneumonitis associated with Mycobacterium avium complex and hot tub use. Mayo Clin Proc. 2002 Nov;77(11):1233-7.
http://www.ncbi.nlm.nih.gov/pubmed/12440560?tool=bestpractice.com
