M Globan1, C Lavender1, D Leslie1, L Brown2, J Denholm3, K Raios1, A Sievers1, H Kelly4, J Fyfe1. 1. Mycobacterium Reference Laboratory, Victorian Infectious Diseases Reference Laboratory (VIDRL), Canberra, Australia. 2. Victorian Tuberculosis Program, Melbourne Health, Doherty Institute, Melbourne, Australia. 3. Victorian Tuberculosis Program, Melbourne Health, Doherty Institute, Melbourne, Department of Microbiology and Immunology, University of Melbourne, Parkville, Australia. 4. Epidemiology Unit, VIDRL, Doherty Institute, Melbourne, Victoria, National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia.
Abstract
SETTING: Victoria, Australia. OBJECTIVE: To measure the level of Mycobacterium tuberculosis transmission in Victoria. DESIGN: Retrospective analysis of mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing profiles from all first M. tuberculosis complex (MTC) isolates obtained from patients residing in Victoria from 2003 to 2010 was performed. State TB reference laboratory records were matched with Department of Health notification records to obtain further laboratory, demographic, contact investigation, clinical and treatment data. These data were used to assign patients to one of four categories: 1) no epidemiological link, 2) possible link, 3) likely transmission event and 4) laboratory contamination. RESULTS: A total of 2377 MTC isolates were genotyped using 15-locus MIRU-VNTR. Of the 2298 M. tuberculosis isolates, 1029 (44.8%) had unique genotypic profiles and were considered epidemiologically unrelated, while 1269 (55.2%) isolates shared a profile with one or more other strains, defined as a genotypic cluster. Systematic investigation of all 268 genotypic clusters, including 24-locus MIRU-VNTR on selected isolates, led to a further 862 patients being classified as unrelated, bringing the total number of patients with no epidemiological links to 1891 (82.3%). Of the remaining patients, 294 (12.8%) were classified as having possible epidemiological links, 96 (4.2%) were classified as having known epidemiological links representing likely transmission events and 17 (0.7%) as the result of laboratory cross-contamination. CONCLUSIONS: There is considerable genotypic diversity among Victorian MTC isolates, and the level of transmission is low.
SETTING: Victoria, Australia. OBJECTIVE: To measure the level of Mycobacterium tuberculosis transmission in Victoria. DESIGN: Retrospective analysis of mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing profiles from all first M. tuberculosis complex (MTC) isolates obtained from patients residing in Victoria from 2003 to 2010 was performed. State TB reference laboratory records were matched with Department of Health notification records to obtain further laboratory, demographic, contact investigation, clinical and treatment data. These data were used to assign patients to one of four categories: 1) no epidemiological link, 2) possible link, 3) likely transmission event and 4) laboratory contamination. RESULTS: A total of 2377 MTC isolates were genotyped using 15-locus MIRU-VNTR. Of the 2298 M. tuberculosis isolates, 1029 (44.8%) had unique genotypic profiles and were considered epidemiologically unrelated, while 1269 (55.2%) isolates shared a profile with one or more other strains, defined as a genotypic cluster. Systematic investigation of all 268 genotypic clusters, including 24-locus MIRU-VNTR on selected isolates, led to a further 862 patients being classified as unrelated, bringing the total number of patients with no epidemiological links to 1891 (82.3%). Of the remaining patients, 294 (12.8%) were classified as having possible epidemiological links, 96 (4.2%) were classified as having known epidemiological links representing likely transmission events and 17 (0.7%) as the result of laboratory cross-contamination. CONCLUSIONS: There is considerable genotypic diversity among Victorian MTC isolates, and the level of transmission is low.
Authors: Taher Azimi; Mohammad Javad Nasiri; Samin Zamani; Ali Hashemi; Hossein Goudarzi; Abbas Ali Imani Fooladi; Mohammad Mehdi Feizabadi; Fatemeh Fallah Journal: J Clin Tuberc Other Mycobact Dis Date: 2018-01-31
Authors: Ingrid Laemmle-Ruff; Stephen M Graham; Bridget Williams; Danielle Horyniak; Suman S Majumdar; Georgia A Paxton; Lila V Soares Caplice; Margaret E Hellard; James M Trauer Journal: Emerg Infect Dis Date: 2022-09 Impact factor: 16.126
Authors: James M Trauer; Bridget Williams; Ingrid Laemmle-Ruff; Danielle Horyniak; Lila V Soares Caplice; Emma S McBryde; Suman S Majumdar; Stephen M Graham; Margaret E Hellard Journal: Lancet Reg Health West Pac Date: 2021-03-26