Emerging Trends in Non-Tuberculous An Epidemiological Analysis over Five Years at a Large Teaching Hospital in London Bharucha T, Shah N, Murphy M, Cropley I, Lipman M, Hopkins S. Corresponding author: [email protected]

Background: Results: In patients with more than one positive Number Time to sample, the second sample was Despite increasing data Number of Single Median Age Sex Non-tuberculous Mycobacterium of Liquid culture Samples species* (IQR) (Male) supporting the pathological Patients positive (IQR) speciated in 68 (57%), with the same significance of non-tuberculous Total 273 708 - 59 (41-73) 151 (56%) 8 (4-15) species identified in approximately one mycobacteria (NTM), Mycobacterium avium 66 127 (17.9%) 17 (63%) 63 (53-75) 36 (55) 7 (4-9) third of speciated isolates. Mycobacterium intracellulare 46 51 (7.2%) 5 (56%) 66 (43-76) 13 (46%) 10 (7-15) epidemiological studies are 40 50 (7.0%) 2 (40%) 56 (41-71) 24 (60%) 7 (4-10) Mycobacterium kansasii was the only surprisingly limited, and Mycobacterium kansasii 24 47 (6.6%) 8 (89%) 67 (56-80) 11 (46%) 7 (5-13) species with data to suggest a possible confounded by improved clinical 19 22 (3.1%) 2 (100%) 72 (55-79) 8 (42%) 12 (7-17) increased frequency of isolation in 16 44 (6.2%) 3 (50%) 66 (41-71) 6 (38%) 4 (3-4) detection, diagnostic sampling and Mycobacterium xenopi 16 28 (4.0%) 3 (43%) 62 (49-68) 13 (77%) 26 (18-35) subsequent specimens. variations in case ascertainment. Mycobacterium gordonae 12 14 (2.0%) 0 (0%) 55 (43-59) 9 (75%) 27 (18-35) 10 14 (2.0%) 2 (67%) 53 (45-62) 5 (50%) 14 (8-24) We analysed five years of NTM Mycobacterium mucogenicum 6 8 (1.1%) - 58 (54-79) 3 (38%) 10 (7-13) Conclusions: positive cultures at our institution, Mycobacterium arupense 2 2 (0.3%) 0 (0%) 80 (79-80) 1 (50%) 17 (12-23) Consistent with existing literature from to identify patients needing further Mycobacterium interjectum 1 1 (0.1%) - 58 0 (0%) 17 Mycobacterium lentiflavum 1 2 (0.3%) 1 (100%) 78 1 (100%) 21 (18-23) resource-rich settings, NTM is now clinical management, and assess 1 1 (0.1%) - 79 0 (0%) 38 more commonly identified than MTB. the impact of updating laboratory Mycobacterium non-chromagenicum 1 1 (0.1%) - 79 0 (0%) 7 Our results suggest NTM isolates are Mycobacterium palustre 1 2 (0.3%) 1 (100%) 40 1 (100%) 15 (14-15) standard operating procedures Mycobacterium scrofulaceum 1 1 (0.1%) - 73 0 (0%) 29 predominantly identified in the sixth (SOPs) to consistently refer NTM Mycobacterium vulneris 1 2 (0.3%) 1 (100%) 79 0 (0%) 4 (2-5) decade, in respiratory specimens. isolates for speciation. *Patients with >1 positive sample Establishing a diagnosis conventionally Table: Non-tuberculous Mycobacterium, 2010-2015. Basic Demographics and Diagnostic Sampling. involves two positive samples, and 1271 samples from 505 patients were identified as Mycobacterium species. 57% of patients had only one positive 560 were MTB, and 708 NTM. NTM was identified in 273 patients, results culture. The updated SOP increased Material/methods: summarised in the Table. The median age was 59 years (IQR 41-73), with a speciation and understanding of NTM. A retrospective analysis was slight male predominance (56% male), and 2% had co-existent MTB isolated. There was a wide range of species performed using electronic data 155 patients (57%) had only one sample positive, 37 (14%) had two samples, identified, with an expected records to review consecutive 25 (9%) had three samples, 13 (5%) had four samples and 43 (16%) had over predominance of Mycobacterium avium patient samples received and four samples. complex. The different species identified as Mycobacterium 568 (80%) samples, from 228 patients, were respiratory specimens and identified in repeated sampling from a species from September 2010 to included all identified NTM species. The most frequently isolated respiratory patient emphasises the need for August 2015. Exclusion criteria species were Mycobacterium avium, Mycobacterium intracellulare and consistent speciation. Clearly the included patients from other Mycobacterium kansasii. Blood (26, 4%), urinary (9, 1%) and stool (4, 0.5%) microbiological data needs to be hospitals or with speciated samples were associated mainly (22, 96%) with Mycobacterium avium assessed alongside clinical and samples only identified by the complex, while bone marrow samples (4, 1%) were only associated with radiographic criteria of disease. National Mycobacterial Reference Mycobacterium mucogenicum. Population studies are urgently Laboratory (where all speciation Updating the SOP for referral of NTM isolates to the reference laboratory required to improve our understanding was performed) as Mycobacterium increased the proportion of speciated samples, from 155 (55%) before of NTM colonisation, infection and tuberculosis complex (MTB). January 2013, to 272 (64%) afterwardsCopyright © 2016 Author(p