Moore et al. BMC Public Health 2010, 10:612 http://www.biomedcentral.com/1471-2458/10/612 R E S E A R C H A R T I C L E Open Access Increasing reports of non-tuberculous mycobacteria in England, Wales and Northern Ireland, 1995-2006 Jonathan E Moore1*, Michelle E Kruijshaar1, L Peter Ormerod2, Francis Drobniewski3, Ibrahim Abubakar1 Abstract Background: Non-tuberculous mycobacteria have long been identified as capable of causing human disease and the number at risk, due to immune-suppression, is rising. Several reports have suggested incidence to be increasing, yet routine surveillance-based evidence is lacking. We investigated recent trends in, and the epidemiology of, non-tuberculous mycobacterial infections in England, Wales and Northern Ireland, 1995-2006. Methods: Hospital laboratories voluntarily report non-tuberculous mycobacterial infections to the Health Protection Agency Centre for Infections. Details reported include age and sex of the patient, species, specimen type and source laboratory. All reports were analysed. Results: The rate of non-tuberculous mycobacteria reports rose from 0.9 per 100,000 population in 1995 to 2.9 per 100,000 in 2006 (1608 reports). Increases were mainly in pulmonary specimens and people aged 60+ years. The most commonly reported species was Mycobacterium avium-intracellulare (43%); M. malmoense and M. kansasii were also commonly reported. M. gordonae showed the biggest increase over the study period rising from one report in 1995 to 153 in 2006. Clinical information was rarely reported. Conclusions: The number and rate of reports increased considerably between 1995 and 2006, primarily in older age groups and pulmonary specimens. Increases in some species are likely to be artefacts but real changes in more pathogenic species, some of which will require clinical care, should not be excluded. Enhanced surveillance is needed to understand the true epidemiology of these infections and their impact on human health. Background The non-tuberculous mycobacteria (NTM), mycobac- teria other than members of the Mycobacterium tuber- culosis complex and M. leprae, have been documented since the 1950s as organisms capable of causing human disease [1], receiving greater clinical recognition as the incidence of tuberculosis fell [2]. Over 100 species of NTM have been identified but only around 15 are con- sidered pathogenic in humans [3]. While NTM can cause pulmonary, lymph node, skin and disseminated disease in humans, many species are found ubiquitously in environmental reservoirs and in various domestic and wild animals and are therefore frequently isolated from * Correspondence: jonathan.moore@hpa.org.uk 1Health Protection Agency Centre for Infections, Respiratory Diseases Department - Tuberculosis Section, 61 Colindale Avenue, London, NW9 5EQ, UK Full list of author information is available at the end of the article clinical samples due to contamination. In general, NTM only cause disease in immunocompromised individuals, which is relative in small children, or actual, e.g. in those with HIV infection or structural tissue damage in the lungs due to chronic obstructive pulmonary disease (COPD), cystic fibrosis, or scarring due to a number of conditions including tuberculosis. These infections can be difficult to treat, are often reported as having in-vitro resistance on single antibiotic testing, although synergy with combinations has been shown [4], and can compli- cate the diagnosis of tuberculosis. NTM infections are not normally transmissible between humans. Determining the clinical relevance of NTM isolates can be difficult and can depend on a combination of the site from where the sample was taken, the number of isola- tions, and the species involved, as well as clinical symp- toms and any predisposing conditions of the patient [5]. M. avium-intracellulare often presents as disseminated © 2010 Moore et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.