Mycobacterium Avium Complex (MAC) Lung Disease in Two Inner City Community Hospitals: Recognition, Prevalence, Co-Infection with Mycobacterium Tuberculosis (MTB) and Pulmonary Function (PF) Improvements After Treatment.
BACKGROUND
The purpose of this study was to separate MAC lung disease from colonization and to define indications for treatment.


METHODS
Over 4 years, we evaluated patients who had positive MAC cultures, MAC infection and coinfection with MTB. In the first study, 42 immunocompetent patients with sputum or BAL culture positive only for MAC during a single year (2004) were reviewed. On clinical and radiographic review, they were classified as disease related to MAC, likely related to MAC or unrelated to MAC. In the second study, we reviewed all immunocompetent patients, during two years (2004-2005), whose respiratory secretions cultured both MTB and nontuberculous mycobacteria (NTM). In the last study, we evaluated pulmonary function (PF) in patients with MAC infection before and after therapy (2006- 2007). PF was evaluated in patients following ATS guidelines.


RESULTS
Lung disease was related/likely related to MAC in 21 patients (50%) and not related in 21 (50%). In patients with MAC-related lung disease, the primary physician did not consider the diagnosis except when that physician was a pulmonologist. Half of those with MAC-related lung disease were smokers, white and US-born. There were 12 immunocompetent patients with MTB and NTM cultures. Eleven were non-white and all were foreign-born. Presentation and clinical course were consistent with MTB. All 8 patients with abnormal PF improved.


CONCLUSIONS
The prevalence of MAC lung infection in two inner city hospitals was four times higher than that of TB. The indication for treatment of MAC infection should also rely heavily on clinical and radiological evidence when there is only one positive sputum culture. The diagnosis was considered only when the admitting physician was a pulmonologist. Most patients with combined infection were clinically consistent with MTB and responded to anti MTB treatment alone. Treatment with anti-MAC therapy improved PF in those patients whose PF was abnormal to begin with.
CARITAS Health Care Inc, Mary Immaculate Hospital-Pulmonary Division, 152-11 89th Ave, Jamaica, New York 11432, USA.
Zinobia
Z
Khan
Albert
A
Miller
Moses
M
Bachan
Joseph
J
Donath
Am Rev Respir Dis. 1968 Dec;98(6):965-77
4972216
Tuber Lung Dis. 1994 Oct;75(5):348-52
7841428
J Clin Microbiol. 1995 Oct;33(10):2757-8
8567919
Am Rev Respir Dis. 1983 Mar;127(3):270-7
6830050
Am J Respir Crit Care Med. 2007 Feb 15;175(4):367-416
17277290
Clin Infect Dis. 2000 Oct;31(4):958-67
11049777
Am Rev Respir Dis. 1959 Nov;80:738-43
13798030
Chest. 2006 Jun;129(6):1653-72
16778288
Bull Eur Physiopathol Respir. 1986 Nov-Dec;22(6):589-97
3828549
Emerg Infect Dis. 2009 Oct;15(10):1562-9
19861046
Am Rev Tuberc. 1957 Feb;75(2):199-222
13403152
N Engl J Med. 1989 Sep 28;321(13):863-8
2770822