Changing Incidence and Characteristics of Nontuberculous Mycobacterial Infections in Scotland and Comparison With Mycobacterium tuberculosis Complex Incidence (2011 to 2019)

Abstract

Background An increase in infections with non-tuberculous mycobacteria (NTM) has been noted globally and their incidence has overtaken that of Mycobacterium tuberculosis complex (MTBc) in many countries. Using data from a national reference laboratory, we aimed to determine if this trend was observed in Scotland. Methods We undertook a retrospective review of all NTM isolates received by the Scottish Mycobacteria Reference Laboratory (SMRL) over 9 years from 2011 to 2019 inclusive. Clinical episodes were defined as per 2017 BTS and 2020 ATS/ERS/ESCMID/IDSA NTM guidelines. These rates were compared with Scottish tuberculosis rates over the same period. Results Of 8552 NTM isolates from 4586 patients in 2011 to 2019, 7739 (90.5%) were considered clinically relevant. These represented 2409 episodes of NTM infection, with M. avium, M. intracellulare and M. abscessus complex being most common. 1953 (81.1%) were pulmonary NTM infection episodes from 1470 patients and 456 extra-pulmonary episodes from 370 patients. We estimated a rise in incidence from 3.4 to 6.5 per 100,000 person-years (2011-2019 inclusive) with an increase in NTM incidence over MTBc incidence in Scotland by 2017. Conclusion The incidence of NTM infection in Scotland has overtaken MTBc incidence. NTM infection leads to a costly healthcare burden, possibly as much as UK £1.47 million (US$ and Euro 1.73 million) annually. We recommend standardisation of isolate referral with clinical surveillance and implementation of agreed standards of care delivered through multi-disciplinary teams. This would improve diagnosis and patient management as well as assessment of diagnostics and novel treatments through clinical trials.

Presence of indicator bacteria, Shiga toxin-producing Escherichia coli, and nontuberculous mycobacteria in oregano

“…The incidence of NTM infections has increased to similar or higher levels than that of Mycobacterium tuberculosis complex infections in England, the United States, and several European countries in the past decade (Jarchow-MacDonald et al, 2023). In this study, M. fortuitum, M. smegmatis, M. conceptionense, M. porcinum, M. parafortuitum, M. flavescens, and M. goodii were identified in the oregano samples.…”

Non-tuberculous mycobacterial pulmonary disease (NTM-PD): Epidemiology, diagnosis and multidisciplinary management

“… 2 In Scotland, NTM infection incidence rose from 3.4/100,000 to 6.5/100,000 between 2011 and 2019. 7 The 5-year all-cause mortality for MAC lung disease ranges between 10 and 48%. 8 …”

Extrapulmonary nontuberculous mycobacterial infections: a guide for the general physician

“…The prevalence of NTM isolates is increasing in the UK and globally. 1 , 2 , 3 This may be attributable to an increased at-risk population (secondary to increased organ transplantation, and the use of immunosuppressive therapies, in particular biologics), alongside increased awareness and improved diagnostics. Despite this rising prevalence, NTM disease remains relatively rare and poorly understood.…”

“…Previous data indicate that 20–30% of NTM infections originate from extrapulmonary sites. 1 , 2 , 3 , 6 , 7 Extra-pulmonary disease is usually defined as a culture-confirmed NTM infection in the presence of clinical features suggestive of skin, soft tissue (wound or abscess) or lymphatic tissue disease, although it may also be found in the spine or joints. NTM may be isolated from body fluids such as urine, blood or cerebrospinal fluid.…”