Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec 12;10(1):ofac665.
doi: 10.1093/ofid/ofac665. eCollection 2023 Jan.

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

Anna Jarchow-MacDonald  1 , Michael Smith  1 , Amie-Louise Seagar  1 , Clark D Russell  2 , Pauline Claxton  1 , Ian F Laurenson  1 , Olga-Lucia Moncayo-Nieto  1
Affiliations

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

Anna Jarchow-MacDonald et al. Open Forum Infect Dis. .

Abstract

Background: An increase in infections with nontuberculous 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 could be 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 British Thoracic Society and 2020 American Thoracic Society/European Respiratory Society/European Society of Clinical Microbiology and Infectious Diseases/Infectious Diseases Society of America 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. A total of 1953 (81.1%) were pulmonary NTM infection episodes from 1470 patients and 456 extrapulmonary 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.

Conclusions: The incidence of NTM infection in Scotland has overtaken MTBc incidence. NTM infection leads to a costly health care burden, possibly as much as UK£1.47 million (US$ and €1.73 million) annually. We recommend standardization of isolate referral with clinical surveillance and implementation of agreed standards of care delivered through multidisciplinary teams. This would improve diagnosis and patient management as well as assessment of diagnostics and novel treatments through clinical trials.

Keywords: Scotland; incidence; multidisciplinary management of infections; nontuberculous mycobacteria; standardized surveillance.

PubMed Disclaimer

Conflict of interest statement

Potential conflicts of interest. We declare no competing interests.

Figures

Figure 1.
Figure 1.
Flowchart of analysis of NTM isolates received at the Scottish Mycobacterial Reference Laboratory, clinically relevant isolates, and episodes of NTM infection; 2011–2019. Abbreviation: NTM, nontuberculous mycobacteria.
Figure 2.
Figure 2.
Infection episodes stratified by Mycobacterium species and age group. The heatmap is showing normalized counts for infection episodes per species.
Figure 3.
Figure 3.
NTM infection episodes in Scotland (2011–2019) detailing the most common mycobacteria causing infection: M. avium complex, M. abscessus complex, M. chelonae complex, and M. malmoense. Abbreviation: NTM, nontuberculous mycobacteria.
Figure 4.
Figure 4.
Incidence of NTM and MTBc infections per 100 000 person-years in Scotland, 2011 to 2019. MTBc data collated from “Enhanced Surveillance of Mycobacterial Infections in Scotland” reports 2018 and 2019 [9, 10]. Abbreviations: MTBc, Mycobacterium tuberculosis complex; NTM, nontuberculous mycobacteria.
Figure 5.
Figure 5.
Distribution of pathogenic NTM pulmonary species and infection episodes in Scotland, 2011–2019. Abbreviation: NTM, nontuberculous mycobacteria.
See this image and copyright information in PMC

References

    1. Shah NM, Davidson JA, Anderson LF, et al. Pulmonary Mycobacterium avium-intracellulare is the main driver of the rise in non-tuberculous mycobacteria incidence in England, Wales and Northern Ireland, 2007–2012. BMC Infect Dis 2016; 16:195. - PMC - PubMed
    1. Schildkraut JA, Zweijpfenning SMH, Nap M, et al. The epidemiology of nontuberculous mycobacterial pulmonary disease in the Netherlands. ERJ Open Res 2021; 7:00207–2021. - PMC - PubMed
    1. Winthrop KL, McNelley E, Kendall B, et al. Pulmonary nontuberculous mycobacterial disease prevalence and clinical features: an emerging public health disease. Am J Respir Crit Care Med 2010; 182:977–82. - PubMed
    1. Veziris N, Andréjak C, Bouée S, Emery C, Obradovic M, Chiron R. Non-tuberculous mycobacterial pulmonary diseases in France: an 8 years nationwide study. BMC Infect Dis 2021; 21:1165. - PMC - PubMed
    1. Prevots DR, Loddenkemper R, Sotgiu G, Migliori GB. Nontuberculous mycobacterial pulmonary disease: an increasing burden with substantial costs. Eur Respir J 2017; 49:1700374. - PMC - PubMed