BioMed Research International
Volume 2015 (2015), Article ID 523697, 2 pages
http://dx.doi.org/10.1155/2015/523697

Editorial

Nontuberculous Mycobacteria: Epidemiologic, Mycobacteriologic, and Clinical Aspects

Mehdi Mirsaeidi,¹ Parissa Farnia,² Ruxana Sadikot,³ Po-Ren Hsueh,⁴ and Stefano Aliberti⁵

¹Division of Pulmonary and Critical Care, University of Illinois, Chicago, USA
²Department of Mycobacteriology, National Research Center of Tuberculosis and Lung Disease, Shahid Beheshti University of Medical Sciences, Tehran, Iran
³Division of Pulmonary and Critical Care, University of Emory, Atlanta, GA, USA
⁴Divisions of Clinical Microbiology and Infectious Diseases, Departments of Laboratory Medicine and Internal Medicine, National Taiwan University College of Medicine, Taipei, Taiwan
⁵Department of Health Science, University of Milano-Bicocca, San Gerardo Hospital, Via Pergolesi 33, 20900 Monza, Italy

Received 2 April 2015; Accepted 2 April 2015

Copyright © 2015 Mehdi Mirsaeidi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Nontuberculous mycobacteria (NTM) are ubiquitous organisms that are highly prevalent in the environment. The evidence that these organisms originate in the environment is overwhelming; and there is no significant evidence for animal-to-human or human-to-human transmission. NTM were first recognized as human pathogens in 1950s [1] and since then more than 150 NTM species have been recognized [2]. Humans may be exposed to NTM on a regular basis through showering, bathing, and other activities using water, soil, or aerosols [3]. How, when, why, and in which population NTM infection might occur are largely unknown.

The incidence rate of NTM infections appears to have increased during the last decade globally resulting in a significant mortality and morbidity [4, 5]. Studies have shown a high incidence rate of NTM in elderly population and increasing susceptibility in very elderly people. It has been estimated that NTM incidence will continue to rise due to increasing elderly population by 2050 [6]. Little is known about the diseases caused by the NTM and only limited data are available showing its prevalence and associated factors [7, 8]. Bronchiectasis, chronic lung diseases, pulmonary fibrosis, and decreased lung immunity are some of known risk factors for pulmonary NTM diseases. NTM disease has also gained increasing attention in countries with high incidence of tuberculosis due to risk of misdiagnosis with multidrug resistant tuberculosis (MDR-TB) [9]. A recently published study showed the frequency of NTM misdiagnosis in up to 30% of patients with suspected MDR-TB [10].

The disease caused by NTM forms a broad clinical spectrum from asymptomatic infection to fatal disseminated disease in human. While many of NTM patients have underlying pulmonary diseases, NTM symptoms are undifferentiated from symptoms of patients with chronic pulmonary structural diseases such as bronchiectasis. Therefore, routine screening and having high suspicion for NTM disease are highly recommended.

Diagnosis of infection by NTM is another challenging issue. The diagnosis of NTM with conventional microbiologic methods may be misleading and molecular approaches are advised [11].

Increased knowledge and understanding of this type of mycobacterial disease could improve patient care of affected persons worldwide. We also highly recommend continuing translational studies to develop precision medicine in mycobacterial diseases [12].

In this special issue, a series of original articles as well as expert reviews on NTM are published to stimulate a greater understanding of NTM infections. Suggested areas of research are included: microbiologic and molecular diagnostic tools, drug susceptibility tests, human genetic susceptibility, prevalence and incidence studies, clinical presentations, and clinical trials for antibiotic therapy. We were particularly interested in studies describing new laboratory diagnostic tools for NTM, modalities for clinical characterization of NTM diseases in patients with and without underlying diseases, and measuring outcomes of treatment trials.

In conclusion, the incidence of NTM disease is increasing and needs urgent attention by health policy makers and international societies. Better molecular tools for rapid diagnosis of NTM, understanding of immunopathogenesis, and host pathogen interactions are needed. In the last years, we have seen an explosion in NTM researches. Consequently, we hope to see more publications from basic and traditional research to answer our questions about NTM in coming years.

Acknowledgment

This project is supported by NIH Grant 5 T32 HL 82547-7.

Mehdi Mirsaeidi
Parissa Farnia
Ruxana Sadikot
Po-Ren Hsueh
Stefano Aliberti

References

J. O. Falkinham III, “Epidemiology of infection by nontuberculous mycobacteria,” Clinical Microbiology Reviews, vol. 9, no. 2, pp. 177–215, 1996.

E. Tortoli, “Microbiological features and clinical relevance of new species of the genus Mycobacterium,” Clinical Microbiology Reviews, vol. 27, no. 4, pp. 727–752, 2014.

J. O. Falkinham III, “Mycobacterial aerosols and respiratory disease,” Emerging Infectious Diseases, vol. 9, no. 7, pp. 763–767, 2003.

M. Mirsaeidi, R. F. Machado, J. G. N. Garcia, and D. E. Schraufnagel, “Nontuberculous mycobacterial disease mortality in the United States, 1999–2010: a population-based comparative study,” PLoS ONE, vol. 9, no. 3, Article ID e91879, 2014.

J. Y. Chien, C. C. Lai, W. H. Sheng, C. J. Yu, and P. R. Hsueh, “Pulmonary infection and colonization with nontuberculous mycobacteria, Taiwan, 2000–2012,” Emerging Infectious Diseases, vol. 20, no. 8, pp. 1382–1385, 2014.

M. Mirsaeidi, M. Farshidpour, G. Ebrahimi, S. Aliberti, and J. O. Falkinham III, “Management of nontuberculous mycobacterial infection in the elderly,” European Journal of Internal Medicine, vol. 25, no. 4, pp. 356–363, 2014.

M. Mirsaeidi, W. Hadid, B. Ericsoussi, D. Rodgers, and R. T. Sadikot, “Non-tuberculous mycobacterial disease is common in patients with non-cystic fibrosis bronchiectasis,” International Journal of Infectious Diseases, vol. 17, no. 11, pp. e1000–e1004, 2013.

C. C. Lai and P. R. Hsueh, “Diseases caused by nontuberculous mycobacteria in Asia,” Future Microbiology, vol. 9, no. 1, pp. 93–106, 2014.

P. Tabarsi, P. Baghaei, P. Farnia et al., “Nontuberculous mycobacteria among patients who are suspected for multidrug-resistant tuberculosis—need for earlier identification of nontuberculosis mycobacteria,” The American Journal of the Medical Sciences, vol. 337, no. 3, pp. 182–184, 2009.

A. H. Shahraki, P. Heidarieh, S. Z. Bostanabad et al., “‘Multidrug-resistant tuberculosis’ may be nontuberculous mycobacteria,” European Journal of Internal Medicine, 2015.

A. A. Velayati, P. Farnia, M. Mozafari et al., “Molecular epidemiology of nontuberculous mycobacteria isolates from clinical and environmental sources of a metropolitan city,” PLoS ONE, vol. 9, no. 12, Article ID e114428, 2014.

M. Mirsaeidi, “Personalized medicine approach in mycobacterial disease,” International Journal of Mycobacteriology, vol. 1, no. 2, pp. 59–64, 2012.