Increasing reports of non-tuberculous mycobacteria in England, Wales and Northern Ireland, 1995-2006

Abstract

BackgroundNon-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.MethodsHospital 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.ResultsThe 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.ConclusionsThe 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.

Clinical and Therapeutic Features of Pulmonary Nontuberculous Mycobacterial Disease, Rio de Janeiro, Brazil

“…Although we were unable to determine the true prevalence of disease caused by these organisms in the state of Rio de Janeiro, the current study confirmed an increasing frequency of patients referred with NTM lung disease. In some industrialized countries, the prevalence of NTM has been found to be increasing ( 5 , 17 ), although it remains unclear whether this increase is related to increasing awareness of physicians that leads to more frequent diagnosis, to improved laboratory capacity, or to a combination of both factors.…”

“…Global geographic variability in M. kansasii has been noted; a high prevalence of M. kansasii lung disease occurs in Western Europe, Switzerland, and the United Kingdom ( 17 , 21 – 23 ). In Brazil, available data suggest regional differences in species distribution, although distinct study populations and methods limit comparability of estimates.…”

Geographical distribution and clinical relevance of non-tuberculous mycobacteria in Croatia

“…In the study from the Netherlands, the increase was mainly caused by a rise in M. avium and M. gordonae isolates from pulmonary samples and it was most pronounced in patients >40 years old [3]. A study from the UK showed that the increase in NTM reports was mainly in pulmonary specimens and people aged >60 years, with M. gordonae showing the biggest increase but MAC remaining the most commonly reported species [14]. In Denmark, the rising trend in NTM isolation was less obvious but the incidence of NTM disease had increased, especially in elderly [4].…”

Pulmonary disease caused by nontuberculous mycobacteria

“…For example, in most of Asia and New Zealand after MAC, RGM have generally been the most frequently identified species but India reports no PNTM due to MAC and attributes 40% to M. fortuitum and 33% to M. kansasii [34]. In Britain, MAC (43%), Mycobacterium malmoense (14%) and M. kansasii (13%) were the most frequently isolated species from respiratory specimens [35].…”